OBJECTIVE: To compare French and American white patients with
idiopathic intracranial hypertension (IIH), and to determine
prognostic factors associated with
visual loss. METHODS: Medical records of all consecutive white patients with definite IIH seen between 2001 and 2006 in three French tertiary care medical centers and one American tertiary medical center were reviewed. Demographics, associated clinical features, and
visual function at presentation and follow-up were collected. French white patients were compared to American white patients. RESULTS: One hundred and thirty-four patients (66 French, 68 American) were included. American patients were 8.7 times more likely than French patients to have
visual acuity 20/60 or worse or
visual field constriction (95% CI: 2.1-36.1, p=0.0001). American patients were treated more aggressively than French patients. French patients were older (31 vs. 28 years, p=0.02) and more likely to have
anemia (20 vs. 2%, p<0.001). American patients had a longer duration of
symptoms prior to diagnosis (12 vs. 4 weeks, p=0.01) and longer follow-up than French patients (26 vs. 11 months, p=0.001).
Multivariable analysis found that nationality was an independent
risk factor for
visual loss. French and American patients did not differ regarding gender proportion,
frequency of
obesity,
sleep apnea,
endocrine diseases, or systemic
hypertension.
Cerebrospinal fluid (CSF) opening pressures were similar in both groups. CONCLUSION: American patients with IIH had worse
visual outcomes than French patients despite more aggressive treatment. These differences are not explained by differences in previously known
risk factors.
