Ultrastructure of skeletal muscle in patients with Parkinson's disease and upper motor lesions.

Ultrastructural studies of muscle biopsies from the vastus lateralis of the quadriceps in seven patients with Parkinson's disease and six patients with upper motor lesions are presented. All patients showed varying degrees of mitochondrial changes. Loss of outer membranes or abnormal inner membranes were observed alone or in combination. A reduced number of mitochondria was also noted in some cases. A disorder of filaments was seen. It is assumed that the mitochondrial changes are connected with the altered oxidative capacity previously observed in these patients.