Physiologic abnormalities of the neuromuscular system in schizophrenia

Abstract

Neurophyysiologic abnormalities are demonstrable in some, but not all schizophrenic patients. Muscular extensor digitorum brevis (EDB) motor unit estimation and H-reflex measures distinguish acute from chronic schizophrenic patients and may be of value in further study of the relationship between these disorders. For example, it will be of interest to determine whether some of the acute schizophrenic patients with decreased excitability of the α-motor neuron go on to develop a chronic clinical course with a shift of their recovery curves toward increased excitability. The H-reflex seems of greatest interest because it may be possible to use it to examine the status of dopaminergic function in the striatum and the effect of drugs that affect dopaminergic neurons in psychotic patients. This is of particular interest because recent studies have postulated a dopaminergic component in schizophrenia, mania, and depression. Thus, further study of the H-reflex in psychotic patients may be of value in elucidating biochemical abnormalities present in the psychoses as well as the mechanism of action of psychotropic drugs and other neuropharmacologic agents.