Disintegration of the motor unit in post-polio syndrome. Part I. Electrophysiological findings in patients after poliomyelitis.

: CN EMG and SF EMG were performed in 12 patients many years after acute poliomyelitis, without symptoms of post-polio syndrome. In 19 muscles with clinical symptoms and in 11 clinically normal muscles chronic neurogenic changes of a similar degree were observed. Fibre density was increased in both groups of muscles. In muscles with clinical symptoms complexes of single fibres with increased jitter and blocking were more frequent than in muscles without clinical manifestations. It seems that the reinnervation after acute polio is a continuing process and thus complete stabilization and integration of the motor unit cannot be achieved.