Samuel Bidot

Brain Imaging in Idiopathic Intracranial Hypertension.

Background: The primary role of brain imaging in idiopathic intracranial hypertension (IIH) is to exclude other pathologies causing intracranial hypertension. However, subtle radiologic findings suggestive of IIH have emerged with modern neuroimaging. This review provides a detailed description of the imaging findings reported in IIH and discusses their possible roles in the pathophysiology and the diagnosis of IIH. Evidence Acquisition: References were identified by searches of PubMed from 1955 to January 2015, with the terms “idiopathic intracranial hypertension,” “pseudotumor cerebri,” “intracranial hypertension,” “benign intracranial hypertension,” “magnetic resonance imaging,” “magnetic resonance venography,” “computed tomography (CT),” “CT venography,” “imaging,” and “cerebrospinal fluid (CSF) leak.” Additional references were identified by hand search of relevant articles. When possible, we extracted the number of patients and control subjects from each study for each radiological finding. When at least 2 studies used the same criteria to define a radiological finding, all patients from these studies were pooled to obtain a mean sensitivity and specificity with 95% confidence interval. Results: Specific neuroimaging findings may suggest long-standing IIH, including empty sella, flattening of the posterior globes, optic nerve head protrusion, distention of the optic nerve sheaths, tortuosity of the optic nerve, cerebellar tonsillar herniation, meningoceles, CSF leaks, and transverse venous sinus stenosis. Conclusion: Although IIH remains a diagnosis of exclusion, the most recently proposed diagnostic criteria have included neuroimaging findings to suggest IIH when major diagnostic criteria are not fulfilled. However, these findings are not diagnostic of IIH, and their presence is not required for the diagnosis of definite IIH. Their incidental discovery on brain imaging should not prompt invasive procedures, unless other signs of IIH, such as papilledema, are present.

Asymmetric papilledema in idiopathic intracranial hypertension

Background: Very asymmetric papilledema in idiopathic intracranial hypertension (IIH) is rare, and few studies have dealt with this atypical presentation of IIH. Our aim was to describe the clinical and radiologic features of patients with IIH and very asymmetric papilledema. Methods: We identified all adult patients from our IIH database with very asymmetric papilledema defined as a ≥2 modified Frisén grade difference between the 2 eyes. Demographic data and initial symptoms were collected, and all brain imaging studies performed at our institution were reviewed. Results: Of the 559 adult patients with definite IIH, 20 (3.6%; 95% confidence interval [CI], 2.3–5.6) had very asymmetric papilledema at initial evaluation. They were older (39 vs 30 years; P < 0.001), had lower cerebrospinal opening pressure (35.5 vs 36 cm of water; P = 0.03), and were more likely to be asymptomatic compared with patients with symmetric papilledema (27% vs 3%; P < 0.001). Visual fields were worse on the side of the highest-grade papilledema (P = 0.02). The bony optic canal was smaller on the side of the lowest-grade edema in all 8 patients (100%) in whom the imaging was sufficient for reliable measurements (P = 0.008). Conclusions: IIH with very asymmetric papilledema is uncommon. Very asymmetric papilledema may result from differences in size of the bony optic canals, supporting the concept of compartmentation of the perioptic subarachnoid spaces.

Teaching Ophthalmoscopy to Medical Students (TOTeMS) II: A One-Year Retention Study

OBJECTIVE: We previously demonstrated that medical students (MS) performed more accurately and preferred using photographs than direct ophthalmoscopy to examine the ocular fundus. We hypothesized that these differences would persist over time. BACKGROUND: Learning direct ophthalmoscopy is challenging, and MS long-term retention of ophthalmoscopy skills is poor. DESIGN/METHODS: One year after initial training, second-year MS were randomized and reevaluated on their ability to examine the ocular fundus using either fundus photographs or direct ophthalmoscopy on eye simulators. Positive and negative affect, preferences, and clinical experiences with ocular fundus examination were assessed. RESULTS: 107/119 students (90%) who participated in the original study completed this one-year retention study. Students answered 34/48 (71%) questions correctly using photographs and 31/48 (65%) correctly using ophthalmoscopy (p<.01). Both photograph and ophthalmoscopy groups answered five fewer questions correctly on average than one year prior (p<.001). Students rated photographs as “easier than ophthalmoscopy” (8/10 vs. 6/10, respectively; p<.001). Students’ positive affect scores were higher in the photograph group (26.5) than in the ophthalmoscopy group (23.2; p=.03). Students tested on simulators reported lower positive affect than one year ago (decrease of 6.4 points, p<0.001). Students’ self-reported median frequency of fundus examination over the preceding year was <10% (IQR 0-20%). Ocular fundus examination was not performed because of discomfort with the examination (38%), discouragement by their preceptor (20%), and insufficient time (15%). 79% of students felt uncomfortable with ophthalmoscopy, and 44% stated that they would not perform ophthalmoscopy during a general physical examination. 76% stated they would prefer using photographs instead of ophthalmoscopy for fundus examination. CONCLUSIONS: Students preferred photographs for examining the ocular fundus and were more accurate using photographs vs. direct ophthalmoscopy one year after training. The increasing availability of non-mydriatic ocular fundus photography may allow more frequent and accurate examination of the ocular fundus by MS and non-ophthalmologists in many clinical settings. Study Supported by: Research to Prevent Blindness, NIH/NEI P30-EY06360, K23-EY019341 Disclosure: Dr. Mackay has nothing to disclose. Dr. Garza has nothing to disclose. Dr. Bruce has received personal compensation for activities with Kaiser Permanente. Dr. Bruce has received research support from Pfizer, Inc. and Teva Neuroscience. Dr. Bidot has nothing to disclose. Dr. Kelly has nothing to disclose. Dr. Graubart has nothing to disclose. Dr. Newman has received personal compensation for activities with Santhera. Dr. Biousse has received personal compensation in an editorial capacity for Up To Date.

The Optic Canal Size Is Associated With the Severity of Papilledema and Poor Visual Function in Idiopathic Intracranial Hypertension.

Background: To determine whether the size of the bony optic canal is associated with the severity of papilledema and poor visual function in idiopathic intracranial hypertension (IIH). Methods: We performed a retrospective review of definite patients with IIH with requisite brain magnetic resonance imaging allowing for optic canal measurement. Clinical characteristics and automated (Humphrey) visual field results were reviewed; papilledema was graded according to the modified Frisén scale. Cross-sectional area of the optic canals was measured independently by 2 readers and averaged for each canal. Logistic regression modeling was applied. Results: Sixty-nine patients with IIH were included (mean age: 33; 91% women; 65% black). Controlling for age, sex, body mass index, race, and cerebrospinal fluid (CSF) opening pressure, each mm2 increase in canal size was associated with a 0.50 dB reduction in Humphrey visual field mean deviation (P = 0.006); this was likely mediated by the increased odds of Grade 4–5 papilledema or optic atrophy in patients with larger canals (odds ratio: 1.30 [95% CI: 1.10–1.55; P = 0.003] for Grade 4–5 papilledema or atrophy vs grade <4 papilledema per mm2 increase in canal size). Conclusions: Poor visual function and severe papilledema or optic atrophy were associated with a larger optic canal. Potential mechanisms include alteration of local CSF flow or bony remodeling at the optic canals.

Nonmydriatic retinal photography in the evaluation of acute neurologic conditions

SummaryOcular fundus examination is a fundamental component of the neurologic examination. Finding papilledema in headache patients or retinal arterial emboli in stroke patients can be extremely useful. Although examination of the ocular fundus with a direct ophthalmoscope is an important skill for all neurologists, it is rarely and unreliably performed. Nonmydriatic ocular fundus photography, which allows direct visualization of high-quality photographs of the ocular fundus, has been recently proposed for screening neurologic patients in urgent care settings such as emergency departments. This new technology has many potential applications in neurology, including e-transmission of images for remote interpretation.

Update on the Diagnosis and Treatment of Idiopathic Intracranial Hypertension

Idiopathic intracranial hypertension (IIH) is a rare disorder occurring more frequently in obese women of childbearing age, resulting in increased intracranial pressure (ICP) from an unknown cause. Recent advances in epidemiology, imaging, and treatment have provided a better understanding of IIH in recent years, with better identification of visual risk factors and atypical forms of IIH, including fulminant IIH and spontaneous cerebrospinal fluid leaks, and a randomized clinical trial providing the rationale for the use of acetazolamide. In addition, a revised version of the modified Dandy criteria for the diagnosis of IIH was suggested in 2013, with better definition of IIH in adults and children; however, controversy regarding nomenclature has precluded its acceptance among IIH experts. Finally, questions regarding the best surgical strategy, the indications for venous sinus stenting, and the diagnostic role of the radiologic findings commonly seen in IIH have remained unanswered.

Optic nerve head edema among patients presenting to the emergency department

Objective To determine the frequency of and predictive factors for optic nerve head edema (ONHE) among patients with headache, neurologic deficit, visual loss, or elevated blood pressure in the emergency department (ED). Methods Cross-sectional analysis was done of patients with ONHE in the prospective Fundus Photography vs Ophthalmoscopy Trial Outcomes in the Emergency Department (FOTO-ED) study. Demographics, neuroimaging results, management, and patient disposition were collected. Patients in the ONHE and non-ONHE groups were compared with bivariate and logistic regression analyses. Results Of 1,408 patients included, 37 (2.6%, 95% confidence interval 1.9–3.6) had ONHE (median age 31 [interquartile range 26–40] years, women 27 [73%], black 28 [76%]). ONHE was bilateral in 27 of 37 (73%). Presenting complaints were headache (18 of 37), visual loss (10 of 37), acute neurologic deficit (4 of 37), elevated blood pressure (2 of 37), and multiple (3 of 37). The most common final diagnoses were idiopathic intracranial hypertension (19 of 37), CSF shunt malfunction/infection (3 of 37), and optic neuritis (3 of 37). Multivariable logistic regression found that body mass index ≥35 kg/m2 (odds ratio [OR] 1.9, p = 0.0002), younger age (OR 0.5 per 10-year increase, p < 0.0001), and visual loss (OR 5, p = 0.0002) were associated with ONHE. Patients with ONHE were more likely to be admitted (62% vs 19%), to be referred to other specialists (100% vs 54%), and to receive neuroimaging (89% vs 63%) than patients without ONHE (p < 0.001). Fundus photographs in the ED allowed initial diagnosis of ONHE for 21 of 37 (57%) patients. Detection of ONHE on ED fundus photography changed the final diagnosis for 10 patients. Conclusions One in 38 patients (2.6%) presenting to the ED with a chief complaint of headache, neurologic deficit, visual loss, or elevated blood pressure had ONHE. Identification of ONHE altered patient disposition and contributed to the final diagnosis, confirming the importance of funduscopic examination in the ED.

Fundus Photography vs. Ophthalmoscopy Outcomes in the Emergency Department (FOTO-ED) Phase III: Web-based, In-service Training of Emergency Providers

ABSTRACT We evaluated a web-based training aimed at improving the review of fundus photography by emergency providers. 587 patients were included, 12.6% with relevant abnormalities. Emergency providers spent 31 minutes (median) training and evaluated 359 patients. Median post-test score improvement was 6 percentage points (IQR: 2–14; p = 0.06). Pre- vs. post-training, the emergency providers reviewed 45% vs. 43% of photographs; correctly identified abnormals in 67% vs. 57% of cases; and correctly identified normals in 80% vs. 84%. The Fundus photography vs. Ophthalmoscopy Trial Outcomes in the Emergency Department studies have demonstrated that emergency providers perform substantially better with fundus photography than direct ophthalmoscopy, but our web-based, in-service training did not result in further improvements at our institution.

A Puzzling Ocular Motility Disorder: Apparent Up-Gaze Fatigability in a Patient With Oculomotor Nerve Compression

ABSTRACT We report the case of a woman who developed right third nerve dysfunction with synkinesis and ocular neuromyotonia secondary to a compressive arterial aneurysm. Surprisingly, our examination showed a downward drift of the right eye in sustained up-gaze resulting in transient hypotropia, suggesting either fatigability of the superior rectus or contraction of the inferior rectus. We believe this ocular motility pattern is secondary to a co-contraction of the inferior rectus in up-gaze caused by synkinesis (explaining the downward drift), followed by failure of the inferior rectus to relax upon return to primary position caused by ocular neuromyotonia (explaining the hypotropia).

Nonmydriatic retinal photography in the evaluation of acute neurologic conditionsAuthors Respond

Ocular fundus examination is a fundamental component of the neurologic examination. Finding papilledema in headache patients or retinal arterial emboli in stroke patients can be extremely useful. Although examination of the ocular fundus with a direct ophthalmoscope is an important skill for all neurologists, it is rarely and unreliably performed. Nonmydriatic ocular fundus photography, which allows direct visualization of high-quality photographs of the ocular fundus, has been recently proposed for screening neurologic patients in urgent care settings such as emergency departments. This new technology has many potential applications in neurology, including e-transmission of images for remote interpretation.The article by Bidot et al.1 is worth appreciation. I would like to share my additional views on this important clinical device. Ophthalmoscopy is an important bedside test by which a clinician can diagnose, offer a differential diagnosis in an undiagnosed patient, and—once diagnosed—contribute to prognosis in various infectious and noninfectious diseases. These tests are well-described in certain noncommunicable diseases, but need validation by randomized double-blind trials in infectious diseases such as malaria and dengue.2,–,4 When a patient in critical condition presents to the emergency department, ophthalmoscopy without pupillary dilatation (time sparing) may be a useful clinical tool for diagnosis. Furthermore, pupillary dilation may at times bias …