Anorectal function in multiple system atrophy and Parkinson's disease

This study was designed to investigate anorectal function in Parkinson's di sease and multiple system atrophy (MSA). After a standardized interview, 17 patients with Parkinson's disease (PD) and 16 patients with multiple syste m atrophy (MSA) underwent anorectal manometry with a continuously perfused multi-lumen catheter, located to record pressures from the anal canal, and a balloon for rectal distension. Data were analyzed by observers blind to t he neurologic diagnosis. Disease duration was shorter in the MSA than in th e PD group (6 +/- 4 versus 10 +/- 5 yrs, p <0.05). Most patients reported a bowel frequency of less than three evacuations per week and some patients had fecal incontinence. Most manometric recordings disclosed an abnormal pa ttern during straining (a paradoxic contraction or lack of inhibition) in 1 3 patients with MSA and 11 patients with PD. Mean anal pressures and rectal sensitivity threshold were not significantly higher in the MSA group, wher eas the inhibitory anal reflex and rectal compliance thresholds were within the normal range in both groups. Manometric patterns did not differentiate patients with MSA from patients with PD. Most patients in both groups show ed an abnormal straining pattern, decreased anal tone, or both dysfunctions . In conclusion, our findings suggest that although bowel and anorectal dys functions do not differentiate MSA from PD, both abnormalities occur earlie r and develop faster in MSA than in PD.