Computer simulation of parkinsonian tremor.

A computer simulation of tremor using a mathematical model is presented, which integrates the traditional two theories; 'peripheral feedback theory' for physiological tremor and central oscillator theory' for Parkinsonian tremor. The model includes a basic stretch-reflex loop, which is modulated by the central nervous system through the gamma fibres. Fatigue of intrafusal fibres, which results from chronic stimulation by the gamma system, is assumed to be the main cause of Parkinsonian tremor. A computer simulation using the model shows that both physiological tremor and Parkinsonian tremor can be caused by the varying contractivity of the intrafusal fibres.