Carvell, PhD, PTUniversity
Parkinsonís Disease: Consequences of
reduced thalamocortical drive from BG
a reduced thalamocortical drive from basal ganglia result in a denervated
A number of studies have suggested that the frontal lobe is hypoactive in PD.
Six normal subjects
(fig 1- left) and six individuals with PD (fig 2- right) practiced a
right-handed sequential movement
task. All subjects were right-handed. PD subjects off meds for 12 hours prior
to testing. After
reaching a criterion level of performance they performed the task while their
brains were imaged
(fMRI). This study shows an increased level of activation in the SMA, sensorimotor cortices, and portions of the
parietal lobe for PD subjects vs. neurologically intact subjects. Table 2 shows no difference in performance
for two groups.
U. Sabatini, et al, Cortical Motor
Reorganization in Akinetic Patients with Parkinsonís Disease A functional MRI
Study. Brain 123: 394-403, 2000.