GENICULOCALCARINE HYPERINTENSITIES ON BRAIN MAGNETIC-RESONANCE-IMAGING ASSOCIATED WITH VISUAL HALLUCINATIONS IN THE ELDERLY

Magnetic resonance scans of five geriatric patients presenting with fo rmed visual hallucinations in the absence of other psychopathology wer e compared with those of 12 healthy elderly subjects for the presence and extent of subcortical and periventricular signal hyperintensity. W hile the number of discrete brain lesions did not differ between group s, scans from the patient group contained a higher incidence (100% vs. 50%) and greater mean size(11.1 vs. 2.9 mm) of periventricular signal hyperintensity in the posterior region. Peripheral visual acuity was impaired in all of the patients, but cerebrovascular risk factors were not elevated in this group. The authors suggest that structural abnor malities in the area of the primary visual pathway may predispose some older individuals, particularly those with poor peripheral visual acu ity, to develop the symptom of visual hallucination.