Transverse Venous Sinus Stenosis Research Articles

Assessment of Reversibility of Transverse Venous Sinus Stenosis in Patients With Papilledema.

Bilateral transverse venous sinus stenosis (TVSS) or stenosis of a dominant venous sinus has been found to be very sensitive radiological findings in patients with intracranial hypertension (IH), yet there is still an ongoing debate whether they constitute reversible or permanent phenomena. Thus, the purpose of this study was to investigate the reversibility of TVSS in patients with IH, including conservatively treated patients with signs of IH as defined by the presence of papilledema. This was a retrospective chart review of all patients diagnosed with IH between 2016 and 2022, assessed from 2 tertiary university-affiliated neuro-ophthalmology practices. Inclusion criteria were the presence of papilledema, as quantified by optical coherence tomography, and bilateral TVSS, which is considered typical of IH on neuroimaging. During follow-up, included patients must have had confirmation of papilledema resolution as well as subsequent neuroimaging after conservative treatment or cerebrospinal fluid flow diversion. Patients with dural sinus vein thrombosis or intrinsic stenosis from sinus trabeculations or significant arachnoid granulations were excluded from the study. Either CT venography or MRI/MR venography was reviewed by a fellowship-trained neuroradiologist, and the degree of stenosis was scored through the combined conduit score (CCS), as described by Farb et al. The primary outcome was to assess TVSS changes after resolution or improvement of papilledema. From 435 patients, we identified a subset of 10 who satisfied all inclusion criteria. Our cohort comprised entirely women with a median age of 29.5 years and a median BMI of 32.5 kg/m2. Treatment consisted of acetazolamide in 7 patients, of which 1 had additional topiramate and 2 underwent cerebrospinal fluid flow diversion. Furthermore, 6 patients demonstrated significant weight loss during follow-up. For the primary outcome, 5 of 10 patients exhibited no appreciable TVSS change, and 5 patients demonstrated significant improvement in TVSS, of which 4 received conservative treatment only. Papilledema resolution or improvement was statistically significantly associated with increasing average CCS, TVSS diameter, and grade. We were able to demonstrate that TVSS can be both irreversible and reversible in patients with resolved papilledema. The finding of TVSS reversibility from conservative treatment alone is novel and has important implications to optimize patient care. Future studies should work to identify factors associated with irreversible TVSS for subsequent targeted intervention and prevention.

Spontaneous CSF fistula as a manifestation of idiopathic intracranial hypertension

IntroductionSpontaneous cerebrospinal fluid (CSF) fistula, of unknown origin, is a rare condition whose aetiology is increasingly related to idiopathic intracranial hypertension (IIH). This study tries to raise awareness that they should not be considered as two different processes, but that fistulas can be a form of debut, requiring a study and subsequent treatment. Repair techniques are described, as well as the study of HII. ResultsWe treated 8 patients, 5 women and three men, aged between 46 and 72 years, with a diagnosis of spontaneous CSF fistula, four nasal and four otics who underwent surgical treatment. After repair, a diagnostic study was performed for IIH by MRI and Angio-MRI, presenting in all cases a transverse venous sinus stenosis. The intracranial pressure values obtained by lumbar puncture showed values of 20mm Hg or higher. All patients were diagnosed with HII. The one-year follow-up did not reveal any recurrence of the fistulas, maintaining a control of the HII. ConclusionDespite their low frequency of both cranial CSF fistula and IIH, an association of both conditions should be considered by continuing the study and surveillance of these patients after fistula closure.

Fistula espontánea de LCR como manifestación de la hipertensión intracraneal idiopática

IntroductionSpontaneous cerebrospinal fluid (CSF) fistula, of unknown origin, is a rare condition whose etiology is increasingly related to idiopathic intracranial hypertension (IIH). This study tries to raise awareness that they should not be considered as two different processes, but that fistulas can be a form of debut, requiring a study and subsequent treatment. Repair techniques are described, as well as the study of IIH. ResultsWe treated eight patients, five women and three men, aged between 46 and 72 years, with a diagnosis of spontaneous CSF fistula, four nasal and four otics who underwent surgical treatment. After repair, a diagnostic study was performed for IIH by MRI and angio-MRI, presenting in all cases a transverse venous sinus stenosis. The intracranial pressure values obtained by lumbar puncture showed values of 20mmHg or higher. All patients were diagnosed with IIH. The one-year follow-up did not reveal any recurrence of the fistulas, maintaining a control of the IIH. ConclusionDespite their low frequency of both cranial CSF fistula and IIH, an association of both conditions should be considered by continuing the study and surveillance of these patients after fistula closure.

Symptom: Runny Nose Six Years After Acoustic Neuroma Surgery

Symptom: Runny Nose Six Years After Acoustic Neuroma Surgery

Investigation of the Prevalence of Cerebral Transverse Venous Sinus Stenosis in Idiopathic Intracranial Hypertension

Purpose: Idiopathic intracranial hypertension (IIH) is an increase in intracranial pressure with a normal cerebrospinal fluid (CSF) composition that is not due to a secondary cause. The existence of cerebral transverse venous sinus stenosis and changes in venous outflow in IIH has recently gotten a lot of attention, and this situation is becoming increasingly important in terms of diagnosis and treatment plan. 
 This study aimed to investigate how frequent cerebral transverse venous sinus stenosis is in patients with IIH. 
 Methods: The demographic profile of 27 patients with IIH who were followed up in the hospital's neurological headache outpatient clinic and the occurrence of cerebral transverse venous stenosis on cranial magnetic resonance venography (MRV) were studied. Considering the pre-diagnosis of cerebral venous thrombosis (SVT), patients who underwent magnetic resonance venography (MRV) and whose SVT was ruled out during their follow-up were included as the control group. This control group consisted of 48 patients diagnosed with migraine, tension-type headache (TTH), and new-onset daily persistent headache.
 Results: When MRVs were investigated, cerebral transverse venous sinus stenosis was detected in %55.6 (n=15) of IIH patients and 25% (n=12) of the control group (p = 0.017).
 Conclusions: The frequency of cerebral transverse sinus stenosis in MRV of patients diagnosed with IIH was found to be significantly higher in this study than in the control group. These findings indicated that cerebral transverse venous stenosis can play a role in the progression of IIH.

Predictors of cognitive impairment in pseudotumor cerebri.

We aimed to define the cognitive burden of the largest pseudotumor cerebri syndrome (PTCS) population to date, compare objective to subjective cognitive dysfunction, and determine clinical predictors of cognitive dysfunction amongst an array of previously unstudied factors. Patients with PTCS commonly report cognitive dysfunction, a factor associated with poor quality of life. It is not definitively known whether cognitive impairment is present in these patients, and what features of the syndrome predict impairment. We administered a cognitive battery consisting of the National Adult Reading Test, Mini-Mental Status Exam, Digit Span, Boston Naming Test, Rey Auditory Verbal Learning Test, Clock Drawing, Trail Making Test, Controlled Oral Word Association, and Category Fluency. Cognitive impairment was defined as mild-single domain with one test score, and mild-multiple domain with two scores, more than two standard deviations below the mean for age-, gender-, and education-adjusted norms. One-hundred and one prospectively recruited PTCS patients were enrolled. The objective testing showed 30 patients had mild-single domain impairment, and 25 had mild-multi domain impairment. More patients without objective cognitive impairment had transverse venous sinus stenosis, but otherwise the groups did not differ. Two measures of headache severity, the Headache Impact Test and pain on the Numeric Rating Scale, were negatively associated with the composite cognitive score, as was ocular pain, vision-related disability, and mental health. Opening pressure and visual function were not associated with objective cognitive impairment. We found no association between subjective and objective cognitive impairment. Patients with PTCS may be cognitively impaired, and this correlates with measures of headache burden. Studies evaluating cognitive impairment before and after remission of the headache disorder would have to be performed to investigate this relationship further. Patients with self-perception of cognitive burden are no more likely to be cognitively impaired.

Prevalence of Incidentally Detected Signs of Intracranial Hypertension on Magnetic Resonance Imaging and Their Association With Papilledema

Magnetic resonance imaging (MRI) signs of intracranial hypertension (IH) are traditionally associated with idiopathic intracranial hypertension (IIH), but these signs are also detected among individuals with primary headaches and among asymptomatic individuals without papilledema. To examine the prevalence of MRI signs of IH among consecutive outpatients undergoing brain MRI for any clinical indication and to explore their association with papilledema. This prospective cross-sectional study of outpatients undergoing brain MRI at 1 outpatient imaging facility was conducted between August 1, 2019, and March 31, 2020, with ocular fundus photographs taken concurrently. Radiographic images from consecutive adult patients who were undergoing brain MRI and able to participate in fundus photography were analyzed for MRI signs of IH. A univariate analysis using either Fisher exact tests or t tests was performed. Prevalence of MRI signs of IH and prevalence of papilledema detected on ocular fundus photographs. Radiographic signs of IH included empty sella, optic nerve head protrusion, posterior scleral flattening, increased perioptic cerebrospinal fluid, optic nerve tortuosity, enlarged Meckel caves, cephaloceles, cerebellar tonsillar descent, and bilateral transverse venous sinus stenosis. A total of 388 patients were screened for eligibility; of those, 92 patients were excluded (58 declined participation, 16 were unable to consent, 14 were unable to complete fundus photography, and 4 completed MRI and fundus photography twice, so their second set of findings was removed). Among the 296 patients included in the study, the median age was 49.5 years (interquartile range, 37.8-62.0 years), and 188 patients (63.5%) were female. The most common indication for MRI was surveillance of a brain neoplasm (82 patients [27.7%]). Investigations of headaches (26 patients [8.8%]) and disorders of intracranial pressure (4 patients [1.4%]) were uncommon. At least 1 radiographic sign of IH was present in 145 patients (49.0%). Among 296 total study patients, 98 patients (33.1%) had empty sella, 47 patients (15.9%) had enlarged Meckel caves, 32 patients (10.8%) had increased perioptic cerebrospinal fluid, 23 patients (7.8%) had optic nerve tortuosity, 2 patients (0.7%) had scleral flattening, and 4 patients (1.4%) had cephaloceles. Bilateral transverse venous sinus stenosis was present in 6 of 198 patients (3.0%). Five patients (1.7%) had papilledema. Compared with patients without papilledema, those with papilledema had a significantly higher body mass index and history of IIH, in addition to an increased prevalence of empty sella, optic nerve tortuosity, and transverse venous sinus stenosis detected on MRI. The prevalence of papilledema increased from 2.8% among patients with at least 1 MRI sign of IH to 40.0% among patients with 4 or more MRI signs of IH. Magnetic resonance imaging signs of IH were common among patients undergoing brain MRI in this study but rarely associated with papilledema. The management of patients with incidentally detected signs of IH likely does not require systematic lumbar puncture unless concerning symptoms or papilledema are present.

Prediction of Postoperative Risk of Raised Intracranial Pressure After Spontaneous Skull Base Cerebrospinal Fluid Leak Repair.

A relationship between idiopathic intracranial hypertension and spontaneous skull base cerebrospinal fluid (CSF) leaks has been proposed, by which CSF leak decreases intracranial pressure (ICP) and masks the symptoms and signs of elevated ICP. These patients are at risk of developing papilledema, symptoms of elevated ICP, or a recurrent CSF leak after CSF leak repair. The objective of this study was to assess whether radiographic signs of raised ICP on preoperative magnetic resonance or computed venography (MRI or CTV) are predictors of postoperative papilledema, recurrence of CSF leak, or need for CSF shunt surgery. We performed a retrospective review of systematically collected demographics, fundus examination, and presurgical brain MRI and magnetic resonance venography/computed tomography venography (MRV/CTV) in patients seen at 1 institution between 2013 and 2019 with spontaneous skull base CSF leak repair. Patients were divided into 2 groups depending on whether they developed papilledema, recurrent CSF leak, or required CSF shunting (Group 1) or not (Group 2). Fifty-seven patients were included, among whom 19 were in Group 1. There was no difference in demographic characteristics or clinical features between patients in Group 1 and Group 2. Controlling for other imaging features, bilateral transverse venous sinus stenosis (TVSS) on preoperative imaging increased the odds of being in Group 1 by 4.2 times (95% confidence interval [CI], 1.04-21.2, P = 0.04), optic nerve tortuosity decreased the odds of being in Group 1 by 8.3 times (95% CI: 1.4-74.6, P = 0.02). Imaging of the intracranial venous system with MRV or CTV is warranted before repair of spontaneous CSF leak, as bilateral TVSS is an independent risk factor for postoperative papilledema, CSF leak recurrence, or need for a CSF shunting procedure.

Association of spontaneous cerebrospinal fluid rhinorrhea with transverse venous sinus stenosis: a retrospective matched case‐control study

A significant proportion of spontaneous cerebrospinal fluid (sCSF) leaks are associated with idiopathic intracranial hypertension (IIH). The aim of this study was to assess the association between sCSF rhinorrhea and transverse venous sinus stenosis (VSS), a feature commonly observed in IIH with a proposed role in its pathophysiology. In this single-center, retrospective, matched case-control study, venous and pituitary imaging data of consecutive patients undergoing endoscopic surgery for sCSF rhinorrhea over the last 10 years were retrospectively reviewed. Measurement of the height of the pituitary gland was used to assess empty sella and VSS was quantified as the ratio between the minimal area of the transverse sinus and the cross-sectional area of the sigmoid sinus. VSS was considered significant when it was ≥50% and bilateral. Cases were compared with 1:1 age- and sex-adjusted controls explored for causes other than IIH, intracranial mass effect, or venous thrombosis. Twenty-nine patients were included (median age 56 years, females 69%, body mass index [BMI] 33.8 kg/m2 ). Cases had a significantly lower height of the pituitary gland than controls (2.5 mm vs 6.6 mm, p < 0.001). Bilateral VSS was found in 23 of 29 cases (79%; 95% confidence interval [CI], 65% to 94%) vs 3 of 29 controls (10%; 95% CI, 0% to 21%), with p < 0.001. In this retrospective study, sCSF leaks were strongly associated with VSS. This novel finding provides a rationale for further investigation of the role of VSS in the onset of sCSF leaks and of the potential interest in venous stenting after the surgical repair of leaks.

Transverse venous sinus stenosis in idiopathic intracranial hypertension: a prospective pilot study

ObjectiveWhether transverse venous sinus stenosis (TVSS) causes idiopathic intracranial hypertension (IIH) or is an effect of the increased intracranial pressures is controversial. The purpose of this study was to assess the feasibility of serial imaging in patients with IIH on medical management. Design and ParticipantsPatients found to have IIH and TVSS on contrast-enhanced magnetic resonance venography (CEMRV) were recruited in a prospective cohort study. Patients were medically managed and followed with a CEMRV immediately after lumbar puncture, 3–6 months after diagnosis with resolution of IIH symptoms, and 1 year after diagnosis. Ophthalmological data were collected at the time of diagnosis, 3–6 months after diagnosis, and 1 year after diagnosis. Feasibility data, including patient recruitment rate, barriers, and logistical issues, were recorded. ResultsTwenty patients with suspected IIH were screened, and 5 of 7 (71.4%; 95% confidence interval: 36.21–100) eligible patients were enrolled in 1 year, at completion. All recruited patients had clinical resolution of their IIH on medical therapy, and none of them had any obvious change in their TVSS. ConclusionsProspective examination of TVSS with serial magnetic resonance imaging in patients with IIH is feasible. TVSS in patients with IIH did not show any change, despite clinical improvement on medical management in all participants.

Spontaneous Skull Base Cerebrospinal Fluid Leaks and Their Relationship to Idiopathic Intracranial Hypertension.

The association between spontaneous skull base cerebrospinal fluid (CSF) leaks and idiopathic intracranial hypertension (IIH) has been suggested, but its significance remains unclear. To estimate the prevalence of IIH in spontaneous skull base CSF leak patients. Systematic collection of demographics, neuro-ophthalmic and magnetic resonance imaging evaluation of spontaneous skull base CSF leak patients seen pre- and post-leak repair in one neuro-ophthalmology service. Patients with preexisting IIH were diagnosed with definite IIH if adequate documentation was provided; otherwise, they were categorized with presumed IIH. Classic radiographic signs of intracranial hypertension and bilateral transverse venous sinus stenosis were recorded. Thirty six patients were included (age [interquartile range]: 50 [45;54] years; 94% women; body mass index: 36.8 [30.5;39.9] kg/m2), among whom six (16.7%, [95% confidence interval, CI]: [6.4;32.8]) had a preexisting diagnosis of definite or presumed IIH. Of the remaining 30 patients, four (13.3%, 95%CI: [3.8;30.7]) had optic nerve head changes suggesting previously undiagnosed IIH, while one was newly diagnosed with definite IIH at initial consultation. One out of 29 patients with normal findings of the optic nerve head at presentation developed new onset papilledema following surgery (3.4%, 95%CI: [0.1;17.8]) and was ultimately diagnosed with definite IIH. Overall, the prevalence of definite IIH was 19.4% (95%CI: [8.2;36.0]). Striking demographic overlap exists between IIH patients and those with spontaneous CSF leak. Definite IIH was present in approximately 20% of our patients. However, its true prevalence is likely higher than identified by using classic criteria. We therefore hypothesize that an active CSF leak serves as an auto-diversion for CSF, thereby "treating" the intracranial hypertension and eliminating characteristic signs and symptoms at initial presentation.

Utility of Magnetic Resonance Imaging Features for Improving the Diagnosis of Idiopathic Intracranial Hypertension Without Papilledema: Response.

Objective Revised diagnostic criteria for idiopathic intracranial hypertension (IIH) were proposed in part to reduce misdiagnosis of intracranial hypertension without papilledema (WOP) by using 3 or 4 MRI features of intracranial hypertension when a sixth nerve palsy is absent. This study was undertaken to evaluate the sensitivity and specificity of the MRI criteria and to validate their utility for diagnosing IIH in patients with chronic headaches and elevated opening pressure (CH + EOP), but WOP. Methods Brain MRIs from 80 patients with IIH with papilledema (WP), 33 patients with CH + EOP, and 70 control patients with infrequent episodic migraine were assessed in a masked fashion for MRI features of intracranial hypertension. Results Reduced pituitary gland height was moderately sensitive for IIH WP (80%) but had low specificity (64%). Increased optic nerve sheath diameter was less sensitive (51%) and only moderately specific (83%). Flattening of the posterior globe was highly specific (97%) but had low sensitivity (57%). Transverse venous sinus stenosis was moderately sensitive for IIH WP (78%) but of undetermined specificity. A combination of any 3 of 4 MRI features was nearly 100% specific, while maintaining a sensitivity of 64%. Of patients with CH + EOP, 30% had 3 or more MRI features, suggesting IIH WOP in those patients. Conclusion A combination of any 3 of 4 MRI features is highly specific for intracranial hypertension and suggests IIH WOP when present in patients with chronic headache and no papilledema.

Utility of Magnetic Resonance Imaging Features for Improving the Diagnosis of Idiopathic Intracranial Hypertension Without Papilledema.

Revised diagnostic criteria for idiopathic intracranial hypertension (IIH) were proposed in part to reduce misdiagnosis of intracranial hypertension without papilledema (WOP) by using 3 or 4 MRI features of intracranial hypertension when a sixth nerve palsy is absent. This study was undertaken to evaluate the sensitivity and specificity of the MRI criteria and to validate their utility for diagnosing IIH in patients with chronic headaches and elevated opening pressure (CH + EOP), but WOP. Brain MRIs from 80 patients with IIH with papilledema (WP), 33 patients with CH + EOP, and 70 control patients with infrequent episodic migraine were assessed in a masked fashion for MRI features of intracranial hypertension. Reduced pituitary gland height was moderately sensitive for IIH WP (80%) but had low specificity (64%). Increased optic nerve sheath diameter was less sensitive (51%) and only moderately specific (83%). Flattening of the posterior globe was highly specific (97%) but had low sensitivity (57%). Transverse venous sinus stenosis was moderately sensitive for IIH WP (78%) but of undetermined specificity. A combination of any 3 of 4 MRI features was nearly 100% specific, while maintaining a sensitivity of 64%. Of patients with CH + EOP, 30% had 3 or more MRI features, suggesting IIH WOP in those patients. A combination of any 3 of 4 MRI features is highly specific for intracranial hypertension and suggests IIH WOP when present in patients with chronic headache and no papilledema.

Magnetic Resonance Imaging Findings in Pediatric Pseudotumor Cerebri Syndrome

BackgroundRevised diagnostic criteria for pseudotumor cerebri syndrome require three of four neuroimaging findings in the absence of papilledema. We examined the sensitivity and specificity of three or more of four of these magnetic resonance imaging (MRI) findings for pseudotumor cerebri syndrome in children. MethodsAs part of clinical care, patients in whom there was suspicion for pseudotumor cerebri syndrome underwent neurological and fundoscopic examinations, lumbar puncture, MRI, or magnetic resonance venogram. For this retrospective study, we used this information to classify 119 subjects into definite (n = 66) or probable pseudotumor cerebri syndrome (n = 12), elevated opening pressure without papilledema (n = 23), or controls who had normal opening pressure without papilledema (n = 24). A neuroradiologist, unaware of the clinical findings or original MRI report, reviewed MRIs for pituitary gland flattening, flattening of the posterior sclera, optic nerve sheath distention, and transverse venous sinus stenosis. ResultsThe presence of three or more MRI findings has a sensitivity of 62% (95% confidence interval: 47% to 75%) and a specificity of 95% (95% confidence interval: 77% to 100%), compared with controls. Two of three (transverse venous sinus stenosis, pituitary gland flattening, flattening of the posterior sclera) had a similar sensitivity and specificity. Transverse venous sinus stenosis alone had a slightly higher sensitivity (74%, 95% confidence interval: 60% to 85%) and specificity (100%, 95% confidence interval: 80% to 100%). ConclusionsIn children, three of four of the proposed neuroimaging criteria and transverse venous sinus stenosis alone have a moderate sensitivity and robust specificity for pseudotumor cerebri syndrome. MRIs should be reviewed for these criteria, and their presence should raise suspicion for pseudotumor cerebri syndrome in children, particularly if the presence of papilledema is uncertain.

Endovascular Stenting in a Transgender Patient With Idiopathic Intracranial Hypertension

Endovascular Stenting in a Transgender Patient With Idiopathic Intracranial Hypertension

Imaging Features of Idiopathic Intracranial Hypertension in Children.

Magnetic resonance imaging (MRI) signs of elevated intracranial pressure and idiopathic intracranial hypertension have been well characterized in adults but not in children. The MRIs of 50 children with idiopathic intracranial hypertension and 46 adults with idiopathic intracranial hypertension were reviewed for optic nerve head protrusion, optic nerve head enhancement, posterior scleral flattening, increased perioptic cerebrospinal fluid, optic nerve tortuosity, empty or partially empty sella, tonsillar herniation, enlargement of Meckel's cave meningoceles, and transverse venous sinus stenosis(TSS). Compared to adolescents (11-17 years, n = 40) and adults (>17 years, n = 46), prepubescent children (<11 years, n = 10) had lower frequencies of scleral flattening (50% vs 89% and 85%, P = .02), increased perioptic cerebrospinal fluid (60% vs 84% and 89%, P = .08), optic nerve tortuosity (20% vs 46% and 59%, P = .07), empty or partially empty sella (56% vs 78% and 93%, P = .007), and TSS (67% vs 93% and 96%, P = .04). Children with idiopathic intracranial hypertension have similar MRI findings as adults, but they are less frequent in prepubescent children.

A school of red herring

A 66-year-old man with chronic kidney disease presented with painless unilateral vision loss and bilateral optic disk swelling. Vision loss progressed in the affected eye and developed in the fellow eye. Evaluation for infectious, neoplastic, ischemic, and inflammatory disorders was unrevealing. High-dose corticosteroids appeared to stabilize his vision temporarily. Eventually he was diagnosed with papilledema in the setting of transverse venous sinus stenosis and dural arteriovenous fistula. His papilledema resolved, and his vision improved following stenting of the venous sinus stenosis and embolization of the fistula.

Does bilateral transverse cerebral venous sinus stenosis exist in patients without increased intracranial pressure?

ObjectiveTransverse cerebral venous sinus stenosis (TSS) is common among patients with idiopathic intracranial hypertension. TSS likely also exists among individuals with normal intracranial pressure (ICP) but the prevalence is unclear. The goal of this study was to identify patients with incidental TSS and normal ICP and describe their characteristics. MethodsAmong 240 adult patients who underwent brain magnetic resonance imaging (MRI) with magnetic resonance venography (MRV) with contrast at our institution between September 2009 and September 2011, 44 had isolated TSS without further substantial imaging abnormality. Medical records were reviewed for symptoms of increased ICP, papilledema, cerebrospinal fluid (CSF) constituents and opening pressure (OP), and reason for brain imaging. Of these, 37 were excluded for confirmed or possible idiopathic intracranial hypertension. Of the remainder, 5 had CSF-OP ≤25cmH2O without papilledema, and 2 did not have measured ICP, but had no papilledema or symptoms of increased ICP. Imaging was re-interpreted to assess for signs suggestive of elevated ICP and to characterize the TSS further. ResultsAll patients were women (mean age: 41, mean BMI: 37.1). CSF contents were normal, but OPs were at the upper limit of normal (22–25cmH2O). Indications for MRI/MRV included query pituitary abnormality (1), migraine (4), and anomalous-appearing optic nerves (2). All had bilateral TSS. Six had short TSS and an empty sella; 1 had long TSS and no empty sella; 1 had flattening of the posterior sclera; 2 had prominence of peri-optic nerve CSF. ConclusionAsymptomatic bilateral TSS exists in patients with ICP≤25cmH2O, but is likely uncommon. CSF-OP was at the upper limit of normal in our patients, who also had other radiologic signs suggestive (but not specific) of chronically-raised ICP. Findings of bilateral TSS on imaging should prompt funduscopic examination for papilledema.

Does Bilateral Transverse Cerebral Venous Sinus Stenosis (TSS) Really Exist in Patients without Increased Intracranial Pressure (ICP)? (P07.263)

Objective: To identify patients with asymptomatic TSS and normal ICP and describe their characteristics. Background TSS is common among patients with elevated ICP, particularly those with idiopathic intracranial hypertension. Although it is believed that TSS exists in the general population, and is not specific to elevated ICP, the prevalence of TSS among individuals with normal ICP is unclear. Design/Methods: Among 240 adult patients who underwent standardized brain MRI/MRV with contrast at our institution between 09/2009 and 09/2011, 50 had TSS. Medical records were reviewed for symptoms of increased ICP, evidence of papilledema, CSF constituents and opening pressure (OP) and reason for brain imaging. We identified 5/50 (10%) well-documented patients without papilledema and CSF-OP ≤25 cmH 2 O, and 2/50 without measured ICP, but who had no papilledema or other symptoms of increased ICP. Imaging was re-interpreted by a neuroradiologist to assess for signs suggestive of elevated ICP and to characterize the stenoses further. Results: All patients were women (5 African-American, 2 Caucasian, mean age: 41, mean BMI: 37.1). CSF contents were normal but OP were at the upper limit of normal (22, 23, 24, 24, 25cm H 2 O). Indications for MRI/MRV included pituitary abnormality (1), migraine (4), and anomalous-appearing optic nerves (2). All had bilateral TSS. Six had a short TSS and empty sella; one had a long TSS but no empty sella; one had flattening of the globes; two had dilated optic nerve sheaths. None had bony changes. Conclusions: Asymptomatic bilateral TSS does exist in patients with ICP ≤25cmH 2 O, but is likely uncommon. Interestingly, CSF-OP was at the upper limit of normal in our patients, who also had other radiologic signs suggestive (but not specific) of chronically-raised ICP. Findings of bilateral TSS on brain imaging should probably prompt further investigations for raised ICP. Disclosure: Dr. Kelly has nothing to disclose. Dr. Saindane has nothing to disclose. Dr. Bruce has nothing to disclose. Dr. Ridha has nothing to disclose. Dr. Riggeal has nothing to disclose. Dr. Newman has received personal compensation for activities with Biogen Idec. Dr. Biousse has nothing to disclose.

Intracranial hypertension, headache and obesity: Insights from magnetic resonance venography

Idiopathic intracranial hypertension without papilloedema (IIHWOP) is uncommon, accounting for, at most, 5% of patients with IIH evaluated by neuroophthalmologists (1). In contrast to patients with IIH and papilloedema, patients with IIHWOP are less obese, have lower cerebrospinal fluid pressures, and are more likely to have non-organic visual loss (1). This entity is perhaps more readily diagnosed among headache specialists than neuro-ophthalmologists and is suspected in obese women with intractable or chronic daily headaches (2). The integral relationship between the central venous system and intracranial pressure has been emphasised over the past several years with the discovery of venous sinus abnormalities in patients with IIH (3). Morphological irregularities and abnormal pressure gradients within the transverse sinuses are well described. In most cases, transverse venous sinus stenosis appears to be a result of high intracranial pressure rather than its cause (4). The transverse sinuses are asymmetric in most individuals and a unilateral hypoplastic sinus is considered a normal variant. However, bilateral transverse sinus stenosis (BTSS) may be associated with intracranial hypertension. In this issue of Cephalalgia, Bono and colleagues studied 98 patients with chronic migraine and chronic tension type headache using magnetic resonance venography and 1-h continuous lumbar CSF pressure monitoring (5). Their findings are notable in several respects. Strikingly, their patients were obese, regardless of CSF pressure status. Patients with normal CSF pressure (Group 1) were less overweight than in the groups with either intermittently (Group 2) or consistently (Group 3) elevated CSF pressure, and some patients in Group 1 had a normal body mass index (BMI), but overall this cohort was overweight. There was no different in BMI between subjects in Groups 2 and 3. Obesity is a risk factor for both IIH and the development of chronic daily headache (6). Although there was a statistically significant difference in both mean CSF pressure and opening pressure between the three groups, only some of the patients in Group 3 met criteria for the diagnosis of IIH by current standards (7). Pressures between 201–249mm CSF are non-diagnostic (8). BTSS has been noted in a majority of patients with IIH by various investigators. It is less commonly encountered in a typical practice setting, even in patients with papilloedema. The high prevalence of BTSS in this cohort is perhaps attributable to the imaging technique used, which the investigators previously found to have a very high detection rate of transverse sinus stenosis (three dimensional phase contrast images with 15 cm/s velocity encoding). Conventional MR venography is often performed using two dimensional time of flight, and the images are likely subjected to less scrutiny in the practice setting than the research setting. All subjects in Groups 2 and 3 had BTSS, whereas only four of 54 patients in group 1 had BTSS. As previously noted, unilateral transverse sinus stenosis was not associated with abnormal intracranial pressure. One-hour monitoring showed mean pressures that were consistently higher than the opening pressure in all groups. The importance of this finding cannot be overemphasised. An isolated CSF pressure measurement is but a ‘snapshot in time’ and may be spuriously high or low, depending on the situation and technique employed. Prolonged monitoring also revealed B-waves in Groups 2 and 3; B-waves are frequently recorded with increased intracranial pressure of various aetiologies, although there is far greater experience defining pressure wave abnormalities with intracranial pressure monitoring systems than with lumbar recording methods. Digre and colleagues (1) found that treatment of patients with IIHWOP with agents conventionally