Urinary Dysfunctions Are More Severe in the Parkinsonian Phenotype of Multiple System Atrophy

MSA is clinically classified into two phenotypes: parkinsonism predominant (MSA-P) and cerebellar ataxia predominant (MSA-C). However, little is known about the differences in urinary dysfunctions between MSA-C and MSA-P. We investigated the differences in urinary and cardiovascular dysfunctions between MSA-C and MSA-P.

We retrospectively reviewed the medical records of patients with MSA diagnosed as having probable or possible MSA according to Gilman's second consensus criteria from January 2007 to September 2013 in our hospital. Data regarding the initial symptoms, onset of urinary symptoms, and results of urodynamic (including anal sphincter electromyography) and head-up tilt tests were collected.

A total of 100 patients with MSA, including 59 patients with MSA-C and 41 with MSA-P, were reviewed. Initial symptoms were autonomic (n = 12) and cerebellar (n = 47) in the MSA-C phenotype and were autonomic (n = 14) and parkinsonian (n = 27) in the MSA-P phenotypes. Urodynamic study indicated that bladder contraction was more severely impaired in patients with MSA-P than in those with MSA-C. In the head-up tilt test, the decrease in diastolic blood pressure was significantly larger in the MSA-P phenotype than that in the MSA-C phenotype. Acontractile bladder during the pressure flow study increased likelihood that the phenotype is MSA-P (odds ratio: 6.67; 95% confidence interval: 1.004-44.284; P = 0.050).

Urinary dysfunctions were more severe in MSA-P compared with MSA-C. Detailed urodynamic study was helpful for detecting subtle differences between MSA-C and MSA-P.