Infratentorial Superficial Siderosis and Spontaneous Intracranial Hypotension.

OBJECTIVE: Spontaneous spinal cerebrospinal fluid (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: A total of 1,589 patients with SIH underwent neuroimaging and iSS was detected in 57 (23 men and 34 women, mean age = 41.3 years [3.6%]). We examined the type of underlying CSF leak by various imaging modalities. Percutaneous and surgical procedures were used to treat the CSF leaks. RESULTS: The 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. INTERPRETATION: The 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. ANN NEUROL 2023;93:64-75.

Incidence of spontaneous intracranial hypotension in a community: Beverly Hills, California, 2006-2020.

BACKGROUND: Spontaneous intracranial hypotension is diagnosed with an increasing frequency, but epidemiologic data are scarce. The aim of this study was to determine the incidence rate of spontaneous intracranial hypotension in a defined population. METHODS: Using a prospectively maintained registry, all patients with spontaneous intracranial hypotension residing in Beverly Hills, California, evaluated at our Medical Center between 2006 and 2020 were identified in this population-based incidence study. Our Medical Center is a quaternary referral center for spontaneous intracranial hypotension and is located within 1.5 miles from downtown Beverly Hills. RESULTS: A total of 19 patients with spontaneous intracranial hypotension were identified. There were 12 women and seven men with a mean age of 54.5 years (range, 28 to 88 years). The average annual incidence rate for all ages was 3.7 per 100,000 population (95% confidence interval [CI]: 2.0 to 5.3), 4.3 per 100,000 for women (95% CI, 1.9 to 6.7) and 2.9 per 100,000 population for men (95% CI, 0.8 to 5.1). CONCLUSION: This study, for the first time, provides incidence rates for spontaneous intracranial hypotension in a defined population.

Multiple Spinal CSF Leaks in Spontaneous Intracranial Hypotension: Do They Exist?

OBJECTIVE: To determine the frequency of multiple spinal CSF leaks in a recent group of patients with spontaneous intracranial hypotension (SIH) who were investigated with digital subtraction myelography (DSM). METHODS: This observational study was conducted using data from a prospectively maintained data base of patients who meet the International Classification of Headache Disorders, third edition, criteria for SIH. The patient population consisted of a consecutive group of 745 patients with SIH who underwent DSM between March 2009 and February 2020. Based on the results of DSM, participants were classified according to the type and number of spinal CSF leaks. RESULTS: Among 398 patients with SIH and extradural CSF on spinal imaging, multiplicity of CSF leaks was observed in none of 291 patients with type 1a ventral leaks and in 4 (6.2%) of 65 patients with type 1b (postero-) lateral leaks. Among 97 patients with SIH from spinal CSF-venous fistulas (type 3 leaks) who did not have extradural CSF on spinal imaging, 9 patients (9.3%) had multiple fistulas (p < 0.0001 for comparison between groups). Type 3 and type 1a or 1b CSF leaks coexisted in an additional 5 patients. CONCLUSIONS: Among patients with SIH, multiplicity of CSF leaks was observed radiographically in none of the patients with ventral leaks, in 6% of patients with lateral leaks, and in 9% of patients with CSF-venous fistulas. These results suggest that patients with SIH can be reassured that the occurrence of multiple CSF leaks is negligible to uncommon at most, depending on the type of CSF leak.

Role of cerebral digital subtraction angiography in the evaluation of pulse synchronous tinnitus.

OBJECTIVES: The aim of this study was to evaluate the value of digital subtraction angiography (DSA) in the diagnostic evaluation of a highly selected patient population presenting with pulse-synchronous tinnitus (PST). METHODS: We retrospectively reviewed the charts of all patients referred for evaluation of possible vascular etiology of pulsatile tinnitus. Patients were evaluated with regards to presenting signs, comorbidities, non-invasive imaging results, angiographic findings and outcomes. RESULTS: Fifteen patients underwent cerebral DSA. Dural arteriovenous fistula (dAVF) was identified in six patients, and five patients had other significant vascular pathology identified on DSA. Seven patients with 'negative' non-invasive imaging were found to have significant pathology on DSA. CONCLUSIONS: Catheter angiography may have a significant yield in appropriately selected patients presenting with pulse synchronous tinnitus.

Lateral decubitus digital subtraction myelography to identify spinal CSF-venous fistulas in spontaneous intracranial hypotension.

OBJECTIVE: Spontaneous spinal CSF-venous fistulas are a distinct type of spinal CSF leak recently described in patients with spontaneous intracranial hypotension (SIH). Using digital subtraction myelography (DSM) with the patient in the prone position, the authors have been able to demonstrate such fistulas in about one-fifth of patients with SIH in whom conventional spinal imaging (MRI or CT myelography) showed no evidence for a CSF leak (i.e., the presence of extradural CSF). The authors compared findings of DSM with patients in the lateral decubitus position versus the prone position and now report a significantly increased yield of identifying spinal CSF-venous fistulas with this modification of their imaging protocol. METHODS: The population consisted of 23 patients with SIH who underwent DSM in the lateral decubitus position and 26 patients with SIH who underwent DSM in the prone position. None of the patients had evidence of a CSF leak on conventional spinal imaging. RESULTS: A CSF-venous fistula was demonstrated in 17 (74%) of the 23 patients who underwent DSM in the lateral decubitus position compared to 4 (15%) of the 26 patients who underwent DSM in the prone position (p < 0.0001). The mean age of these 16 women and 5 men was 52.5 years (range 36-66 years). CONCLUSIONS: Among SIH patients in whom conventional spinal imaging showed no evidence of a CSF leak, DSM in the lateral decubitus position demonstrated a CSF-venous fistula in about three-fourths of patients compared to only 15% of patients when the DSM was performed in the prone position, an approximately five-fold increase in the detection rate. Spinal CSF-venous fistulas are not rare among patients with SIH.

False localizing signs of spinal CSF-venous fistulas in spontaneous intracranial hypotension: report of 2 cases.

A spinal CSF-venous fistula is one of three specific types of spinal CSF leak that can be seen in patients with spontaneous intracranial hypotension (SIH). They are best demonstrated on specialized imaging, such as digital subtraction myelography (DSM) or dynamic myelography, but often they are diagnosed on the basis of increased contrast density in the draining veins (the so-called hyperdense paraspinal vein sign) on early postmyelography CT scans. The authors report on 2 patients who underwent directed treatment (surgery in one patient and glue injection in the other) based on the hyperdense paraspinal vein sign, in whom the actual site of the fistula did not correspond to the level or laterality of the hyperdense paraspinal vein sign. The authors suggest consideration of DSM or dynamic myelography prior to undertaking treatment directed at these fistulas.

Rebound high-pressure headache after treatment of spontaneous intracranial hypotension: MRV study.

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

Coma: A serious complication of spontaneous intracranial hypotension.

OBJECTIVE: To review our experience with patients with spontaneous intracranial hypotension (SIH) and coma because, although disorders of consciousness may complicate SIH, no comprehensive study of such patients has been reported. METHODS: Using a prospectively maintained registry, we identified all patients with SIH in whom coma developed. Patients or their caregivers/families were contacted for follow-up. Patients were compared to a cohort of patients with SIH without coma. RESULTS: The mean age of the 12 men and 3 women with SIH was 56.2 years (range 34-72 years) at the time of onset of coma. In one-third of patients, coma developed after craniotomy for subdural hematomas or for an unrelated intracranial pathology. Imaging showed brain sagging, including bilateral temporal lobe herniation, in all 15 patients and brainstem edema in 8 patients (53%). Overall, coma was reversible in 7 of 15 patients treated with epidural blood patches, in 2 of 4 treated with percutaneous glue injections, and in 6 of 6 treated surgically. Only 1 patient had residual neurologic deficit related to coma (Glasgow Outcome Scale score 4 [moderate disability]). Compared to patients with SIH without coma (n = 568), those with coma were older, more often were male, and more often underwent surgery. CONCLUSIONS: Coma in SIH is rare, reversible, and invariably associated with brain sagging. Coma due to SIH may be refractory to the usual percutaneous procedures, and surgical closure of the CSF leak may be required to regain consciousness.

Behavioral Variant Frontotemporal Dementia as a Serious Complication of Spontaneous Intracranial Hypotension.

BACKGROUND: Behavioral variant frontotemporal dementia (bvFTD) is a devastating early onset dementia. Symptoms of bvFTD may be caused by spontaneous intracranial hypotension (SIH), a treatable disorder, but no comprehensive study of such patients has been reported. OBJECTIVE: To describe detailed characteristics of a large cohort of patients with SIH and symptoms of bvFTD. METHODS: We identified patients with SIH who met clinical criteria for bvFTD. Patients were compared to a cohort of SIH patients without bvFTD. RESULTS: The mean age for the 21 men and 8 women was 52.9 yr (range, 37-65 yr). All 29 patients with bvFTD symptoms had hypersomnolence. Magnetic resonance imaging showed brain sagging in all patients, cerebrospinal fluid (CSF) opening pressure low in about half of patients, but a spinal CSF leak could not be detected in any patient. All patients underwent epidural blood patching, but 26 patients eventually underwent 1 or more surgical procedures. Overall, a good outcome was obtained in 21 patients (72%); 20 (91%) of 22 patients who had not undergone prior Chiari surgery compared to 1 (14%) of 7 patients who did undergo Chiari surgery (P < .003). Compared to SIH patients without symptoms of bvFTD (n = 547), those with bvFTD symptoms were older, more often male, less often demonstrated CSF leak on spinal imaging, and more often underwent surgery (P < .02). CONCLUSION: bvFTD in SIH is rare and associated with brain sagging and hypersomnolence. Spinal CSF leaks are rarely detected. bvFTD symptoms are often refractory to the usual percutaneous procedures but most patients can be cured.

Digital subtraction myelography in the investigation of post-dural puncture headache in 27 patients: technical note.

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

A classification system of spontaneous spinal CSF leaks.

OBJECTIVE: Spontaneous spinal CSF leaks cause spontaneous intracranial hypotension but no systematic study of the different types of these CSF leaks has been reported. Based on our experience with spontaneous intracranial hypotension, we propose a classification system of spontaneous spinal CSF leaks. METHODS: We reviewed the medical records, radiographic studies, operative notes, and any intraoperative photographs of a group of consecutive patients with spontaneous intracranial hypotension. RESULTS: The mean age of the 568 patients (373 [65.7%] women) was 45.7 years. Three types of CSF leak could be identified. Type 1 CSF leaks consisted of a dural tear (151 patients [26.6%]) and these were almost exclusively associated with an extradural CSF collection. Type 1a represented ventral CSF leaks (96%) and type 1b posterolateral CSF leaks (4%). Type 2 CSF leaks consisted of meningeal diverticula (240 patients [42.3%]) and were the source of an extradural CSF collection in 53 of these patients (22.1%). Type 2a represented simple diverticula (90.8%) and type 2b complex meningeal diverticula/dural ectasia (9.2%). Type 3 CSF leaks consisted of direct CSF-venous fistulas (14 patients [2.5%]) and these were not associated with extradural CSF collections. A total of 163 patients (28.7%) had an indeterminate type and extradural CSF collections were noted in 84 (51.5%) of these patients. CONCLUSIONS: We identified 3 types of spontaneous spinal CSF leak in this observational study: the dural tear, the meningeal diverticulum, and the CSF-venous fistula. These 3 types and the presence or absence of extradural CSF form the basis of a comprehensive classification system.

Digital subtraction myelography for the identification of spontaneous spinal CSF-venous fistulas.

OBJECTIVE In most patients with spontaneous intracranial hypotension, a spinal CSF leak can be found, but occasionally, no leak can be demonstrated despite extensive spinal imaging. Failure to localize a CSF leak limits treatment options. The authors recently reported the discovery of CSF-venous fistulas in patients with spontaneous intracranial hypotension and now report on the use of digital subtraction myelography in patients with spontaneous intracranial hypotension but no CSF leak identifiable on conventional spinal imaging (i.e., non-digital subtraction myelography). METHODS The patient population consisted of 53 consecutive patients with spontaneous intracranial hypotension who underwent digital subtraction myelography but in whom no spinal CSF leak (i.e., presence of extradural CSF) was identifiable on conventional spinal imaging. RESULTS The mean age of the 33 women and 20 men was 53.4 years (range 29-71 years). A CSF-venous fistula was demonstrated in 10 (19%) of the 53 patients. A CSF-venous fistula was found in 9 (27%) of the 33 women and in 1 (5%) of the 20 men (p = 0.0697). One patient was treated successfully with percutaneous injection of fibrin sealant. Nine patients underwent surgery for the fistula. Surgery resulted in complete resolution of symptoms in 8 patients (follow-up 7-25 months), and in 1 patient, symptoms recurred after 4 months. CONCLUSIONS In this study, the authors found a CSF-venous fistula in approximately one-fifth of the patients with recalcitrant spontaneous intracranial hypotension but no CSF leak identifiable on conventional spinal imaging. The authors suggest that digital subtraction myelography be considered in this patient population.

Vanishing calcification associated with a spontaneous ventral spinal cerebrospinal fluid leak.

BACKGROUND: Some patients with spontaneous intracranial hypotension have a ventral spinal cerebrospinal fluid (CSF) leak and these CSF leaks may be associated with calcified disk herniations. Identifying these calcifications is helpful in directing treatment. We report here the unusual case of a patient with a ventral CSF leak in whom the associated calcification absorbed over a five-month period. CASE REPORT: A 42-year-old woman developed orthostatic headaches and bilateral abducens nerve palsies. Magnetic resonance imaging of her brain showed typical findings of spontaneous intracranial hypotension. Magnetic resonance imaging of her spine showed an extensive cervicothoracic CSF leak. Computed tomographic myelography showed calcification at the Th1-2 disk space. Three epidural blood patches were performed, but her symptoms persisted. Digital subtraction myelography performed five months later showed an upper thoracic ventral CSF, but the calcification was no longer present. A dural tear, found at surgery at the Th1-2 level, was repaired and the patient made an uneventful recovery. DISCUSSION: The resorption of calcifications at the level of a ventral spinal CSF leak could explain the absence of any calcifications in at least some patients with such leaks and demonstrates the usefulness of reviewing previous imaging in patients with ventral CSF leaks if the exact site of the leak remains unknown.

Diffuse non-aneurysmal SAH in spontaneous intracranial hypotension: Sequela of ventral CSF leak?

BACKGROUND: Spontaneous intracranial hypotension due to a spinal cerebrospinal fluid (CSF) leak has become a well-recognized cause of headaches. Recently, various unusual neurological syndromes have been described in such patients with chronic ventral CSF leaks, including superficial siderosis and an amyotrophic lateral sclerosis-like syndrome. The authors now report two patients with spontaneous intracranial hypotension due to a chronic ventral CSF leak who suffered a diffuse non-aneurysmal subarachnoid hemorrhage (SAH). DESCRIPTION OF CASES: A 62-year-old woman underwent uneventful microsurgical repair of a ventral thoracic CSF leak that had been present for 13 years. Seventeen months after surgery, she was found unresponsive and CT showed a diffuse intracranial SAH. Cerebral angiography and spine and brain MRI did not reveal a source of the SAH. A 73-year-old woman was found unresponsive and CT showed a diffuse intracranial SAH. Cerebral angiography and brain MRI did not reveal a source of the SAH, although superficial siderosis was detected. Spine MRI showed a ventral thoracic CSF leak that by history had been present for 41 years. She underwent uneventful microsurgical repair of the CSF leak. DISCUSSION: The authors suggest that patients with a ventral spinal CSF leak of long duration may be at risk of diffuse non-aneurysmal SAH.

Intraspinal hemorrhage in spontaneous intracranial hypotension: link to superficial siderosis? Report of 2 cases.

Spontaneous intracranial hypotension due to a spinal CSF leak has become a well-recognized cause of headaches, but such spinal CSF leaks also are found in approximately half of patients with superficial siderosis of the CNS. It has been hypothesized that friable vessels at the site of the spinal CSF leak are the likely source of chronic bleeding in these patients, but such an intraspinal hemorrhage has never been visualized. The authors report on 2 patients with spontaneous intracranial hypotension and intraspinal hemorrhage, offering support for this hypothesis. A 33-year-old man and a 62-year-old woman with spontaneous intracranial hypotension were found to have a hemorrhage within the ventral spinal CSF collection and within the thecal sac, respectively. Treatment consisted of microsurgical repair of a ventral dural tear in the first patient and epidural blood patching in the second patient. The authors suggest that spontaneous intracranial hypotension should be included in the differential diagnosis of spontaneous intraspinal hemorrhage, and that the intraspinal hemorrhage can account for the finding of superficial siderosis when the CSF leak remains untreated.

False localizing sign of cervico-thoracic CSF leak in spontaneous intracranial hypotension.

OBJECTIVE: Spontaneous spinal CSF leaks are an important cause of new-onset headaches. Such leaks are reported to be particularly common at the cervico-thoracic junction. The authors undertook a study to determine the significance of these cervico-thoracic CSF leaks. METHODS: The patient population consisted of a consecutive group of 13 patients who underwent surgery for CSF leak repair based on CT myelography showing CSF extravasation at the cervico-thoracic junction but without any evidence of an underlying structural lesion. RESULTS: The mean age of the 9 women and 4 men was 41.2 years. Extensive extrathecal longitudinal CSF collections were demonstrated in 11 patients. At surgery, small leaking arachnoid cysts were found in 2 patients. In the remaining 11 patients, no clear source of CSF leakage could be identified at surgery. Resolution of symptoms was achieved in both patients with leaking arachnoid cysts, but in only 3 of the 11 patients with negative intraoperative findings. Postoperative spinal imaging was performed in 9 of the 11 patients with negative intraoperative findings and showed persistence of the longitudinal intraspinal extradural CSF. Further imaging revealed the site of the CSF leak to be ventral to the thoracic spinal cord. Five of these patients underwent microsurgical repair of the ventral CSF leak with resolution of symptoms in all 5 patients. CONCLUSIONS: Cervico-thoracic extravasation of dye on myelography does not necessarily indicate the site of the CSF leak. Treatment directed at this site should not be expected to have a high probability of sustained improvement of symptoms.

Hyperprolactinemia due to spontaneous intracranial hypotension.

OBJECT Spontaneous intracranial hypotension is an increasingly recognized cause of headaches. Pituitary enlargement and brain sagging are common findings on MRI in patients with this disorder. The authors therefore investigated pituitary function in patients with spontaneous intracranial hypotension. METHODS Pituitary hormones were measured in a group of 42 consecutive patients with spontaneous intracranial hypotension. For patients with hyperprolactinemia, prolactin levels also were measured following treatment. Magnetic resonance imaging was performed prior to and following treatment. RESULTS The study group consisted of 27 women and 15 men with a mean age at onset of symptoms of 52.2 ± 10.7 years (mean ± SD; range 17-72 years). Hyperprolactinemia was detected in 10 patients (24%), ranging from 16 ng/ml to 96.6 ng/ml in men (normal range 3-14.7 ng/ml) and from 31.3 ng/ml to 102.5 ng/ml in women (normal range 3.8-23.2 ng/ml). In a multivariate analysis, only brain sagging on MRI was associated with hyperprolactinemia. Brain sagging was present in 60% of patients with hyperprolactinemia and in 19% of patients with normal prolactin levels (p = 0.02). Following successful treatment of the spontaneous intracranial hypotension, hyperprolactinemia resolved, along with normalization of brain MRI findings in all 10 patients. CONCLUSIONS Spontaneous intracranial hypotension is a previously undescribed cause of hyperprolactinemia. Brain sagging causing distortion of the pituitary stalk (stalk effect) may be responsible for the hyperprolactinemia.

Spontaneous intracranial hypotension in childhood and adolescence.

OBJECTIVES: To describe the clinical and radiographic manifestations of spontaneous intracranial hypotension, a rarely diagnosed cause of headache in children. STUDY DESIGN: This study included patients 19 years of age or younger evaluated between January 1, 2001, and June 30, 2012, for spontaneous intracranial hypotension. RESULTS: We evaluated 24 children (18 girls and 6 boys) with spontaneous intracranial hypotension (age at onset of symptoms: 2-19 years, mean 14.3 years). Twenty-three patients presented with orthostatic headaches and 1 presented with a nonpositional headache. A generalized connective tissue disorder was diagnosed in 54% of patients. Magnetic resonance imaging showed the typical changes of spontaneous intracranial hypotension in most patients (79%). Spinal imaging demonstrated a cerebrospinal fluid (CSF) leak with or without an associated meningeal diverticulum in 12 patients (50%) and with dural ectasia or meningeal diverticula in 10 patients (42%), and it was normal in 2 patients (8%). Twenty-three patients initially underwent epidural blood patching, but 8 patients also were treated with percutaneous injections of fibrin glue and 11 patients eventually required surgical correction of the underlying CSF leak. There was no morbidity or mortality associated with any of the treatments, but 5 patients required acetazolamide for rebound high intracranial pressure headache. Overall, outcome was good in 22 patients (92%) and poor in 2 patients (8%). CONCLUSIONS: Spontaneous intracranial hypotension in childhood is rare. Most patients can be treated effectively using a combination of epidural blood patching and percutaneous injections of fibrin glue or surgical CSF leak repair in refractory cases.