Central motor conductivity in aged people.

The conductivity of motor neurons in 26 aged females (mean age 79 years) was analyzed by the conventional conduction method and by pulsed magnetic stimulation and compared with that in 14 younger controls. In aged people, slow motor conduction velocities were found in peripheral nerves. Central motor conduction time (CMCT) in relaxed muscle was shorter in the aged people, although CMCT was normal in mildly contracted muscle. These findings coincide with the results studied in Parkinson's disease, although these subjects were not diagnosed as having Parkinson's disease. Aged people generally have an anteflexed posture, slow movements, and poor postural reflexes, and have been reported to have a decrease in the dopamine level which is relatively earlier than that of other transmitters in the basal ganglia. This may account for the present finding that aged people have neurophysiological abnormalities in CNS which are similar to those in Parkinson's disease.