Racial differences in idiopathic intracranial hypertension

Abstract

Objective: To evaluate racial differences in idiopathic intracranial hypertension (IIH).

Methods: Medical records of all consecutive patients with definite IIH seen between 1989 and 2006 were reviewed. Demographics, associated factors, and visual function at presentation and follow-up were collected. Black patients were compared to non-black patients.

Results: We included 450 patients (197 black, 253 non-black). Obesity, systemic hypertension, anemia, and sleep apnea were more common in black patients than in non-black patients (p </= 0.01). CSF opening pressure was higher in black patients (40 vs 34 cm CSF, p < 0.001). Visual acuity, visual field loss, and degree of papilledema at presentation and follow-up were worse in black patients (p </= 0.01). Diagnostic and therapeutic measures were similar between black patients and non-black patients, except for optic nerve sheath fenestration (p = 0.01) and lumbar puncture (p = 0.03), both more commonly performed on black patients. The relative risk of severe visual loss for black patients compared with non-black patients was 3.5 (95% CI 2.0 to 5.8, p < 0.001) in at least one eye and 4.8 (95% CI 2.1 to 10.9, p < 0.001) in both eyes. Logistic regression analysis supported race, anemia, body mass index, and male gender as independent risk factors for severe visual loss and suggested that racial differences may be partially accounted for by differences in CSF opening pressure, body mass index, and frequency of anemia.

Conclusion: Black patients with idiopathic intracranial hypertension (IIH) were more likely than non-black patients with IIH to have severe visual loss in at least one eye. This difference did not appear to result from diagnosis, treatment, or access to care, but may partially relate to differences in other risk factors. Black patients have a more aggressive disease and may need closer follow-up and lower thresholds for early intervention.