Spontaneous absorption of osteophytic calcification associated with chronic dural tear and ventral spinal CSF leak

Spontaneous intracranial hypotension (SIH) is associated with cerebrospinal fluid (CSF) hypovolemia, often from a traumatic dural tear from a calcified spinal osteophyte. Visualizing osteophytes on CT imaging can guide decision making on candidate leak sites. We report the atypical case of a 41-year-old woman whose ventral CSF leak was associated with an osteophyte that resorbed over an 18-month period. Full workup and treatment were delayed due to unexpected pregnancy and completion of gestational cycle with delivery of a healthy term infant. The patient initially presented with persistent orthostatic headaches with nausea and blurred vision. Initial MRI suggested brain sagging among other findings consistent with SIH. CT myelogram showed an extensive thoracic CSF leak with a prominent ventral T11-T12 osteophyte and multiple small disc herniations. The patient did not respond to epidural blood patches and deferred additional imaging due to her pregnancy. CT myelography performed 5 months post-partum showed an absence of the osteophyte; a follow-up digital subtraction myelogram performed 10 months post-partum showed evidence of source leak at T11-T12 level. T11-T12 laminectomy visualized and repaired a 5 mm ventral dural defect with symptom resolution. This report highlights the potential for a resorbed osteophyte to be the causative agent for long-standing dural tears that do not show visible calcifications on myelography.

Progressive superficial siderosis despite complete remission of intracranial hypotension symptoms following epidural patching: Case report

Spontaneous intracranial hypotension (SIH) commonly results from ventral spinal cerebrospinal fluid (CSF) leaks and epidural patches are advocated as first-line treatment. Complications such as superficial siderosis can arise but have previously been reported only in the context of long-term persistent, ongoing, CSF leak and SIH. We report a case of a patient with SIH from a ventral spinal CSF leak that was treated with epidural patching and experienced complete resolution of SIH. Four years later SIH symptoms recurred, and brain magnetic resonance imaging unexpectedly showed the interval accumulation of hemosiderin pigmentation on the cerebellum and brainstem during the period when the patient was without symptoms of SIH. This case uniquely demonstrates the progression of superficial siderosis despite the apparent resolution of SIH. Our findings suggest two divergent pathophysiological outcomes from spinal ventral dural tear: (1) CSF loss causing SIH; and (2) persistent low-level bleeding arising from the spinal dural tear leading to superficial siderosis. These divergent pathophysiologies had a discordant response to epidural patching. Epidural patching successfully treated the SIH but did not prevent the progression of superficial siderosis, indicating that some patients may require more than epidural patching despite symptom resolution. This case highlights the need for post-treatment monitoring protocols in patients with ventral spinal CSF leaks and SIH and raises important questions about the adequacy of epidural patching in certain SIH cases arising from ventral spinal CSF leak.

Factors to predict recurrence after epidural blood patch in patients with spontaneous intracranial hypotension

OBJECTIVES

This study aimed to identify predictors for the recurrence of spontaneous intracranial hypotension (SIH) after epidural blood patch (EBP).

BACKGROUND

Epidural blood patch is the main treatment option for SIH; however, the characteristics of patients who experience relapse after successful EBP treatment for SIH remain understudied.

METHODS

In this exploratory, retrospective, case-control study, we included 19 patients with SIH recurrence after EBP and 36 age- and sex-matched patients without recurrence from a single tertiary medical institution. We analyzed clinical characteristics, neuroimaging findings, and volume changes in intracranial structures after EBP treatment. Machine learning methods were utilized to predict the recurrence of SIH after EBP treatment.

RESULTS

There were no significant differences in clinical features between the recurrence and no-recurrence groups. Among brain magnetic resonance imaging signs, diffuse pachymeningeal enhancement and cerebral venous dilatation were more prominent in the recurrence group than no-recurrence group after EBP (14/19 [73%] vs. eight of 36 [22%] patients, p = 0.001; 11/19 [57%] vs. seven of 36 [19%] patients, p = 0.010, respectively). The midbrain-pons angle decreased in the recurrence group compared to the no-recurrence group after EBP, at a mean (standard deviation [SD]) of -12.0 [16.7] vs. +1.8[18.3]° (p = 0.048). In volumetric analysis, volume changes after EBP were smaller in the recurrence group than in the no-recurrence group in intracranial cerebrospinal fluid (mean [SD] -11.6 [15.3] vs. +4.8 [17.1] mL, p = 0.001) and ventricles (mean [SD] +1.0 [2.0] vs. +2.0 [2.5] mL, p = 0.003). Notably, the random forest classifier indicated that the model constructed with brain volumetry was more accurate in discriminating SIH recurrence (area under the curve = 0.80 vs. 0.52).

CONCLUSION

Our study suggests that volumetric analysis of intracranial structures may aid in predicting recurrence after EBP treatment in patients with SIH.

Myelography Using Energy-Integrating Detector CT Versus Photon-Counting Detector CT for Detection of CSF-Venous Fistulas in Patients With Spontaneous Intracranial Hypotension

BACKGROUND. CSF-venous fistulas (CVFs), which are an increasingly recognized cause of spontaneous intracranial hypotension (SIH), are often diminutive in size and exceedingly difficult to detect by conventional imaging. OBJECTIVE. This purpose of this study was to compare energy-integrating detector (EID) CT myelography and photon-counting detector (PCD) CT myelography in terms of image quality and diagnostic performance for detecting CVFs in patients with SIH. METHODS. This retrospective study included 38 patients (15 men and 23 women; mean age, 55 ± 10 [SD] years) with SIH who underwent both clinically indicated EID CT myelography (slice thickness, 0.625 mm) and PCD CT myelography (slice thickness, 0.2 mm; performed in ultrahigh-resolution mode) to assess for CSF leak. Three blinded radiologists reviewed examinations in random order, assessing image noise, discernibility of spinal nerve root sleeves, and overall image quality (each assessed using a scale of 0-100, with 100 denoting highest quality) and recording locations of the CVFs. Definite CVFs were defined as CVFs described in CT myelography reports using unequivocal language and having an attenuation value greater than 70 HU. RESULTS. For all readers, PCD CT myelography, in comparison with EID CT myelography, showed higher mean image noise (reader 1: 69.9 ± 18.5 [SD] vs 37.6 ± 15.2; reader 2: 59.5 ± 8.7 vs 49.3 ± 12.7; and reader 3: 57.6 ± 13.2 vs 42.1 ± 16.6), higher mean nerve root sleeve discernibility (reader 1: 81.6 ± 21.7 [SD] vs 30.4 ± 13.6; reader 2: 83.6 ± 10 vs 70.1 ± 18.9; and reader 3: 59.6 ± 13.5 vs 50.5 ± 14.4), and higher mean overall image quality (reader 1: 83.2 ± 20.0 [SD] vs 38.1 ± 13.5; reader 2: 80.1 ± 10.1 vs 72.4 ± 19.8; and reader 3: 57.8 ± 11.2 vs 51.9 ± 13.6) (all p < .05). Eleven patients had a definite CVF. Sensitivity and specificity of EID CT myelography and PCD CT myelography for the detection of definite CVF were 45% and 96% versus 64% and 85%, respectively, for reader 1; 36% and 100% versus 55% and 96%, respectively, for reader 2; and 57% and 100% versus 55% and 93%, respectively, for reader 3. The sensitivity was significantly higher for PCD CT myelography than for EID CT myelography for reader 1 and reader 2 (both p < .05) and was not significantly different between the two techniques for reader 3 (p = .45); for all three readers, specificity was not significantly different between the two modalities (all p > .05). CONCLUSION. In comparison with EID CT myelography, PCD CT myelography yielded significantly improved image quality with significantly higher sensitivity for CVFs (for two of three readers), without significant loss of specificity. CLINICAL IMPACT. The findings support a potential role for PCD CT myelography in facilitating earlier diagnosis and targeted treatment of SIH, avoiding high morbidity during potentially prolonged diagnostic workups.

Intrathecal hematoma following epidural blood patch: An alternative mechanism to intrathecal puncture

Intrathecal blood after a percutaneous epidural blood patch is a known complication, one that has been previously attributed to inadvertent needle tip position in the subarachnoid space. We present two cases with imaging confirmation of an alternative mechanism, one that includes blood transferring from the epidural space to the subarachnoid space through a pre-existing dural defect.

Spontaneous intracranial hypotension or spontaneous intraspinal hypovolume?

Objectives

Spontaneous intracranial hypotension (SIH) is frequently complicated by subacute subdural hematoma (SDH) and more rarely by bilateral thalamic ischemia. Here, we report a case of SIH-related SDH treated with three epidural patches (EPs), with follow-up of the intracranial pressure and lumbar intrathecal pressure.

Methods

A 46-year-old man presented bilateral thalamic ischemia, then a growing SDH. After failure of urgent surgical evacuation, he underwent three saline EPs, two dynamic myelography examinations and one digital subtraction angiography-phlebography examination. However, because of no dural tear and no obstacle to the venous drainage of the vein of Galen, no therapeutic procedure was available, and the patient died.

Results

The case exhibited a progressive increase in the transmission of lumbar intrathecal pressure to intracranial pressure during the three EPs. The EPs may have successfully treated the SIH, but the patient did not recover consciousness because of irreversible damage to both thalami.

Conclusion

Clinicians should be aware of the bilateral thalamic ischemia picture that may be the presenting sign of SIH. Moreover, the key problem in the pathophysiology of SIH seems to be intraspinal and intracranial volumes rather than pressures. Therefore, intracranial hypotension syndrome might actually be an intraspinal hypovolume syndrome.

Surgical closure of spinal cerebrospinal fluid leaks improves symptoms in patients with superficial siderosis

BACKGROUND AND PURPOSE

Spinal cerebrospinal fluid (CSF) leaks may cause a myriad of symptoms, most common being orthostatic headache. In addition, ventral spinal CSF leaks are a possible etiology of superficial siderosis (SS), a rare condition characterized by hemosiderin deposits in the central nervous system (CNS). The classical presentation of SS involves ataxia, bilateral hearing loss, and myelopathy. Unfortunately, treatment options are scarce. This study was undertaken to evaluate whether microsurgical closure of CSF leaks can prevent further clinical deterioration or improve symptoms of SS.

METHODS

This cohort study was conducted using data from a prospectively maintained database in two large spontaneous intracranial hypotension (SIH) referral centers in Germany and Switzerland of patients who meet the modified International Classification of Headache Disorders, 3rd edition criteria for SIH. Patients with spinal CSF leaks were screened for the presence of idiopathic infratentorial symmetric SS of the CNS.

RESULTS

Twelve patients were included. The median latency between the onset of orthostatic headaches and symptoms attributed to SS was 9.5 years. After surgical closure of the underlying spinal CSF leak, symptoms attributed to SS improved in seven patients and remained stable in three. Patients who presented within 1 year after the onset of SS symptoms improved, but those who presented in 8-12 years did not improve. We could show a significant association between patients with spinal longitudinal extrathecal collections and SS.

CONCLUSIONS

Long-standing untreated ventral spinal CSF leaks can lead to SS of the CNS, and microsurgical sealing of spinal CSF leaks might stop progression and improve symptoms in patients with SS in a time-dependent manner.

Significance of upper cervical epidural venous engorgement on head computed tomography in the initial diagnosis of spontaneous intracranial hypotension: patient series

BACKGROUND

Spontaneous intracranial hypotension (SIH) is a rare condition characterized by positional headache, for which contrast-enhanced magnetic resonance imaging (MRI) is the preferred diagnostic method. Although MRI reveals characteristic findings, head computed tomography (CT) is usually the first diagnostic step, but identifying features of SIH on CT is often difficult. This study was specifically designed to evaluate the utility of head CT in detecting upper cervical epidural venous engorgement as a sign of SIH.

OBSERVATIONS

Of 24 patients with SIH diagnosed between March 2011 and May 2023, 10 did not undergo upper cervical CT. In the remaining 14 patients, engorgement of the upper cervical epidural venous plexus was observed. CT detection rates were consistent with MRI for spinal fluid accumulation or dural thickening. After treatment, in 92.9% of patients, the thickness of the epidural venous plexus decreased statistically significantly from 4.8 ± 1.3 mm to 3.6 ± 1.2 mm.

LESSONS

This study suggests that upper cervical spine CT focused on epidural venous engorgement may be helpful in the initial diagnosis of SIH and may complement conventional MRI evaluation. Extending CT imaging to the upper cervical spine will improve the diagnostic accuracy of patients with positional headaches suspected to be SIH.

Headache associated with intracranial hypotension: diagnostic challenges and difficulties in everyday neurological practice

Low pressure of cerebrospinal fluid (CSF) is a rare cause of headache, except when the patient undergoes a lumbar puncture. Headache associated with a low CSF pressure i.e. intracranial hypotension causes diagnostic difficulties. Headaches related to spontaneous intracranial hypotension (SIH) pose a significant diagnostic challenge in everyday neurological practice. Patients with headaches due to SIH are usually diagnosed only after a long delay. Diagnostic problems may result in unnecessary invasive diagnostic procedures, or even neurosurgical operations. Diagnosing headaches attributed to SIH requires the consideration of several clinical scenarios, and the disease's features causing primary or secondary disturbances. In this review, we discuss the differential diagnosis of SIH-related headaches with reference to accumulated knowledge, including meta-analyses, guidelines, casuistry, and the applicable criteria of the International Classification of Headache Disorders. In addition, we discuss head and spine magnetic resonance imaging abnormalities, which may indicate intracranial hypotension.

Spontaneous Intracranial Hypotension and Subdural Hematomas Treatment Management Using MMA Embolization and Target Blood Patch: A Case Report

We report a patient suffering from spontaneous intracranial hypotension (SIH) who, following a non-selective lumbar blood patch, returned to his healthcare provider with severe symptoms of neurological deficits. It was subsequently discovered that the aforementioned deficits were due to a bilateral subdural hematoma, and an emergency surgical drainage of the hematoma has been performed. However, the hematoma reformed and potential cerebrospinal fluid leakage was consequently investigated through myelography. Following the diagnostic finding of a venous diverticulum, a selective blood patch was executed in the affected area, and in order to stabilize the hematoma, an embolization of the middle meningeal arteries was performed. The combination of such operations allowed for the resorption of the hematoma and the improvement of neurological symptoms.

Acquired tonsillar herniation related to spontaneous intracranial hypotension: case reports

Background

Acquired prolapse of the cerebellar tonsils in spontaneous intracranial hypotension (SIH) patients is rare. This study aims to evaluate neuroimaging changes of acquired prolapse of the cerebellar tonsils below the foramen magnum in SIH patients due to spontaneous spinal cerebrospinal fluid leakage, which was treated by targeted epidural blood patches (EBP).

Methods

We retrospectively reviewed clinical and neuroimaging characteristics of 5 cases of SIH with acquired prolapse of the cerebellar tonsils that received targeted EBP in our institution from January 2013 to December 2016.

Results

Of these SIH patients, all of them suffered from an orthostatic headache. Initial cranial MRI demonstrated descent of the cerebellar tonsils ≥5 mm. Intrathecal gadolinium-enhanced spinal MR myelography and/or spinal MR hydrography were performed to evaluate the level of spinal cerebrospinal fluid leakage. Symptoms were alleviated in all 5 patients after two (n = 4), or three (n = 1) targeted EBP during hospitalization. Follow-up cranial MRI revealed that the descent of cerebellar tonsils was reversed after EBP treatment.

Conclusion

Acquired tonsillar herniation can occur in patients with SIH and spinal cerebrospinal fluid leakage. Symptoms of these patients may be resolved and radiologic findings may be reversed after EBP treatment.

Management of Labor and Anesthesia in a Patient With a History of Spontaneous Intracranial Hypotension: A Case Report With Literature Review

Spontaneous intracranial hypotension (SIH) is a rare disorder characterized by continuous or intermittent cerebrospinal fluid (CSF) leakage from the CSF cavity, which causes symptoms such as headache or neck pain upon standing. However, no well-established measures concerning the type of delivery and anesthesia for pregnant women with a history of SIH have been reported. A woman had developed SIH 9 years earlier from lifting luggage into an overhead bin with stretching movements, which required continuous saline epidural infusion for recovery. Upon the patient's pregnancy at the age of 35 years, although an elective cesarean section (CS) under general anesthesia was planned to avoid SIH recurrence, the patient had an emergency CS at 36 weeks. Since there is no prescribed method of delivery and anesthetic management for patients with a history of SIH, it is important to plan and adapt a treatment strategy based on the patient's wishes and the institution's protocols. As a sidenote, we reviewed the available literature regarding the type of delivery and anesthesia for pregnant women with a history of SIH.

Spontaneous Intracranial Hypotension: A Review of Neuroimaging and Current Concepts

Spontaneous intracranial hypotension (SICH) is the emerging cause of orthostatic headache as it has been better recognized in recent years. SICH happens due to spinal cerebrospinal fluid (CSF) leak; however, the manifestations are predominantly cranial and hence imaging in SICH includes brain and spine. There are few characteristic brain imaging features to be concerned about to diagnose SICH in patients with vague symptoms or low clinical suspicion. Spine screening is recommended in these patients to assess spinal CSF leaks. While neuroradiologists play a significant role from the time of diagnosis to treatment of SICH, there is a need for all the general radiologists to be aware of the condition. Computed tomography myelogram and digital subtraction myelogram are performed for diagnostic and therapeutic management of SICH. There is a known risk for SICH recurrence in patients with sagittal longitudinal epidural collection and hence, targeted blood patch should be used instead of blind patch. Most importantly, slow mobilization is recommended following the patch to avoid recurrence.

[Spinal Presentation of Spontaneous Intracranial Hypotension]

Spontaneous intracranial hypotension (SIH), which generally presents as orthostatic headache, is increasingly being identified due to improved imaging technologies and heightened awareness. Many prior studies have reported the characteristic brain MRI findings of SIH. However, recently, focus has shifted to spinal MRI, as SIH is believed to be caused by leakage of cerebrospinal fluid from the spinal dural sac. Advanced techniques such as ultrafast CT myelography and digital subtraction myelography have emerged as useful technique to identify the site of cerebrospinal fluid leakage. In this review, we discuss the diagnosis, spinal MRI findings, imaging techniques, and treatment of SIH.

Distinct Pattern of Membrane Formation With Spinal Cerebrospinal Fluid Leaks in Spontaneous Intracranial Hypotension

BACKGROUND AND OBJECTIVES

To systematically describe pertinent, intraoperative anatomic findings encountered when approaching spinal cerebrospinal fluid (CSF) leaks and CSF-venous fistulas in spontaneous intracranial hypotension (SIH).

METHODS

In a retrospective study, we included surgically treated patients suffering from SIH at our institution from April 2018 to March 2022. Anatomic, intraoperative data were extracted from operative notes and supplemented with data from surgical videos and images. Prominent anatomic features were compared among different types of CSF leaks.

RESULTS

The study cohort consists of 120 patients with a mean age of 45.2 years. We found four distinct patterns of spinal membranes specifically associated with different types of CSF leaks: (i) thick, dorsal membranes, which were hypervascular and may mimic the dura (pseudodura); (ii) thin, lateral membranes encapsulating a ventral epidural CSF compartment (confining the spinal longitudinal extradural CSF collection); (iii) ventral membranes constituting a transdural funnel-like CSF channel; and (iv) lateral membranes forming spinal cysts/meningeal diverticulae associated with lateral CSF leaks. The latter three types resemble a layer of arachnoid herniated through the dural defect.

CONCLUSION

We describe four distinct spinal (neo-)membranes in association with spinal CSF leaks. Formation of these membranes, or emergence by herniation of arachnoid through a dural defect, constitutes a specific pathoanatomic feature of patients with SIH and CSF leaks. Recognition of these membranes is of paramount importance for diagnosis and treatment of patients with spinal CSF leaks.

Patient-reported symptomatology and its course in spontaneous intracranial hypotension - Beware of a chameleon

OBJECTIVE

Although orthostatic headache is the hallmark symptom of spontaneous intracranial hypotension (SIH), patients can present with a wide range of different complaints and thereby pose a diagnostic challenge for clinicians. Our aim was to describe and group the different symptoms associated with SIH and their course over time.

METHODS

We retrospectively surveyed consecutive patients diagnosed and treated for SIH at our institution from January 2013 to May 2020 with a specifically designed questionnaire to find out about their symptomatology and its course.

RESULTS

Of 112 eligible patients, 79 (70.5%) returned the questionnaire and were included in the analysis. Of those, 67 (84.8%) reported initial orthostatic headaches, whereas 12 (15.2%) denied having this initial symptom. All except one (98.7%) patients reported additional symptoms: most frequently cephalic pressure (69.6%), neck pain (68.4%), auditory disturbances (59.5%), nausea (57%), visual disturbances (40.5%), gait disturbance (20.3%), confusion (10.1%) or sensorimotor deficits (21.5%). Fifty-seven (72.2%) patients reported a development of the initial symptoms predominantly in the first three months after symptom onset. Age and sex were not associated with the symptomatology or its course (p > 0.1).

CONCLUSION

Although characteristic of SIH, a relevant amount of patients present without orthostatic headaches. In addition, SIH can manifest with non-orthostatic headaches at disease onset or during the course of the disease. Most patients report a wide range of associated complaints. A high degree of suspicion is crucial for an early diagnosis and targeted treatment.

Evaluation and management of orthostatic headache in hypermobility disorders

Headache is a frequent symptom among patients with hypermobility spectrum disorders. This mini review focuses specifically on a challenging aspect of headache evaluation in all patients, but especially those with hypermobility - the orthostatic headache. While the differential for an orthostatic headache is overall limited, patients with hypermobility disorders have risk factors for all of the most commonly encountered orthostatic headache disorders. The most common conditions to produce orthostatic headaches are discussed - spontaneous intracranial hypotension, cervicogenic headache, and postural orthostatic tachycardia syndrome. Less common etiologies of orthostatic headache pertinent to any patient are presented in table format.

Prevalence of SLEC-negative spontaneous intracranial hypotension in patients with spinal nerve root sleeve diverticula on MRI

PURPOSE

While there is thought to be an association between spinal nerve root diverticula (NRD) and spontaneous intracranial hypotension (SIH) without a spinal longitudinal epidural collection (SLEC), it remains unclear what the overall prevalence of SLEC-negative SIH is in patients with NRD on MRI.

METHODS

Spine MRI imaging reports from our single institution were electronically screened for instances of NRD over a 9-year period (2016-2023). From these cases, patients with brain MRIs consistent with SIH were also identified. Subsequently, the overall proportion of SLEC-negative SIH was determined as a function of total cases with NRD based on spinal level.

RESULTS

In total, 83,843 patients with spinal MRIs were screened which identified 4174 (4.97%) with NRD. From these, there were 1203 cervical, 622 thoracic, and 2979 lumbosacral spine MRIs. In total, 16 patients (0.38%; Standard Error [SE]: 0.48%-0.28%) had a brain MRI compatible with SLEC-negative SIH and met ICHD-3 criteria. Patients with cervical NRD had SIH in 2 cases (0.16%; SE: 0.27%-0.05%). SLEC-negative SIH was present in 11 patients with lumbosacral NRD (0.34%; SE: 0.44%-0.24%). In patients with diverticula in the thoracic spine, 14 (2.3%; SE: 2.8%-1.8%) had SLEC-negative SIH. SLEC-negative SIH was significantly more prevalent in patients with thoracic diverticula compared to those with cervical (p<.0001) or lumbosacral NRD (p<.0001).

CONCLUSION

In patients with spinal NRD, concurrent SLEC-negative SIH is present in approximately 0.38% of patients, suggesting that in the vast majority of cases, they are an incidental finding. However, SIH is present in approximately 2.3% of patients with thoracic NRD and may be more specific for leak localization.

An Uncommon Case of Multiple, Recurrent Cerebrospinal Fluid Venous Fistulas

We present a clinical case to discuss the use of computed tomography (CT) spine myelograms alongside a complete history to diagnose multiple cerebrospinal fluid (CSF) venous fistulas (CVFs). The goal of this study is to familiarize clinicians with this challenging diagnosis and the utility of these studies in localizing leaks. A 63-year-old male patient with a history of cervical spinal stenosis, intermittent double vision, and sinus pressure managed with intermittent steroids presented to the clinic. He provided a detailed timeline of his previous symptoms and previous workups leading to the suspicion of intracranial hypotension due to CSF leak vs. CVF. Our workup, including magnetic resonance imaging (MRI) of the cervical spine and lumbar puncture (LP), was conducted. A CT thoracic spine myelogram was completed to localize the fistula site which was followed by the embolization of the fistula. The patient revealed complete resolution of his symptoms confirmed by imaging done one week postoperatively. This was a difficult case complicated by chronic misdiagnosis and confounding factors. CVFs were first described less than a decade ago; however, they are an extremely important cause of spontaneous intracranial hypotension. CVFs can be challenging to detect on conventional anatomical imaging like MRI. Thus, CT myelogram studies and a thorough history are crucial for accurate diagnosis. It is essential that clinicians, including ophthalmologists, learn to recognize CVFs as a potential cause of intracranial hypotension and become familiar with this diagnosis and its workup in the hopes that, unlike this case, the diagnosis and resolution of patients' life-altering symptoms are not delayed.

Cerebral venous thrombosis caused by spontaneous intracranial hypotension due to spontaneous spinal cerebrospinal fluid leakage in the high cervical region: a case report

Spontaneous intracranial hypotension (SIH) may lead to cerebral venous thrombosis (CVT). This case report describes the diagnostic and treatment processes used for a patient with CVT caused by SIH due to spontaneous spinal cerebrospinal fluid (CSF) leakage in the high cervical region. Clinical data were collected from a 37-year-old man with an initial symptom of spontaneous posterior cervical pain. The diagnostic and treatment processes of SIH-induced CVT were described. A magnetic resonance imaging (MRI) study showed superior sagittal sinus thrombosis, and a lumbar puncture revealed a low initial CSF pressure of less than 60 mmH2O. The patient underwent anticoagulation and fluid rehydration therapies. No abnormalities were observed in the thoracic MRI scan, but a cervical MRI scan revealed a spontaneous CSF leak. An epidural blood patch with autologous blood was performed, and symptoms completely resolved 3 days after the procedure. This report proposes a diagnostic procedure for detecting rare cases of SIH-induced CVT, thereby preventing future misdiagnoses and delayed treatment. When a patient presenting with CVT in conjunction with intracranial hypotension has no history of trauma or piercing, SIH caused by spontaneous spinal CSF leakage should be considered as a potential cause of secondary low intracranial pressure. For detection of CSF leaks at rare sites, an MRI of the whole spine rather than a localized MRI of the spine needs to be performed to avoid misdiagnosis. An epidural blood patch should be performed as soon as possible as it may shorten the length of hospitalization and improve prognosis.

Incremental diagnostic yield and clinical outcomes of lateral decubitus CT myelogram immediately following negative lateral decubitus digital subtraction myelogram

INTRODUCTION

Spontaneous intracranial hypotension (SIH) caused by a spinal cerebrospinal fluid (CSF) leak classically presents with orthostatic headache. Digital subtraction myelography (DSM) has a well-established diagnostic yield in the absence of extradural spinal collection. At our institution, DSM is followed by lateral decubitus CT myelogram (LDCTM) in the same decubitus position to increase diagnostic yield of the combined study. We evaluated the incremental diagnostic yield of LDCTM following negative DSM and reviewed patient outcomes.

METHODS

Retrospective review of consecutive DSMs with subsequent LDCTM from April 2019 to March 2021 was performed. Combined reports were reviewed, and studies with positive DSMs were excluded. Of the exams with negative DSM, only studies with LDCTM reports identifying potential leak site were included. Interventions and follow-up clinical notes were reviewed to assess symptoms improvement following treatment.

RESULTS

Of the 83 patients with negative DSMs, 11 (13.2%) had positive leak findings on LDCTMs, and 21 (25.3%) were equivocal. Of 11 positive LDCTMs, 6 leaks were nerve sheath tears (NSTs) and 5 were CSF-venous fistulas (CVFs). 10/11 (90.9%) had intervention and follow-up, with 9/10 (90%) having positive clinical outcome. Of the 21 equivocal LDCTM patients (19 CVFs and 2 NSTs), 15 (71.4%) had interventions and follow-up, with 3/15 (20.0%) with positive clinical outcomes.

CONCLUSION

LDCTM following negative DSM has an incremental diagnostic yield up to 38.6%, with up to 14.5% of positive patient outcomes following treatment. LDCTM should be considered after DSM to maximize diagnostic yield of the combined exam.

Spontaneous Intracranial Hypotension Occurring after Craniotomy for Brain Tumor Biopsy Mimicking Postoperative Bleeding

In this study, we report on a previously healthy 44-year-old man who underwent an open biopsy under general anesthesia for a tumorous lesion found in his left frontal lobe via a small supratentorial craniotomy. While both postoperative course and brain computed tomography (CT) scans had been considered unremarkable, the patient became stuporous on postoperative day (POD) 4. A brain CT obtained on that day showed a subdural hematoma with marked brain shift which we thought might have been due to postoperative bleeding; he was immediately brought to an operating theater for hematoma removal. However, no bleeding source was found, and the brain remained depressed after hematoma evacuation. Furthermore, the brain shift remained unchanged on postoperative CT. While spontaneous intracranial hypotension (SIH) was considered, imaging studies to search for possible cerebrospinal fluid (CSF) leakage in the spinal column were not performed as the patient's condition has improved. However, he became stuporous again on POD 8, which urged us to perform CT myelogram. The CT myelogram showed a massive CSF leakage at the L1-L2 level. Subsequent autologous blood patch has successfully terminated the CSF leakage, and he became fully oriented shortly after the blood patch therapy. Thus, it should be noted that SIH may occur during postoperative period of intracranial surgery, and it may manifest radiographically as a subdural hematoma indistinguishable from postoperative bleeding. SIH should also be included in a differential diagnosis of postoperative headache, regardless of its characteristics, because headache associated with SIH may not always be orthostatic.

Spontaneous Intracranial Hypotension: An Uncommon Cause of Postural Vestibulocochlear Symptoms

Spontaneous intracranial hypotension is an uncommon but increasingly recognized condition characterized by an orthostatic headache secondary to low cerebrospinal fluid pressure. Vestibulocochlear symptoms are common but rarely the only presenting feature and can be challenging to differentiate from Meniere's disease. We present a case series that highlights the common vestibulocochlear symptoms and a review of the literature to increase awareness amongst otolaryngologists and highlight the path to diagnosis and management of this condition.

Caffeine for Headaches: Helpful or Harmful? A Brief Review of the Literature

Consumption of caffeine in the diet, both daily and occasional, has a significant biological effect on the nervous system. Caffeine, through various and not yet fully investigated mechanisms, affects headaches. This is especially noticeable in migraine. In other headaches such as hypnic headache, post-dural puncture headache and spontaneous intracranial hypotension, caffeine is an important therapeutic agent. In turn, abrupt discontinuation of chronically used caffeine can cause caffeine-withdrawal headache. Caffeine can both relieve and trigger headaches.

Cerebellar Tonsillar Descent Mimicking Chiari Malformation

Chiari I malformation has been defined as cerebellar tonsillar descent greater than 5 mm below the foramen magnum. Suboccipital decompression remains the mainstay of treatment for symptomatic patients. Other conditions sometimes have imaging features that mimic Chiari I malformation. These patients are at risk of misdiagnosis and mismanagement, including surgery that may be unnecessary or may even worsen the underlying condition. The aim of this study was to analyse a series of Chiari I malformation mimics and identify differentiating imaging features. The mimics are categorised as post-traumatic cranio-cervical junction arachnoiditis, dural band, spontaneous intracranial hypotension, idiopathic intracranial hypertension, and cysts. Better understanding of these conditions will assist with diagnosis and optimal management, including avoiding unnecessary surgery.

68Ga-DOTA PET for Diagnosis of Spinal Cerebrospinal Fluid Leaks

Spontaneous intracranial hypotension due to spinal cerebrospinal fluid (CSF) leakage causes substantial disease burden. In many patients, the course is protracted and refractory to conservative treatment, requiring targeted therapy. We propose PET of the CSF space with ⁶⁸Ga-DOTA as a state-of-the-art approach to radionuclide cisternography (RC) and validate its diagnostic value. Methods: This study is a retrospective analysis of patients with suspected intracranial hypotension due to spinal CSF leaks and who underwent whole-body PET/CT at 1, 3, and 5 h after intrathecal lumbar injection of ⁶⁸Ga-DOTA. Two independent raters unaware of the clinical data analyzed all scans for direct and indirect RC signs of CSF leakage. Volume-of-interest analysis was performed to assess the biologic half-life of the tracer in the CSF space and the ratio of decay-corrected activity in the CSF space at 5 and 3 h (simplified marker of tracer clearance). Comprehensive stepwise neuroradiologic work-up served as a reference; additional validation was provided by surgical findings and follow-up. Results: Of 40 consecutive patients, 39 patients with a working diagnosis of intracranial hypotension due to a spinal CSF leak (spontaneous, n = 31; postintervention, n = 8) could be analyzed. A spinal CSF leak was verified by the neuroradiologic reference method in 18 of 39 patients. As the only direct and indirect diagnostic signs, extrathecal tracer accumulation at the cervicothoracic junction (67% sensitivity and 90% specificity) and lack of activity over the cerebral convexities (5 h; 94% sensitivity and 67% specificity) revealed a high diagnostic value for spinal CSF leaks. Their combination provided little improvement (71% sensitivity and 95% specificity). Additional quantitative analyses yielded no benefit (94% sensitivity and 53% specificity for biological half-life; 94% sensitivity and 58% specificity for the ratio of total radioactivity within the CSF space at 5 and 3 h). The location of direct signs (extrathecal tracer accumulation) did not correlate with verified sites of spinal CSF leakage. Conclusion: We propose CSF PET with ⁶⁸Ga-DOTA as a novel, fast, and convenient approach to RC for verification but not localization of spinal CSF leaks with high sensitivity and specificity. CSF PET may fulfill an important gatekeeper function for stratifying patients toward escalation (ruling in) or deescalation (ruling out) of diagnostic and therapeutic measures. Further prospective studies are needed to validate the present results and determine the potential of the methods to reduce the burden to patients.

Discovering spontaneous intracranial hypotension after failed middle meningeal artery embolization for subdural hematomas: illustrative cases

BACKGROUND

Spontaneous intracranial hypotension (SIH) is a relatively rare and underdiagnosed disease. SIH can lead to subdural hematomas (SDHs) and other complications. SDHs secondary to SIH are difficult to manage, with no consensus in management, and SDHs commonly recur if underlying SIH is not treated.

OBSERVATIONS

A 46-year-old male with vague sensory and orientation symptoms presented with bilateral SDHs, which were treated with middle meningeal artery (MMA) embolization and burr hole evacuation. The patient improved initially but had recurrent encephalopathy and SDHs. The patient received 3 epidural blood patches (EBPs) over 8 days with continued improvement. A 78-year-old female presented with headaches, and imaging revealed a left chronic SDH. She underwent MMA embolization and mini-craniotomy for SDH evacuation. Her symptoms returned and imaging revealed a recurrent SDH. Pan spine computed tomography myelography showed a high thoracic cerebrospinal fluid (CSF) leak. She underwent 3 EBPs over 8 days with neurological improvement and stabilization of her SDH.

LESSONS

The authors show that, if SDH recurs after initial treatment with MMA embolization, then SIH should be strongly considered and treated with EBPs. Further investigation is required to determine the role of targeted or blind EBPs and the use of imaging to find the source of occult CSF leaks causing SIH.

Arteriovenous Malformations: An Update on Models and Therapeutic Targets

Arteriovenous malformations (AVMs) are an anomaly of the vascular system where feeding arteries are directly connected to the venous drainage network. While AVMs can arise anywhere in the body and have been described in most tissues, brain AVMs are of significant concern because of the risk of hemorrhage which carries significant morbidity and mortality. The prevalence of AVM's and the mechanisms underlying their formation are not well understood. For this reason, patients who undergo treatment for symptomatic AVM's remain at increased risk of subsequent bleeds and adverse outcomes. The cerebrovascular network is delicate and novel animal models continue to provide insight into its dynamics in the context of AVM's. As the molecular players in the formation of familial and sporadic AVM's are better understood, novel therapeutic approaches have been developed to mitigate their associated risks. Here we discuss the current literature surrounding AVM's including the development of models and therapeutic targets which are currently being investigated.

Spontaneous intracranial hypotension complicated by unilateral subdural hematoma, coma, and the rare Kernohan's notch phenomenon

Spontaneous intracranial hypotension (SIH) is a highly underdiagnosed condition with a wide range of manifestations. Although SIH has traditionally been viewed as having a benign disease course, recent evidence suggests otherwise. In this case report, we present a 71-year-old woman who was previously treated with a tapered dose of corticosteroids for an episode of SIH with behavioral manifestations. In this current report, we present her second episode which was complicated by a unilateral sub-acute subdural hematoma leading to loss of consciousness and coma. While the patient regained full consciousness and recovered considerably, she still suffers from ipsilateral hemiparesis as a result of Kernohan's notch phenomenon 2 years post-hospitalization. To the author's knowledge, this is the first case to involve persistent motor deficit after the resolution of SIH. We believe that surgical hematoma evacuation prior to addressing the cerebrospinal fluid leak may have contributed to aggregated downward displacement of the brain precipitating Kernohan's notch phenomenon.

Two Cases of Chronic Subdural Hematoma with Spontaneous Intracranial Hypotention Treated with Hematoma Drainage Followed by Epidural Blood Patch Under Intracranial Pressure Monitoring

Both chronic subdural hematoma (CSDH) and spontaneous intracranial hypotension (SIH) cause headaches. However, the etiologies are different: SIH headache is caused by decreased intracranial pressure (ICP), whereas CSDH headache results from increased ICP. Moreover, CSDH is treated by hematoma drainage, while SIH is treated by epidural blood patch (EBP). Treatment for the cases of combined SIH and CSDH is not well-established. Herein, we report two cases wherein ICP was monitored and safely controlled by EBP after hematoma drainage. Case 1: A 55-year-old man with progressive consciousness disturbance was diagnosed with bilateral CSDH. He underwent bilateral hematoma drainage; however, the headache became apparent during standing. We diagnosed SIH by diffuse pachymeningeal enhancement on brain MRI and epidural contrast medium leakage on CT myelography. Due to the re-enlargement of bilateral CSDH, we performed EBP after hematoma drainage and ICP monitor insertion. Finally, the headache and bilateral CSDH were resolved. Case 2: A 54-year-old man with persistent headache was diagnosed with bilateral CSDH. He underwent multiple hematoma drainage sessions. However, headache on standing persisted. We diagnosed SIH by diffuse pachymeningeal enhancement on brain MRI and epidural contrast medium leakage on CT myelography. Due to the re-enlargement of the left CSDH, we performed EBP after left hematoma drainage and ICP monitor insertion. Finally, the headache and bilateral CSDH were resolved. EBP after hematoma drainage and ICP monitoring was useful for SIH with bilateral CSDH. By monitoring ICP before EBP, the ICP was safely controlled and CSDH was resolved.

Cerebrospinal fluid biomarkers of superficial siderosis in patients with spontaneous intracranial hypotension

BACKGROUND AND PURPOSE

Spontaneous intracranial hypotension (SIH) is an important etiology of infratentorial superficial siderosis (iSS) of the central nervous system. However, the prevalence of iSS amongst patients with SIH is unknown and the imaging findings of iSS might represent a late stage of disease. The aim was to identify cerebrospinal fluid (CSF) biomarkers of iSS in patients with SIH.

METHODS

Consecutive patients evaluated for SIH at our institution between May 2017 and January 2019 were included. Lumbar CSF samples were analyzed for the presence of ferritin and bilirubin. Magnetic resonance imaging was assessed for the presence of iSS.

RESULTS

Twenty-four patients with SIH were included. 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 amongst patients demonstrating iSS compared to those without (median 45.0 vs. 11.0 μg/l; p = 0.003). Symptom duration was longer in patients with iSS than in patients without iSS (median 40 months vs. 9 months, p = 0.018).

CONCLUSION

Cerebrospinal fluid alterations indicative of iSS are prevalent amongst patients with SIH. It is speculated that a preclinical phase without symptoms or imaging signs but during which elevated biomarkers of the disease are apparent from CSF analysis might exist. It is suggested that measurement of CSF ferritin is incorporated in the work-up of patients with SIH to identify those at risk of developing iSS.

Spinal dural cerebrospinal fluid fistula as a cause of spontaneous intracranial hypotension syndrome: Diagnosis and surgical treatment

Spontaneous intracranial hypotension (SIH) syndrome most often occurs following a cerebrospinal fluid (CSF) fistula that develops in the spinal space. Neurologists and neurosurgeons lack an understanding of the pathophysiology and diagnosis of this disease, which can make timely surgical care difficult. With the correct diagnostic algorithm, it is possible to identify the exact location of the liquor fistula in 90% of cases; subsequent microsurgical treatment can save the patient from the symptoms of intracranial hypotension and restore the ability to work. Female patient, 57 years old, was admitted with SIH syndrome. Magnetic resonance imaging (MRI) of the brain with contrast confirmed signs of intracranial hypotension. Computed tomography (CT) myelography was performed to pinpoint the location of the CSF fistula. The diagnostic algorithm and successful microsurgical treatment of a patient with spinal dural CSF fistula at the Th3-4 level using a posterolateral transdural approach. The patient was discharged on day 3 after the surgery when these complaints regressed completely. At the control examination of the patient 4 months postoperatively, there were no complaints. Identification of the cause and location of spinal the CSF fistula is a complex process that requires several stages of diagnosis. Examination of the entire back with MRI, CT myelography, or subtraction dynamic myelography is recommended. Microsurgical repair of a spinal fistula is an effective method for the treatment of SIH. The posterolateral transdural approach is effective in the repair of a spinal CSF fistula located ventrally in the thoracic spine.

The reversible impairment of behavioral variant frontotemporal brain sagging syndrome: Challenges and opportunities

Introduction

Due to loss of brain buoyancy, spontaneous spinal cerebrospinal fluid (CSF) leaks cause orthostatic headaches but also can cause symptoms indistinguishable from behavioral variant frontotemporal dementia (bvFTD) due to severe brain sagging (including the frontal and temporal lobes), as visualized on brain magnetic resonance imaging. However, the detection of these CSF leaks may require specialized spinal imaging techniques, such as digital subtraction myelography (DSM).

Methods

We performed DSM in the lateral decubitus position under general anesthesia in 21 consecutive patients with frontotemporal dementia brain sagging syndrome (4 women and 17 men; mean age 56.2 years [range: 31-70 years]).

Results

Nine patients (42.8%) were found to have a CSF-venous fistula, a recently discovered type of CSF leak that cannot be detected on conventional spinal imaging. All nine patients underwent uneventful surgical ligation of the fistula. Complete or near-complete and sustained resolution of bvFTD symptoms was obtained by all nine patients, accompanied by reversal of brain sagging, but in only three (25.0%) of the twelve patients in whom no CSF-venous fistula could be detected (P = 0.0011), and who were treated with non-targeted therapies.

Discussion

Concerns about a spinal CSF leak should not be dismissed in patients with frontotemporal brain sagging syndrome, even when conventional spinal imaging is normal. However, even with this specialized imaging the source of the loss of spinal CSF remains elusive in more than half of patients.

Cavernous Sinus Swelling and Abducens Nerve Paresis Due to Intracranial Hypotension

The most common neurological symptom of spontaneous intracranial hypotension (SIH) is abducens nerve paresis, and the precise pathophysiology is unclear. The accepted explanation is traction on the cranial nerves caused by the downward displacement of the cranial content. We herein report magnetic resonance imaging of SIH that can explain the mechanism underlying abducens nerve paresis. The cavernous sinuses were particularly thickened compared with the surrounding dura. This phenomenon can be explained by venous swelling, which can occur after leakage of cerebrospinal fluid in a closed cavity. This swelling pushes the abducens nerve up, which then causes abducens nerve paresis.

Current perspectives on the recognition and diagnosis of low CSF pressure headache syndromes

INTRODUCTION

Headaches occur when cerebrospinal fluid (CSF) pressure drops following dural puncture or trauma or spontaneously. As the features of these headaches and their accompanying symptoms might not be typical, low CSF pressure headache syndromes, and spontaneous intracranial hypotension in particular, are often misdiagnosed and underdiagnosed.

AREAS COVERED

The aim of this narrative review is to summarize the most recent evidence regarding the clinical presentation and the diagnosis of low CSF pressure headache syndromes.

EXPERT OPINION

The clinical spectrum low CSF pressure headache syndromes varies significantly and key signs might be missing. Low CSF pressure headache syndromes should be included in the differential diagnosis of any case of refractory headache, even when the headache is not orthostatic, or there are normal neuroimaging findings, and/or lumbar puncture opening pressure is within normal limits. Future research should focus on controlled interventional studies on the treatment of low CSF pressure headache syndromes, which are currently lacking.

Linear indices of ventricular volume on brain computed tomography as markers of effectiveness of epidural blood patch for spontaneous intracranial hypotension: A case report

RATIONALE

Epidural blood patch (EBP) is an effective treatment for spontaneous intracranial hypotension (SIH). However, its effectiveness can only be judged through subjective symptom improvement; no objective markers have been reported. Linear indices of ventricular volume on brain computed tomography (CT) may aid the objective evaluation of the effectiveness of EBP in patients with SIH.

PATIENT CONCERNS

A 45-year-old man was hospitalized due to a 3-week history of orthostatic headache, dizziness, and neck pain. He had visited a local emergency department at symptom onset. His neurological examination results were normal and vital signs were stable.

DIAGNOSES

Brain magnetic resonance imaging (MRI) revealed pachymeningeal enhancement in both convexities with a small subdural hematoma (SDH). Based on the clinical features and MRI findings, he was diagnosed with SIH complicated by SDH.

INTERVENTIONS

Non-targeted EBP was performed, first at the lumbar level and subsequently at the thoracic level. Linear indices of ventricular volume, including the Evans' index, frontal-occipital horn ratio, and bicaudate index, were measured through brain CT performed before and after EBP.

OUTCOMES

After lumbar EBP, there was no symptom relief or increase in linear indices of ventricular volume on brain CT. In contrast, the patient's symptoms completely resolved and the linear indices of ventricular volume increased after thoracic EBP.

LESSONS

The effectiveness of EBP, which is currently evaluated solely based on changes in symptom severity, can be assessed using linear indices of ventricular volume.

A Single-Level Epidural Blood Patch for Multiple Cerebrospinal Fluid Leaks: How it Works

Spontaneous intracranial hypotension caused by cerebrospinal fluid (CSF) leak is a rarely encountered cause of persistent postural headaches in the absence of trauma or dural puncture. It presents with postural headache and is characterized by radiological findings of spinal CSF leak. The mainstay of management is an epidural patch with the patient's own blood (epidural blood patch [EBP]) and/or a fibrin glue product. We report here a case of spontaneous intracranial hemorrhage presenting with persistent headaches and bilateral subdural hematomas secondary to CSF leaks at multiple levels along the spinal cord, which was successfully managed with a single lumbar EBP.

Efficacy and safety of cervicothoracic epidural blood patch for patients with spontaneous intracranial hypotension

BACKGROUND

Epidural blood patch (EBP) is a generally effective treatment for spontaneous intracranial hypotension (SIH) caused by cerebrospinal fluid (CSF) leakage through the spinal dura mater. It is still unclear, however, whether application near the leakage site (targeted EBP) is more effective than distal application (untargeted EBP). Further, EBP targeted to high thoracic or cervical spine levels is infrequent due to greater technical requirements and potential complications. Here we examined the safety and efficacy of EBP applied to high thoracic or cervical spine levels.

METHODS

We retrospectively reviewed the clinical and outcome data of 13 patients receiving cervical or high thoracic EBP for SIH. All patients were referred by neurologists following poor response to conservative treatment and presented with persistent headache aggravated by orthostatic changes.

RESULTS

Neuroimaging confirmed CSF leakage, and targeted EBP resulted in immediate pain improvement. Repeated injections provided additional improvement for patients with recurrent headache. No serious adverse events were documented during follow-up.

CONCLUSION

Based on recent studies and our clinical experience, we conclude that EBP targeted to the high thoracic and cervical spine is safe and effective for early-stage SIH.

Minimally invasive surgery for spinal cerebrospinal fluid-venous fistula ligation: patient series

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.

Airplane flights triggering spontaneous intracranial hypotension: Observations from the Danish headache centre

Objective

Spontaneous intracranial hypotension (SIH) manifests as orthostatic headache, which can be confirmed by radiological signs of low intracranial pressure on magnetic resonance imaging of the brain. The most common mechanisms of SIH are ruptured meningeal diverticula, ventral dural tears and CSF‐venous fistulas. SIH is associated with connective tissue disorders, and cases of SIH onset after trivial trauma have been reported. As SIH is often underdiagnosed, the aim of this study is to identify possible new risk factors of SIH onset in a case series of SIH patients.

Materials and methods

We retrospectively reviewed the medical records of 36 patients diagnosed with SIH. We reviewed and identified potential factors that led to or presented at headache onset in SIH patients.

Results

We identified 4/36 (11%) patients that had a close temporal relationship between the onset of SIH symptoms and airplane travel. In all four patients, the clinical and imaging features confirmed the diagnosis of SIH.

Conclusion

This is the first report of a case series of four patients with SIH that could be related to airplane travel. Describing four cases (11%) is not proof but should alert us to a possible causal relationship, which calls for further research. We suggest that when taking medical history, thorough details about the patient's activities, such as headache onset, should be documented because of their importance in correctly diagnosing SIH, which is a debilitating, yet treatable, disease.

Cerebrospinal fluid leak in epidural venous malformations and blue rubber bleb nevus syndrome

OBJECTIVE

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

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

RESULTS

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.

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.

Surgical treatment of spontaneous intracranial hypotension syndrome secondary to the cervical cerebrospinal leak - a case report

Spontaneous Intracranial Hypotension (SIH) is formed as a result of the leakage of cerebrospinal fluid (CSF) into the extradural space. The most common symptom caused by SIH is headache associated with changes in body position. Imaging, especially magnetic resonance imaging (MRI) of the head and spine with contrast, is the most important examination method in the diagnosis of SIH. In the case of no improvement after symptomatic treatment, surgery is very effective, especially in the case of finding the site of CSF leakage within the spinal canal.

A CASE REPORT

We present a case of a 28-year-old patient with 2- month history of severe increasing headaches. The patient denied any head injuries, nasal CSF leakage or lumbar puncture in the past. The neurological examination showed no abnormalities. MRI of the head showed typical features of the intracranial hypotension syndrome. MRI of the cervical spine revealed potential sites for leakage of the cerebrospinal fluid at the C1-C2 level. The patient was qualified for surgical treatment - dural plastic surgery in the cervical section. After treatment the symptoms of intracranial hypotension resolved, and subsequent control MRI examinations showed regression of typical changes of the spontaneous intracranial hypotension.

CONCLUSIONS

The authors would like to take notice that imaging diagnostics due to headaches should include MRI of the head and spine, as it is the most important test in diagnosing SIH. Moreover, surgical treatment is a quick and very effective method of treatment.

Intracranial hypotension as a contributor to isolated cortical vein thrombosis

BACKGROUND

Isolated cortical vein thrombosis (ICVT), a rare type of cerebral venous thrombosis (CVT), is diagnostically challenging in some cases, and intracranial hypotension (IH) is known to cause CVT.

METHODS

In this study, we reviewed the clinical and imaging characteristics of ICVT in patients with IH caused by spinal cerebrospinal fluid leakage, based on a literature review and investigation of cases from our hospital.

RESULTS

Between January 1, 2007, and November 1, 2019, 735 patients were diagnosed with IH at our hospital; three patients developed ICVT (incidence ~ 0.4%, 3/735), and the literature review yielded an additional 23 cases. Therefore, 26 patients (mean age 35.9 ± 11.4 years old) were included in this study. The most common symptoms were headache (100.0%, 26/26), focal neurological deficits (53.8%, 14/26), and seizure (34.6%, 9/26). The initial headache was orthostatic in 96.2% (25/26) of patients, and 38.5% (10/26) of patients reported a change in the headache pattern following diagnosis of ICVT. Neuroimaging findings associated with ICVT included the cord sign (61.5%, 16/26) and parenchymal brain lesions (46.2%, 12/26), such as intracerebral hemorrhage (30.8%, 8/26), hemorrhagic infarcts (11.5%, 3/26), and localized edema (11.5%, 3/26). The percentage of patients who received anticoagulation and epidural blood patch therapy was similar (69.2% [18/26] vs. 65.4% [17/26]), and most patients recovered completely (92.3%, 24/26).

CONCLUSION

IH should be considered in the differential diagnosis in patients with ICVT. Knowledge of the relevant clinical and neuroimaging features is important to facilitate early diagnosis for favorable prognosis.

[Spinal CSF-venous fistula: case report and literature review]

Syndrome of spontaneous intracranial hypotension is increasingly described in the literature as a multifactorial disease with impairment of the quality of life and risk of mortality. CSF-venous fistula as a cause of intracranial hypotension syndrome is extremely rare and requires complex diagnosis and timely surgical treatment.

OBJECTIVE

We present a 55-year-old patient with acute spontaneous intracranial hypotension and spinal CSF-venous fistula. Literature data are also analyzed.

RESULTS

Algorithm for diagnosis and efficacy of microsurgical resection of CSF-venous fistula is demonstrated.

CONCLUSION

Intracranial hypotension following spinal fistula requires careful examination. Accurate understanding of pathophysiological and anatomical features of this disease is necessary to select an effective treatment method.

Targeted Epidural Blood Patch Treatment for Refractory Spontaneous Intracranial Hypotension: A Case Report

Purpose of Review  Spontaneous intracranial hypotension (SIH) is recognized far more commonly than before, and it is well known that SIH is sometimes complicated by chronic subdural hematoma (SDH). We reported a patient who was treated with epidural blood patch (EBP) five times for refractory SIH and SDH surgery.

Recent Findings  We experienced that targeted EBP was useful in refractory SIH, and also can be performed safely prior to drainage of the hematoma.

Summary  We report the case of SIH patient with a bilateral SDH who came to our hospital and was discharged 2 weeks later with no neurologic deficit after trephination and five times EBP treatment. It shows that targeted EBP was useful in refractory SIH, and also can be performed safely prior to drainage of the hematoma.

Incidence of Spinal CSF Leakage on CT Myelography in Patients with Nontraumatic Intracranial Subdural Hematoma

The aim of the present study was to demonstrate the incidence of spinal cerebrospinal fluid (CSF) leaks in patients with nontraumatic intracranial subdural hematoma (SDH) and determine clinical parameters favoring such leaks. This retrospective study was approved by the institutional review board. Patients diagnosed with nontraumatic intracranial SDH who underwent computed tomography (CT) myelography between January 2012 and March 2018 were selected. 60 patients (male: female, 39:21; age range, 20–82 years) were enrolled and divided into CSF leak-positive and CSF leak-negative groups according to CT myelography data. Clinical findings were statistically compared between the two groups. Spinal CSF leak was observed in 80% (48/60) of patients, and it was significantly associated with an age of <69 years (p = 0.006). However, patients aged ≥69 years also had a tendency to exhibit spontaneous intracranial hypotension (SIH)-induced nontraumatic intracranial SDH (60.87%; 14/23). Therefore, CT myelography is recommended to be performed for the evaluation of possible SIH in patients with nontraumatic intracranial SDH, particularly those aged <69 years. Patients aged ≥69 years are also good candidates for CT myelography because SIH tends to occur even in this age group.

Spontaneous Intracranial Hypotension Without CSF Leakage-Concept of a Pathological Cranial to Spinal Fluid Shift

Objective: Spontaneous intracranial hypotension (SIH) is typically caused by CSF leakage from a spinal dural tear, a meningeal diverticulum, or a CSF venous fistula. However, some patients present with classic orthostatic symptoms and typical intracranial imaging findings without evidence of CSF leakage despite repeated diagnostic work-up. This article aims to elaborate a hypothesis that would explain a pathologically increased orthostatic shift of CSF from the cranial to the spinal compartment in the absence of a CSF leak.

Medical Hypothesis: The symptoms of SIH are caused by a decrease in intracranial CSF volume, intracranial hypotension, and downward displacement of intracranial structures. A combination of pathologically increased spinal compliance, decreased intracranial CSF volume, low CSF outflow resistance, and decreased venous pressure might result in a pathological orthostatic cranial-to-spinal CSF shift. Thus, in rare cases, intracranial hypotension may occur in the absence of CSF leakage from the dural sac.

Conclusion: We propose a pathophysiological concept for the subgroup of SIH patients with typical cranial imaging findings and no evidence of CSF leakage. In these patients, reducing the compliance or the volume of the spinal compartment seems to be the appropriate therapeutic strategy.

Differentiation of Chiari malformation type 1 and spontaneous intracranial hypotension using objective measurements of midbrain sagging

OBJECTIVE

Chiari malformation type 1 (CM-1) and spontaneous intracranial hypotension (SIH) are causes of headache in which cerebellar tonsillar ectopia (TE) may be present. An accurate method for differentiating these conditions on imaging is needed to avoid diagnostic confusion. Here, the authors sought to determine whether objective measurements of midbrain morphology could distinguish CM-1 from SIH on brain MRI.

METHODS

This is a retrospective case-control series comparing neuroimaging in consecutive adult subjects with CM-1 and SIH. Measurements obtained from brain MRI included previously reported measures of brain sagging: TE, slope of the third ventricular floor (3VF), pontomesencephalic angle (PMA), mamillopontine distance, lateral ventricular angle, internal cerebral vein-vein of Galen angle, and displacement of iter (DOI). Clivus length (CL), an indicator of posterior fossa size, was also measured. Measurements for the CM-1 group were compared to those for the entire SIH population (SIHall) as well as a subgroup of SIH patients with > 5 mm of TE (SIHTE subgroup).

RESULTS

Highly significant differences were observed between SIHall and CM-1 groups in the following measures: TE (mean ± standard deviation, 3.1 ± 5.7 vs 9.3 ± 3.5 mm), 3VF (-16.8° ± 11.2° vs -2.1° ± 4.6°), PMA (44.8° ± 13.1° vs 62.7° ± 9.8°), DOI (0.2 ± 4.1 vs 3.8 ± 1.6 mm), and CL (38.3 ± 4.5 vs 44.0 ± 3.3 mm; all p < 0.0001). Eight (16%) of 50 SIH subjects had TE > 5 mm; in this subgroup (SIHTE), a cutoff value of < -15° for 3VF and < 45° for PMA perfectly discriminated SIH from CM-1 (sensitivity and specificity = 1.0). DOI showed perfect specificity (1.0) in detecting SIH among both groups. No subjects with SIH had isolated TE without other concurrent findings of midbrain sagging.

CONCLUSIONS

Measures of midbrain sagging, including cutoff values for 3VF and PMA, discriminate CM-1 from SIH and may help to prevent misdiagnosis and unnecessary surgery.