Anal sphincter dysfunction in Parkinson's disease
S. E. Mathers, P. A. Kempster, P. J. Law, J. P. Frankel, C. I. Bartram, A. J. Lees, G. M. Stern and M. Swash
Department of Physiology, St Mark's Hospital, London, England.
Striated anal sphincter function was studied electrophysiologically and
radiologically in six patients with Parkinson's disease and chronic
constipation. In five cases, there was paradoxic anal sphincter muscle
contraction during simulated defecation straining resembling anismus-type
pelvic outlet obstruction. Radiologic studies showed functional improvement
of the defecatory mechanism following the administration of the dopamine
receptor agonist apomorphine in four patients. Dysfunction of the striated
anal sphincter musculature may be a significant cause of constipation in
some parkinsonian patients, occurring as part of the generalized
extrapyramidal motor disorder.
