AimTo evaluate differences in idiopathic intracranial hypertension (IIH) between french and american white patients.Aim and MethodsMedical records of all consecutive patients with definite IIH seen between 2001 and 2005 were reviewed in 4 academic medical centers (1 in the USA and 3 in France). Demographics, associated factors, and visual function at presentation and follow-up were collected. American white patients were compared to french white patients. American black patients are reported apart.ResultsWe included 197 patients (68 american white, 68 french white, and 61 american black). Obesity, recent gain weight, and other risk factors were similar in french and american white patients. The prediagnosis duration was longer in american white patients. They had similar cerebrospinal opening pressure. Visual acuity was similar in both groups at presentation and follow-up. Visual field loss was more severe in american white patients at presentation and follow-up, despite amelioration. Papilledema was more important in french white patients at presentation but american white patients presented more optic atrophy at follow-up. Medications, dietary changes, CSF shunt procedures, and optic nerve sheath fenestration were more frequently used in american white patients. Three percent of american white patients and no french white patient experienced severe visual loss in at least one eye but this difference did not reach statistical significance (p = 0,41).DiscussionThe initial examination was more severe among american white patients. This initial difference did not appear to result from the degree of obesity, nor other risk factors, but may be related to the prediagnosis duration, longer in american patients. American white patients had more agressive treatments. The final examination was quite similar in both populations.ConclusionAmerican white patients were compared to french white patients. The outcome was a little bit worse at presentation among american white patients, and similar at follow-up, after more agressive treatments.