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.

Venous Sinus Stenting in the Management of Patients with Intracranial Hypertension Manifesting with Skull Base Cerebrospinal Fluid Leaks.

BACKGROUNDRhinorrhea due to lateral skull base cerebrospinal fluid (CSF) leaks can be a challenge to manage. Multiple strategies exist for treating CSF leaks in this region including direct repair, posterior Eustachian tube packing, and CSF diversion. Endonasal closure of the Eustachian tube has been reported using cerclage and mucosal flaps.OBSERVATIONSWe present the first reported case of endoscopic autologous fat packing of the Eustachian tube orifice to repair a CSF leak. In this case a 42-year-old woman who underwent middle fossa meningioma resection 20 years ago presented with refractory CSF rhinorrhea despite blind sac closure of the ear canal. This persisted after CSF diversion and only resolved after endoscopic endonasal Eustachian tube closure described herein.LESSONSThis technique is simple to perform with minimal risk of morbidity. Eustachian tube orifice fat packing may be particularly useful for patients with refractory CSF rhinorrhea with low CSF pressure.

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.

Changes in intracranial venous hemodynamics in a patient with idiopathic intracranial hypertension after lumbar puncture precedes therapeutic success.

Skull base cerebrospinal fluid (CSF) leaks can lead to severe complications and require appropriate diagnosis and treatment. Cisternography is applied when exact localization via conventional imaging is not successful. The present study is aimed at identifying factors with potential impact on radiological results and surgical success. Cisternography followed by surgical repair due to skull base CSF leaks was performed in 63 cases between 2002 and 2020. The clinical and radiological findings were analyzed retrospectively. The etiology of CSF leaks was traumatic in 30.2%, spontaneous in 36.5%, and iatrogenic in 33.3%. The sensitivity of cisternography was 87.9%. Spontaneous CSF leaks tended to be diagnosed less frequently via cisternography and were significantly less frequently localized intraoperatively. The median postoperative follow-up period was 34 months. The primary surgical success rate was 79.4%, with a significantly higher success rate for lateral than for anterior skull base defects. Surgical failure tended to be lower in iatrogenic and higher in traumatic defects. Cisternography proved to be a highly sensitive method to localize skull base CSF leaks and can be recommended for advanced diagnostics. Iatrogenic leaks seemed to be more likely to have a favorable surgical outcome, whereas traumatic leaks tended to have a lower surgical success rate.

To the Editor: Salih et al1 recently published a meta-analysis on cerebrospinal fluid (CSF) shunting in idiopathic intracranial hypertension (IIH). This publication among others2 is important in highlighting the lack of detail provided in common data points and the need for uniformity in reporting outcome measures when assessing the success of any intervention. IIH is a condition managed by neurologists, ophthalmologists, neurosurgeons, and more recently interventional radiologists. Each specialist sees a different angle of the condition; however, the contemporary literature is there to guide us in the advances in our understanding of the disease and how to manage it. IIH is a systemic metabolic disease and comes under the classification of pseudotumor cerebri syndrome.3 This distinction is important as pseudotumor cerebri syndrome may be primary (IIH) or arise from an identifiable secondary cause such as anemia, medication use, or indeed cerebral venous sinus thrombosis.3-5 Outcomes from shunting in secondary pseudotumor vs IIH can be expectantly different, and why classifying the underlying pathology in this context is essential. The authors have not detailed this nuance for readers nor provided an assessment of quality of the studies specifically against any version of the diagnostic criteria. The 2002 Friedman and Jacobson criteria6 are cited as useful for diagnosis, which is in part true but for the time frame when most included studies performed data capture. However, in modern practice, these have been superseded by the revised diagnostic criteria for pseudotumor cerebri syndrome which were published in 2013.3 A key concern we have is the discussion detailing management strategies which was not the focus of the meta-analysis. Papilloedema is a key single point of entry to the investigational pathway,3-5 which has been omitted in their discussion. We agree that establishing the diagnosis of IIH early is important, but this is not based on symptoms of headache, visual loss or visual changes, and tinnitus, which are nonspecific. Yri and Jensen7 eloquently showed that in a control population, one-third reported transient visual obscurations, one-quarter had pulsatile tinnitus, and one-quarter experienced double vision. Indeed, the controls' headache phenotype had features of a raised ICP headache. More intriguing still was that one-quarter of those without IIH had improvement of their headache after lumbar puncture. We, and a multidisciplinary group, therefore strongly discourage the use of symptoms to guide surgical management in IIH.4,5 We agree that venography is absolutely critical in the assessment of papilledema to exclude cerebral venous sinus thrombosis which has devasting consequences if missed.4,5 We would be concerned about this over emphasis on dural venous sinus stenting (DVSS) in the absence of randomized control trial evidence. The tsunami of institutional-based case series in stenting is challenging to unpick the indications for the intervention and indeed the heterogenous outcomes that have been reported.8 We agree that there is a role for DVSS in IIH, and to address this gap in the literature, we are spearheading a randomized control trial in the United Kingdom for the evaluation of CSF diversion and DVSS in those with visual failure in IIH. We are encouraged by the reducing complication rate reported.1 This too has been our local experience which we believe is due to a dedicated CSF shunt pathway, CSF specialist surgeons, and a standardized protocol: where there is a preference for a frontal ventriculoperitoneal shunt, use of adjustable gravitational valves, an implantable ICP monitoring device in line with the shunt to optimize CSF drainage and identify possible future malfunction, frameless stereotactic image guidance for insertion of the ventricular catheter, and laparoscopic placement of the peritoneal end in patients with high body mass index.9,10 Horizon scanning in IIH reveals an avenue where the need for surgical intervention could be reduced. This has been the translation of glucagon-like peptide-1 receptor agonists from an animal model with raised ICP (hydrocephalic)11 to the first phase 2 study assessing the biological effect of the glucagon-like peptide-1 receptor agonist exenatide on ICP using highly accurate telemetric ICP monitors. Exenatide was successful in reducing ICP at 2.5, 24 hours, and 12 weeks.12 To our final point, there is firm evidence that IIH is a metabolic disease encompassing a spectrum of systemic manifestations. There is 2-fold risk of cardiovascular disease, presence of insulin resistance, increased truncal adiposity, hyperleptinemia, fertility, and pregnancy complications.13-15 These features are in excess than that driven by the presence of obesity. Adipose tissue in IIH has a unique profile of transcription and metabolic dysregulation driving lipogenesis and promoting increased adipose deposition.15 Hormonal perturbations have been identified with patients noted to have a unique phenotype of serum and CSF androgen excess and a dysregulated glucocorticoid phenotype.16,17 Weight loss is now established as the only disease-modifying therapy with bariatric surgery producing long-term control of ICP.18 Although venous sinus stenosis is almost universally observed in active IIH, we strongly believe that this reflects a consequence of the disease rather than the casual driver in the majority.

Background: Patients with skull base cerebrospinal fluid (CSF) leaks present with headaches, fluid in the ear(s), and/or rhinorrhea, which are vague symptoms. Beta-2-transferrin protein assays are the gold standard for identifying CSF leaks, but adequate samples cannot always be collected, and the results give no specific localizing information. Medical imaging, including Computed Tomography (CT), Magnetic Resonance (MR), and Nuclear Medicine (NM) cisternography can be utilized to identify and localize CSF leaks, but are imperfect tests. This study aims to determine the best imaging modality for identifying and localizing skull base CSF leaks by comparing CT, MR, and NM Cisternogram results to beta-2-transferrin assay and intraoperative visualization as criterion standards. Methods: In this ongoing study, patient cisternogram and pre-cisternogram imaging and results were acquired from the electronic medical record, radiology information system, and picture archiving and communication system. Inclusion criteria include age greater than 18, suspected skull base CSF leak, and CT, MR, and/or NM cisternogram performed. MR cisternogram procedure included intrathecal gadolinium and NM SPECT-CT cisternogram procedure included intrathecal Tc-99m Sulfur Colloid. These data will be analyzed for positive and negative predictive values, sensitivity, specificity, and ROC Curve comparing to beta-2-transferrin assay results and surgical findings. Results: From 2018-2022, 30 patients with suspected skull base CSF leaks were evaluated. In this limited preliminary data set, MR was more sensitive than CT, CT was more sensitive than NM, there were three false negatives, and there were no false positives. Performing two types of cisternogram increased the chance of identifying leaks. More data is needed to draw stronger conclusions in this ongoing study. Conclusion/Potential Impact: The initial data suggests that MR cisternogram with intrathecal gadolinium is superior to CT and SPECT-CT cisternogram for detecting skull base CSF leaks. Localizing skull base CSF leaks helps enable surgeons to perform less invasive corrective procedures.

Venous sinus stenting is a valuable treatment for fulminant idiopathic intracranial hypertension

Imaging of Acquired Skull Base Cerebrospinal Fluid Leaks.

Pseudotumor Cerebri (Benign Intracranial Hypertension): Etiopathogenesis, Diagnosis, And Management

Although the two included RCTs showed modest benefits for acetazolamide for some outcomes, there is insufficient evidence to recommend or reject the efficacy of this intervention, or any other treatments currently available, for treating people with IIH. Further high-quality RCTs are required in order to adequately assess the effect of acetazolamide therapy in people with IIH.

Intrathecal Contrast-enhanced Computed Tomography and MR Cisternography for Skull Base Cerebrospinal Fluid Leaks and Other Intracranial Applications

Low cerebrospinal fluid protein in prepubertal children with idiopathic intracranial hypertension.

The scientific sessions this year included 2021 platform presentations and posters. There were 11 educational courses in neuro-ophthalmology and neuro-otology given by the following faculty: Robert Baloh, Laura Balcer, Valerie Biousse, James Corbett, Wayne Cornblath, Fiona Costello, Kathleen Digre, Eric Eggenberger, Scott Eggers, Terry Fife, Steven Galetta, Christopher Glisson, Timothy Hain, Janet Helminski, Aki Kawasaki, David Kumpe, R. John Leigh, Grant Liu, Mark Moster, Nancy Newman, David Newman-Toker, Victoria Pelak, Sharon Polensek, Valerie Purvin, John Pula, Janet Rucker, Jonathan Trobe, Ronald Tusa, Gregory Van Stavern, and David Zee. The topics most relevant to neuro-ophthalmologists are summarized here. NEURODEGENERATIVE DISEASES Adam Boxer and colleagues (San Francisco, CA) used eye movement recordings to identify clinical differences in patients with frontotemporal lobar degeneration (FTLD) who had tau vs. TDP-43 autopsy pathology. The investigators recorded saccades in 11 patients with FTLD-TDP-43 and 10 patients with FTLD-tau. Horizontal and vertical saccade times were higher in the tau group than the TDP-43 group (P < 0.02). Using a receiver operating curve (ROC) analysis, the authors demonstrated that slowed saccades accurately distinguished TDP-43 from tau patients. Detailed examination of the brainstem ocular motor nuclei was conducted in 5 representative patients and revealed increased pathologic burden in the tau patients. The authors concluded that saccadic abnormalities are a useful predictor of pathologic subtypes of FTLD, possibly due to greater brainstem involvement in the tau subtype. (S42.006) Shawn Smyth and colleagues (Aurora, CO) conducted a retrospective study of computerized visual field (CVF) defects in 9 patients with clinically diagnosed posterior cortical atrophy (PCA). Eight patients were found to have homonymous hemianopia (HH) or quadrantanopia and 1 had bilateral visual field constriction. All patients progressed to dementia (8 had probable Alzheimer disease and 1 had probable dementia with Lewy bodies). The authors concluded that the characteristic visual field defects seen in PCA patients probably reflect pathology to the primary and visual association cortices. (P09.171) OPTIC NEURITIS AND MULTIPLE SCLEROSIS Noa Raz and colleagues (Jerusalem, Israel) conducted psychophysical tests of visual function in patients with acute optic neuritis (ON) to characterize the deficits with respect to parvocellular and magnocellular pathways. Ten patients and 10 control subjects were studied at presentation, after 1 month, and after 4 months with visual acuity, computerized visual fields, contrast sensitivity, color perception, static high-contrast object detection, motion detection, coherent moving noise perception, and object-from-motion (OFM) perception. One month after the acute phase, the initial deficits of visual acuity, contrast sensitivity, color perception, visual fields, and static object detection had returned to normal or near-normal levels in 9 of 10 patients. However, the patients had persistently defective motion processing, with reduced OFM perception, higher motion detection thresholds, and prolonged reaction times. The level of OFM impairment correlated with the conduction delay detected on visual evoked potentials. The authors suggested that abnormalities of the magnocellular pathway after ON may be responsible for the patients’ persistent visual complaints, particularly regarding motion processing, despite normal standard visual testing. Low-contrast acuity, which is probably mediated by the parvocellular pathway, was not assessed. (P04.077) Takafumi Hosokawa and colleagues (Osaka, Japan) reported a retrospective analysis of Goldmann visual field defects after ON in 15 patients with neuromyelitis optica (NMO) and 20 patients with multiple sclerosis (MS). Anti-aquaporin 4 antibodies were positive in all patients with NMO and negative in all patients with MS. Altitudinal hemianopia was seen in 33% of patients with NMO and in none of the patients with MS (P < 0.05). (The patients with MS all showed central scotomas.) The authors suggested that an altitudinal field defect may distinguish NMO from MS and postulated an ischemic mechanism for the optic neuropathy in NMO. The study was limited by a small sample size, and the results are at variance with the Optic Neuritis Treatment Trial, which found that 15% of typical patients with ON had altitudinal defects. (P04.093) Claire Riley and colleagues (New York, NY) conducted a meta-analysis to evaluate the prognostic value of cerebrospinal fluid (CSF) abnormalities in patients with a clinically isolated syndrome (CIS) and >2 MRI lesions to determine progression to clinically definite multiple sclerosis (cdMS). Using unpublished data from the trials of glatiramer acetate and interferon beta for patients with CIS (BENEFIT, IFNβ-1a ETOMS, and GA PreCISe), they examined the CSF results and clinical outcomes from patients receiving placebo. Abnormal CSF was defined as oligoclonal banding (OCBs) and/or an elevated IgG index, and patients without both sets of these data were excluded. The presence of a CSF abnormality did not predict the likelihood of progression to cdMS. In addition, this study demonstrated that most patients with CIS and MRI abnormalities also have CSF abnormalities, but that the presence of CSF abnormalities does not have significant additional prognostic value in predicting the risk of cdMS over 2 years. (P02.119) Jonathan McNulty and colleagues (Dublin, Ireland) conducted a diffusion tensor tractography study to evaluate the integrity of the medial longitudinal fasciculus (MLF) in patients with internuclear ophthalmoplegia (INO). They studied 12 patients with INO and 12 matched control subjects. Participants underwent conventional MRI and diffusion tensor imaging. Regions of interest approximating the MLF were identified. Qualitative MLF abnormalities were detected in all 12 subjects and in no control subjects. One shortcoming was that this method is not specific and produces extraneous fiber tracts apart from the MLF. (P04.082) Ari Green and colleagues (San Francisco, CA) reported the correlation between N-acetylaspartate (NAA) levels in normal-appearing gray matter (NAGM) and a measurement of retinal nerve fiber layer (RNFL) thickness performed 2 years later in a cohort of patients with MS and CIS. They studied 179 patients (aged 32.9 ± 9.5, 65% women) using proton spectroscopy imaging (1H-magnetic resonance spectroscopy [MRS]). NAGM NAA values correlated with average RNFL measures (R = 0.22, P < 0.0001). This study demonstrates that reduced cerebral NAA levels are predictive of future axonal loss in the anterior visual pathway. (P05.156) Esther Bisker and colleagues (Philadelphia, PA) conducted a longitudinal study to assess the degree of RNFL thinning associated with the loss of low-contrast acuity and high-contrast acuity in patients with MS. In their study, 365 patients (725 eyes) underwent optical coherence tomography (OCT)-3 imaging at baseline and at 6-month intervals during a mean follow-up period of 1.5 years (range 0.5-3.7 years) at three academic centers. Visual function testing was performed using low-contrast (2.5 and 1.25% levels) and Early Treatment Diabetic Retinopathy Study (ETDRS) acuity charts. Worsening of low-contrast acuity was noted in 33% of MS eyes. Of these eyes with visual loss, only one third had a known history of ON. Two-line (10-letter) losses of 2.5% low-contrast acuity were associated with a 1.6-μm decrement in RNFL thickness over time (P = 0.009), and losses of 1.25% contrast acuity were associated with a 3.7-μm decrement (P = 0.02). The authors concluded that visual loss may be present even in the absence of a history of ON and that reduced low-contrast acuity is associated with RNFL thinning over time. These findings suggest that gradual optic nerve axonal loss may be an important feature of MS. (S57.004) Deanna Cettomai and colleagues (Baltimore, MD) reported the concordance between RNFL thickness measured by OCT and the clinical findings of optic nerve pallor or afferent pupillary defect (APD) on 212 consecutive patients. The mean RNFL was 96 ± 15 m (n = 366) in eyes without pallor and 78.7 ± 20.6 m (n = 58) in eyes with pallor. Mean RNFL was 84.7±16.1 m (n = 41) for eyes with an APD was detected and 95.4±16.8 μm (n = 383) for eyes without an APD. In patients for whom the ratio of the mean RNFL between the two eyes was <90%, an APD was detected on clinical examination in 86% (sensitivity = 0.28, specificity = 0.93). There was wide variability across physicians in the accuracy of detecting pallor or an APD. The authors suggested that OCT is a more sensitive measure of subclinical optic nerve damage than clinical examination alone and that OCT may be a useful adjunct in the management of patients with MS. (P05.158) Salim Abboud and colleagues (Hinckley, OH) reported their findings on the reproducibility of serial OCT without pharmacologic pupillary dilation (PPD). They conducted 2 serial measurements at least 1 week apart of the peripapillary RNFL thickness and macular volume (MV) in 10 consecutive healthy volunteers by Stratus OCT without PPD. All studies were conducted by a single operator. Across subjects, the coefficient of variation (COV) for independent serial measures of RNFL was 2.86% and for MV was 1.90%. The authors concluded that serial measurements of RNFL and MV are sufficiently precise to use as outcome measures in longitudinal studies, even when implemented without PPD. (P05.164) Sally Chang and colleagues (Philadelphia, PA) evaluated the utility of measuring low-contrast acuity in addition to the standard Multiple Sclerosis Functional Composite (MSFC) by assessing the strength of correlations of these assessments with RNFL thickness measurements. They studied 164 patients (326 eyes, aged 47 ± 10 years), measuring low-contrast letter acuity (2.5% and 1.25% levels), high-contrast acuity (ETDRS charts), and standard MSFC. Scores for MSFC with low-contrast acuity added (MSFC-4) had greater correlations with RNFL thickness compared with the standard MSFC (P = 0.07 for MSFC, P = 0.005 for MSFC-4 with 2.5% low-contrast, and P = 0.007 for MSFC-4 with 1.25% contrast). The authors concluded that measurement of low-contrast acuity increases the capacity of the MSFC to capture the effects of axonal loss in the anterior visual pathway. (P04.076) Gurdesh Bedi and colleagues (Miami Beach, FL) conducted a retrospective study to evaluate the efficacy of rituximab on the relapse rate and disability in NMO. Among 19 patients treated with rituximab, relapses occurred in 5 patients. The authors concluded that rituximab leads to a significant reduction in relapses in patents with NMO. (P04.099) NONARTERITIC ANTERIOR ISCHEMIC OPTIC NEUROPATHY Edward Atkins and colleagues (Atlanta, GA) evaluated the treatment of nonarteritic anterior ischemic optic neuropathy (NAION) in the United Stated using a Web-based anonymous survey (n = 1595) of US neuro-ophthalmologists (US-NO = 350), Georgia ophthalmologists (GA-O = 340), Georgia neurologists (GA-N = 322), and Georgia optometrists (GA-OD = 583). For acute treatment, 63% of GA-N and GA-O and 80% of US-NO use antiplatelet agents, 10% of physicians use oral steroids, 19% of GA-N use high-dose intravenous steroids, 22% of US-NO and 13% of GA-O use topical brimonidine, and 7% of US-NO use intravitreal bevacizumab. For secondary prevention of fellow eye involvement, >74% physicians use antiplatelet agents, whereas 10%-15% of ophthalmology-trained US-NO and GA-O also use brimonidine in this setting. More than 80% of physicians manage vascular risk factors aggressively; 15% of US-NO obtain carotid ultrasound compared with 51% of GA-O and 72% of GA-N, and 16% of US-NO obtain neuro-imaging compared with 25% of GA-O and 84% of GA-N. The authors conclude that, despite insufficient evidence, most physicians currently use antiplatelet agents for acute treatment and secondary prevention of NAION. Other popular treatments include intravitreal bevacizumab, topical brimonidine, and steroids. Neurologists are less familiar with the management of NAION than ophthalmologists and neuro-ophthalmologists. (P04.079) VISUAL LOSS Wolfgang Heide and colleagues (Celle, Germany) investigated visual search patterns in patients with acute HH. They tested the hypothesis that visual search in HH is determined purely by the visual-sensory deficit by comparing 9 patients with HH due to acute occipital stroke with 9 healthy subjects with a simulated “virtual” HH (VHH) and 9 control subjects with normal visual fields. They recorded eye movements while subjects searched for targets among distractors. All patients, even those with small lesions restricted to the visual cortex, showed longer search durations than VHH subjects. Their longer search duration correlated with a higher number of both fixations and “re-fixations” (repeated scanning of fixated items). Scan-path strategies were similar in HH and VHH subjects. The authors concluded that pure visual input failure alone does not fully account for abnormal visual search in patients with isolated occipital lesions. They postulate that the longer search durations may result either from changes in visual attention due to disconnections of the visual cortex or from an early stage of compensatory eye movements. (S57.005) Sashank Prasad (Philadelphia, PA) received the S. Weir Mitchell award for excellence in basic science research from the American Academy of Neurology Alliance. He and his colleagues studied structural and functional changes of the visual pathway in patients with early-onset blindness. They studied 10 blind subjects and 10 sighted control subjects, collecting BOLD functional MRI (fMRI) data (during a language comprehension/semantic decision task), a volumetric anatomical scan, a resting perfusion scan, and diffusion tensor imaging. They found that during sentence comprehension, blind subjects demonstrated significant occipital activation in addition to left hemispheric language areas (BOLD Δ, blind 0.9% vs. sighted 0.0%; P < 0.05). Furthermore, they found a positive correlation across subjects between resting occipital perfusion and the amount of cross-modal task activation (R = 0.5; P < 0.05). In addition, white matter atrophy and a reduction in anisotropy were correlated (R = 0.7; P = 0.07). On the other hand, no structural measures predicted the amount of functional cross-modal activation (P > 0.1). The authors concluded that significant structural and functional differences exist between early-blind and sighted subjects. In addition, lack of correlation between structural and functional measures may suggest that these forms of plasticity are independent in the brain's response to early blindness. A larger study is necessary to explore that possibility. IDIOPATHIC INTRACRANIAL HYPERTENSION In a retrospective review of 230 consecutive patients with idiopathic intracranial hypertension (IIH) over 8 years, Sachin Kedar and colleagues (Jackson, MS) studied the effect of patient factors on the level of opening pressure (OP) in patients at presentation and the effect of OP on visual outcomes. They found an OP at presentation of 388 ± 93 mm H2O that negatively correlated with age (r = 0.2). Gender, race, initial body mass index (BMI), weight change, presenting symptom, and time interval to presentation were not associated with OP. Higher OP was associated with worse initial vision. Patients with visual acuity (VA) ≥20/100 had an OP of 382 ± 90 mm H2O and those with a VA <20/100 had an OP of 515 ± 77 mm H2O; patients with normal visual fields (VFs) had an OP of 390 ± 85 mm H2O and those with severely constricted VFs had an OP of 439 ± 110 mm H2O. Patients with normal-appearing optic nerves had an OP of 358 ± 94 mm H2O, whereas those with grade 4-5 papilledema had an OP of 439 ± 109 mm H2O. There was no significant association, however, between OP and visual outcome (improvement or worsening of VA or VFs or appearance of ON during follow-up). The authors concluded that a higher presenting OP in patients with IIH is associated with worse initial VA, VF loss, and ON appearance, but that OP is not predictive of the clinical course. (P04.080) J. Alexander Fraser and colleagues (Atlanta, GA) conducted a case-control study to evaluate potential risk factors for IIH in 24 men and matched control subjects. They administered a telephone questionnaire (including the Androgen Deficiency of Aging Men [ADAM] questionnaire for hypogonadism and the Berlin questionnaire for sleep apnea) and explored medical comorbidities, obesity patterns, endocrinologic problems, reproductive and and sleep for men with IIH were more than control subjects to have of The authors concluded that men with IIH have a higher of of and sleep and that these factors may be and colleagues GA) conducted a retrospective cohort study of consecutive with IIH and matched control subjects from three centers. In this group they 20 patients than years at and with a normal were more to be white (P = vs. than the of the IIH patients with IIH had a but were (P = vs. presentation, they were less to (P < vs. and more to of visual changes (P = vs. they were more to have persistent optic (P = but they had not visual outcomes than patients Among patients with normal IIH was more (P = vs. patient with IIH who had a normal had visual loss in either eye (P = vs. The authors concluded that patients and those with a normal a small of those with IIH but to have visual outcomes than typical patients with DISEASES and colleagues reported a patient with ophthalmoplegia and a in without associated visual loss or optic The patient was a who had loss, and in addition to There was no loss of visual acuity, optic visual field or optical coherence tomography visual evoked were revealed and revealed not Multiple were identified. The associated with multiple and were and no were A was in which reported in two patients with optic The the of associated with by multiple abnormalities in the absence of optic nerve and colleagues conducted a retrospective study of patients with ophthalmoplegia to the of to In a review of patients with who underwent and had they found that the of a was of and that of a was of of the subjects who had negative had positive The authors suggested that patients with a of that of higher and colleagues reported abnormalities of the and visual pathway in patients with studied by They studied 5 patients with and 10 healthy control subjects. They the correlations between diffusion tensor tractography and data with OCT measures and activation of the visual revealed optic nerve and as as a significant reduction of occipital gray in all patients with There was reduced anisotropy in the left optic which correlated across subjects with OCT RNFL measurements. The patients demonstrated reduced activation in The authors concluded that optic nerve damage in may structural and functional changes of the visual the study does not the that are also due to and colleagues visual disability in the of risk factors in = = and = from independent Of were clinically and of the subjects were received a questionnaire on and visual loss for and the Visual which impairment in of from to patients with the had higher compared with those with the and (P < 0.0001). was associated with visual loss in a ratio interval P = of on the other hand, did not with visual loss on analysis P = The authors concluded that the a useful in assessing visual in and that may to reduced visual The of is not and colleagues reported a correlation in between axonal number and the of in optic nerve Their were on a analysis of 2 patients eyes) and control subjects They found that the of the optic nerve was (P < than in the and They concluded that the of the are the most in and have the amount of The mechanism by which reduced number and are to be and colleagues the integrity of the that from the retinal in optic They studied 5 patients with 4 patients with optic and 9 control subjects. They optic neuropathy by A was collecting from to and a using between and The was by comparing the level to the baseline A significant of levels by was in control subjects ± and in patients ± ± without a between eyes of 2 patients with and 2 control subjects, analysis of retinal the optic nerve revealed a of in patients with compared with control subjects, despite the loss of The authors concluded that in and is of Their autopsy study in that this may to of Mark (New York, NY) conducted a retrospective analysis of patients with ocular to determine the effect of in and progression to Patients who had for longer than 4 years or who were identified. patients with received was present at the examination in of the group and of the the study is limited by retrospective the authors concluded that in patients with may the of delay and control and colleagues evaluated the outcomes of a cohort of patients with treated with trials have to of over alone as initial but these studies were limited by duration or sensitive outcome The authors the clinical outcomes of patients with receiving (n = or (n = for longer than Patients were by and follow-up was were Patients treated with to between and 12 80% of patients for months had an and of or pharmacologic Patients treated with had a reduction after 12 at had from and patients of The authors concluded that is an treatment as either or to The follow-up demonstrated a effect of during the and third year of that not be demonstrated by studies of This study, however, did not include patients treated with a of the of and colleagues reported the utility of the to In the the is by the while the patient on the is a deficit in the one a saccade at the of the The authors by measuring the of the at patients demonstrated an deficit of a from normal to bilateral The deficits occurred even at the Across subjects, correlated with testing = P = than with testing = P = The of saccades was times greater in patients than in control subjects. The authors concluded that the is a sensitive measure of and colleagues studied the value of in patients with acute syndrome in a study over 9 years. Their cohort of consecutive patients with who with and/or motion and had at least one stroke risk They underwent and testing for ocular of and were by MRI or A of patients with were of whom had a and had a brainstem ischemic 2 1 and 1 was present in 15% of the study and correlated with brainstem occurred in of with a of with pure and of with a brainstem (P = Of the presence of predicted the presence of stroke in 2 of the patients in whom positive results for a had suggested a The authors concluded that is an of central pathologic when is detected is specific for brainstem involvement among patients with David and colleagues (Baltimore, MD) evaluated the of decision to clinical for stroke among patients with in the are that use a and patient data to suggest that the The authors evaluated by and of and with to The was a patient in average without disability presenting either with persistent at risk for or at risk for ischemic The strategies were and measures were and The authors found that for persistent operating at and specificity or at be less and not be For operating at and specificity at and less for the and not be The authors concluded that among patients at and colleagues CA) evaluated the association between and by patients with a with a In their study, of patients the of for with and without did not for Among patients with or with or all of their the for definite The of patients did not and The age of and duration of did not between patients with ± years) and patients without ± In patients with the age of of the of by an average of years and by 8 years. The duration of was between 1 and 1 The authors concluded that the association between and as a However, patients with and have during the The of as of a syndrome may be by later to the of and and colleagues (Baltimore, MD) evaluated the correlation between retinal vascular abnormalities and in They studied a study in assessments included and were evaluated for small or to a greater degree in with than in those without to and to even after for and with had increased of the on There was no association between and retinal vascular The authors concluded that with measures in possibly by as a for cerebral vascular and colleagues conducted an retrospective review to assess the of with the of They examined other and outcomes. The included and with a mean age at presentation of years (range years) and mean age of years at of was most to by eye syndrome eye and other ocular was found in 25% of the patients, among whom most were Among these patients, reported that the with of and reported with were for of the patients, among whom a reported The authors concluded that a and is associated with a of and other and ocular and reduced of were among these patients. Sashank of of the of Mark Moster, of of