Primary involvement of the motor area in association with the nigrostriatal pathway in multiple system atrophy: neuropathological and morphometric evaluations
M. Su et al., Primary involvement of the motor area in association with the nigrostriatal pathway in multiple system atrophy: neuropathological and morphometric evaluations, ACT NEUROP, 101(1), 2001, pp. 57-64
To evaluate the changes that occur in the motor and supplementary motor cor
tices in cases of multiple system atrophy (MSA), we carried out morphologic
al and morphometric studies in 7 cases of MSA and 11 age-matched controls.
Neuropathological study revealed presence of glial cytoplasmic inclusions (
GCIs) in the cortex and subcortical white matter of the motor and supplemen
tary motor areas, loss of small to medium-sized pyramidal neurons, and astr
ocytosis in the motor cortex in all cases of MSA, showing a definite predil
ection in the cortical layers V and VI. The severity of neuronal loss in th
e motor cortex was highly correlated with the incidence of GCIs and the inv
olvement of the nigrostriatal pathway. Morphometrically, significant reduct
ions of both the thickness of motor cortical layers V and VI and the number
of neurons were observed. In addition, a reduction in the number of neuron
s in the supplementary motor cortex was detected in three out of the seven
MSA cases. The results of this study suggest that the motor area is a cardi
nal target in MSA, and that in association with the nigrostriatal pathway i
t forms a motor loop degeneration in this disease.