Involuntary movements and neurotransmitters.

The clinical study of involuntary movements is helped by neurophysiological and neuropharmacological methods which are very useful for defining the different components of complex movements. Two main groups of involuntary movements can be contrasted according to whether or not they display a rhythm. The defect of a neurotransmitter or the hypersensitivity of the receptors are considered for the different types of movements.