Abstracts 2019

Duvall JR, Robertson CE, Cutsforth-Gregory JK, Carr CM, Atkinson JL, Garza I.
Cephalalgia 2019 Dec;39(14):1847-1854. Epub 2019 Oct 9.
Abstract
Objective: Cerebrospinal fluid-venous fistula is an uncommon cause of spontaneous spinal cerebrospinal fluid leak (SSCSFL). We aim to describe the clinical presentation, imaging evaluation, treatment and outcome of SSCSFL secondary to cerebrospinal fluid-venous fistula.
Methods: A retrospective review was undertaken of SSCSFL cases secondary to cerebrospinal fluid-venous fistula confirmed radiologically or intraoperatively, seen at our institution from January 1994 to March 2019. Cases with undetermined SSCSFL etiology, alternative etiology or unconfirmed fistula were excluded.
Results: Forty-four of 156 patients met the inclusion criteria (31 women, 13 men). Mean age of symptom onset was 52.6 years (SD 8.7, range 33-71 years). Headache was the presenting symptom in almost all, typically daily (69%), and most often in occipital/suboccipital regions. Headache character was most commonly pressure (38%), followed by throbbing/pulsing (21.4%). Orthostatic headache worsening occurred in 69% and an even greater percentage of patients (88%) reported Valsalva-induced headache exacerbation or precipitation. Headache occurred in isolation to Valsalva maneuvers in 12%. Of 37 patients with documented cerebrospinal fluid opening pressure, 13% were <6 cmH₂O; 84%, 7-20 cmH₂O; and one, 25 cmH₂O. Fistulas were almost exclusively thoracic (95.5%). Only one patient responded definitively to epidural blood patch (EBP). Forty-two patients underwent surgery. Most improved following surgery; 48.7% were completely headache free and 26.8% had at least 50% improvement.
Conclusion: In our series, cerebrospinal fluid-venous fistula was associated with a greater occurrence of Valsalva-induced headache exacerbation or precipitation than orthostatic headache and did not respond to EBP. Surgery provided significant improvement. Cerebrospinal fluid-venous fistula should be considered early in the differential diagnosis of Valsalva-induced (“cough”) headache.
PMID:  31597463
DOI: 10.1177/0333102419881673

Kranz PG, Gray L, Malinzak MD, Amrhein TJ.
Neuroimaging Clin N Am. 2019 Nov;29(4):581-594. doi: 10.1016/j.nic.2019.07.006. Epub 2019 Aug 26.
Abstract
Spontaneous intracranial hypotension (SIH) is a clinical syndrome that is increasingly recognized as an important and treatable secondary cause of headaches. Insight into the condition has evolved significantly over the past decade, resulting in a greater understanding of the underlying pathophysiology, development of new diagnostic imaging tools, and a broadening array of targeted treatment options. This article reviews the clinical presentation and pathogenesis of SIH, discusses the important role of imaging in diagnosis, and describes how imaging guides treatment.
PMID: 31677732 
DOI: 10.1016/j.nic.2019.07.006

Schievink WI, Maya MM, Moser FG, Tuchman A, Cruz RB, Farb RI, Rebello R, Reddy K, Prasad RS.
J Neurosurg Spine. 2019 Nov 1:1-6. doi: 10.3171/2019.8.SPINE19716. [Epub ahead of print]
Abstract
Spontaneous CSF-venous fistulas may be present in up to one-fourth of patients with spontaneous intracranial hypotension. This is a recently discovered type of CSF leak, and much remains unknown about these fistulas. Spinal CSF-venous fistulas are usually seen in coexistence with a spinal meningeal diverticulum, suggesting the presence of an underlying structural dural weakness at the proximal portion of the fistula. The authors now report the presence of soft-tissue venous/venolymphatic malformations associated with spontaneous spinal CSF-venous fistulas in 2 patients with spontaneous intracranial hypotension, suggesting a role for distal venous pathology. In a third patient with spontaneous intracranial hypotension and a venolymphatic malformation, such a CSF-venous fistula is strongly suspected.
PMID: 31675703
DOI: 10.3171/2019.8.SPINE19716

Duvall JR, Robertson CE, Cutsforth-Gregory JK, Carr CM, Atkinson JL, Garza I.
Cephalalgia. 2019 Oct 9:333102419881673. doi: 10.1177/0333102419881673. [Epub ahead of print]
Abstract
OBJECTIVE: Cerebrospinal fluid-venous fistula is an uncommon cause of spontaneous spinal cerebrospinal fluid leak (SSCSFL). We aim to describe the clinical presentation, imaging evaluation, treatment and outcome of SSCSFL secondary to cerebrospinal fluid-venous fistula.
METHODS: A retrospective review was undertaken of SSCSFL cases secondary to cerebrospinal fluid-venous fistula confirmed radiologically or intraoperatively, seen at our institution from January 1994 to March 2019. Cases with undetermined SSCSFL etiology, alternative etiology or unconfirmed fistula were excluded.
RESULTS: Forty-four of 156 patients met the inclusion criteria (31 women, 13 men). Mean age of symptom onset was 52.6 years (SD 8.7, range 33-71 years). Headache was the presenting symptom in almost all, typically daily (69%), and most often in occipital/suboccipital regions. Headache character was most commonly pressure (38%), followed by throbbing/pulsing (21.4%). Orthostatic headache worsening occurred in 69% and an even greater percentage of patients (88%) reported Valsalva-induced headache exacerbation or precipitation. Headache occurred in isolation to Valsalva maneuvers in 12%. Of 37 patients with documented cerebrospinal fluid opening pressure, 13% were <6 cmH₂O; 84%, 7-20 cmH₂O; and one, 25 cmH₂O. Fistulas were almost exclusively thoracic (95.5%). Only one patient responded definitively to epidural blood patch (EBP). Forty-two patients underwent surgery. Most improved following surgery; 48.7% were completely headache free and 26.8% had at least 50% improvement.
CONCLUSION: In our series, cerebrospinal fluid-venous fistula was associated with a greater occurrence of Valsalva-induced headache exacerbation or precipitation than orthostatic headache and did not respond to EBP. Surgery provided significant improvement. Cerebrospinal fluid-venous fistula should be considered early in the differential diagnosis of Valsalva-induced (“cough”) headache.
PMID:  31597463 
DOI: 10.1177/0333102419881673

Cipriani D, Rodriguez B, Häni L, Zimmermann R, Fichtner J, Ulrich CT, Raabe A, Beck J, Z’Graggen WJ.
PLoS One. 2019 Oct 9;14(10):e0223484. doi: 10.1371/journal.pone.0223484. eCollection 2019.
Abstract
BACKGROUND: Postural orthostatic tachycardia syndrome is a disorder of the autonomic nervous system. Approximately 30% of patients experience orthostatic headaches. Orthostatic headaches also are a hallmark symptom in spontaneous intracranial hypotension. While the cause of orthostatic headaches in spontaneous intracranial hypotension can be linked to the cerebrospinal fluid loss at the spinal level and consecutively reduced intracranial pressure in the upright position, the cause of orthostatic headaches in postural orthostatic tachycardia syndrome still remains unknown. The present study examined orthostatic changes of intracranial pressure using dynamic ultrasound of the optic nerve and optic nerve sheath diameter in postural orthostatic tachycardia syndrome, spontaneous intracranial hypotension and healthy subjects.
METHODS: Data was obtained from postural orthostatic tachycardia syndrome patients with (n = 7) and without orthostatic headaches (n = 7), spontaneous intracranial hypotension patients (n = 5) and healthy subjects (n = 8). All participants underwent high-resolution transorbital ultrasound in the supine and upright position to assess optic nerve and optic nerve sheath diameter.
RESULTS: Group differences were found in percentage deviations when changing position of optic nerve sheath diameter (p < 0.01), but not regarding the optic nerve diameter. Pairwise comparisons indicated differences in optic nerve sheath diameter only between spontaneous intracranial hypotension and the other groups. No differences were found between postural orthostatic tachycardia syndrome patients with and without orthostatic headaches.
CONCLUSION: This study shows that the size of the optic nerve sheath diameter dynamically decreases during orthostatic stress in spontaneous intracranial hypotension, but not in postural orthostatic tachycardia syndrome with or without orthostatic headaches, which indicates different underlying causes.
PMID:  31596889
DOI:  10.1371/journal.pone.0223484

Martin R, Louy C, Babu V, Jiang Y, Far A, Schievink W.
Reg Anesth Pain Med. 2019 Sep 20. pii: rapm-2018-100158. doi: 10.1136/rapm-2018-100158. [Epub ahead of print]
Abstract
BACKGROUND: We report a retrospective analysis of a two-level, variable-volume epidural blood patch (EBP) technique for the treatment of spontaneous intracranial hypotension (SIH).
METHODS: Ninety-four patients with SIH underwent EBPs. Injectate volume was variable and guided by the onset of back pain, radiculopathy or symptoms referable to the EBP. Patients were a responder if no invasive treatment was necessary for SIH symptoms after the first EBP. Baseline patient characteristics, including presenting symptoms and imaging findings, were compared between responders and non-responders. Adverse events were recorded.
RESULTS: The mean first EBP volume was 45.3±23.2 (range 4-124 mL). The responder rate was 28.7% after the first EBP, improving to 41.5% and 46.8% after a second and third EBP, respectively. Baseline characteristics were similar between groups, except for the greater prevalence of subdural fluid collections in the responder group (48% vs 18%, p=0.003). Two severe complications occurred: transient bilateral paraplegia and cauda equina syndrome from arachnoiditis.
CONCLUSIONS: Our protocol can be used to treat SIH but carries risks that require meticulous attention. EBP volumes were variable across patients, demonstrating the variability in the elastance of the epidural space. Rigorous monitoring for neurological symptoms is necessary throughout the procedure to limit complications and determine the endpoint of the EBP. We advocate for rigorous confirmation of epidural placement of the EBP with contrast-imaging studies to limit intrathecal placement of blood, which can lead to arachnoiditis. Randomized controlled trials are needed to determine the safety and efficacy of large-volume EBPs.
PMID:  31541008
DOI:  10.1136/rapm-2018-100158

Schievink WI, Maya MM, Moser FG, Prasad RS, Cruz RB, Nuño M, Farb RI.
J Neurosurg Spine. 2019 Sep 13:1-4. doi: 10.3171/2019.6.SPINE19487. [Epub ahead of print]
Abstract
OBJECTIVE: Spontaneous spinal CSF-venous fistulas are a distinct type of spinal CSF leak recently described in patients with spontaneous intracranial hypotension (SIH). Using digital subtraction myelography (DSM) with the patient in the prone position, the authors have been able to demonstrate such fistulas in about one-fifth of patients with SIH in whom conventional spinal imaging (MRI or CT myelography) showed no evidence for a CSF leak (i.e., the presence of extradural CSF). The authors compared findings of DSM with patients in the lateral decubitus position versus the prone position and now report a significantly increased yield of identifying spinal CSF-venous fistulas with this modification of their imaging protocol.
METHODS: The population consisted of 23 patients with SIH who underwent DSM in the lateral decubitus position and 26 patients with SIH who underwent DSM in the prone position. None of the patients had evidence of a CSF leak on conventional spinal imaging.
RESULTS: A CSF-venous fistula was demonstrated in 17 (74%) of the 23 patients who underwent DSM in the lateral decubitus position compared to 4 (15%) of the 26 patients who underwent DSM in the prone position (p < 0.0001). The mean age of these 16 women and 5 men was 52.5 years (range 36-66 years).
CONCLUSIONS: Among SIH patients in whom conventional spinal imaging showed no evidence of a CSF leak, DSM in the lateral decubitus position demonstrated a CSF-venous fistula in about three-fourths of patients compared to only 15% of patients when the DSM was performed in the prone position, an approximately five-fold increase in the detection rate. Spinal CSF-venous fistulas are not rare among patients with SIH.
PMID: 31518974
DOI: 10.3171/2019.6.SPINE19487

Redon S, Elzière M, Kaphan E, Donnet A.
Headache. 2019 Aug 24. doi: 10.1111/head.13621. [Epub ahead of print]
Abstract
BACKGROUND: The diagnosis of spontaneous or post-traumatic intracranial hypotension mainly rely on clinical features and neuroimaging. In atypical presentations, other non-invasive tests are missing to support the diagnosis of intracranial hypotension. The assessment of otoacoustic emissions (OAE) shown interest to monitor intracranial pressure mainly in cases of intracranial hypertension. This non-invasive method was also assessed in response to pressure change after lumbar puncture. A few reports showed abnormal results of distortion product otoacoustic emissions (DPOAE) in cases of spontaneous or post-traumatic intracranial hypotension. We describe additional results in a series of intracranial hypotension cases. We discuss the interest of DPOAE assessment in atypical presentations of intracranial hypotension. We review the other non-invasive tests reported in literature.
METHODS: We studied 4 atypical or recurrent cases of spontaneous or post-traumatic intracranial hypotension by recording OAE in sitting then supine position.
RESULTS: Unilateral or bilateral abnormal changes of DPOAE were recorded in all cases, in response to postural test. These changes were present even in the absence of vestibular symptoms.
CONCLUSION: The study of OAE may be a non-invasive tool for the diagnosis of spontaneous intracranial hypotension.
PMID: 31444878 
DOI: 10.1111/head.13621

Freesmeyer M, Schwab M, Besteher B, Gröber S, Waschke A, Drescher R. Clin Nucl Med. 2019 Sep;44(9):735-737. doi: 10.1097/RLU.0000000000002695.
Abstract
Intracranial hypotension may lead to chronic, debilitating symptoms, and severe complications. The underlying CSF leak may be difficult to localize. To establish a new diagnostic option for the detection of CSF leaks, Cu-DOTA was developed as a tracer for PET imaging. PET/CT imaging was possible with high resolution and without complications. In one patient, the exact site of a dural tear was identified, enabling successful surgical treatment. PET cisternography with Cu-DOTA appears to be safe and able to locate a CSF leak. It has the potential to be a problem-solving modality in cases with inconclusive CT, MR, and/or scintigraphic findings.
PMID: 31274554
DOI: 10.1097/RLU.0000000000002695

Morishima R, Takai K, Ando T, Nakata Y, Shimizu T, Taniguchi M.
J Neurol. 2019 Jul 16. doi: 10.1007/s00415-019-09469-9. [Epub ahead of print]
Abstract
OBJECTIVE:
Common symptoms in patients with a spinal CSF leak include orthostatic headaches, neck stiffness, and hearing difficulties. The main outcome of this report was to introduce and characterize brachial multisegmental amyotrophy, a rare, but treatable symptom associated with a spinal CSF leak.
METHODS:
Between 2013 and 2017, five patients who developed progressive amyotrophy were referred to our hospital. A retrospective and prospective analysis of clinical, electrophysiological, and neuroimaging findings is presented. Data were analyzed between August 2013 and April 2019.
RESULTS:
Amyotrophy was observed in the C5-C8 myotomes and was more prominent in the proximal muscles than in the distal muscles. Amyotrophy was unilateral in three patients and asymmetric bilateral in two. Electromyography revealed active and chronic denervation in the C5-C8 myotomes, particularly C5-6, of all patients. Although the clinical manifestations of these cases were similar to amyotrophic lateral sclerosis, unusual neuroimaging findings were observed: spinal T2-weighted MRI revealed high-signal-intensity lesions in the bilateral anterior horns at the C2-C4 spinal levels in all five cases; ventral epidural fluid collection was also observed. Thin-cut MRI or digital subtraction myelography showed ventral dural defects associated with CSF leaks at high thoracic levels in four patients; four underwent surgical dural repair, which attenuated or stabilized neurological symptoms, while upper limb weakness worsened in the other patient who did not undergo surgery.
CONCLUSIONS:
A spinal dural defect may be the essential cause of brachial multisegmental amyotrophy. Surgical dural repair may alter the progressive course of this rare condition.
PMID: 31312956
DOI: 10.1007/s00415-019-09469-9

Kent L, Butterworth R, Butler C.
Clin Med (Lond). 2019 Jul;19(4):336-337. doi: 10.7861/clinmedicine.19-4-336.
Abstract
We present a case of a man with headache and progressive behavioural disturbance. His cognitive decline progressed over a few months such that he was unable to hold a conversation or carry out any daily tasks such as washing and dressing. He had some upper motor neurone signs in his limbs and features of brainstem dysfunction including dysarthria and ocular abnormalities. His brain magnetic resonance imaging showed signs of brain ‘sagging’. He was thought to have frontotemporal brain sagging syndrome. Prior to any treatment, he began to improve. Over the course of a week he became markedly better, was back to normal within 3 months and remains so 7 months later. We propose that resolution of spontaneous intracranial hypotension led to resolution of frontotemporal brain sagging syndrome. We believe this is the first case described where this has occurred without any intervention. It is important to recognise this condition as a potentially reversible cause of dementia.
PMID: 31308118
DOI: 10. 7861/clinmedicine.19-4-336

Wang DJ, Pandey SK, Lee DH, Sharma M.
AJNR Am J Neuroradiol. 2019 Jul 11. doi: 10.3174/ajnr.A6120. [Epub ahead of print]
Abstract
BACKGROUND AND PURPOSE:
Classic findings of intracranial hypotension on MR imaging, such as brain stem slumping, can be variably present and, at times, subjective, potentially making the diagnosis difficult. We hypothesize that the angle between the cerebral peduncles correlates with the volume of interpeduncular cistern fluid and is decreased in cases of intracranial hypotension. We aimed to investigate its use as an objective assessment for intracranial hypotension.
MATERIALS AND METHODS:
Brain MRIs of 30 patients with intracranial hypotension and 30 age-matched controls were evaluated by 2 fellowship-trained neuroradiologists for classic findings of intracranial hypotension and the interpeduncular angle. Group analysis was performed with a Student t test, and receiver operating characteristic analysis was used to identify an ideal angle threshold to maximize sensitivity and specificity. Interobserver reliability was assessed for classic findings of intracranial hypotension using the Cohen κ value, and the interpeduncular angle, using the intraclass correlation.
RESULTS:
The interpeduncular angle had excellent interobserver reliability (intraclass correlation coefficient value = 0.833) and was significantly lower in the intracranial hypotension group compared with the control group (25.3° versus 56.3°; P < .001). There was significant correlation between the interpeduncular angle and the presence of brain stem slumping (P < .001) and in cases with ≥3 classic features of intracranial hypotension (P = .01). With a threshold of 40.5°, sensitivity and specificity were 80% and 96.7%, respectively.
CONCLUSIONS:
The interpeduncular angle is a sensitive and specific measure of intracranial hypotension and is a reliably reproducible parameter on routine clinical MR imaging.
PMID: 31296521
DOI: 10.3174/ajnr.A6120

Schievink WI, Maya MM, Moser FG.
J Neurosurg Spine. 2019 Jul 5:1-4. doi: 10.3171/2019.4.SPINE19283. [Epub ahead of print]
Abstract
A spinal CSF-venous fistula is one of three specific types of spinal CSF leak that can be seen in patients with spontaneous intracranial hypotension (SIH). They are best demonstrated on specialized imaging, such as digital subtraction myelography (DSM) or dynamic myelography, but often they are diagnosed on the basis of increased contrast density in the draining veins (the so-called hyperdense paraspinal vein sign) on early postmyelography CT scans. The authors report on 2 patients who underwent directed treatment (surgery in one patient and glue injection in the other) based on the hyperdense paraspinal vein sign, in whom the actual site of the fistula did not correspond to the level or laterality of the hyperdense paraspinal vein sign. The authors suggest consideration of DSM or dynamic myelography prior to undertaking treatment directed at these fistulas.
PMID: 31277063
DOI: 10.3171/2019.4.SPINE19283

Wang TY, Karikari IO, Amrhein TJ, Gray L, Kranz PG.
Oper Neurosurg (Hagerstown). 2019 May 28. pii: opz134. doi: 10.1093/ons/opz134. [Epub ahead of print]
Abstract
BACKGROUND:
Cerebrospinal fluid-venous fistula (CVF) is a recently described cause of spontaneous intracranial hypotension (SIH). Surgical ligation of CVF has been reported, but clinical outcomes are not well described.
OBJECTIVE:
To determine the clinical efficacy of surgical ligation for treatment of CVF.
METHODS:
Outcomes metrics were collected in this prospective, single-arm, cross-sectional investigation. Inclusion criteria were as follows: diagnosis of SIH, demonstration of CVF on myelography, and surgical treatment of CVF. Pre- and postoperative headache severity was assessed with the Headache Impact Test (HIT-6), a validated headache scale ranging from 36 (asymptomatic) to 78 (most severe). Patient satisfaction with treatment was measured with Patient Global Impression of Change (PGIC).
RESULTS:
Twenty subjects were enrolled, with mean postoperative follow-up at 16.0 ± 9.7 mo. All CVFs were located in the thoracic region (between T4 and T12). Pretreatment headache severity was high (mean HIT-6 scores 65 ± 6). Surgical treatment resulted in marked improvement in headache severity (mean HIT-6 change of -21 ± -9, mean postoperative HIT-6 of 44 ± 8). Of subjects with baseline headache scores in the most severe category, 83% showed a major improvement in severity (transition to the lowest 2 severity categories) after surgery. All subjects (100%) reported clinically significant levels of satisfaction with treatment (PGIC score 6 or 7); 90% reported the highest level of satisfaction. There were no short- or long-term complications or 30-d readmissions.
CONCLUSION:
Surgical ligation is highly effective for the treatment of SIH due to CVF. Larger controlled trials with longer follow-up period are indicated to better assess its long-term efficacy and safety profile.
PMID: 31134267
DOI: 10.1093/ons/opz134

Schievink WI, Maya MM, Jean-Pierre S, Moser FG, Nuño M, Pressman BD.
Neurol Clin Pract. 2019 Apr;9(2):93-100. doi: 10.1212/CPJ.0000000000000550.
Abstract
BACKGROUND:
Rebound high-pressure headaches may complicate treatment of spontaneous intracranial hypotension (SIH), but no comprehensive study of such patients has been reported and little is known about its frequency and risk factors. We therefore studied patients undergoing treatment for SIH and performed magnetic resonance venography (MRV) to assess for cerebral venous sinus stenosis, a risk factor for idiopathic intracranial hypertension.
METHODS:
We studied a consecutive group of patients who underwent treatment for SIH. Rebound high-pressure headache was defined as a reverse orthostatic headache responsive to acetazolamide. MRV was obtained in all patients and lateral sinus stenosis was scored according to the system published by Higgins et al., with 0 being normal and 4 signifying bilateral signal gaps.
RESULTS:
The mean age of the 46 men and 67 women was 45.9 years (range 13-71 years) at the time of onset of SIH. Rebound high-pressure headache was diagnosed in 31 patients (27.4%); 14% of patients with an MRV score of 0, 24% with a score of 1, and 46% with a score of 2 or 3 (p = 0.0092). Also, compared to SIH patients who did not develop rebound high-pressure headaches (n = 82), those with rebound high-pressure headaches were younger, more often female, and more often had an extradural CSF collection on spinal imaging.
CONCLUSIONS:
Rebound high-pressure headache occurs in about one-fourth of patients following treatment of SIH and is more common in those with restriction of cerebral venous outflow.
PMID: 31041122
DOI: 10.1212/CPJ.0000000000000550

Kim JH, Roh H, Yoon WK, Kwon TH, Chong K, Hwang SY, Kim JH.
Headache. 2019 May;59(5):775-786. doi: 10.1111/head.13525. Epub 2019 Apr 15.
Abstract
BACKGROUND:
Subdural hygromas are often found bilaterally in spontaneous intracranial hypotension (SIH). They frequently progress to chronic subdural hematomas (CSDHs), and if the hematomas are formed, it is difficult to consider SIH as an underlying cause. Whether SIH is underlying or not among the patients presenting bilateral subdural fluid collections (hygromas or CSDHs) is clinically important because the treatment strategy should be different between them.
OBJECTIVES:
We designed a retrospective case-control study to figure out differential clinical features of the patients presenting bilateral symptomatic subdural fluid collections owing to SIH.
METHODS:
Sixty-two patients with bilateral symptomatic subdural fluid collections were enrolled, and their data on general demographics, clinical courses, radiological findings, treatments, and outcomes were collected. The patients were divided into “SIH” and “Non-SIH” groups, and a simple logistic regression analysis was performed to clarify the differences between the groups. The consequent receiver operating characteristics (ROC) curve analyses were performed with the significant predictors.
RESULTS:
Eight patients (13%) were diagnosed with SIH. Young age (odds ratio [OR] = 0.831, 95% confidence interval [CI]: 0.743-0.929, P = .0012), no underlying disease (OR = 0.062, 95% CI: 0.007-0.544, P = .0121), radiological features of brain sagging (OR = 10.36, 95% CI: 0.912-93.411, P = .0017), pseudo-subarachnoid hemorrhage (OR = 15.6, 95% CI: 2.088-116.52, P = .0074), and small amount of fluid collections (OR = 0.719, 95% CI: 0.579-0.893, P = .0029) were significantly associated with SIH group. ROC curve analyses were performed in parameters of age and amount of fluid collection and the cut-off values for each parameter were ≤55 years old and ≤22.08 mm, respectively. Patients diagnosed with SIH underwent epidural blood patches and showed good results, except 1 patient who underwent burr-hole trephinations.
CONCLUSION:
Bilateral subdural fluid collections due to underlying SIH is associated with young age (≤55 years old), no underlying diseases, smaller amount of fluid collections (≤22.08 mm of depth), and radiological findings of brain sagging or pseudo-subarachnoid hemorrhages.
PMID: 30985923
DOI: 10.1111/head.13525

Chan SM, Chodakiewitz YG, Maya MM, Schievink WI, Moser FG.
Neuroimaging Clin N Am. 2019 May;29(2):213-226. doi: 10.1016/j.nic.2019.01.002. Epub 2019 Feb 21.
Abstract
Review of the clinical presentation, imaging findings, and management of headache secondary to intracranial hypotension.
PMID: 30926112
DOI: 10.1016/j.nic.2019.01.002

Farb RI, Nicholson PJ, Peng PW, Massicotte EM, Lay C, Krings T, terBrugge KG.
AJNR Am J Neuroradiol. 2019 Mar 28. doi: 10.3174/ajnr.A6016. [Epub ahead of print]
Abstract
BACKGROUND AND PURPOSE:
Localization of the culprit CSF leak in patients with spontaneous intracranial hypotension can be difficult and is inconsistently achieved. We present a high yield systematic imaging strategy using brain and spine MRI combined with digital subtraction myelography for CSF leak localization.
MATERIALS AND METHODS:
During a 2-year period, patients with spontaneous intracranial hypotension at our institution underwent MR imaging to determine the presence or absence of a spinal longitudinal extradural collection. Digital subtraction myelography was then performed in patients positive for spinal longitudinal extradural CSF collection primarily in the prone position and in patients negative for spinal longitudinal extradural CSF collection in the lateral decubitus positions.
RESULTS:
Thirty-one consecutive patients with spontaneous intracranial hypotension were included. The site of CSF leakage was definitively located in 27 (87%). Of these, 21 were positive for spinal longitudinal extradural CSF collection and categorized as having a ventral (type 1, fifteen [48%]) or lateral dural tear (type 2; four [13%]). Ten patients were negative for spinal longitudinal extradural CSF collection and were categorized as having a CSF-venous fistula (type 3, seven [23%]) or distal nerve root sleeve leak (type 4, one [3%]). The locations of leakage of 2 patients positive for spinal longitudinal extradural CSF collection remain undefined due to resolution of spontaneous intracranial hypotension before repeat digital subtraction myelography. In 2 (7%) patients negative for spinal longitudinal extradural CSF collection, the site of leakage could not be localized. Nine of 21 (43%) patients positive for spinal longitudinal extradural CSF collection were treated successfully with an epidural blood patch, and 12 required an operation. Of the 10 patients negative for spinal longitudinal extradural CSF collection (8 localized), none were effectively treated with an epidural blood patch, and all have undergone (n = 7) or are awaiting (n = 1) an operation.
CONCLUSIONS:
Patients positive for spinal longitudinal extradural CSF collection are best positioned prone for digital subtraction myelography and may warrant additional attempts at a directed epidural blood patch. Patients negative for spinal longitudinal extradural CSF collection are best evaluated in the decubitus positions to reveal a CSF-venous fistula, common in this population. Patients with CSF-venous fistula may forgo further epidural blood patch treatment and go on to surgical repair.
PMID: 30923083
DOI: 10.3174/ajnr.A6016

Amrhein TJ, Kranz PG.
Radiol Clin North Am. 2019 Mar;57(2):439-451. doi: 10.1016/j.rcl.2018.10.004. Epub 2018 Dec 7.
Abstract
This article reviews the role of imaging in the diagnosis, management, and treatment of spontaneous intracranial hypotension (SIH). SIH is a debilitating and often misdiagnosed condition caused by either a spinal cerebrospinal fluid (CSF) leak or a CSF to venous fistula. This pathologic condition is identified and localized via spinal imaging, including computed tomographic (CT) myelography, dynamic myelography, dynamic (ultrafast) CT myelography, MR imaging, or MR myelography with intrathecal gadolinium. Treatment of SIH involves conservative measures, surgery, or imaging-guided epidural blood patching.
PMID: 30709479
DOI:  10.1016/j.rcl.2018.10.004

Kranz PG, Gray L, Amrhein TJ
AJNR Am J Neuroradiol, 2019 Feb 28, DOI: https://doi.org/10.3174/ajnr.A5995 [epub ahead of print]
Abstract
Spontaneous intracranial hypotension is caused by spinal CSF leaks, but the site of the leak is not always detected on spinal imaging. We report on the additional value of decubitus positioning during CT myelography in enhancing the detection of subtle leaks.
PMID: 30819772
DOI:  10.3174/ajnr.A5995

Kim SC, Ryoo I, Sun HY, Park SW.
AJR Am J Roentgenol. 2019 Feb 26:1-7. doi: 10.2214/AJR.18.20369. [Epub ahead of print]
Abstract
OBJECTIVE:
Spontaneous intracranial hypotension (SIH) shows various characteristic MRI findings. We evaluated the usefulness of straight sinus distention compared with transverse sinus distention and also evaluated other MRI findings of SIH.
MATERIALS AND METHODS:
Forty-three consecutive patients (28 female and 15 male patients) treated for SIH and 43 age- and sex-matched control subjects at two institutions from 2012 through 2014 were included in this study. Two reviewers determined whether the transverse sinus distention sign and straight sinus distention sign were present on MRI. Diagnostic performance values and interobserver agreement were calculated. Reviewers also assessed MRI examinations in consensus for the presence of the following findings: pachymeningeal enhancement, subdural effusion or hematoma, enlargement of the pituitary gland, and downward displacement of the brainstem and tonsils.
RESULTS:
The sensitivity, specificity, and diagnostic accuracy of the transverse sinus distention sign for SIH were 76.7%, 83.7%, and 80.2%, whereas those of the straight sinus distention sign were 79.1%, 95.4%, and 87.2%, respectively. The specificity of the straight sinus distention sign for SIH was significantly higher (p = 0.025) than that of the transverse sinus distention sign. In addition, the straight sinus distention sign showed substantial agreement (κ = 0.79), whereas the transverse sinus distention sign showed moderate agreement (κ = 0.60). The diagnostic accuracy of the presence of either transverse or straight sinus distention (83.7%) was significantly higher than that of pachymeningeal enhancement (80.2%, p = 0.032).
CONCLUSION:
The straight sinus distention sign could be helpful for the diagnosis of SIH because it has sensitivity comparable to other imaging findings and higher specificity and higher level of interobserver agreement than other imaging findings.
PMID: 30807225
DOI:  10.2214/AJR.18.20369

Dobrocky T, Grunder L, Breiding PS, Branca M, Limacher A, Mosimann PJ, Mordasini P, Zibold F, Haeni L, Jesse CM, Fung C, Raabe A, Ulrich CT, Gralla J, Beck J, Piechowiak EI.
JAMA Neurol. 2019 Feb 18. doi: 10.1001/jamaneurol.2018.4921. [Epub ahead of print]
Abstract
IMPORTANCE:
Various signs may be observed on brain magnetic resonance imaging (MRI) in patients with spontaneous intracranial hypotension (SIH). However, the lack of a classification system integrating these findings limits decision making in clinical practice.
OBJECTIVE:
To develop a probability score based on the most relevant brain MRI findings to assess the likelihood of an underlying spinal cerebrospinal fluid (CSF) leak in patients with SIH.
DESIGN, SETTING, AND PARTICIPANTS:
This case-control study in consecutive patients investigated for SIH was conducted at a single hospital department from February 2013 to October 2017. Patients with missing brain MRI data were excluded. Three blinded readers retrospectively reviewed the brain MRI scans of patients with SIH and a spinal CSF leak, patients with orthostatic headache without a CSF leak, and healthy control participants, evaluating 9 quantitative and 7 qualitative signs. A predictive diagnostic score based on multivariable backward logistic regression analysis was then derived. Its performance was validated internally in a prospective cohort of patients who had clinical suspicion for SIH.
MAIN OUTCOMES AND MEASURES:
Likelihood of a spinal CSF leak based on the proposed diagnostic score.
RESULTS:
A total of 152 participants (101 female [66.4%]; mean [SD] age, 46.1 [14.3] years) were studied. These included 56 with SIH and a spinal CSF leak, 16 with orthostatic headache without a CSF leak, 60 control participants, and 20 patients in the validation cohort. Six imaging findings were included in the final scoring system. Three were weighted as major (2 points each): pachymeningeal enhancement, engorgement of venous sinus, and effacement of the suprasellar cistern of 4.0 mm or less. Three were considered minor (1 point each): subdural fluid collection, effacement of the prepontine cistern of 5.0 mm or less, and mamillopontine distance of 6.5 mm or less. Patients were classified into groups at low, intermediate, or high probability of having a spinal CSF leak, with total scores of 2 points or fewer, 3 to 4 points, and 5 points or more, respectively, on a scale of 9 points. The discriminatory ability of the proposed score could be demonstrated in the validation cohort.
CONCLUSIONS AND RELEVANCE:
This 3-tier predictive scoring system is based on the 6 most relevant brain MRI findings and allows assessment of the likelihood (low, intermediate, or high) of a positive spinal imaging result in patients with SIH. It may be useful in identifying patients with SIH who are leak positive and in whom further invasive myelographic examinations are warranted before considering targeted therapy.
PMID: 30776059
DOI: 10.1001/jamaneurol.2018.4921

Levi V, Di Laurenzio NE, Franzini A, Tramacere I, Erbetta A, Chiapparini L, D’Amico D, Franzini A, Messina G.
J Neurosurg. 2019 Feb 8:1-9. doi: 10.3171/2018.10.JNS181597. [Epub ahead of print]
Abstract
OBJECTIVE
Although epidural blood patch (EBP) is considered the gold-standard treatment for drug-resistant orthostatic headache in spontaneous intracranial hypotension (SIH), no clear evidence exists regarding the best administration method of this technique (blind vs target procedures). The aim of this study was to assess the long-term efficacy of blind lumbar EBP and predictors on preoperative MRI of good outcome.
METHODS
Lumbar EBP was performed by injecting 10 ml of autologous venous blood, fibrin glue, and contrast medium in 101 consecutive patients affected by SIH and orthostatic headache. Visual analog scale (VAS) scores for headache were recorded preoperatively, at 48 hours and 6 months after the procedure, and by telephone interview in July 2017. Patients were defined as good responders if a VAS score reduction of at least 50% was achieved within 48 hours of the procedure and lasted for at least 6 months. Finally, common radiological SIH findings were correlated with clinical outcomes.
RESULTS
The median follow-up was 60 months (range 8-135 months); 140 lumbar EBPs were performed without complications. The baseline VAS score was 8.7 ± 1.3, while the mean VAS score after the first EBP procedure was 3.5 ± 2.2 (p < 0.001). The overall response rate at the 6-month follow-up was 68.3% (mean VAS score 2.5 ± 2.4, p < 0.001). Symptoms recurred in 32 patients (31.7%). These patients underwent a second procedure, with a response rate at the 6-month follow-up of 78.1%. Seven patients (6.9%) did not improve after a third procedure and remained symptomatic. The overall response rate at the last follow-up was 89.1% with a mean VAS score of 2.7 ± 2.3 (p < 0.001). The only MRI predictors of good outcome were location of the iter > 2 mm below the incisural line (p < 0.05) and a pontomesencephalic angle (PMA) < 40° (p < 0.05).
CONCLUSIONS
Lumbar EBP may be considered safe and effective in cases of drug-refractory SIH. The presence of a preprocedural PMA < 40° and location of the iter > 2 mm below the incisural line were the most significant predictors of good outcome. Randomized prospective clinical trials comparing lumbar with targeted EBP are warranted to validate these results.
PMID: 30738382
DOI: 10.3171/2018.10.JNS181597

Kinsman KA, Verdoorn JT, Luetmer PH, Clark MS, Diehn FE.
AJNR Am J Neuroradiol. 2019 Jan 17. [Epub ahead of print]
Abstract
BACKGROUND AND PURPOSE:
The significance of renal contrast on CT myelography is uncertain. This project examined different patient populations undergoing CT myelography for the presence of renal contrast to determine whether this finding is of diagnostic value in spontaneous intracranial hypotension.
MATERIALS AND METHODS:
Four groups of patients were analyzed for renal contrast on CT myelography. The control group underwent CT myelography for reasons other than spontaneous intracranial hypotension (n = 47). Patients in study group 1 had spontaneous intracranial hypotension but CT myelography negative for dural CSF leak and CSF venous fistula (n = 83). Patients in study group 2 had spontaneous intracranial hypotension and CT myelography positive for dural CSF leak (n = 44). Patients in study group 3 had spontaneous intracranial hypotension and CT myelography suggestive of CSF venous fistula due to a hyperdense paraspinal vein (n = 17, eleven surgically confirmed).
RESULTS:
Renal contrast was present on the initial CT myelography in 0/47 patients in the control group, 10/83 patients in group one, 1/44 patients in group 2, and 7/17 patients in group 3. Renal contrast on initial CT myelography in patients with suspected or surgically confirmed CSF venous fistula was significantly more likely than in patients with a dural CSF leak (P = .0003).
CONCLUSIONS:
Renal contrast on initial CT myelography was seen only in patients with spontaneous intracranial hypotension. This was more common in confirmed/suspected CSF venous fistulas compared with dural leaks. Early renal contrast in patients with spontaneous intracranial hypotension should prompt scrutiny for a hyperdense paraspinal vein, and, if none is found, potentially advanced diagnostic studies.
PMID: 30655256

Pagani-Estévez GL, Cutsforth-Gregory JK, Morris JM, Mokri B, Piepgras DG, Mauck WD, Eldrige JS, Watson JC.
Reg Anesth Pain Med. 2019 Jan 13. pii: rapm-2018-000021. [Epub ahead of print]
Abstract
BACKGROUND AND OBJECTIVE:
Epidural blood patch (EBP) is a safe and effective treatment for spontaneous intracranial hypotension (SIH), but clinical and procedural variables that predict EBP efficacy remain nebulous.
METHODS:
This study is an institutional review board-approved retrospective case series with dichotomized EBP efficacy defined at 3 months. The study included 202 patients receiving 604 EBPs; iatrogenic cerebrospinal fluid leaks were excluded.
RESULTS:
Of the EBPs, 473 (78%) were single-level, 349 (58%) lumbar, 75 (12%) bilevel, and 56 (9%) multilevel (≥3 levels). Higher volume (OR 1.64; p<0.0001), bilevel (3.17, 1.91-5.27; p<0.0001), and multilevel (117.3, 28.04-490.67; p<0.0001) EBP strategies predicted greater efficacy. Only volume (1.64, 1.47-1.87; p<0.0001) remained significant in multivariate analysis. Site-directed patches were more effective than non-targeted patches (8.35, 0.97-72.1; p=0.033). Lower thoracic plus lumbar was the most successful bilevel strategy, lasting for a median of 74 (3-187) days.
CONCLUSIONS:
In this large cohort of EBP in SIH, volume, number of spinal levels injected, and site-directed strategies significantly correlated with greater likelihood of first EBP efficacy. Volume and leak site coverage likely explain the increased efficacy with bilevel and multilevel patches. In patients with cryptogenic leak site, and either moderate disability, negative prognostic brain MRI findings for successful EBP, or failed previous lumbar EBP, a low thoracic plus lumbar bilevel EBP strategy is recommended. Multilevel EBP incorporating transforaminal administration and fibrin glue should be considered in patients refractory to bilevel EBP. An algorithmic approach to treating SIH is proposed.
PMID: 30636714