Motor endplate alterations in schizophrenic patients

NEUROMUSCULAR pathology has been described in a variety of mentally ill patients, primarily those suffering from schizophrenia or the affective psychosis. Some psychotic patients have increased electrical activity of skeletal muscle at rest¹, abnormal electromyograms², perform poorly on various tests of neuromuscular coordination³, have elevated serum creatine phosphokinase activity during an acute psychotic episode⁴ and show an increased incidence of morphological abnormalities of skeletal muscle^5,6. Such studies have suggested that there may be an alteration of muscle innervation in such patients. We have previously reported that psychotic patients have an increased incidence of branching and sprouting of intramuscular nerve twigs⁶. We now report significant alterations in the morphology of the nerve terminals at the motor endplate in psychotic patients. This suggests that there may be an abnormality of transmission at neuromuscular synapses in some psychotic patients.