| Publication Abstract Display | | Type: Published Abstract | | Title: FMRI activation with increasing motor complexity in subjects seronegative and seropositive for HIV. | | Authors: Fennema-Notestine C, Archibald SL, Kwok W, Kinderman S, Jernigan TL, Grant I | | Year: 1998 | | Publication: Society for Neuroscience Abstracts | | Volume: 24 Issue: 2 Pages: 1960 | | Abstract:In an fMRI study, a group of controls (CTRL) and a group of subjects seropostivie for HIV (HIV+) performed motor tasks of increasing complexity to examine basal ganglia and motor cortex activation. In previous studies, persons with HIV have demonstrated motor and psychomotor slowing and significant white matter and basal ganglia volume loss on structural MRI. The motor task included simple finger tapping (TAP), alternating finger movements (ALT), and switching between different finger movements within the same epoch (SWI). Seven normal CTRL subjects and four HIV+ subjects and four HIV+ subjects that showed evidence of psychomotor slowing on neuropsychological assessment were selected. The CTRL group demonstrated similar levels of motor cortex activation across all tasks. Basal ganglia (primarily putamen) activation was not evident for TAP, was moderate in ALT, and was strong in SWI. For the SWI task, the CTRL group also demonstrated some activation in the ventral lateral nucleus of the thalamus and anterior cingulate. The demands of switching between motor tasks may be responsible for the strong basal ganglia response and cingulate activation. The planning, sequencing, and motor control required by SWI may increase the output of the thalamic nucleus and the activation of he cingulate. The HIV+ group showed a smaller, more posterior area of the motor cortex activation on TAP. On ALT, he HIV+ group demonstrated unexpected ipsilateral motor cortex activation in addition to the contralateral motor cortex activation seen in the CTRL group. No basal ganglia activation was evident. On SWI, and HIV+ group again demonstrated bilateral motor cortex activation and some thalamic and basal ganglia activation (primarily caudate). There was no evidence of cingulate activation in the HIV+ group. These results are consistent with the hypothesis that in HIV disease there may be functional disturbance of the basal ganglia and the frontostriatal circuit. |
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