Abstracts 2017

Kranz PG, Amrhein TJ, Gray L.
AJR Am J Roentgenol. 2017 Dec;209(6):1360-1366. doi: 10.2214/AJR.17.18351. Epub 2017 Oct 12.
Abstract
OBJECTIVE:
The objective of this study is to describe the anatomic and imaging features of CSF venous fistulas, which are a recently reported cause of spontaneous intracranial hypotension (SIH).
MATERIALS AND METHODS:
We retrospectively reviewed the records of patients with SIH caused by CSF venous fistulas who received treatment at our institution. The anatomic details of each fistula were recorded. Attenuation of the veins involved by the fistula was compared with that of adjacent control veins on CT myelography (CTM). Visibility of the CSF venous fistula on CTM and a modified conventional myelography technique we refer to as dynamic myelography was also compared.
RESULTS:
Twenty-two cases of CSF venous fistula were identified. The fistulas were located between T4 and L1. Ninety percent occurred without a concurrent epidural CSF leak. In most cases (82%), the CSF venous fistula originated from a nerve root sleeve diverticulum. On CTM, the abnormal veins associated with the CSF venous fistula were seen in a paravertebral location in 45% of cases, centrally within the epidural venous plexus in 32%, and lateral to the spine in 23%. Differences in attenuation between the fistula veins and the control veins was highly statistically significant (p < 0.0001), with a threshold of 70 HU perfectly discriminating fistulas from normal veins in our series. When both CTM and dynamic myelography were performed, the fistula was identified on both modalities in 88% of cases. CONCLUSION: CSF venous fistulas are an important cause of SIH that can be detected on both CTM and dynamic myelograph y and may occur without an epidural CSF leak. Familiarity with the imaging characteristics of these lesions is critical to providing appropriate treatment to patients with SIH. PMID: 29023155
DOI: 10.2214/AJR.17.18351

Fredrickson VL, Patel A, Pham MH, Strickland BA, Ohiorhenuan I, Chen T.
World Neurosurg. 2017 Dec 14. pii: S1878-8750(17)32143-5. doi: 10.1016/j.wneu.2017.12.027. [Epub ahead of print]
Abstract
BACKGROUND:
Over-shunting of cerebral spinal fluid may lead to intracranial hypotension and dilation of spinal epidural veins. Radiculopathy may rarely occur secondary to these engorged spinal epidural veins. In addition, the etiology of the radiculopathy may be obscured by concomitant spinal degenerative changes.
CASE DESCRIPTION:
We present a case of a 29-year-old female with positional headaches from intracranial hypotension in the setting of cerebral spinal fluid over-shunting. The patient also had back pain and lumbar radiculopathy which became more severe following lumboperitoneal shunt placement. On radiographic workup, there was evidence of right L5 nerve root impingement secondary to a disc bulge, as well as an engorged lumbar epidural venous plexus due to over-shunting. The patient underwent surgery for a planned L4-5 decompression with a transforaminal lumbar interbody fusion. The operation was complicated by rapid blood loss originating from the epidural venous plexus, therefore we were unable to safely place the interbody graft. Herein, we review the case, the pathogenesis, and the current clinical literature.
CONCLUSION:
Spinal surgeons need to be aware of the rare diagnosis of radiculopathy secondary to epidural venous plexus engorgement, as it may change the treatment approach or lead to deleterious intraoperative consequences, such as hemorrhage.
PMID: 29248773
DOI: 10.1016/j.wneu.2017.12.027

Nath S, Koziarz A, Badhiwala JH, Alhazzani W, Jaeschke R, Sharma S, Banfield L, Shoamanesh A, Singh S, Nassiri F, Oczkowski W, Belley-Côté E, Truant R, Reddy K, Meade MO, Farrokhyar F, Bala MM, Alshamsi F, Krag M, Etxeandia-Ikobaltzeta I, Kunz R, Nishida O, Matouk C, Selim M, Rhodes A, Hawryluk G, Almenawer SA.
Lancet. 2017 Dec 6. pii: S0140-6736(17)32451-0. [Epub ahead of print]
Abstract
BACKGROUND:
Atraumatic needles have been proposed to lower complication rates after lumbar puncture. However, several surveys indicate that clinical adoption of these needles remains poor. We did a systematic review and meta-analysis to compare patient outcomes after lumbar puncture with atraumatic needles and conventional needles.
METHODS:
In this systematic review and meta-analysis, we independently searched 13 databases with no language restrictions from inception to Aug 15, 2017, for randomised controlled trials comparing the use of atraumatic needles and conventional needles for any lumbar puncture indication. Randomised trials comparing atraumatic and conventional needles in which no dural puncture was done (epidural injections) or without a conventional needle control group were excluded. We screened studies and extracted data from published reports independently. The primary outcome of postdural-puncture headache incidence and additional safety and efficacy outcomes were assessed by random-effects and fixed-effects meta-analysis. This study is registered with the International Prospective Register of Systematic Reviews, number CRD42016047546.
FINDINGS:
We identified 20 241 reports; after exclusions, 110 trials done between 1989 and 2017 from 29 countries, including a total of 31 412 participants, were eligible for analysis. The incidence of postdural-puncture headache was significantly reduced from 11·0% (95% CI 9·1-13·3) in the conventional needle group to 4·2% (3·3-5·2) in the atraumatic group (relative risk 0·40, 95% CI 0·34-0·47, p<0·0001; I2=45·4%). Atraumatic needles were also associated with significant reductions in the need for intravenous fluid or controlled analgesia (0·44, 95% CI 0·29-0·64; p<0·0001), need for epidural blood patch (0·50, 0·33-0·75; p=0·001), any headache (0·50, 0·43-0·57; p<0·0001), mild headache (0·52, 0·38-0·70; p<0·0001), severe headache (0·41, 0·28-0·59; p<0·0001), nerve root irritation (0·71, 0·54-0·92; p=0·011), and hearing disturbance (0·25, 0·11-0·60; p=0·002). Success of lumbar puncture on first attempt, failure rate, mean number of attempts, and the incidence of traumatic tap and backache did not differ significantly between the two needle groups. Prespecified subgroup analyses of postdural-puncture headache revealed no interactions between needle type and patient age, sex, use of prophylactic intravenous fluid, needle gauge, patient position, indication for lumbar puncture, bed rest after puncture, or clinician specialty. These results were rated high-quality evidence as examined using the grading of recommendations assessment, development, and evaluation. INTERPRETATION: Among patients who had lumbar puncture, atraumatic needles were associated with a decrease in the incidence of postdural-puncture headache and in the need for patients to return to hospital for additional therapy, and had similar efficacy to conventional needles. These findings offer clinicians and stakeholders a comprehensive assessment and high-quality evidence for the safety and efficacy of atraumatic needles as a superior option for patients who require lumbar puncture. FUNDING: None. PMID: 29223694
DOI: 10.1016/S0140-6736(17)32451-0

Beretta E, Franzini A, Cordella R, Nazzi V, Valentini LG, Franzini A.
World Neurosurg. 2017 Nov;107:1053.e7-1053.e10. doi: 10.1016/j.wneu.2017.08.145. Epub 2017 Sep 1.
Abstract
BACKGROUND:
Secondary intracranial hypotension is a clinical syndrome associated with reduction of cerebrospinal fluid volume and dural continuity violation. The main symptoms are orthostatic headache associated with nausea, vomiting, diplopia, dizziness, and tinnitus. The treatment is usually nonspecific.
CASE DESCRIPTION:
A 37-year-old woman developed secondary intracranial hypotension caused by lumbosacral iatrogenic dural ectasia following detethering surgery. An orthostatic headache was the mainstay of her clinical picture, and it was confirmed by intracranial pressure monitoring. Conservative treatment including spinal blood patch improved symptoms for a limited amount of time (<1 month). Altered compliance of the dural spinal sac was suspected. Therefore thecal sac remodeling by placing autologous fat at the level of the dural ectasia was performed, improving the symptoms for 2 years. CONCLUSION: Volumetric reduction of the epidural space may be considered as a valuable therapeutic option in case of intracranial hypotension that is unresponsive to medical treatments and spinal blood patch, as well as when an altered compliance of the dural sac is hypothesized. PMID: 28866058
DOI: 10.1016/j.wneu.2017.08.145

Hussein O, Torbey M.
Neurocrit Care. 2017 Nov 17. doi: 10.1007/s12028-017-0481-9. [Epub ahead of print]
Abstract
INTRODUCTION:
Hyperpyrexia is a severely elevated core body temperature secondary to an elevated hypothalamic set thermo-regulatory threshold. Hyperthermia is an elevated core body temperature beyond the normal hypothalamic set thermo-regulatory threshold. Intracranial hypotension can present with a wide variety of symptoms ranging from orthostatic headache up to coma. We report a rare case of hyperpyrexia associated with intracranial hypotension.
METHODS:
A case report of a 55-year-old female patient with a history of angiogram-negative subarachnoid hemorrhage status post-ventriculoperitoneal (VP) shunt placement six years prior to admission who suddenly developed encephalopathy and high fever. Conventional management of the fever was unsuccessful.
RESULTS AND MANAGEMENT:
Brain magnetic resonance imaging revealed signs of significant intracranial hypotension. When the VP shunt was tapped, no cerebrospinal fluid (CSF) could be obtained. Once the VP shunt settings were adjusted, the patient’s encephalopathy and hyperpyrexia resolved.
CONCLUSION:
Hyperpyrexia might be a presenting symptom of intracranial hypotension, likely, secondary to hypothalamic dysfunction and compression. In our case, hyperpyrexia was reversible as the intracranial hypotension was emergently treated. Spontaneous intracranial hypotension might be difficult to diagnose, especially if it presented with non-classical symptoms like fever; thus, physicians should be aware of such association.
PMID: 29150776
DOI: 10.1007/s12028-017-0481-9

Gallina P, Savastano A, Becattini E, Orlandini S, Scollato A, Rizzo S, Carreras G, Di Lorenzo N, Porfirio B.
J Neurosurg. 2017 Nov 17:1-7. doi: 10.3171/2017.5.JNS163062. [Epub ahead of print]
Abstract
OBJECTIVE Changes in the pressure gradient between intraocular and intracranial compartments at the lamina cribrosa level are a possible explanation of normal tension glaucoma (NTG). Shunt-treated normal pressure hydrocephalus (NPH) is a model for testing whether the increase (time from disease onset to CSF shunt placement, i.e., “protection period”) and decrease (time from shunt placement to observation, i.e., “exposure period”) in intracranial pressure (ICP) are glaucoma protective or risk factors, respectively. The authors estimated the prevalence of NTG in patients with shunt-treated NPH and calculated the extent of optic nerve exposure to changes in the trans-lamina cribrosa gradient. METHODS Data obtained in patients with NPH who had undergone ventriculoperitoneal (VP) shunt placement were analyzed. Patients with more than 6 months’ follow-up, no pathologies associated with ICP changes or CSF dynamics disturbances, and no surgical or valve-related complications were scheduled for ophthalmic evaluation. RESULTS Nine of 22 patients had NTG, which is about a 40-fold increase in rate compared with the rate in the general elderly population without hydrocephalus (p < 0.001). The median protection period was 12.0 months in patients with NTG and 18.0 months in those without NTG (p = 0.033). The median ICP decrease multiplied by duration of exposure in months was 76.0 mm Hg × months in the NTG group and 24.1 mm Hg × months in the no-NTG group (p = 0.048). The patients’ median adjusted age (adjusted for “protection” and “exposure” times) was 85.1 years in the NTG group and 78.8 years in the no-NTG group (p = 0.001). CONCLUSIONS A crucial risk factor for development of NTG in patients with shunt-treated NPH is the duration of optic nerve exposure to the lowering of ICP. Patients with NPH who are candidates for CSF shunting should be informed of the risk of incurring glaucoma. Longitudinal studies could provide estimates of tolerated times for a given ICP decrease. PMID: 29148901
DOI: 10.3171/2017.5.JNS163062

Nomura M, Ota T, Ishizawa M, Yoshida S, Hara T.
Asian J Neurosurg. 2017 Oct-Dec;12(4):794-796. doi: 10.4103/1793-5482.185070.
Abstract
Cranioplasty is a comparatively simple neurosurgical procedure, and fatal complications are rare. This report describes two cases of critical brain swelling after otherwise uneventful cranioplasty. Both cases had subarachnoid hemorrhage and extremely similar clinical courses. They underwent decompressive craniotomy and clipping in the acute phase and had cranioplasty in the chronic phase, resulting in serious cerebral swelling and death. Deep venous sinus thrombosis was revealed in the autopsy for one case. Although no venous occlusion was identified in the other case, radiological findings suggested venous congestion. In both cases, intraoperative cerebrospinal fluid leakage was massive and was prolonged by a drain; therefore, we hypothesized that intracranial hypotension (IH) caused stagnation of venous flow. Neurosurgeons should be aware that fatal venous congestion induced by IH may occur after cranioplasty. To avoid this, tight dural closure should be obtained, and avoidance of the use of subcutaneous drains should be considered.
PMID: 29114315
PMCID: PMC5652127DOI: 10.4103/1793-5482.185070

Staudt MD, Pasternak SH, Sharma M, Pandey SK, Arango MF, Pelz DM, Lownie SP.
J Neurosurg. 2017 Oct 6:1-6. doi: 10.3171/2017.5.JNS17249. [Epub ahead of print]
Abstract
Spontaneous intracranial hypotension (SIH) is a progressive clinical syndrome characterized by orthostatic headaches, nausea, emesis, and occasionally focal neurological deficits. Rarely, SIH is associated with neurocognitive changes. An epidural blood patch (EBP) is commonly used to treat SIH when conservative measures are inadequate, although some patients require multiple EBP procedures or do not respond at all. Recently, the use of a large-volume (LV) EBP has been described to treat occult leak sites in treatment-refractory SIH. This article describes the management of a patient with profound neurocognitive decline associated with SIH, who was refractory to conservative management and multiple interventions. The authors describe the successful use of an ultra-LV-EBP of 120 ml across multiple levels, the largest volume reported in the literature, and describe the technical aspects of the procedure. This procedure has resulted in dramatic and sustained symptom resolution.
PMID: 28984516
DOI: 10.3171/2017.5.JNS17249

Ferrante E, Rubino F, Beretta F, Regna-Gladin C, Ferrante MM.
Acta Neurol Belg. 2017 Oct 20. doi: 10.1007/s13760-017-0845-0. [Epub ahead of print]
Abstract
Spontaneous intracranial hypotension (SIH) is characterized by orthostatic headache, low CSF pressure and diffuse pachymeningeal enhancement on brain MRI. SIH results from spontaneous CSF leakage leading to brain sag. Sometimes, tearing of bridging veins may produce subdural hematomas (SDHs). Patients with SDH were identified retrospectively from 212 consecutive SIH patients. Data were collected on demographics, clinical courses, neuroimaging findings, treatment and outcome of SDH. Thirty-five patients (16%), (6 women, 29 men; aged 33-68; mean, 50 years) with SDH were recruited. They were divided into two groups: initially withSIH diagnosed (n = 29) and undiagnosed (n = 6). After conservative treatment, the first group underwent a lumbar epidural blood patch (EBP) (n = 27) and emergent evacuation of symptomatic SDH (n = 2). After EBP, ten patients had enlarged SDH. Nine of them underwent evacuation of symptomatic SDH with mass effect (ME). In the second group, three patients with clinical worsening from SIH underwent, erroneously, evacuation of mild SDH. They worsened after the evacuation; after SIH diagnosis was made, they underwent one EBP (n = 2) and three EBPs (the patient with coma). The other three cases with symptomatic SDH with ME underwent evacuation with recurrence of SDH (n = 2). All 35 patients enjoyed a good outcome. If conservative treatment is insufficient, EBP should be performed prior to hematoma irrigation. When an emergent evacuation is necessary before EBP, it is preferable to perform, after surgery, one early EBP before the patient gets up to prevent frequent recurrences of SDH by underlying CSF leakage.
PMID: 29052799
DOI: 10.1007/s13760-017-0845-0

Cardinale M, Meaudre E, Cungi PJ, Nguyen C, Esnault P, Joubert C.
Br J Neurosurg. 2017 Sep 8:1-2. doi: 10.1080/02688697.2017.1374350. [Epub ahead of print]
Abstract
Duret hemorrhage has always been reported during an episode of increased intracranial pressure with transtentorial herniation. We reported a Duret hemorrhage occurring during an episode of intracranial hypotension resulted in sinking skin flap syndrome which was responsible for acute paradoxal descending transtentorial herniation and Duret hemorrhage, 10 days after large hemicraniectomy which could indicate early cranioplasty.
PMID: 28885045
DOI: 10.1080/02688697.2017.1374350

Bensam B, Sy HL, Sotudeh N, Bhalla PK, Hwang ST, LeDoux DE.
J Clin Neurophysiol. 2017 Aug 30. doi: 10.1097/WNP.0000000000000409. [Epub ahead of print]
Abstract
PURPOSE:
Brain sagging after craniotomy and clipping of a ruptured aneurysm is a rare complication. Clinical and electrographic changes in patients with a final diagnosis of intracranial hypotension are not well described, and can be mistaken on rare occasions for other entities such as nonconvulsive status epilepticus. There may be resulting delay in the diagnosis and treatment of this potentially life-threatening disorder.
METHODS:
Case report and imaging.
RESULTS:
We present a case of intracranial hypotension in which concerning continuous electroencephalogram (cEEG) and quantitative EEG (qEEG) findings were noted during active sagging of the brain, which resolved with supine positioning. During upright seating, cEEG showed high-amplitude bilateral rhythmic 2-Hz slow-wave activity, and bilateral increase of spectral delta power on qEEG, in association with neurologic decline in function. When placed in supine position, the cEEG and qEEG abnormalities resolved in conjunction with the recovery of neurologic function.
CONCLUSIONS:
Brain sagging can be diagnosed using simple maneuvers such as supine positioning. This case report describes changes seen in cEEG and qEEG monitoring that accompany these maneuvers, which may provide further evidence for the diagnosis of brain sagging. Thus, cEEG and qEEG monitoring may have a role in the early detection and treatment of brain sagging.
PMID: 28858905
DOI: 10.1097/WNP.0000000000000409

Gunaydin B, Acar M, Emmez G, Akcali D, Tokgoz N.
J Anesth. 2017 Aug 19. doi: 10.1007/s00540-017-2400-9. [Epub ahead of print]
Abstract
We aimed to perform an epidural patch using platelet rich plasma (PRP), which has the potential to regenerate and heal tissues via degranulation of platelets, in a 34-year-old parturient suffering from persistent post-dural puncture headache (PDPH) after failed epidural blood patch (EBP). After her admission to our unit, we reconfirmed the clinical and radiologic diagnosis of PDPH. Cranial MRI with contrast showed diffuse pachymeningeal thickening and contrast enhancement with enlarged pituitary consistent with intracranial hypotension. Clinical and radiological improvements were observed 1 week after the epidural patch using autologous PRP. Therefore, we recommend using autologous PRP for epidural patching in patients with incomplete recovery after standard EBP as a novel successful approach.
PMID: 28823090
DOI: 10.1007/s00540-017-2400-9

Onofrj M, Franciotti R, Di Stefano V, Cioffi E, Caulo M, Bonanni L.
J Neurol Neurosurg Psychiatry. 2017 Aug 17. pii: jnnp-2017-316436. doi: 10.1136/jnnp-2017-316436. [Epub ahead of print]
KEYWORDS:
audio; clinical; evoked potentials; headache; mri; neurophysiol
PMID: 28819061
DOI: 10.1136/jnnp-2017-316436

Li YL, Tsang CS.
BMJ Case Rep. 2017 Aug 7;2017. pii: bcr-2017-221098. doi: 10.1136/bcr-2017-221098.
Abstract
A middle-aged man presented with progressive confusion. Initial brain CT was misinterpreted to have ‘cerebral atrophy and bilateral subdural effusions’ by the emergency physician, and the patient was admitted to a medical ward for further investigation. Two days later, the patient experienced acute neurological deterioration, and burr hole drainage was performed to relieve the effusions. It was later confirmed that the effusions were caused by intracranial hypotension secondary to spinal cerebrospinal fluid leakage. The patient improved on conservative treatment with no lasting neurological sequela.
PMID: 28784900
DOI: 10.1136/bcr-2017-221098

Takai K, Taniguchi M.
World Neurosurg. 2017 Aug 5. pii: S1878-8750(17)31269-X. doi: 10.1016/j.wneu.2017.07.168. [Epub ahead of print]
Abstract
OBJECTIVE:
Targeted epidural blood patch (EBP) at the site of a presumed cerebrospinal fluid leak reportedly has better outcomes than non-targeted EBP; however, it is associated with a higher risk of wrong-site injection such as iatrogenic subarachnoid or intramuscular injections, which lead to reintervention due to the insufficient coverage of injected blood.
METHODS:
Eight patients with intracranial hypotension due to a CSF leak diagnosed by myelographic CT and thin-cut MRI received an epidural blood patch under O-arm-guided stereotactic navigation.
RESULTS:
The leak site was identified based on myelographic CT findings of a micro-spur and epidural contrast medium extravasations as well as MRI findings of a ventral dural defect. During the EBP procedure, no iatrogenic dural puncture or subarachnoid injection occurred because O-arm-guided stereotactic navigation provided real-time feedback on the needle trajectory. O-arm CT revealed the sufficient coverage of injected blood following the first injection in six out of eight patients. In the two remaining patients, a second injection was performed during the same session due to insufficient coverage at the previous site. In all patients, complete recovery from orthostatic headaches was achieved after a single session.
CONCLUSIONS:
O-arm-guided navigation facilitated EBP by enabling real-time observations of the needle trajectory and distribution of injected blood while simultaneously avoiding major complications such as wrong-site injections or reintervention.
PMID: 28790007
DOI: 10.1016/j.wneu.2017.07.168

Kranz PG, Malinzak MD, Amrhein TJ, Gray L.
Curr Pain Headache Rep. 2017 Aug;21(8):37. doi: 10.1007/s11916-017-0639-3.
Abstract
PURPOSE OF REVIEW:
The purpose of this study is to provide an update on recent developments in the understanding, diagnosis, and treatment of spontaneous intracranial hypotension (SIH).
RECENT FINDINGS:
SIH is an important cause of headaches caused by spinal cerebrospinal fluid (CSF) leaks, with an increasingly broad spectrum of clinical presentations and diagnostic findings. A simple conception of the condition as being defined by the presence of low CSF pressure is no longer sufficient or accurate. A number of etiologies for spinal CSF leaks have been identified, including the recent discovery of CSF-venous fistulas, and these various etiologies may require different diagnostic and therapeutic pathways in order to affect a cure. Familiarity with the spectrum of presentations and causes of SIH is critical to accurate and timely diagnosis and management. Challenges exist in both diagnosis and treatment, and require understanding of the underlying pathogenesis of the condition in order to appropriately select testing and treatment. Prospective studies are needed going forward in order to inform workup and guide treatment decisions.
PMID: 28755201
DOI: 10.1007/s11916-017-0639-3

Iyer RS, Wattamwar P, Thomas B.
BMJ Case Rep. 2017 Jul 27;2017. pii: bcr-2017-220348. doi: 10.1136/bcr-2017-220348.
Abstract
Holmes’ tremor is a low-frequency hand tremor and has varying amplitude at different phases of motion. It is usually unilateral and does not respond satisfactorily to drugs and thus considered irreversible. Structural lesions in the thalamus and brainstem or cerebellum are usually responsible for Holmes’ tremor. We present a 23-year-old woman who presented with unilateral Holmes’ tremor. She also had hypersomnolence and headache in the sitting posture. Her brain imaging showed brain sagging and deep brain swelling due to spontaneous intracranial hypotension (SIH). She was managed conservatively and had a total clinical and radiological recovery. The brain sagging with the consequent distortion of the midbrain and diencephalon was responsible for this clinical presentation. SIH may be considered as one of the reversible causes of Holmes’ tremor.
PMID: 28754752
DOI: 10.1136/bcr-2017-220348

Bateman GA, Lechner-Scott J, Copping R, Moeskops C, Yap SL.
Fluids Barriers CNS. 2017 Jul 6;14(1):18. doi: 10.1186/s12987-017-0066-1.
Abstract
There is evidence that patients with multiple sclerosis (MS) and hydrocephalus share some common pathophysiological mechanisms. Alterations in CSF pressure are known to affect cerebral venous sinus geometry. To further explore these mechanisms, we measured the superior sagittal sinus (SSS) cross-sectional area 3 cm above the torcular using T2 images in 20 MS, 10 spontaneous intracranial hypotension (SIH), 21 hydrocephalus and 20 idiopathic intracranial hypertension (IIH) patients and compared with 20 matched controls. The SSS area was reduced by 25% in hydrocephalus (p = 0.0008), increased by 22% (p = 0.037) in SIH and unchanged in IIH compared to matched controls. In MS there was a 16% increase in SSS area (p = 0.01).The findings suggest that changes in SSS cross-sectional are common between MS and SIH patients, while in hydrocephalus and IIH these are different.
PMID: 28679427
PMCID: PMC5499004
DOI: 10.1186/s12987-017-0066-1

Yao LL, Hu XY.
J Zhejiang Univ Sci B. 2017 Jul;18(7):577-585. doi: 10.1631/jzus.B1600343.
Abstract
OBJECTIVE:
Spontaneous intracranial hypotension (SIH) is recognized far more commonly than ever before. Though usually characterized by low cerebrospinal fluid (CSF) pressure, some patients with SIH are observed to have normal pressure values. In this study, we aimed to confirm the proportion of patients with normal CSF opening pressure (CSF OP) and explore the factors affecting CSF OP in SIH patients.
METHODS:
We retrospectively reviewed 206 consecutive SIH patients and analyzed their clinical and imaging variables (including demographic data, body mass index (BMI), duration of symptoms, and brain imaging findings). Univariate and multivariate analyses were performed to identify the potential factors affecting CSF OP.
RESULTS:
In a total of 114 (55.3%) cases the CSF OP was ≤60 mmH2O (1 mmH2O=9.806 65 Pa), in 90 (43.7%) cases it was between 60 and 200 mmH2O, and in 2 (1.0%) cases it was >200 mmH2O. Univariate analysis showed that the duration of symptoms (P<0.001), BMI (P<0.001), and age (P=0.024) were positively correlated with CSF OP. However, multivariate analysis suggested that only the duration of symptoms (P<0.001) and BMI (P<0.001) were strongly correlated with CSF OP. A relatively high R2 of 0.681 was obtained for the multivariate model. CONCLUSIONS: Our study indicated that in patients without a low CSF OP, a diagnosis of SIH should not be excluded. BMI and the duration of symptoms can influence CSF OP in SIH patients, and other potential factors need further investigation.
PMID: 28681582
PMCID: PMC5498838
DOI: 10.1631/jzus.B1600343

Schievink WI, Maya MM, Moser FG.
J Neurosurg Spine. 2017 Jun;26(6):760-764. doi: 10.3171/2016.11.SPINE16968. Epub 2017 Mar 31.
Abstract
OBJECTIVE Post-dural puncture headaches are common, and the treatment of such headaches can be complex when they become chronic. Among patients with spontaneous spinal CSF leaks, digital subtraction myelography (DSM) can localize the exact site of the leak when an extradural CSF collection is present, and it can also demonstrate CSF-venous fistulas in those without an extradural CSF collection. The authors now report on the use of DSM in the management of patients with chronic post-dural puncture headaches. METHODS The patient population consisted of a consecutive group of 27 patients with recalcitrant post-dural puncture headache that had lasted from 2 to 150 months (mean 26 months). RESULTS The mean age of the 17 women and 10 men was 39.1 years (range 18-77 years). An extensive extradural CSF collection was present in 5 of the 27 patients, and DSM was able to localize the exact site of the dural defect in all 5 patients. Among the 22 patients who did not have an extradural CSF collection, DSM showed a CSF-venous fistula in 1 patient (5%). Three other patients had a small pseudomeningocele at the level of the dural puncture. Percutaneous glue injection or microsurgical repair resulted in resolution of symptoms in 8 of the 9 patients in whom an abnormality had been identified on imaging. CONCLUSIONS Digital subtraction myelography is able to precisely localize the dural puncture site in patients with a post-dural puncture headache and an extensive extradural CSF collection, and it may rarely detect a CSF-venous fistula in such patients without an extradural CSF collection.
PMID: 28362213
DOI: 10.3171/2016.11.SPINE16968

Kim YJ, Cho HY, Seo DW, Sohn CH, Ahn S, Lee YS, Kim WY, Lim KS.
Headache. 2017 Jun 26. doi: 10.1111/head.13132. [Epub ahead of print]
Abstract
OBJECTIVE:
This study aimed to evaluate the association between misdiagnosis of spontaneous intracranial hypotension (SIH) and subdural hematoma development.
BACKGROUND:
Although SIH is more prevalent than expected and causes potentially life-threatening complications including subdural hematoma (SDH), the association between misdiagnosis of SIH and SDH development is not yet evaluated.
METHODS:
Retrospective observational study was conducted between January 1, 2005, and December 31, 2014. Adult patients with spontaneous intracranial hypotension (age ≥ 18 years) were enrolled.
RESULTS:
Of the 128 patients with SIH, 111 (86.7%) were in no SDH group and 17 (13.3%) were in SDH group. Their clinical presentation did not show significant different between the two groups, except age, the days from symptom onset to correct diagnosis, and the number of misdiagnoses. Age (odds ratio [OR], 1.15; 95% confidence interval [CI], 1.07-1.23) and the number of times SIH was misdiagnosed (OR, 1.82; 95% CI, 1.03-3.21) were independent risk factors for the development of SDH in SIH patients by multivariate logistic analysis. The clinical outcomes, including length of hospital stay and revisit rate, were similar in the two groups.
CONCLUSIONS:
The number of times SIH was misdiagnosed was associated with the later development of SDH perhaps because of delay in correct diagnosis of SIH. Clinicians would prevent the later complication of SDH in SIH patients by increasing the awareness and a high index of suspicion of SIH.
PMID: 28653430
DOI: 10.1111/head.13132

Lin JP, Zhang SD, He FF, Liu MJ, Ma XX.
J Headache Pain. 2017 Dec;18(1):4. doi: 10.1186/s10194-016-0708-8. Epub 2017 Jan 13.
Abstract
Intracranial hypotension, especially spontaneous intracranial hypotension (SIH), is a well-recognized entity associated with cerebrospinal fluid (CSF) leaks, and has being recognized better in recent years, while still woefully inadequate. An increasing number of factors including iatrogenic factors are realized to involve in development and progression of intracranial hypotension. The diagnosis remains difficult due to the various clinical manifestations, some of which are nonspecific and easily to be neglected. Multiple imaging tests are optional in CSF leakage identification while clinicians are still confronted with difficulties when making selection resulting from superiorities and disadvantages of different imaging tests. Treatments for intracranial hypotension are multifarious but evidence is anecdotal. Values of autologous epidural blood patching (EBP), the mainstay of first-line interventional treatment currently, is getting more and more regards while there are no systematic review of its efficacy and risks. Hereby, the purpose of this review was to reveal the present strategy of intracranial hypotension diagnosis and treatment by reviewing literatures, coupled with our experience in clinical work.
PMID: 28091819
PMCID: PMC5236046
DOI: 10.1186/s10194-016-0708-8

Schönberger J, Möhlenbruch M, Seitz A, Bußmann C, Bächli H, Kölker S.
Eur J Paediatr Neurol. 2017 Jul;21(4):678-681. doi: 10.1016/j.ejpn.2017.02.004. Epub 2017 Feb 20.
Abstract
BACKGROUND:
Spontaneous intracranial hypotension is a rarely diagnosed cause of headache, especially in children and adolescents. It is due to cerebrospinal fluid (CSF) leakage via spinal fistulae occurring without major trauma.
CASE PRESENTATION:
An adolescent patient presented with a 3-month history of strictly postural headache. Cranial magnetic resonance imaging (MRI) showed pronounced Chiari-like prolapse of the cerebellar tonsils, narrow ventricles and enlarged cerebral veins. On spinal MRI, myelographic sequences revealed a large collection of CSF around the first sacral roots. CT myelography proved extensive spinal CSF leakage. Hence, we applied epidural patches at multiple levels. Afterwards, symptoms and radiologic findings, including Chiari-like displacement, completely resolved.
CONCLUSION:
A Chiari-like descent of the cerebellar tonsils alone does not secure the diagnosis of a Chiari I malformation. Especially if other findings indicate spinal CSF leakage, a systematic work-up should be initiated. In most cases, interventional techniques seal the leak successfully, resulting in a favorable outcome.
PMID: 28283371
DOI: 10.1016/j.ejpn.2017.02.004

Jeon SH, Lee SH, Tsang YS, Jung TG, Moon KH, Choi G, Dilip KD.
Clin Spine Surg. 2017 Jul;30(6):E702-E706. doi: 10.1097/BSD.0000000000000249.
Abstract
STUDY DESIGN:
A retrospective review.
OBJECTIVES:
To evaluate the therapeutic efficacy of the triple layer closure technique to establish watertight sealing without diversion of lumbar drainage, in preventing persistent incidental subarachnoid-pleural fistula and other neurological complications related to excessive drainage of cerebrospinal fluid (CSF) after dural defect in transthoracic ossified posterior longitudinal ligament (OPLL) surgery.
SUMMARY OF BACKGROUND DATA:
CSF leakage into the pleural cavity leads to unfavorable conditions for natural healing of incidental durotomy due to the negative pressure environment of the pleural space and lack of wound healing around the bony cavity near the decompressed spinal cord. This often leads to a persistent incidental subarachnoid-pleural fistula. In addition, diversion of lumbar drainage may lead to excessive CSF drainage resulting in intracranial hypotension. To avoid this, we studied the efficacy of a modified sealing method to establish a more watertight covering at the ventral dural defect without lumbar CSF drainage.
METHODS:
Fifty-three patients who had CSF leakage from the ventral aspect of the spinal cord during transthoracic spine surgery for thoracic OPLL between 2004 and 2013 were retrospectively reviewed. Patients were divided into 2 groups: a conventional group (group A) and a triple layer closure group (group B). In group A (n=33 patients), the dural defect was covered with fibrin glue (Beriplast P) mixed with gelfoam (Spongostan Standard) with subsequent subarachnoid lumbar drainage. In group B (n=20 patients), the dural defect was sealed using the triple layer technique with 2 layers of fibrin glue and gelatin sponge plus a third layer of synthetic hydrogel (Duraseal, Dural Sealant System) without subsequent subarachnoid lumbar drainage. Both groups had chest tubes that drained through an underwater seal. Clinical data including duration and total amount of drainage (chest tube and lumbar drainage), related complications, and duration of hospital stay were compared between the 2 groups.
RESULTS:
Compared with the patients in group A, group B had a significantly smaller total volume of drainage and shorter chest tube drainage time (P<0.05) during their hospital stay. In group A, complications occurred in 6 cases (18.2%), including 3 cases of intracranial hypotension combined with transient mental status alteration, postural headache, and dizziness, 1 case of regional atelectasis with pneumonia, and 2 cases of revision thoracotomy. Revision thoracotomy was performed to treat persistent subarachnoid-pleural fistula due to significant and prolonged CSF leakage. In group B, there were no complications and no revision thoracotomy was needed. The mean duration of hospital stay was shorter in group B (15.6 d) compared with group A (22.4 d). CONCLUSIONS: The established watertight closure of the dural defect using the triple layer sealing method without lumbar drainage was more effective and safe.
PMID: 28632556
DOI: 10.1097/BSD.0000000000000249

Low JCM, Shtaya A, Hettige S.
World Neurosurg. 2017 Jun 14. pii: S1878-8750(17)30952-X. doi: 10.1016/j.wneu.2017.06.060. [Epub ahead of print]
Abstract
BACKGROUND:
Intracranial hypotension (IH) is a recognised cause of coma, however, the diagnosis is often challenging, especially in patients with superimposed traumatic brain injury (TBI).
CASE REPORT:
We report a case of a 67-year-old patient who became comatose following evacuation of bilateral acute subdural haematomas with concurrent respiratory failure. Imaging and intraparenchymal intracranial pressure (ICP) monitoring confirmed secondary IH. She was managed with an epidural blood patch, and a 72 hours period in the trendelenberg position guided by ICP monitoring and clinical assessment. She subsequently made an excellent neurological recovery from an initial Glasgow coma scale (GCS) of 3 to a GCS of 15.
CONCLUSION:
A diagnosis of secondary IH can easily be missed in patients who have suffered a primary brain injury. In patients with a poor neurological recovery, clinicians should rule out secondary IH as a potential cause as immediate treatment can lead to a profound clinical improvement.
PMID: 28624560
DOI: 10.1016/j.wneu.2017.06.060

Agarwal N, Kashkoush AI, Prabhu AV, Sekula RF Jr.
World Neurosurg. 2017 Jun;102:697.e5-697.e7. doi: 10.1016/j.wneu.2017.01.133. Epub 2017 Feb 10.
Abstract
BACKGROUND:
Dural breaches have a diverse etiology, including spontaneous rupture and trauma. Most cases resolve with bed rest; in refractory cases, an epidural blood patch can be placed to obstruct further leakage. We discuss a unique case of a spontaneous ventral durotomy following vaginal delivery that was managed with injections of autologous blood through bilateral transforaminal needles.
CASE DESCRIPTION:
A previously healthy, 36-year-old pregnant woman presented to the inpatient maternity ward with positional occipital headaches and neck pain 24 hours after normal spontaneous vaginal delivery. Two dorsally placed epidural blood patches provided only transient relief. Computed tomography myelography revealed ventral cerebrospinal fluid leak. Targeted therapy was provided with computed tomography-guided ventral placement of a blood patch.
CONCLUSIONS:
Spontaneous durotomy is a rare phenomenon and should be considered in patients who present with positional headaches. Ventrally targeted therapy via an epidural blood patch should be considered to provide optimal relief.
PMID: 28192271
DOI: 10.1016/j.wneu.2017.01.133

Sinnaeve L, Vanopdenbosch L, Paemeleire K.
J Stroke Cerebrovasc Dis. 2017 Jun 13. pii: S1052-3057(17)30234-3. doi: 10.1016/j.jstrokecerebrovasdis.2017.05.015. [Epub ahead of print]
Abstract
Cerebral venous thrombosis is a rare complication of intracranial hypotension. We describe 3 cases in which this phenomenon occurred, as a result of a lumbar puncture or due to a spontaneous cerebrospinal fluid leak. We emphasize the importance of early detection of the intracranial hypotension syndrome, the most common clinical manifestation being orthostatic headache. It is not an innocent condition as it is associated with other potential complications such as subdural hygroma/hematoma, cranial nerve palsies, cerebellar tonsillar descent, and even brainstem manifestations. Any change in the typical features of the syndrome should lead to further investigation. Repeat cerebral imaging is important in that situation, including ruling out cerebral venous thrombosis.
PMID: 28623115
DOI: 10.1016/j.jstrokecerebrovasdis.2017.05.015

Niraj G, Critchley P, Kodivalasa M, Dorgham M.
Headache. 2017 Jun;57(6):952-955. doi: 10.1111/head.13095. Epub 2017 May 2.
Abstract
BACKGROUND:
Clinical presentation of spontaneous intracranial hypotension headache (SIHH) has similarities with postdural puncture headache (PDPH). Recommended treatment for both conditions is an epidural blood patch. Successful outcomes following greater occipital nerve blocks have been reported in the management of PDPH. We present the first report of greater occipital nerve treatment in SIHH.
METHODS:
A 40-year-old male presented with a 2-year history of daily postural headaches having a significant impact on quality of life. Magnetic resonance imaging revealed bilateral convexity subdural collections. Post gadolinium scan revealed pachymeningeal enhancement with reduced pontomesencephalic angle below 50 degrees. The patient was offered an epidural blood patch and greater occipital nerve block with corticosteroids. The patient chose occipital nerve block.
RESULT:
The patient reported significant short-term benefit lasting 4 months. Thereafter, the patient underwent pulsed radiofrequency treatment to bilateral greater occipital nerves. He reported significant benefit lasting 10 months.
CONCLUSION:
Greater occipital nerve treatment may have a role in management of SIHH.
PMID: 28466552
DOI: 10.1111/head.13095

Beck J, Fung C, Ulrich CT, Fiechter M, Fichtner J, Mattle HP, Mono ML, Meier N, Mordasini P, Z’Graggen WJ, Gralla J, Raabe A.
J Neurosurg Spine. 2017 Jun 2:1-8. doi: 10.3171/2017.1.SPINE16548. [Epub ahead of print]
Abstract
OBJECTIVE Spinal CSF leakage causes spontaneous intracranial hypotension (SIH). The aim of this study was to characterize CSF dynamics via lumbar infusion testing in patients with and without proven spinal CSF leakage in order to explore possible discriminators for the presence of an open CSF leak.
METHODS This analysis included all patients with suspected SIH who were treated at the authors’ institution between January 2012 and February 2015. The gold standard for “proven” CSF leakage is considered to be extrathecal contrast accumulation after intrathecal contrast injection. To characterize CSF dynamics, the authors performed computerized lumbar infusion testing to measure lumbar pressure at baseline (opening pressure) and at plateau, as well as pulse amplitude, CSF outflow resistance (RCSF), craniospinal elastance, and pressure-volume index.
RESULTS Thirty-one patients underwent clinical imaging and lumbar infusion testing and were included in the final analysis. A comparison of the 14 patients with proven CSF leakage with the 17 patients without leakage showed a statistically significantly lower lumbar opening pressure (p < 0.001), plateau pressure (p < 0.001), and RCSF (p < 0.001) in the group with leakage. Sensitivity, specificity, and positive and negative predictive values for an RCSF cutoff of ≤ 5 mm Hg/(ml/min) were 0.86, 1.0, 1.0, and 0.89 (area under the curve of 0.96), respectively. The median pressure-volume index was higher (p = 0.003), and baseline (p = 0.017) and plateau (p < 0.001) pulse amplitudes were lower in patients with a proven leak. CONCLUSIONS Lumbar infusion testing captures a distinct pattern of CSF dynamics associated with spinal CSF leakage. RCSF assessed by computerized lumbar infusion testing has an excellent diagnostic accuracy and is more accurate than evaluating the lumbar opening pressure. The authors suggest inclusion of RCSF in the diagnostic criteria for SIH.
PMID: 28574328
DOI: 10.3171/2017.1.SPINE16548

Sakurai K, Kanoto M, Nakagawa M, Shimohira M, Tokumaru AM, Kameyama M, Shimoji K, Morimoto S, Matsukawa N, Nishio M, Shibamoto Y.
Headache. 2017 Jun;57(6):917-925. doi: 10.1111/head.13075. Epub 2017 Apr 16.
Abstract
OBJECTIVE:
To evaluate the imaging characteristics and diagnostic utility of the “Dinosaur tail sign” in the diagnosis of cerebrospinal fluid (CSF) leakage.
BACKGROUND:
The authors propose the “Dinosaur tail sign,” defined as a combination of the dorsal epidural hyperintensities, fat tissue, spinal cord, and cauda equine on lumbosacral sagittal fat-suppressed T2-weighted image (FST2WI), as a sensitive indicator for diagnosing CSF leakage.
METHODS:
Imaging characteristics of the “Dinosaur tail sign” was evaluated in seven spontaneous intracranial hypotension (SIH) and 23 iatrogenic CSF leakage (ICSFL) patients. Additionally, the diagnostic index was compared between the “Dinosaur tail sign” and other previously reported useful magnetic resonance imaging (MRI) and magnetic resonance myelography (MRM) findings.
RESULTS:
In contrast to other imaging findings including the epidural expansion, floating dural sac sign, and distension of the spinal epidural veins on MRI, and paraspinal fluid collections (PFC) on MRM, the “Dinosaur tail sign” was found equally in both SIH and ICSFL patients (6 SIH and 19 ICSFL; 83% of all patients with CSF leakage). The “Dinosaur tail sign” showed sufficient diagnostic utility (sensitivity 83%, specificity 94%, accuracy 89%) that was comparable to that of PFC.
CONCLUSION:
The “Dinosaur tail sign” is a useful imaging finding suggestive of CSF leakage. Evaluation of subtle interspinous arched hyperintensities on spinal MRI is mandatory for the diagnosis of SIH and ICSFL.
PMID: 28419438
DOI: 10.1111/head.13075

Davidson B, Nassiri F, Mansouri A, Badhiwala JH, Witiw CD, Shamji MF, Peng PW, Farb RI, Bernstein M.
World Neurosurg. 2017 May;101:343-349. doi: 10.1016/j.wneu.2017.01.123. Epub 2017 Feb 9.
Abstract
BACKGROUND:
Spontaneous intracranial hypotension (SIH) is a condition of low cerebrospinal fluid volume and pressure caused by a leak of cerebrospinal fluid through a dural defect. Diagnosis and management can be difficult, often requiring coordination between multiple disciplines for myelography, blood patching, and possible surgical repair. Patients should be monitored closely, because they can deteriorate into a coma or even death. There are no widely accepted guidelines for the management of SIH.
METHODS AND CONCLUSIONS:
We review the existing SIH literature, illustrate management challenges via a case review, and propose an algorithm developed by neurosurgeons, radiologists, and anesthesiologists intended to simplify and streamline the management of SIH.
PMID: 28192268
DOI: 10.1016/j.wneu.2017.01.123

Decramer T1, Van Dyck-Lippens PJ2, Franken TP3, Demaerel P4, van Loon J5, Theys T5.
World Neurosurg. 2017 May;101:816.e1-816.e3. doi: 10.1016/j.wneu.2017.02.086. Epub 2017 Feb 27.
Abstract
BACKGROUND:
Spontaneous intracranial hypotension syndrome results from spontaneous spinal cerebrospinal fluid (CSF) leaks. The first treatment of choice consists of lumbar epidural blood patching. If this fails, further imaging is mandatory to explore the possibility of targeted therapy.
CASE DESCRIPTION:
We describe a case of a 50-year-old woman who developed spontaneous intracranial hypotension after minor blunt cervical trauma, complicated with bilateral subdural hematomas. Two lumbar epidural blood patches were unsuccessful. Magnetic resonance imaging with intrathecal gadolinium revealed a CSF leak at the C1-C2 level. A targeted blood patch via a percutaneous high thoracic epidural approach was performed, and symptoms disappeared in the immediate postoperative period with a regression of the subdural hematomas on subsequent imaging.
CONCLUSIONS:
A targeted epidural blood patch using an epidural catheter represents an elegant approach to a CSF leak at the C1-C2 region and can be successful in treating patients with severe intracranial hypotension syndrome.
PMID: 28254591
DOI: 10.1016/j.wneu.2017.02.086

Mariappan R, Philip A, Gandham EJ, Raju K.
J Neurosurg Anesthesiol. 2017 May 19. doi: 10.1097/ANA.0000000000000440. [Epub ahead of print]
PMID: 28538330
DOI: 10.1097/ANA.0000000000000440

Rosebrock RE, Diehn FE, Luetmer PH, Wald JT, Lane JI, Morris JM, Lehman VT, Carr CM, Mokri B, Thielen KR.
Clin Neuroradiol. 2017 May 16. doi: 10.1007/s00062-017-0596-6. [Epub ahead of print]
Abstract
OBJECTIVE/BACKGROUND:
We have anecdotally observed patients with high-flow ventral cerebrospinal fluid (CSF) leaks resulting from penetrating osseous spicules or calcified discs to be relatively thin. The purpose of this study was to explore the validity of this observation and determine if a potential association exists between low body mass index (BMI) and high-flow spinal ventral CSF leaks resulting from such dura-penetrating lesions.
METHODS:
Sixteen consecutive patients with precisely localized high-flow ventral spinal CSF leaks on dynamic myelography were identified. The cause of the CSF leak was determined. The BMI on the date nearest to and within 2 weeks of myelography was recorded. Utilizing exact sign test, the body mass index was compared to the average BMI from the National Health and Nutrition Examination Survey (Centers for Disease Control), matched to sex and age-range.
RESULTS:
The cohort consisted of 10 males (63%) and 6 females with a mean age of 54 years (range 37-72 years). In all patients, a spiculated osteophyte/calcified disc was identified at the site of the leak. Fourteen patients (88%) had a BMI below the matched national average, while only two patients (13%) had values above the national average (p = 0.004).
CONCLUSIONS:
Patients with high-flow ventral CSF leaks resulting from spiculated osteophyte or calcified disc as identified by dynamic myelography are more likely to have a BMI below the U.S. national average, matched for gender and age-range. This exploratory analysis requires confirmation as well as further characterization of potential pathophysiologic mechanisms and impact on radiographic and clinical assessments.
PMID: 28509936
DOI: 10.1007/s00062-017-0596-6

Chan DW, Wu AI, Wynne K.
BMJ Case Rep. 2017 May 12;2017. pii: bcr-2017-220057. doi: 10.1136/bcr-2017-220057.
PMID: 28500117
DOI: 10.1136/bcr-2017-220057

Chen HC, Chen PL, Tsai YH, Chen CH, Chen CC, Chai JW.
AJNR Am J Neuroradiol. 2017 May;38(5):1061-1067. doi: 10.3174/ajnr.A5134. Epub 2017 Apr 6.
Abstract
BACKGROUND AND PURPOSE:
CSF hypovolemia is a core feature of spontaneous intracranial hypotension. Spontaneous intracranial hypotension is characterized by orthostatic headache and radiologic manifestations, including CSF along the neural sleeves, diffuse pachymeningeal enhancement, and/or venous engorgement. However, these characteristics are only qualitative. Quantifying intraspinal CSF volumes could improve spontaneous intracranial hypotension diagnosis and evaluation of hypovolemic statuses in patients with spontaneous intracranial hypotension. The purpose of this study was to compare intraspinal CSF volumes across spontaneous intracranial hypotension stages and to test the clinical applicability of these measures.
MATERIALS AND METHODS:
A cohort of 23 patients with spontaneous intracranial hypotension and 32 healthy controls was subjected to brain MR imaging and MR myelography with 1.5T imaging. An automatic threshold-based segmentation method was used to calculate intraspinal CSF volumes at initial hospitalization (spontaneous intracranial hypotension-initial), partial improvement (spontaneous intracranial hypotension-intermediate), and complete recovery (spontaneous intracranial hypotension-recovery) stages.
RESULTS:
The mean intraspinal CSF volumes observed were the following: 95.31 mL for healthy controls, 72.31 mL for spontaneous intracranial hypotension-initial, 81.15 mL for spontaneous intracranial hypotension-intermediate, and 93.74 mL for spontaneous intracranial hypotension-recovery. Increased intraspinal CSF volumes were related to disease recovery (P < .001). The intraspinal CSF volumes of patients before complete recovery were significantly lower than those of healthy controls. With the estimated intradural CSF volumes as a reference, the intraspinal CSF volume percentage was lower in patients with spontaneous intracranial hypotension with venous engorgement than in those without it (P = .058). CONCLUSIONS: With a threshold-based segmentation method, we found that spinal CSF hypovolemia is fundamentally related to spontaneous intracranial hypotension. Intraspinal CSF volumes could be a sensitive parameter for the evaluation of treatment response and follow-up monitoring in patients with spontaneous intracranial hypotension.
PMID: 28385881
DOI: 10.3174/ajnr.A5134

Maurya VK, Ravikumar R, Bhatia M, Sirohi YS.
Med J Armed Forces India. 2017 Apr;73(2):188-196. doi: 10.1016/j.mjafi.2016.11.012. Epub 2017 Jan 6.
Abstract
Headache disorders are among the most common presenting complaints in any neurology outpatient department. International Headache Society classifies headaches as “primary” or “secondary”. The causes of secondary headaches are varied and intracranial hypotension is one of them. It typically presents clinically with postural headaches but most of the times, its diagnosis is delayed, as it is an uncommon cause and there is poor awareness among the medical fraternity about this condition. Imaging, especially magnetic resonance imaging (MRI), plays a crucial role in the diagnosis of intracranial hypotension by not only confirming the diagnosis but also detecting the cause in some cases. This case series tries to highlight the MRI findings of intracranial hypotension in three cases with different etiologies.
PMID: 28924323
PMCID: PMC5592273 Will be available April 1 2018
DOI: 10.1016/j.mjafi.2016.11.012

Epstein NE.
Surg Neurol Int. 2017 Apr 26;8:60. doi: 10.4103/sni.sni_38_17. eCollection 2017.
Abstract
BACKGROUND:
Various types of lumbar dural punctures may contribute to neurological injury. The etiologies of dural injury include; inadvertent dural punctures due to epidurals placed for labor anesthesia, epidural steroid injections (ESI/transforaminal TESI; approximately 9 million ESI performed in the US per year), deliberate placement of intradural pain devices, and spontaneous cerebrospinal fluid (CSF) fistulas. Resulting neurological complications may include; spinal headaches/intracranial hypotension, subdural hematomas, and 6th nerve cranial palsies. Furthermore, uniquely in the cervical spine, inadvertent cervical dural punctures attributed to cervical ESI (CESI) may lead to intramedullary spinal cord injuries (e.g. resulting in monoparesis to quadriplegia) or spinal cord strokes due to intravascular/vertebral artery injections.
METHODS/RESULTS:
In 8 studies, inadvertent lumbar dural punctures contributed to intracranial hypotension, subdural hematomas, and double vision/6th cranial nerve palsies. In 5 of the 6 studies, inadvertent dural punctures occurring during CESI were responsible for intramedullary spinal cord injuries, or direct intravascular/vertebral injections resulting in monoplegia/quadriplegia.
CONCLUSIONS:
Inadvertent lumbar dural punctures led to multiple neurological complications including intracranial hypotension, subdural hematomas, and double vision/6th cranial nerve palsies. Uniquely, inadvertent cervical dural punctures solely due to CESI directly resulted in intramedullary spinal cord injuries or cord stroked and monoplegia/quadriplegia attributed to intravascular/vertebral artery injections. The potential neurological risks/complications/adverse events attributed to lumbar and cervical ESI must be taken into account before spine surgeons and others order these procedures.
PMID: 28540126
PMCID: PMC5421209
DOI: 10.4103/sni.sni_38_17

Kearney S, Flynn P, Hughes S, Spence W, McCarron MO.
Pract Neurol. 2017 Apr 22. pii: practneurol-2016-001497. doi: 10.1136/practneurol-2016-001497. [Epub ahead of print]
Abstract
A 47-year-old man presented with a 9-year history of a hypoalert hypoactive behaviour syndrome, caused by the deep brain swelling variant of spontaneous intracranial hypotension. Along with apathy with retained cognition, he had stable ataxia, impaired upgaze and episodes of central apnoea. MRI brain showed a sagging brainstem, pointed ventricles and reduced angle between the vein of Galen and the straight sinus, but no meningeal enhancement or subdural collections. A dopamine transporter scan showed preganglionic dopamine receptor deficiency; a fluorodeoxy glucose positron emission tomography scan showed bilateral hypothalamic hypometabolism. This variant of spontaneous intracranial hypotension may alter deep brain functioning within the basal ganglia and thalamus, causing the hypoactive-hypoalert behaviour phenotype.
PMID: 28433974
DOI: 10.1136/practneurol-2016-001497

Preethish-Kumar V, Vengalil S, Tiwari S, Polavarapu K, Netravathi M, Ramalingaiah AH, Nalini A.
J Spinal Cord Med. 2017 Apr 12:1-6. doi: 10.1080/10790268.2017.1314901. [Epub ahead of print]
Abstract
CONTEXT:
Ventral longitudinal intraspinal fluid collection (VLISFC) presenting as hand amyotrophy has been described only in a few cases and there are no reports on associated intracranial CSF hypovolemia (ICH). We describe the clinical and imaging findings of a case with combined brachial amyotrophy and ICH secondary to VLISFC.
FINDINGS:
A 31 year old man presented with severe positional neck discomfort, radiating pain, progressive asymmetrical wasting and weakness of distal upper limbs. Contrast Magnetic Resonance Imaging (MRI) of the spine demonstrated a ventral extradural intraspinal fluid collection extending from upper border of C6 to lower border of T3 vertebra with pockets of dorsal collection. Three-dimensional constructive interference in steady state (CISS 3D) used in spinal imaging for identification of CSF leak corroborated with the extent seen on T2 sagittal sections; however, the site of the leak was not identified. After a year he developed disturbing postural headache which was relieved in recumbent position. Follow up MRI of brain was normal while spine demonstrated significant cervical cord atrophy and bilateral cord white matter hyperintensities. Conclusion / Clinical Relevance: We report this unusual case where local compression by VLISFC located at the cervical and upper thoracic level not only caused distal bi-brachial amyotrophy mimicking Hirayama disease but also led to secondary intracranial hypotension. An early identification and intervention could possibly have prevented the onset of ICH.
PMID: 28402198
DOI: 10.1080/10790268.2017.1314901

Kingston W, Hoxworth J, Halker-Singh R.
Neurology. 2017 Mar 28;88(13):1294. doi: 10.1212/WNL.0000000000003775.
No Abstract Available.
PMID: 28348118
DOI: 10.1212/WNL.0000000000003775

Tipirneni A, Shah NH, Atchaneeyasakul K, Berry AC, Adams DJ.
Intern Emerg Med. 2017 Mar;12(2):259-261. doi: 10.1007/s11739-016-1456-0. Epub 2016 Apr 28.
PMID: 27126682
Full text

Lai YC, Chia YY, Lien WH.
Pain Physician. 2017 Mar;20(3):E465-E468.
Abstract
Intracranial hypotension syndrome (IHS) is generally caused by cerebrospinal fluid (CSF) leakage. Complications include bilateral subdural hygroma or haematoma and herniation of the cerebellar tonsils. Epidural blood patch (EBP) therapy is indicated if conservative treatment is ineffective. We reported the case of a 46-year-old man with a history of postural headache and dizziness. The patient was treated with bed rest and daily hydration with 2000 mL of fluid for 2 weeks. However, dizziness and headache did not resolve, and he became drowsy and disoriented with incomprehensible speech. Magnetic resonance imaging demonstrated diffuse dural enhancement on the postcontrast study, sagging of the midbrain, and CSF leakage over right lateral posterior thecal sac at C2 level. We performed EBP at the level of T10-T11. We injected 14 mL of autologous blood slowly in the Trendelenburg position. Within 30 minutes, he became alert and oriented to people, place, and time. We chose thoracic EBP as first line treatment in consideration of the risk of cervical EBP such as spinal cord and nerve root compression or puncture, chemical meningitis. Also we put our patient in Trendelenburg position to make blood travel towards the site of the leak. Untreated IHS may delay the course of resolution and affect the patient’s consciousness. Delivery of EBP via an epidural catheter inserted from the thoracic spine is familiar with most of anesthesiologists. It can be a safe and effective treatment for patients with IHS caused by CSF leak even at C2.Key words: Anaesthetic techniques, regional, thoracic; cerebrospinal fluid leakage; epidural blood patch; heavily T2-weighted magnetic resonance myelography; intracranial hypotension syndrome; Trendelenburg position.
PMID: 28339449
Open Access: painphysicianjournal.com/current/pdf?article=NDMyNA%3D%3D&journal=104

Headache. 2017 Mar;57(3):467-471. doi: 10.1111/head.12974. Epub 2016 Nov 10.
Lin SF, Weng HY.
Abstract
BACKGROUND:
Postural headaches are commonly associated with spontaneous intracranial hypotension and cerebrospinal fluid (CSF) leakage from the spine. A subarachnoid-pleural fistula (SPF) is a very rare and serious type of CSF fistula that has mostly been reported following traumatic causes.
CASE REPORT:
Here, the case of a 36-year-old woman who suffered from postural headaches after chiropractic manipulation of her neck was reported. Brain and spinal magnetic resonance (MR) imaging showed brain sagging, a C7-T1 dural defect, and overt CSF leakage. Heavy T2-weighted MR myelography revealed paravertebral fluid collections, communicating with pleural effusions through bilateral SPFs. The postural headaches were relieved by 3 courses of epidural blood patches.
DISCUSSIONS:
From the patient’s history, her severe SPFs were attributed to rupture of the spinal leptomeninges during vigorous chiropractic manipulation of her neck. Heavy T2-weighted MR myelography could delineate the route of SPFs and CSF leakages.
PMID: 27861828
DOI: 10.1111/head.12974

Haider AS1, Sulhan S1, Watson IT1, Leonard D1, Arrey EN2, Khan U3, Nguyen P1, Layton KF4.
Cureus. 2017 Feb 16;9(2):e1034. doi: 10.7759/cureus.1034.
Abstract
Spontaneous intracranial hypotension (SIH) is classified as a decrease in cerebrospinal fluid (CSF) pressure secondary to a CSF leakage and consequent descent of the brain into the foramen magnum. Diagnosing SIH can be difficult due to its overlapping findings with Arnold-Chiari type 1 Malformation (CM1) where the cerebellar tonsils herniate into the foramen magnum. The similarity of both conditions calls for a more reliable imaging technique to localize the CSF leak which could narrow the differential diagnosis and aid in choosing the correct treatment. Here, we present a case of a 28-year-old female, ten weeks post-partum with symptoms similar to SIH. MRI of the brain was remarkable for tonsillar herniation below the foramen magnum. Literature was reviewed for additional neuroradiology techniques that would aid in narrowing our differential diagnosis. Interestingly, computed tomography-, digital subtraction-, and magnetic resonance myelography with intrathecal gadolinium are the preferred techniques for diagnosis of high flow and low flow CSF leaks, respectively. These modalities further aid in choosing the correct treatment while avoiding complications. Literature suggests that treatment for CM1 involves posterior fossa decompression, whereas the mainstay of treatment for SIH involves an epidural blood patch (EBP). Thus, our patient was treated with an EBP and recovered without complication.
PMID: 28357166
PMCID: PMC5354398
DOI: 10.7759/cureus.1034

Chambers DJ, Bhatia K.
Int J Obstet Anesth. 2017 Feb 20. pii: S0959-289X(16)30180-7. doi: 10.1016/j.ijoa.2017.02.003. [Epub ahead of print]
Abstract
BACKGROUND:
Cranial nerve palsy is a rarely reported complication of central neuraxial block in obstetrics. The aetiology is diverse and includes both decreased and increased intracranial pressure.
METHODS:
Medline, CINAHL, and EMBASE databases were searched to identify cases of cranial nerve palsy following obstetric central neuraxial block. Possible aetiology, clinical symptoms and signs, treatment, and time to resolution were assessed.
RESULTS:
Forty-one articles containing 43 case reports of cranial nerve palsy following obstetric central neuraxial block were identified. Four cranial nerve palsies were bilateral; the remainder being unilateral. The cranial nerves most commonly affected were the abducens (17 case reports) and facial (12 case reports) nerves. Epidural block was implicated in 25 cases. Classical post-dural puncture headache preceded cranial nerve palsy in 27 cases. Subdural haematomas were reported in six cases and cortical venous or transverse sinus thrombosis in one case. Epidural blood patch was administered for treatment of cranial nerve palsy in 17 cases. Thirty-five patients had complete resolution of symptoms but in eight the cranial nerve palsy was permanent. No case reports of olfactory, oculomotor, glossopharyngeal, accessory or hypoglossal nerve palsy were identified.
CONCLUSION:
Intracranial hypotension is the most common aetiology of cranial nerve palsy after central neuraxial block in obstetrics. Neuroimaging is recommended in every case, to exclude other neurological causes. Epidural blood patch was the most utilised treatment for post-dural puncture cranial nerve palsy, but outcomes were variable. The majority of cranial nerve palsies resolved over the subsequent weeks and months.
PMID: 28343842
DOI: 10.1016/j.ijoa.2017.02.003

Siedler DG, Ibbett IM, Thani NB.
World Neurosurg. 2017 Mar;99:810.e5-810.e10. doi: 10.1016/j.wneu.2016.12.106. Epub 2017 Jan 3.
Abstract
BACKGROUND:
Intracranial hypotension secondary to spontaneous spinal cerebrospinal fluid (CSF) fistula is a rare condition that can have serious sequelae. Early diagnosis and treatment can be challenging.
CASE DESCRIPTION:
We present the case of a 17-year-old male who presented with a history of sudden-onset, postural headaches associated with upper thoracic back pain. Magnetic resonance imaging (MRI) demonstrated a thoracic extradural fluid collection and slumping of the brain within the posterior fossa. The patient was initially managed with a period of bed rest, followed by a thoracic epidural blood patch. Symptoms recurred and subsequent operative exploration found a large arachnoid cyst with CSF egress through a linear split in the axilla of the right T7 nerve root. The arachnoid cyst was resected, and the defect was closed primarily. All symptoms completely resolved. MRI at 3 months postoperatively demonstrated normal spinal configuration and resolution of brain sagging.
CONCLUSIONS:
Spontaneous CSF leaks are a rare cause of postural headache. Although epidural blood patching is an easy and safe intervention, early serial imaging to ascertain the evolution of the pathology may identify cases that are amenable to early surgical management.
PMID: 28057591
DOI: 10.1016/j.wneu.2016.12.106

Schievink WI, Maya MM.
Neurology. 2017 Feb 28;88(9):916-917. doi: 10.1212/WNL.0000000000003665. Epub 2017 Jan 27.
No Abstract Available.PMID: 28130464
DOI: 10.1212/WNL.0000000000003665

Feil K, Forbrig R, Thaler FS, Conrad J, Heck S, Dorn F, Pfister HW, Straube A.
Neurocrit Care. 2017 Feb;26(1):103-108. doi: 10.1007/s12028-016-0320-4.
Abstract
BACKGROUND:
Reversible cerebral vasoconstriction syndrome (RCVS) and posterior reversible encephalopathy syndrome (PRES) are both rare disorders. The pathophysiology of both diseases is not yet fully understood.
METHODS:
We report the unique case of a 19-year-old comatose woman who was brought to the ER after a series of generalized tonic-clonic seizures 6 days post peridural anesthesia for cesarean section. Vital signs and initial laboratory testing including urine analysis and drug screening were unremarkable. Initial cranial CT scan showed an acute small subdural hematoma (17 mm length × 6 mm width × 30 mm height), cerebral edema with slit ventricles, and slight cerebellar tonsillar herniation as signs of intracranial hypotension. CT angiography depicted narrowing of the proximal intracranial vessels consistent with RCVS. MR imaging was also suggestive of both intracranial hypotension and RCVS and showed, in addition, vasogenic edema consistent with PRES. An extensive CSF leakage involving T1 to L2/L3 was confirmed by spinal MRI.
RESULTS:
The patient underwent conservative therapy for intracranial hypotension (e.g., head-down position) as well as epidural blood patch, which led to regression of the clinical symptoms within a few days. Follow-up MRI showed complete resolution of all radiological changes.
CONCLUSIONS:
In summary, our patient developed clinical and neuroradiological signs of intracranial hypotension and a combination of PRES and RCVS associated with a CSF leakage caused by peridural anesthesia; by treating the intracranial hypotension, the other syndromes resolved. From a clinical point of view, it is important to look for CSF leakage as a treatable possible cause of PRES and/or RCVS triggered by intracranial hypotension as in our patient postpartum. Moreover, it is vital to obtain a good history as, in cases of suspected CSF leakage with classic postural headache, a recent spinal/cranial procedure is typically present.
PMID: 27848124
DOI: 10.1007/s12028-016-0320-4

Karakis I, Nuccio AH, Amadio JP, Fountain AJ Jr.
World Neurosurg. 2017 Feb;98:868.e11-868.e15. doi: 10.1016/j.wneu.2016.12.046. Epub 2016 Dec 23.
Abstract
BACKGROUND:
Posterior reversible leukoencephalopathy syndrome (PRES) is linked to various etiologies, including most importantly systemic hypertension. Its association with intracranial hypotension (IH), a potential sequela of various neurosurgical procedures, is underrecognized. We report a case of lumboperitoneal shunt-induced IH resulting in PRES with the goal to increase awareness and elaborate on the potential biologic mechanism, based on the Monro-Kellie hypothesis.
CASE DESCRIPTION:
A 26-year-old woman with acquired immunodeficiency syndrome and epilepsy was admitted for recurrent cryptococcal meningitis and breakthrough seizures. There was radiologic evidence of ventricular enlargement, and opening pressure on serial lumbar punctures was constantly elevated. Owing to persistently elevated, symptomatic intracranial pressure and transient relief with serial lumbar punctures, a lumboperitoneal shunt was placed. The patient subsequently had a breakthrough seizure and became encephalopathic. Repeat head imaging showed reduced ventricular size, engorged venous sinuses, and tonsillar herniation in keeping with IH, coupled with extensive white matter abnormalities in bilateral parieto-occipital lobes indicative of PRES. The patient had an emergent programmable valve placed in the lumboperitoneal shunt to prevent excessive cerebrospinal fluid drainage, leading to clinical and radiologic improvement. Subsequent cerebrospinal fluid leak resulted in recurrent presentation.
CONCLUSIONS:
IH appears to be a distinct cause of PRES not previously reported in the neurosurgical literature. It occurs in susceptible patients, on average 1-5 days after the IH trigger, and seems clinically and radiologically similar to more common hypertensive cases in terms of initial presentation and prognosis. Increased vigilance is required for prompt recognition and management.
PMID: 28017759
DOI: 10.1016/j.wneu.2016.12.046

Planas-Ballvé A, Da Silva C, Martin L, Broto J, Crespo-Cuevas AM, López-Cancio E, Munuera J, Millán M, Dávalos A.
Headache. 2017 Feb;57(2):302-308. doi: 10.1111/head.13015.
No abstract
PMID: 28128462
DOI: 10.1111/head.13015

Holbrook JF, Hudgins PA, Bruce BB, Saindane AM.
Clin Imaging. 2017 Jan – Feb;41:125-131. doi: 10.1016/j.clinimag.2016.10.019. Epub 2016 Oct 29.
Abstract
PURPOSE:
To determine whether orbital findings on routine brain MRI can be used to differentiate patients with intracranial hypotension from controls.
METHODS:
The authors evaluated axial T2-weighted images for the amount of optic nerve sheath CSF and 3D-T1-weighted images for optic nerve angle of sixteen patients with intracranial hypotension and 60 controls.
RESULTS:
Patients with intracranial hypotension demonstrated significantly decreased CSF in the optic nerve sheath. Optic nerve angle was higher in the intracranial hypotension group compared to controls.
CONCLUSIONS:
Decreased optic nerve sheath CSF and straightened optic nerve angle are significantly more common in the setting of intracranial hypotension.
PMID: 27840264
DOI: 10.1016/j.clinimag.2016.10.019

Wu JW, Hseu SS, Fuh JL, Lirng JF, Wang YF, Chen WT, Chen SP, Wang SJ.
Brain. 2017 Jan 2. pii: aww328. doi: 10.1093/brain/aww328. [Epub ahead of print]
Abstract
Spontaneous intracranial hypotension results from cerebrospinal fluid leakage. Currently, the treatment of choice for spontaneous intracranial hypotension is the epidural blood patch, which has a variable response rate and no clear outcome predictors. This study aimed to identify predictors for response rate of a first targeted epidural blood patch in patients with spontaneous intracranial hypotension. We reviewed cases of patients with spontaneous intracranial hypotension who received targeted epidural blood patch at our hospital between 1 January 2007 and 1 July 2014. The outcome measure was first epidural blood patch response. We analysed demographics, clinical manifestations, neuroimaging findings (non-contrast heavily T2-weighted magnetic resonance myelography and brain magnetic resonance imaging), and blood volume as potential outcome predictors. Significant predictors were tested and a decision tree was used to construct a predictive model. In total, 150 patients with spontaneous intracranial hypotension were included for final analyses. Their overall first targeted epidural blood patch response rate was 58.7%. Among patients with a greater injected blood volume (≥22.5 versus <22.5 ml), the response rate was higher (67.9% versus 47.0%, P = 0.01). In brain and spinal magnetic resonance imaging studies, significant predictors included anterior epidural cerebrospinal fluid collection length (<8 versus ≥8 segments; 72.5% versus 37.3%, odds ratio = 4.4, 95% confidence interval: 2.2-8.9, P < 0.001) and midbrain-pons angle (≥40° versus <40°; 71.3% versus 37.5%, odds ratio = 4.1, 95% confidence interval 2.1-8.3, P < 0.001). Decision tree analyses showed that patients with anterior epidural CSF collection involving <8 segments and an injected blood volume ≥22.5 ml had an 80.0% response rate. Patients with anterior epidural cerebrospinal fluid collection involving ≥8 segments and a midbrain-pons angle <40° had a 21.2% response rate. These three variables predicted first epidural blood patch response in 71.3% of patients. Brain and spinal neuroimaging findings and epidural blood patch blood volume can be used to predict targeted first epidural blood patch response in patients with spontaneous intracranial hypotension.
PMID: 28043956
DOI: 10.1093/brain/aww328

Choi H, Lee MJ, Choi HA, Cha J, Chung CS.
Cephalalgia. 2017 Jan 1:333102417690106. doi: 10.1177/0333102417690106. [Epub ahead of print]
Abstract
Background Intracranial structural dislocation in spontaneous intracranial hypotension (SIH) can be measured by various intracranial angles and distances. We aimed to identify the clinical significance of structural dislocation in relation to treatment outcome in patients with SIH. Methods In this retrospective analysis, we identified patients with SIH who received an epidural blood patch (EBP) at Samsung Medical Center from January 2005 to March 2015. Structural dislocation in pretreatment MRIs of SIH patients was assessed by measuring tonsillar herniation, mamillopontine distance, the angle between the vein of Galen and straight sinus (vG/SS angle), the pontomesencephalic angle, and the lateral ventricular angle. After the first EBP, poor response was defined as the persistence of symptoms that prompted a repeat EBP. Results Out of the 95 patients included, 31 (32.6%) showed poor response. Among the radiological markers of structural dislocation, the vG/SS angle was associated with poor response (49.82 ± 16.40° vs 66.58 ± 26.08°, p = 0.002). Among clinical variables, premorbid migraine ( p = 0.036) was related to poor response. In multivariate analysis, reduced vG/SS angle was independently associated with poor response (OR 1.04 [95% CI 1.01 – 1.07] per 1° decrease, p = 0.006). In 23 patients who underwent MRI after successful treatment, the vG/SS angle significantly increased after the EBP ( p < 0.001, by paired t-test), while two patients with aggravation or recurrence showed a further reduction of their vG/SS angles. Conclusions Intracranial structural dislocation, measured by the vG/SS angle, is associated with poor response to the first EBP in patients with SIH. Successful treatment can reverse the structural dislocation. PMID: 28110544
DOI: 10.1177/0333102417690106