Loss of striatal neurons in Parkinson's disease: a cytometric study.

By means of a cell-counting technique, it has been shown that patients with Parkinson's disease underwent decreased density of striatal nerve cell population. Large cells were more severely affected than small cells. These findings support the view that striatal involvement, although not severe enough to be easily recognized by conventional neuropathological examination, might be responsible of the progressive loss of benefit that most patients experience during chronic L-dopa treatment.