The authors studied the relationship between brain metabolic activity and quantitative electroencephalographic power in AIDS. Basal ganglia and thalamic metabolic activity, measured with positron emission tomography, correlated positively with EEG power in the 6-10-Hz band across most head regions. Metabolic activity of anatomically defined cortical regions did not correlate with EEG power recorded over each region. These results support previously reported associations between abnormalities in subcortical metabolic activity and EEG activity. The lack of correlation between cortical metabolic activity and EEG activity suggests that previously observed abnormalities in EEG activity are primarily subcortical in origin.

The authors studied the relationship between cerebral metabolism and brain electrical activity in patients with acquired immunodeficiency syndrome (AIDS), using positron-emission tomography and quantitative electroencephalography. Electroencephalographic coherence in the 6-to 10-Hz band correlated positively with thalamic metabolic activity. Coherence adjusted for background activity correlated strongly and positively with basal ganglia metabolic activity. Posterior interhemispheric coherence showed the highest correlations with measures of metabolic activity. These results suggest that changes in coherence may reflect AIDS-related subcortical disease. The high correlations between the two different measures of cerebral activity support the validity of electroencephalographic coherence measures in studies of AIDS-related neuropsychiatric dysfunction.