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Biomedical subjects

Menaka DeSilva

Publications and source records attributed to Menaka DeSilva.

2 recordsLinked to original sources

Persistent brain abnormalities in antiretroviral-naive HIV patients 3 months after HAART.

BACKGROUND: Proton magnetic resonance spectroscopy (1H-MRS) and neuropsychological tests may be useful for monitoring the effectiveness of highly active antiretroviral therapy (HAART) in HIV-associated brain injury. We aimed to evaluate whether brain abnormalities will improve 3 months after HAART. METHOD: Thirty-three HIV patients naive to antiretroviral medications were evaluated before and 3 months after HAART using 1H-MRS and neuropsychological tests; results were compared with those of 26 seronegative control subjects. RESULTS: Despite significant improvement in CD4 counts, and suppression of plasma and cerebrospinal fluid (CSF) viral loads, elevated brain metabolites (choline compounds and myoinositol in the frontal lobes) and neuropsychological tests abnormalities (including the computerized tests [CalCAP]) persisted after 3 months of HAART. In the basal ganglia, choline and myoinositol became elevated only after treatment. No interaction effect was observed between the number of CSF-penetrating drugs (one vs two) and changes (baseline vs 3 months) in any of the brain metabolites, cognitive performance or CSF viral load. CONCLUSIONS: The persistent brain abnormalities suggest ongoing repair or reactive inflammatory processes in the brain after 3 months of HAART. Regimens with two CSF-penetrating antiretroviral medications do not appear to be more effective than those with one CSF-penetrating drug in treating HIV brain injury at 3 months.

AIDS Dementia Complex↗

Perfusion MRI and computerized cognitive test abnormalities in abstinent methamphetamine users.

This study aims to determine possible persistent abnormalities in regional cerebral blood flow (relative rCBF) and cognitive function in abstinent methamphetamine (METH) users. Twenty METH-dependent subjects (abstinent for 8+/-2 months) and 20 age- and gender-matched controls were evaluated with perfusion magnetic resonance imaging (pMRI) and neuropsychological tests. METH users showed decreased relative rCBF bilaterally in putamen/insular cortices (right: -12%; left: -10%) and the right lateral parietal brain region (-11%), but increased relative rCBF bilaterally in the left temporoparietal white matter (+13%), the left occipital brain region: (+10%) and the right posterior parietal region (+24%). Interaction effects were observed between METH and gender in the right occipital cortex and a midline brain region; female METH users showed increased relative rCBF (+15% both regions) whereas the male METH users had decreased relative rCBF (-10% and -18%, respectively). METH users performed within normal ranges on standard neuropsychological tests; however, they were slower on several tasks on the California Computerized Assessment Package (CalCAP), especially tasks that required working memory. These findings suggest that METH abuse is associated with persistent physiologic changes in the brain, and these changes are accompanied by slower reaction times on computerized measures of cognitive function.

Adult↗