Visual hallucinations in giant cell arteritis: association with visual loss

To evaluate the frequency and characteristics of visual hallucinations (VH) in patients with giant cell arteritis (GCA) and to determine their relationship to other visual phenomena.

This prospective study included 31 consecutive patients with GCA. All were asked whether they had experienced recent visual phenomena. Patients with visual symptoms underwent a comprehensive ophthalmologic examination. When unusual visual phenomena were reported, patients were asked to describe their nature, duration, and frequency of occurrence.

Visual symptoms occurred in 6 patients: permanent visual loss in 5 and amaurosis fugax in one. In 4 of the 5 patients with permanent visual loss, it was preceded by intermittent VH over a period of 1-10 days. Patients were aware of the unreal nature of the visions. Hallucinations disappeared within 2 weeks, but in one patient, recurred 6 months later in association with further visual deterioration.

The occurrence of visual hallucinations in patients with GCA-associated visual loss is more common than previously appreciated. As hallucinations preceded permanent loss of vision, this phenomenon may serve as a harbinger of imminent visual loss.