LOCALIZED PROTON MAGNETIC-RESONANCE SPECTROSCOPY OF THE BRAIN IN CHILDREN INFECTED WITH HUMAN-IMMUNODEFICIENCY-VIRUS WITH AND WITHOUT ENCEPHALOPATHY

Twenty children older than 2 y infected with human immu- nodeficiency virus (HIV) were examined by in vivo proton magnetic resonance spectro scopy (H-1 MRS) to study their cerebral metabolism and to identify met abolic profiles in relation with different stages of the disease. Pati ents were rated regarding their clinical and immunologic status accord ing to the Centers for Disease Control classification and were divided into two groups: without encephalopathy (E-, n = 15) and with progres sive encephalopathy (E+, n = 5). The acquisition was performed in the centrum semiovale using the short echo stimulated echo acquisition mod e 20-ms sequence. The MRS profile was abnormal in all HIV-infected chi ldren compared with healthy age-matched controls (a = 7), even when ma gnetic resonance images were normal. A significant increase of the pro portion of the lipid signals (ANOVA, p < 0.05) was found in all HN-inf ected children. In addition, a significant decrease of the proportion of the N-acetylaspartate signal and a significant increase of the prop ortion of the myo-inositol signal (ANOVA, p < 0.05) characterized the E+ group. The principal component analysis performed on eight variable s on 30 spectra confirms that the spectra of HIV-infected children dif fer from control spectra, The E+ group and the E- group are clearly se parated on the map of subjects on the principal plane. The E- group li es in an intermediate position between the E+ group and the control gr oup. The evolution of metabolic alterations in the brain of HIV-infect ed children can clearly be monitored by H-1 MRS and associated with th e occurrence of an encephalopathy.