Giant cell (temporal) arteritis: a treatable cause of multi-infarct dementia.

Dementia occurs infrequently in patients with giant cell (temporal) arteritis (GCA). Three elderly women with biopsy-proven GCA showed abrupt cognitive decline during periods of clinically active GCA, 1 to 6 months after diagnostic temporal artery biopsy, during periods of corticosteroid taper. One patient had additional clinical signs of cerebral infarction and other ischemic phenomena. Reinstitution of higher oral doses of corticosteroids successfully prevented further cognitive losses and permitted gradual but incomplete improvement of cognitive function in 1 patient. Neuropsychologic data from 2 patients 7 to 10 months after temporal artery biopsy suggested multifocal cognitive impairment, and the 3rd patient appeared clinically to be globally, severely demented. Neuroimaging studies revealed multiple areas of infarction, predominantly in the posterior circulation territory. One patient had bilateral vertebral artery occlusions (digital subtraction angiography) and bilaterally reduced carotid system perfusion pressures (oculoplethysmography). There were no associated cardiovascular risk factors or family history of dementia in these patients.