Greater than expected prevalence of pseudotumor cerebri: a prospective study.

BACKGROUND

The overall incidence of pseudotumor cerebri (PTC) has been estimated at 1 per 100,000 in the general population, with an increase to 19 per 100,000 among overweight patients. About 25% of affected patients are asymptomatic until they present with vision loss. We hypothesized that PTC would be highly prevalent among obese patients seeking bariatric surgery. The setting of our study was a university hospital.

METHODS

During a 2-year period, clinical data were collected from candidates for bariatric surgery. A group of the study population was concurrently screened for papilledema using fundus imaging. All images were reviewed by a single neuro-ophthalmologist. All patients with abnormal images were referred for neuro-ophthalmic evaluation.

RESULTS

The imaging group (78% women) had a mean age of 45.4 ± 10.7 years, and the mean body mass index of 47.8 ± 8.7 kg/m(2). High definition nonmydriatic fundus imaging was normal in 489 patients (91.9%) and abnormal in 43 patients (8.9%). The subsequent evaluation by the neuro-ophthalmologist revealed ocular abnormalities other than optic disc edema in 27 patients (5.1%) and normal findings in 7 patients (1.3%). Five patients (.9%) declined additional evaluation. Four patients (.8%) had confirmed optic disc edema and normal brain magnetic resonance imaging findings. Of these patients, 3 underwent lumbar puncture, which confirmed the diagnosis of PTC.

CONCLUSIONS

We identified a greater prevalence of PTC overall (.65%) and in the imaging group (.9%) than previously reported or would have been predicted from the current data. Although routine funduscopic examination is of limited utility, these findings warrant additional investigation into the utility of, and optimal method for, screening morbidly obese patients for this co-morbidity.