Idiopathic intracranial hypertension in atypical demographics

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a condition that most often occurs in women of reproductive age with elevated body mass index (BMI) (typical patients). Individuals outside of this demographic group (atypical patients) may have a different pathophysiology underlying raised intracranial pressure (ICP) leading to unique clinical presentations and prognosis. METHODS: Retrospective chart review of patients with IIH in typical and atypical demographic groups: men, those diagnosed at age 40 or older and those with BMI <26.0 kg/m². RESULTS: 193 typical and 50 atypical patients with IIH were included. Age at diagnosis was higher in men and patients with normal BMI (37.2 ± 11.8 and 32.3 ± 9.8 years versus 27.3 ± 5.6 years). Older patients presented with headache less often than typical patients (42.9% versus 77.2%). Opening pressure on lumbar puncture (LP) and degree of optic disc edema were not significantly different between groups, though men had worse mean deviation (MD) on visual fields (VFs) (10.16 ± 10.40 dB versus 4.52 ± 5.53 dB in typical group). There was no significant difference between the typical and atypical groups in visual outcomes including number of patients requiring surgical treatment, development of optic atrophy and presence of persistent papilledema, though a trend toward worse VF MD was seen in men. In a pooled analysis of all patients, MD on VF at presentation was the only significant predictor of final visual outcome. CONCLUSION: Men and patients with normal BMI are diagnosed with IIH later in life. Clinical presentations of typical and atypical groups are similar, although older patients report headaches less frequently. Final visual outcomes were not significantly different between typical and atypical patients and VF loss at presentation is the most consistent predictor of final visual outcome in all patients.