Bilateral transient visual obscurations with headaches during alpha-II interferon therapy: a case report.

A 40 year-old woman receiving alpha interferon therapy for chronic active hepatitis C presented transient bilateral visual obscurations with associated visual field defects and headaches, with elevated cryoglobulin levels. These manifestations mimicked the clinical picture of migraine and were associated with worsening of previous moderate Raynaud's syndrome and diffuse paraventricular lesions of the white matter seen in cerebral MRI. Bilateral posterior cerebral transient ischemic episodes rather than an anterior visual pathway lesion were thought to be responsible for the clinical symptoms though the exact role of interferon in these vasospastic-like disorders remains speculative. Their possible relationship with increased cryoglobulinemia is uncertain. We suggest that Raynaud's phenomenon may have a predisposing role for these manifestations.