Defecatory function in Parkinson's disease: response to apomorphine

We evaluated the effects of the dopaminergic agent apomorphine on defecation and anorectal function in patients with Parkinson's disease (PD). A gastrointestinal symptom survey, extrapyramidal assessment, defecating proctogram, and anorectal manometric study were performed in 8 subjects with PD. Basal studies showing abnormalities were repeated following apomorphine administration. Prior defecographic abnormalities were normalized following apomorphine injection in 1 of 3 subjects and significant improvements in manometric parameters were observed in all 5 subjects who underwent repeat anorectal manometry. We conclude that apomorphine can correct anorectal dysfunction in PD, and that these abnormalities may be a consequence of dopamine deficiency secondary to the PD process. These findings may also have therapeutic implications.