LOW-AMPLITUDE EEGS IN DEMENTED AIDS PATIENTS

We have observed an unusual low amplitude, slow and featureless electr oencephalogram (EEG) pattern in some human immunodeficiency virus (HIV ) infected patients without focal lesions on computerized tomography ( CT scan) of the head. Out of 17 cases, 13 with AIDS and 4 with HIV pos itive status, 6 had low amplitude EEGs with slowing, all in the AIDS g roup. Nine of the 13 AIDS patients were demented, and 4 of these demen ted patients had slow verbal responses and mutism, indicating advanced HIV-related dementia. All 4 had low amplitude, slow EEGs. The patient s with low amplitude, slow EEGs also had atrophy on CT scan by visual assessment and by measurement of ventricular indices. Of 17 age-matche d controls referred for non-specific complaints such as headache and d izziness or for psychiatric disorders, 3 had EEGs read as low amplitud e with slowing; two had normal mental status and one was psychotic. Al though this EEG pattern is not etiologically specific, it may correlat e with advanced dementia and atrophy on CT scan in AIDS patients.