CHARACTERISTICS OF FUNCTIONAL CHANGES IN THE BRAIN UPON HIV-ASSOCIATED ENCEPHALOPATHY
The nervous system is next to immunity with regard to the prevalence of lesions produced HIV infection. MRI, PET, EEG and evoked potential studies (EPS) were used to assess brain conditions in 20 patients at stages I—III (Group 1) and IV (Group 2) of HIV infection. The control group comprised 19 apparently healthy people. Glucose metabolism changes in HIV patients correlated with changes in the bioelectric brain activity. Hypometabolic zones were predominantly mapped to the temporal lobes (72%) and brain stem (72%). The vast majority of the patients showed diffuse (85% in Group 1 and 100% in Group 2) and local (92% in Group 1 and 100% in Group 2) EEG changes, which did not correlate with the duration and stage of HIV infection. Local epileptiform activity, which was most frequently observed in the temporal areas and was associated with a moderate decrease in the rate cognitive processes, was more prevalent in Group 2. Changes in the electrophysiological and metabolic parameters in the brain of HIV patients at the subclinical stages of HIV infection were found upon no signes of structural changes and were not associated with opportunistic infections. Changes in glucose metabolism associated with epileptiform changes are presumably indicative of the development of irritation zones and zones of functional deficit in the epileptogenic foci At the subclinical stages of HIV-associated encephalopathy upon preserved balance between epileptogenic and antiepileptic systems of the brain; therefore, no seizure fits are observed in clinical practice