Objective: To describe the incidence and characteristics of acute and rapidly progressive visual loss in idiopathic intracranial hypertension (IIH).
Methods: We reviewed the medical records of all patients with IIH seen at two institutions. "Fulminant IIH" was defined as the acute onset of symptoms and signs of intracranial hypertension (less than 4 weeks between onset of initial symptoms and severe visual loss), rapid worsening of visual loss over a few days, and normal brain MRI and MR venography (or CT venogram).
Results: Sixteen cases with "fulminant IIH" were included (16 women, mean age 23.8 years [range 14 to 39 years]). All were obese. One patient had iron-deficiency anemia, four had systemic hypertension, and none had known sleep apnea syndrome. Acute or subacute headache, nausea and vomiting, and visual loss were present in all patients. The first lumbar puncture performed for the diagnosis showed a mean CSF opening pressure of 54.1 cm H(2)O (range 29 to 60 cm H(2)O). In addition to the initial lumbar puncture, medical treatment included acetazolamide (1 to 2 g/day) in all patients, and IV methylprednisolone in four patients. Repeat lumbar punctures were performed in 11 of the 16 patients. Surgical treatment (optic nerve sheath fenestration in five cases, lumboperitoneal CSF shunting procedure in nine cases, and ventriculoperitoneal shunting procedure in two cases) was performed because of ongoing visual loss in all cases. The median delay between evaluation in neuro-ophthalmology and surgery was 3 days (range a few hours to 37 days). All patients reported dramatic improvement of headaches and vomiting following surgery. Visual function improved in 14 cases, although 8 patients (50%) remained legally blind. Visual fields remained severely altered in all cases.
Conclusion: Severe and rapidly progressive visual loss suggests "fulminant idiopathic intracranial hypertension" and should prompt aggressive management. Urgent surgery may be required in these patients, and temporizing measures such as repeat lumbar punctures, lumbar drainage, and IV steroids considered.