Electroencephalography in the early diagnosis of HIV-related subacute encephalitis: analysis of 185 patients.

Of subjects with asymptomatic HIV infection or Lymphoadenopathy Syndrome, 185 were studied by means of electroencephalography coupled with computerized spectral analysis and mapping (EEG-CSA). Abnormal EEGs were found in 30 of 118 (25.4%) patients with asymptomatic infection (CDC Group II) and in 20 of 67 (29.9%) patients with Lymphoadenopathy Syndrome (CDC Group III). The most common EEG abnormalities were represented by theta slowing on the frontal and fronto-temporal lobes and, in some cases, by delta slowing and paroxysmal sharp activity on the forebrain. Among 50 patients with abnormal EEGs, 16 showed some abnormalities on neuropsychological testing, whereas mild signs of cerebral atrophy were evident on CT scan in only 12 patients. These findings suggest that EEG-CSA could be a useful and sensitive method in the early detection and monitoring of HIV-related subacute encephalitis.