Abstracts 2022

AUTHORS: Niklas Lützen, Christian Fung, Jürgen Beck, and Horst Urbach

CITATION: Clin Neuroradiol (2022). doi: 10.1007/s00062-022-01234-2

INTRODUCTION: CSF-venous fistulas (CVF) were first described in 2014 and have become increasingly identified as a cause of spontaneous intracranial hypotension (SIH) in up to 25% of patients. The most likely pathomechanism is a rupture of an arachnoid granulation at the level of a nerve root sleeve, leading to a direct connection between the CSF and a paravertebral vein.

In 2021, Schievink et al. reported multiple CVFs in 9/97 (9.3%) and multiple lateral leaks in 4/65 (6.2%) of 745 SIH patients (97 and 65 patients are subgroups of 745 SIH patients), where a co-incidence of different types of leaks was observed in 5 patients.

We report on a severely disabled 56-year-old woman with a frontotemporal brain sagging syndrome who developed 10 CVFs after surgical ligation of a single CVF 6 months before. To our knowledge, this is the first report of more than four fistulas in a single patient. Multiple de novo CVFs represent a therapeutic challenge suggesting that a definite cure of the disease is not possible and low invasive treatment should be adapted to the patient’s symptoms.

CONCLUSION: In a single patient with a frontotemporal brain sagging syndrome, more than 10 CSF-venous fistulas occurred over the course of the disease. Only gradual closure of the fistulas seemed reasonable and was accompanied by temporary improvement of clinical symptoms and on imaging.

PMID: 36459174
DOI: 10.1007/s00062-022-01234-2

AUTHORS: Katharina Wolf, Niklas Luetzen, Hansjoerg Mast, Nico Kremers, Marco Reisert, Saúl Beltrán, Christian Fung, Jürgen Beck, Horst Urbach

CITATION: Neurology, November 2022. doi: 10.1212/WNL.0000000000201527

BACKGROUND AND OBJECTIVES OF THE STUDY: Spontaneous intracranial hypotension (SIH) is characterized by loss of CSF-volume. We hypothesize that in this situation of low volume, a larger CSF-flow and spinal cord motion at the upper spine can be measured by non-invasive phase-contrast MRI.

STUDY METHODS: A prospective, age-, gender- and BMI- matched controlled cohort study on SIH patients presenting with spinal longitudinal extradural fluid collection (SLEC) was conducted November 2021 to February 2022. Adapted cardiac-gated 2D phase-contrast MRI sequences were acquired at segment C2/C3, and C5/C6 for CSF-flow, and spinal cord motion analysis. Data processing was fully automated. CSF-flow and spinal cord motion were analyzed by peak-to-peak-amplitude and total displacement per segment and heartbeat, respectively. Clinical data included: age, height, body mass index, duration of symptoms, Bern score according to Dobrocky et al. 2019, and type of the spinal CSF leak according to Schievink et al. 2016. Groups were compared via Mann-Whitney U-test; multiple linear regression analysis was performed to address possible relations.

RESULTS OF THE STUDY: 20 SIH patients and 40 healthy controls were analyzed; each group consisted of 70% women. 11 SIH patients presented with Type 1 leak, eight with Type 2, and one was indeterminate. CSF flow per heartbeat was increased at C2/C3 (peak-to-peak-amplitude 65.68 ± 18.3 mm/s vs. 42.50 ± 9.8 mm/s, total displacement 14.32 ± 3.5 mm vs. 9.75 ± 2.7 mm, p<0.001, respectively). Craniocaudal spinal cord motion per heartbeat was larger at segment C2/C3 (peak-to-peak-amplitude 7.30 ± 2.4 mm/s vs. 5.82 ± 2.0 mm/s, total displacement 1.01 ± 0.4 mm vs. 0.74 ± 0.4 mm, p=0.006, respectively) and at segment C5/C6 (total displacement 1.41 ± 0.7 mm vs. 0.97 ± 0.4 mm, p=0.021).

DISCUSSION: SLEC-positive SIH patients show higher CSF-flow and higher spinal cord motion at the upper cervical spine. This increased craniocaudal motion of the spinal cord per heartbeat might produce increased mechanic strain on neural tissue and adherent structures which may be a mechanism leading to cranial nerve dysfunction, neck pain and stiffness in SIH. Non-invasive phase-contrast MRI of CSF-flow and spinal cord motion is a promising diagnostic tool in SIH.

CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that non-invasive phase-contrast MRI of the upper spine identifies differences in CSF-flow and spinal cord motion in SIH patients compared to healthy controls.

German Clinical Trials Register, identification number: DRKS00017351

PMID: 36357188
DOI: 10.1212/WNL.0000000000201527

AUTHORS: I.T. Mark, P.P. Morris, W. Brinjikji, A.A. Madhavan, J.K. Cutsforth-Gregory, and J.T. Verdoorn

CITATION: American Journal of Neuroradiology, November 2022. doi: https://doi.org/10.3174/ajnr.A7699

SUMMARY: This is the first study to describe CSF-venous fistulas involving the sacrum, a location that may be underrecognized on the basis of current imaging techniques. We describe a delayed decubitus flat CT myelogram technique that may be useful to identify sacral CSF-venous fistulas.

PMID: 36328406 
DOI: 10.3174/ajnr.A7699

AUTHORS: Wouter I. Schievink M.D., M. Marcel Maya M.D., Jennifer Harris M.D., Javier Galvan M.D., Rachelle B. Taché N.P.-C., M.S.N., Miriam Nuño Ph.D.

CITATION: Ann Neurol. 2022 Oct 6. doi: 10.1002/ana.26521. ePub ahead of print.

OBJECTIVE: Spontaneous spinal CSF leaks cause intracranial hypotension (SIH) and also may cause infratentorial superficial siderosis (iSS) but the rate of development among different CSF leak types and outcome of treatment are not known. We determined the time interval from SIH onset to iSS and the outcome of treatment.

METHODS USED: 1589 patients with SIH underwent neuroimaging and iSS was detected in 57 (23 men and 34 women, mean age 41.3) (3.6%). We examined the type of underlying CSF leak by various imaging modalities. Percutaneous and surgical procedures were used to treat the CSF leak.

RESULTS OF THE STUDY: iSS was detected in 46 (10.3%) of 447 patients with ventral CSF leaks, in 2 (3.9%) of 51 patients with dural ectasia, in 5 (2.6%) of 194 patients with CSF-venous fistulas, in 4 (0.9%) of 457 patients with simple meningeal diverticula, and in none of the 101 patients with lateral CSF leaks or the 339 patients with leaks of indeterminate origin (p<0.001). The estimated median latency period from SIH onset to iSS was 126 months. Ventral CSF leaks could not be eliminated with percutaneous procedures in any patient and surgical repair was associated with low risk (<5%) and resulted in resolution of the CSF leak in all patients in whom the exact site of the CSF leak could be determined. Other types of CSF leak were treated with percutaneous or surgical procedures.

STUDY INTERPRETATION: iSS can develop in most types of spinal CSF leak, including CSF-venous fistulas, but mainly in chronic ventral CSF leaks, which require surgical repair.

PMID: 36200700
DOI: 10.1002/ana.26521

AUTHORS: Häni L, Fung C, Jesse CM, Schild C, Piechowiak EI, Dobrocky T, Raabe A, Beck J.

CITATION: European Journal of Neuroradiology Oct 9 2022. doi: 10.1111/ene.15591; ePub ahead of print

BACKGROUND: Spontaneous intracranial hypotension (SIH) is an important etiology of infratentorial superficial siderosis (iSS) of the central nervous system (CNS).1-7 However, the prevalence of iSS among patients with SIH is unknown and the imaging findings of iSS might represent a late stage of disease. We aimed to identify cerebrospinal fluid (CSF) biomarkers of iSS in patients with SIH.

METHODS USED: We included consecutive patients evaluated for SIH at our institution between 05/2017 and 01/2019. Lumbar CSF samples were analyzed for the presence of ferritin and bilirubin. MRI was assessed for the presence of iSS.

RESULTS OF THE STUDY: We included 24 patients with SIH. CSF samples were positive for bilirubin in 2/19 (10.5%). CSF ferritin was elevated in 7/23 (30.4%). Signs of iSS on imaging were present in four patients (16.7%). All patients with imaging signs of iSS demonstrated elevated CSF ferritin. Ferritin level was significantly higher among patients demonstrating iSS compared to those without (median 45.0 versus 11.0 μg/l; p=0.003). Symptom duration was longer in patients with iSS than in patients without iSS (median 40 months versus 9 months, p=0.018).

STUDY CONCLUSIONS: CSF alterations indicative of iSS are prevalent among patients with SIH. We speculate that a preclinical phase without symptoms or imaging signs, but during which elevated biomarkers of the disease are apparent from CSF analysis, might exist. We suggest incorporating measurement of CSF ferritin in the work-up of patients with SIH to identify those at risk of developing iSS.

PMID: 36209476
DOI: 10.1111/ene.15591

AUTHORS: I.T. Mark, M.R. Amans, V.N. Shah, K.H. Narsinh, M.T. Caton, S. Teixeira and W.P. Dillon.

CITATION: American Journal of Neuroradiology September 2022. doi: https://doi.org/10.3174/ajnr.A7636

SUMMARY: We describe a technique termed “resisted inspiration” that could be used during myelography to decrease superior vena cava venous pressure and increase lumbar CSF pressure, potentially aiding in the detection of CSF-venous fistulas.

DOI: 10.3174/ajnr.A7636

AUTHORS: Beck, J., Hubbe, U., Klingler, J., Roelz, R., Kraus, L. M., Volz, F., Lützen, N., Urbach, H., Kieselbach, K., & Fung, C.

CITATION: J Neurosurg Spine. 2022 Sep 9:1-6. doi: 10.3171/2022.7.SPINE2252

OBJECTIVE: Spinal CSF leaks cause spontaneous intracranial hypotension (SIH). Surgical closure of spinal CSF leaks is the treatment of choice for persisting leaks. Surgical approaches vary, and there are no studies in which minimally invasive techniques were used. In this study, the authors aimed to detail the safety and feasibility of minimally invasive microsurgical sealing of spinal CSF leaks using nonexpandable tubular retractors.

METHODS: Consecutive patients with SIH and a confirmed spinal CSF leak treated at a single institution between April 2019 and December 2020 were included in the study. Surgery was performed via a dorsal 2.5-cm skin incision using nonexpandable tubular retractors and a tailored interlaminar fenestration and, if needed, a transdural approach. The primary outcome was successful sealing of the dura, and the secondary outcome was the occurrence of complications.

RESULTS: Fifty-eight patients, 65.5% of whom were female (median age 46 years [IQR 36–55 years]), with 38 ventral leaks, 17 lateral leaks, and 2 CSF venous fistulas were included. In 56 (96.6%) patients, the leak could be closed, and in 2 (3.4%) patients the leak was missed because of misinterpretation of the imaging studies. One of these patients underwent successful reoperation, and the other patient decided to undergo surgery at another institution. Two other patients had to undergo reoperation because of insufficient closure and a persisting leak. The rate of permanent neurological deficit was 1.7%, the revision rate for a persisting or recurring leak was 3.4%, and the overall revision rate was 10.3%. The rate of successful sealing during the primary closure attempt was 96.6% and 3.4% patients needed a secondary attempt. Clinical short-term outcome at discharge was unchanged in 14 patients and improved in 25 patients, and 19 patients had signs of rebound intracranial hypertension.

CONCLUSIONS: Minimally invasive surgery with tubular retractors and a tailored interlaminar fenestration and, if needed, a transdural approach is safe and effective for the treatment of spinal CSF leaks. The authors suggest performing a minimally invasive closure of spinal CSF leaks in specialized centers.

PMID: 36087332
DOI: 10.3171/2022.7.SPINE2252

AUTHORS: Ajay A. Madhavan, John C. Benson, Jeremy K. Cutsforth-Gregory, John D. Atkinson, and Carrie M. Carr

CITATION: Radiol Case Rep. 2022 Sep; 17(9): 2968–2971. doi: 10.1016/j.radcr.2022.05.053

SUMMARY: Spontaneous intracranial hypotension can be caused by spinal dural tears or CSF-venous fistulas. It is rare for patients to have more than one type of leak at any given time. Here, we illustrate 3 examples of dural tears that co-existed with CSF-venous fistulas, with both being seen on dynamic CT myelography. To our knowledge, coexistent CSF-venous fistulas and dural tears have not been previously illustrated on dynamic CT myelography, even though this is one of the most commonly used modalities to work-up patients with CSF leaks. We discuss the clinical importance of the rare co-occurrence of these leaks with regard to diagnosis and treatment, as well as implications for understanding and classifying CSF leaks.

PMID: 35755098
doi: 10.1016/j.radcr.2022.05.053

AUTHORS: Piechowiak, E.I.; Aeschimann, B.; Häni, L.; Kaesmacher, J.; Mordasini, P.; Jesse, C.M.; Schankin, C.J.; Raabe, A.; Schär, R.T.; Gralla, J.; Beck, J.; Dobrocky, T.
CITATION: Clin Neuroradiol, 26 Aug 2022. DOI: 10.1007/s00062-022-01205-7

PURPOSE: Epidural blood patch (EBP) is a minimally invasive treatment for spontaneous intracranial hypotension (SIH). Follow-up after EBP primarily relies on clinical presentation and data demonstrating successful sealing of the underlying spinal cerebrospinal fluid (CSF) leak are lacking. Our aim was to evaluate the rate of successfully sealed spinal CSF leaks in SIH patients after non-targeted EBP.

METHODS USED: Patients with SIH and a confirmed spinal CSF leak who had been treated with non-targeted EBP were retrospectively analyzed. Primary outcome was persistence of CSF leak on spine MRI or intraoperatively. Secondary outcome was change in clinical symptoms after EBP.

RESULTS OF THE STUDY: In this study 51 SIH patients (mean age, 47 ± 13 years; 33/51, 65% female) treated with non-targeted EBP (mean, 1.3 EBPs per person; range, 1–4) were analyzed. Overall, 36/51 (71%) patients had a persistent spinal CSF leak after EBP on postinterventional imaging and/or intraoperatively. In a best-case scenario accounting for missing data, the success rate of sealing a spinal CSF leak with an EBP was 29%. Complete or substantial symptom improvement in the short term was reported in 45/51 (88%), and in the long term in 17/51 (33%) patients.

STUDY CONCLUSIONS: Non-targeted EBP is an effective symptomatic treatment providing short-term relief in a substantial number of SIH patients; however, successful sealing of the underlying spinal CSF leak by EBP is rare, which might explain the high rate of delayed symptom recurrence. The potentially irreversible and severe morbidity associated with long-standing intracranial hypotension supports permanent closure of the leak.

PMID: 36028627
DOI: 10.1007/s00062-022-01205-7

AUTHORS: Mark D. Mamlouk MD, Peter Y. Shen MD, Brian C. Dahlin MD
CITATION: Headache. 2022 Aug 26; 00: 1– 12. doi: 10.1111/head.14379

OBJECTIVE: To assess headache response and patient perception of improvement after computed tomography (CT)-guided fibrin glue occlusion of cerebrospinal fluid-venous fistulas (CVFs) in a large sample size and with a long clinical follow-up.

BACKGROUND: CVFs are an increasingly identified type of spinal leak in patients with spontaneous intracranial hypotension (SIH), and CT-guided fibrin glue occlusion has been introduced as a treatment option in a prior small series.

METHODS USED: Retrospective case series review of medical records from a single institution was performed for all patients with CVFs that were treated with CT-guided fibrin glue occlusion between August 2018 and April 2022 in an outpatient or inpatient setting. Pre- and posttreatment Headache Impact Tests (HIT-6) were administered to patients, and a change in scores was evaluated. In some patients, pretreatment HIT-6 tests were not obtained prior to the fibrin glue procedure, and the patient was asked to fill out the pretreatment test based on personal recall of their symptoms prior to treatment. Patients completed a Patient Global Impression of Change (PGIC) scale after treatment. Pre- and posttreatment brain imaging was compared using Bern SIH scores.

RESULTS OF THE STUDY: Thirty-five patients (19 females, 16 males; mean age 60 years) with CVFs treated with CT-guided fibrin glue occlusion met the inclusion criteria. Mean pretreatment and posttreatment HIT-6 scores were 64.7 ± 10.2 and 43.4 ± 9.9 (p < 0.001), respectively. The posttreatment HIT-6 questionnaires were completed on average 10.3 months after treatment, and 20 patients filled out the pretreatment HIT-6 form after their treatment. The mean PGIC score was 6.1 ± 1.3. Mean pretreatment and posttreatment Bern SIH scores were 5.9 ± 2.5 and 1.5 ± 1.5 (p < 0.001), respectively.

STUDY CONCLUSIONS: We report a large series of patients who underwent CT-guided fibrin glue occlusion of CVFs. We showed that headache scores decreased after treatment, and the majority of patients had high PGIC scores. Posttreatment brain MRIs also showed improved Bern SIH scores.

PMID: 36018057
DOI: 10.1111/head.14379

AUTHORS: J.C. Babcock, D.R. Johnson, J.C. Benson, D.K. Kim, P.H. Luetmer, D.P. Shlapak, C.P. Cross, M.P. Johnson, J.K. Cutsforth-Gregory and C.M. Carr
CITATION: American Journal of Neuroradiology Jul 2022, 43 (7) 978-983; DOI: 10.3174/ajnr.A7557

BACKGROUND AND PURPOSE: Diagnosing spontaneous intracranial hypotension and associated CSF leaks can be challenging, and additional supportive imaging findings would be useful to direct further evaluation. This retrospective study evaluated whether there was a difference in the prevalence of calvarial hyperostosis in a cohort of patients with spontaneous intracranial hypotension compared with an age- and sex-matched control population.

MATERIALS AND METHODS USED: Cross-sectional imaging (CT of the head or brain MR imaging examinations) for 166 patients with spontaneous intracranial hypotension and 321 matched controls was assessed by neuroradiologists blinded to the patient’s clinical status. The readers qualitatively evaluated the presence of diffuse or layered calvarial hyperostosis and measured calvarial thickness in the axial and coronal planes.

RESULTS OF THE STUDY: A significant difference in the frequency of layered hyperostosis (31.9%, 53/166 subjects versus 5.0%, 16/321 controls, P < .001, OR = 11.58) as well as the frequency of overall (layered and diffuse) hyperostosis (38.6%, 64/166 subjects versus 13.2%, 42/321 controls, P < .001, OR = 4.66) was observed between groups. There was no significant difference in the frequency of diffuse hyperostosis between groups (6.6%, 11/166 subjects versus 8.2%, 26/321 controls, P = .465). A significant difference was also found between groups for calvarial thickness measured in the axial (P < .001) and coronal (P < .001) planes.

STUDY CONCLUSIONS: Layered calvarial hyperostosis is more prevalent in spontaneous intracranial hypotension compared with the general population and can be used as an additional noninvasive brain imaging marker of spontaneous intracranial hypotension and an underlying spinal CSF leak.

PMID: 35772803
DOI: 10.3174/ajnr.A7557

AUTHORS: W.I. Schievink, R.B. Tache, M.M. Maya
CITATION: American Journal of Neuroradiology Jul 2022, 43 (7) 1073-1076; DOI: 10.3174/ajnr.A7558

SUMMARY: A spinal CSF-venous fistula is an increasingly recognized type of CSF leak that causes spontaneous intracranial hypotension. The detection of these fistulas requires specialized imaging such as digital subtraction myelography or dynamic CT myelography, and several treatment options are available. A novel treatment for these CSF-venous fistulas consisting of transvenous embolization with the liquid embolic agent Onyx has been described recently, but some patients require further treatment if embolization fails. The purpose of this study was to evaluate the safety and effectiveness of surgery following transvenous embolization. In a series of 6 consecutive patients who underwent surgical ligation of the fistula after endovascular embolization, there were no surgical complications. Postoperatively, complete resolution of symptoms was reported by 5 of the 6 patients, and brain MR imaging findings of spontaneous intracranial hypotension resolved in all patients. This study suggests that surgical ligation of spontaneous spinal CSF-venous fistulas after endovascular embolization is effective and safe.

PMID: 35738676
DOI: 10.3174/ajnr.A7558

AUTHORS: Mark D. Mamlouk MD, P.Y. Shen, P. Jun, and M.F. Sedrak
CITATION: American Journal of Neuroradiology Jun 2022, DOI: 10.3174/ajnr.A7548

BACKGROUND AND PURPOSE: There are 3 main types of spinal CSF leaks, and the imaging appearances are well-reported. Specific patient demographics and spinal locations of the various types of spinal leaks are less frequently described. The purpose of this article was to stratify the various types of spontaneous CSF leaks on the basis of age, body mass index, and spinal level.

MATERIALS AND METHODS USED: Retrospective review was performed for all patients with spontaneous spinal CSF leaks identified on CT myelography. Age, body mass index, and spinal CSF leak type and level were recorded.

RESULTS OF THE STUDY: Sixty-five patients (37 women and 28 men) had spinal CSF leaks. Type 1 CSF leaks (dural tears) were observed in 25 patients (mean age, 44.5 years; mean body mass index, 24.3) and were most common in the upper thoracic spine (72%), particularly at the T1–T2 level (36%). Type 2 CSF leaks (ruptured meningeal diverticula) were observed in 4 patients (mean age, 45.5 years; mean body mass index, 27.5) and were all seen in the lower thoracic spine. Type 3 CSF leaks (CSF-venous fistulas) were observed in 36 patients (mean age, 58.8 years; mean body mass index, 27.0) and were most common on the right side (72%) and in the lower thoracic spine (56%).

STUDY CONCLUSIONS: Type 1 CSF leaks occurred in younger patients with a normal body mass index, while patients with type 3 CSF leaks were relatively older and had an elevated body mass index. Type 1 leaks mostly occurred in the upper thoracic spine, and types 2 and 3 leaks mostly occurred in the lower thoracic spine.

PMID: 35738670
DOI: 10.3174/ajnr.A7548

AUTHORS: Christopher Marvin Jesse, Levin Häni, Christian Fung, Christian Thomas Ulrich, Ralph T. Schär, Tomas Dobrocky, Eike Immo Piechowiak, Johannes Goldberg, Christoph Schankin, Harri Sintonen, Jürgen Beck & Andreas Raabe
CITATION: J Neurol. 2022 Jun 14. doi: 10.1007/s00415-022-11207-7

OBJECTIVE: Spontaneous intracranial hypotension (SIH), which is often caused by a spinal cerebrospinal fluid leak, is an important cause of disabling headaches. Many patients report devastating changes in their quality of life because of their symptoms. This study aimed to evaluate the impact of SIH on patients’ social/ working life and health-related quality of life (HRQoL).

METHODS USED: We included consecutive patients with proven SIH treated at our institution from January 2013 to May 2020. Patients were contacted and asked to complete the 15D questionnaire for the collection of HRQoL data and to provide additional information on their social life status.

RESULTS OF THE STUDY: Of 112 patients, 79 (70.5%) returned the questionnaire and were included in the analysis. Of those, 69 were treated surgically (87.3%), and 10 were managed non-operatively (12.7%). Twenty-five (31.6%) patients reported a severe impact on their partnership, 32 (41.5%) reported a moderate or severe impact on their social life. Forty (54.8%) patients reported sick leave for more than 3 months. The mean 15D score was 0.890 (± 0.114) and significantly impaired compared to an age- and sex-matched general population (p = 0.001), despite treatment. Patients with residual SIH-symptoms (36, 45.6%) had significantly impaired HRQoL compared to those without any residual symptoms (41, 51.9%) (p < 0.001).

STUDY CONCLUSIONS: SIH had a notable impact on the patients’ social life and HRQoL. It caused long periods of incapacity for work, and is therefore, associated with high economic costs. Although all patients were appropriately treated, reduced HRQoL persisted after treatment, underlining the chronic character of this disease.

PMID: 35701531
DOI: 10.1007/s00415-022-11207-7

AUTHORS: Lohkamp, L., Marathe, N., Nicholson, P., Farb, R. I., & Massicotte, E. M.
CITATION: Journal of Neurosurgery: Case Lessons, 3(18), CASE21730. May, 2022. DOI: 10.3171/CASE21730

BACKGROUND: Cerebrospinal fluid–venous fistulas (CVFs) may cause cerebrospinal fluid leaks resulting in spontaneous intracranial hypotension (SIH). Surgical treatment of CVFs aims to eliminate abnormal fistulous connections between the subarachnoid space and the epidural venous plexus at the level of the nerve root sleeve. The authors propose a percutaneous minimally invasive technique for surgical ligation of CVF as an alternative to the traditional open approach using a tubular retractor system.

OBSERVATIONS: Minimally invasive surgical (MIS) ligation of spinal CVF was performed in 5 patients for 6 CVFs. The definite disconnection of the CVF was achieved in all patients by clipping and additional silk tie ligation of the fistula. None of the patients experienced surgical complications or required transition to an open procedure. One patient underwent 2 MIS procedures for 2 separate CVFs. Postoperative clinical follow-up and cranial magnetic resonance imaging confirmed resolution of symptoms and radiographic SIH stigmata.

LESSONS: MIS ligation of CVFs is safe and efficient. It represents an elegant and less invasive procedure, reducing the risk of wound infections and time to recovery. However, preparedness for open ligation is warranted within the same surgical setting in cases of complications and difficult accessibility.

ABBREVIATIONS: CSF = cerebrospinal fluid; CT = computed tomography; CVF = cerebrospinal fluid–venous fistula; DSM = digital subtraction myelography; EBP = epidural blood patching; FU = follow-up; IOM = intraoperative neurophysiological monitoring; MIS = minimally invasive surgical; MRI = magnetic resonance imaging; SIH = spontaneous intracranial hypotension

DOI: 10.3171/CASE21730

AUTHORS: Aslan Lashkarivand, Per Kristian Eide
CITATION: Neurology May 2022, 98 (19) 798-805; DOI: 10.1212/WNL.0000000000200511

SUMMARY: Brain sagging dementia (BSD), caused by spontaneous intracranial hypotension (SIH), is a rare syndrome that is only recently recognized, mimicking the clinical findings of behavioral variant frontotemporal dementia (bvFTD). Being aware of its signs and symptoms is essential for early diagnosis and treatment in this potentially reversible form of dementia. Our objective was to identify cases of BSD in the literature and present its clinical characteristics, diagnostic workup, treatment options, and outcome. The review was reported according to PRISMA guidelines and registered with the PROSPERO database (CRD42020150709). MEDLINE, EMBASE, PsychINFO, and Cochrane Library were searched. There was no date restriction. The search was updated in April 2021. A total of 983 articles were screened and assessed for eligibility. Twenty-nine articles (25 case reports and 4 series) and 70 patients were selected for inclusion. No cranial leak cases were identified. BSD diagnosis should be made based on clinical signs and symptoms and radiologic findings. There is a male predominance (F:M ratio 1:4) and a peak incidence in the 6th decade of life. The main clinical manifestation is insidious onset, gradually progressive cognitive and behavioral changes characteristic for bvFTD. Headache is present in the majority of patients (89%). The presence of brain sagging and absence of frontotemporal atrophy is an absolute criterion for the diagnosis. CSF leak is identified with myelography and digital subtraction myelography. The treatment and repair depend on the etiology and extent of the dural defect, although an epidural blood patch is the first-line treatment in most cases. With treatment, 81% experienced partial and 67% complete resolution of their symptoms. This review highlights the most important clinical aspects of BSD. Due to the sparse evidence and lack of BSD awareness, many patients are likely left undiagnosed. Recognizing this condition is essential to provide early treatment to reverse the cognitive and behavioral changes that may otherwise progress and fully impair the patient. Moreover, patients with longstanding SIH must be assessed carefully for cognitive and behavioral changes.

ABBREVIATIONS: BSD=brain sagging dementia; bvFTD=behavioral variant frontotemporal dementia; EBP=epidural blood patch; PRISMA=Preferred Reporting Items for Systematic Reviews and Meta-Analyses; SIH=spontaneous intracranial hypotension
35338080

PMID: 35338080
DOI: 10.1212/WNL.0000000000200511

AUTHORS: L. Carlton Jones, P.J. Goadsby
CITATION: American Journal of Neuroradiology Apr 2022, 43 (4) 645-648;  DOI: 10.3174/ajnr.A7476

SUMMARY: Lateral decubitus CT myelography is a sensitive technique for detecting CSF-venous fistulas in patients with spontaneous intracranial hypotension. It might be necessary to perform bilateral studies to locate a fistula. We report on the feasibility of obtaining diagnostic-quality bilateral decubitus CT myelography in a single session, avoiding the need to schedule separate examinations for the left and right sides on different days.

PMID: 35332017
DOI: 10.3174/ajnr.A7476

AUTHORS: Sulioti, G, Gray, L, Amrhein, TJ.
CITATION: Headache. 2022; 62: 208– 211. 24 Jan 2022. doi: 10.1111/head.14264

OBJECTIVES: Spontaneous intracranial hypotension (SIH) is a debilitating neurologic condition that is often thought of as separate from idiopathic intracranial hypertension (IIH). The unique case presented here details a spontaneous spinal cerebrospinal fluid (CSF) leak that developed abruptly following a CSF pressure elevating maneuver in a patient with pre-existing intracranial hypertension, raising the possibility of a causative link between the two conditions.

RESULTS: A 40-year-old woman with symptomatic IIH developed a dural tear of a thoracic spinal nerve root sleeve during an episode of Valsalva maneuver leading to a CSF leak and development of symptomatic SIH. This was successfully treated with epidural blood and fibrin glue patch and the patient is now symptom-free.

DISCUSSION: The implication of a possible causative link between elevated CSF pressure and subsequent development of dural rupture and SIH raises important questions regarding the pathophysiology of SIH in some cases. Furthermore, it suggests that there could be a potential prophylactic benefit of CSF pressure lowering medications in preventing the development of SIH in patients with IIH.

PMID: 35072949
DOI: 10.1111/head.14264

AUTHORS: Alomari, M. H., Shahin, M. M., Fishman, S. J., Kerr, C. L., Smith, E. R., Eng, W., Ruiz-Gutierrez, M., Adams, D. M., Orbach, D. B., Chaudry, G., Shaikh, R., Chewning, R., & Alomari, A. I.
CITATION: Journal of Neurosurgery: Spine (published online ahead of print, 01 Apr 2022. DOI: 10.3171/2022.1.SPINE2138

OBJECTIVE OF THE STUDY: Clinical manifestations of blue rubber bleb nevus syndrome (BRBNS) and multifocal venous malformation (MVM) vary depending on the location of the lesions. The aim of this study was to assess the risk of developing CSF leaks in patients with epidural venous malformations (VMs).

METHODS USED: The authors retrospectively investigated the relationship between the development of a CSF leak and the presence of epidural VMs.

RESULTS OF THE STUDY: Nine patients (5 females) had epidural VMs and presentation that was confirmatory or suggestive of a CSF leak: 4 had BRBNS, 4 had MVMs, and 1 had a solitary VM. Of 66 patients with BRBNS, clinical and imaging features of CSF leak were noted in 3 (4.5%) with epidural VMs at the age of 11–44 years. A fourth patient had suggestive symptoms without imaging confirmation. An epidural blood patch was ineffective in 2 patients, both with more than one source of leakage, requiring surgical repair or decompression. Symptomatic downward displacement of the cerebellar tonsils was noted in 3 patients with MVM and 1 with a solitary VM; 3 required surgical decompression.

STUDY CONCLUSIONS: These findings suggest an increased risk of CSF leak in patients with epidural VM, including BRBNS, MVMs, and solitary VMs. Awareness of the association between epidural VM and CSF leakage may facilitate earlier diagnosis and therapeutic intervention.

ABBREVIATIONS: BRBNS = blue rubber bleb nevus syndrome; GI = gastrointestinal; KTS = Klippel-Trenaunay syndrome; MVM = multifocal VM; SIH = spontaneous intracranial hypotension; VAC = Vascular Anomalies Center; VM = venous malformation.

PMID: 35364593
DOI: 10.3171/2022.1.SPINE2138

AUTHORS: Jessica L Houk, Daniele M Marin, Michael D Malinzak, Peter G Kranz, Timothy J Amrhein
CITATION: Radiol Case Rep. 2022 Mar 29;17(5):1824-1829. DOI: 10.1016/j.radcr.2022.02.053

ABSTRACT SUMMARY: Spontaneous intracranial hypotension (SIH) is a debilitating condition caused by spinal CSF leaks or CSF-venous fistulas (CVFs). Localizing the causative CSF leak or CVF is critical for definitive treatment but can be difficult using conventional myelographic techniques because these lesions are often low contrast compared to background, diminutive, and in some cases may be mistaken for calcified structures. Dual energy CT (DECT) can increase the conspicuity of iodinated contrast compared to background and can provide the ability to distinguish materials based on differing anatomic properties, making it well suited to address the shortcomings of conventional myelography in SIH. The purpose of this report is to illustrate the potential benefits of using DECT as an adjunct to traditional myelographic techniques in order to increase the conspicuity of these often-subtle CVFs and CSF leaks. This retrospective case series included 4 adult patients with SIH who demonstrated findings equivocal for either CVF or CSF leak using our institution’s standard initial CT myelogram and in whom subsequent evaluation with DECT ultimately helped to identify the CVF or CSF leak. DECT demonstrated utility by increasing the conspicuity of two subtle CVFs compared to background and also helped to differentiate between calcified osteophytes and extradural contrast in 2 CSF leaks, confirming their presence and identifying the causative pathology. Our observations demonstrate the benefit of DECT as a problem-solving tool in the accurate diagnosis and localization of CVFs and CSF leaks.

PMID: 35369539
DOI: 10.1016/j.radcr.2022.02.053

AUTHORS: Andrew L. Callen, MD, Vincent M. Timpone, MD, Adam Schwertner, MD, David Zander, MD, Fabio Grassia, MD, Peter Lennarson, MD, Joshua Seinfeld, MD, Kevin O. Lillehei, MD, Marius Birlea, MD and Ashesh A. Thaker, MD
CITATION: American Journal of Roentgenology. 2022;219: 292-301. DOI: 10.2214/AJR.22.27485

ABSTRACT SUMMARY:  Spontaneous intracranial hypotension (SIH) is a disorder of CSF dynamics that causes a complex clinical syndrome and severe disability. SIH is challenging to diagnose because of the variability of its presenting clinical symptoms, the potential for subtle imaging findings to be easily overlooked, and the need for specialized diagnostic testing. Once SIH is suggested by clinical history and/or supported by initial neuroim-aging, many patients may undergo initial nontargeted epidural blood patching with variable and indefinite benefit. However, data suggest that precise localization of the CSF leak or CSF-venous fistula (CVF) can lead to more effective and durable treatment strategies. Leak localization can be achieved using a variety of advanced diagnostic imaging techniques, although these may not be widely performed at nontertiary medical centers, leaving many patients with the potential for inadequate workup or treatment. This review describes imaging techniques including dynamic fluoroscopic and CT myelography as well as delayed MR myelography and treatment options including percutaneous, endovascular, and surgical approaches for SIH. These are summarized by an algorithmic framework for radiologists to approach the workup and treatment of patients with suspected SIH. The importance of a multidisciplinary approach is emphasized.

PMID: 35261281
DOI: 10.2214/AJR.22.27485

AUTHORS: Waleed Brinjikji, Ivan Garza, Mark Whealy, Narayan Kissoon, John L D Atkinson, Luis Savastano, Ajay Madhavan, Jeremy Cutsforth-Gregory
CITATION: J Neurointerv Surg. 2022 Jan 24; DOI: 10.1136/neurintsurg-2021-018466 

BACKGROUND: We report outcomes of spontaneous intracranial hypotension (SIH) patients who underwent transvenous embolization of cerebrospinal fluid-venous fistulas (CSFVFs) confirmed on digital subtraction myelography (DSM) performed at our institution.

METHODS USED:This is a retrospective evaluation of a prospectively collected database of SIH patients who underwent transvenous embolization of CSFVFs. Only patients who had fistulas confirmed on DSM performed at our institution were included. All patients had a baseline MRI and an MRI performed at least 90 days post-embolization, as well as clinical evaluation using the six item Headache Impact Test (HIT-6) and the Patient Global Impression of Change (PGIC) scales. Paired t-test was used to report changes in Bern MRI scores and HIT-6 scores at follow-up.

RESULTS OF THE STUDY: 40 patients were included (29 female, 11 male). Mean age was 57.4±10.3 years. Mean Bern score improved from 5.7±3.0 at baseline to 1.3±2.0 at follow-up (p<0.0001). Mean HIT-6 score at baseline was 67.2±11.1 and at follow-up was 41.5±10.1 (p<0.0001). Median PGIC was 1, with 36 patients (90.0%) reporting at least minimal improvement and 32 patients (82.5%) reporting much or very much improvement. Complications included persistent local site pain in 12 patients (30%), suspected rebound intracranial hypertension requiring medical intervention in 7 patients (17.5%), and asymptomatic tiny Onyx emboli to the lungs in 3 patients (7.5%).

STUDY CONCLUSIONS: Transvenous embolization of CSFVFs using Onyx is safe and effective, resulting in significant improvement in headache and overall clinical outcomes in nearly 90% of patients, and substantial improvements in brain MRI abnormalities.

PMID: 35074899
DOI: 10.1136/neurintsurg-2021-018466

AUTHORS: J.T. Philip, M.A. Flores, R.D. Beegle, S.C. Dodson, S.A. Messina, J.V. Murray
CITATION: American Journal of Neuroradiology Feb 2022, 43 (2) 315-318; DOI: 10.3174/ajnr.A7397

BACKGROUND AND PURPOSE: Postdural puncture headache, a known complication of lumbar puncture, typically resolves with conservative management. Symptoms persist in a minority of patients, necessitating an epidural blood patch. One method of decreasing rates of postdural puncture headache is using atraumatic, pencil-point needles rather than bevel-tip needles. To the best of our knowledge, this is the first study comparing epidural blood patch rates between pencil- and bevel-tip needles with a subgroup analysis based on body mass index.

MATERIALS AND METHODS USED: This single-institution retrospective study identified 4435 patients with a recorded body mass index who underwent a lumbar puncture with a 22-ga pencil-tip Whitacre needle, a 20-ga bevel-tip Quincke needle, or a 22-ga Quincke needle. The groups were stratified by body mass index. We compared epidural blood patch rates between 22-ga pencil-tip Whitacre needles versus 22-ga Quincke needles and 22-ga Quincke needles versus 20-ga bevel-tip Quincke needles using the Fischer exact test and χ2 test.

RESULTS OF THE STUDY: Postdural puncture headache necessitating an epidural blood patch was statistically more likely using a 22-ga Quincke needle in all patients (P < .001) and overweight (P = .03) and obese (P < .001) populations compared with using a 22-ga pencil-tip Whitacre needle. In the normal body mass index population, there was no statistically significant difference in epidural blood patch rates when using a 22-ga pencil-tip Whitacre needle compared with a 22-ga Quincke needle (P = .12). There was no significant difference in epidural blood patch rates when comparing a 22-ga Quincke needle versus a 20-ga bevel-tip Quincke needle in healthy (P = .70), overweight (P = .69), or obese populations (P = .44).

STUDY CONCLUSIONS: Using a 22-ga pencil-tip Whitacre needle resulted in lower epidural blood patch rates compared with a 22-ga Quincke needle in all patients. Subgroup analysis demonstrated a statistically significant difference in epidural blood patch rates in overweight and obese populations, but not in patients with a normal body mass index.

PMID: 35027350
DOI: 10.3174/ajnr.A7397