Urodynamic analysis in multiple system atrophy: characterisation of detrusor-sphincter dyssynergia.

In multiple system atrophy (MSA), parkinsonism and a cerebellar syndrome are associated with autonomic dysfunction. Both bladder neck dysfunction and external sphincter denervation have been implicated in detrusor-sphincter dyssynergia. However, urethral dysfunction may not be adequately reflected by a single global measurement of urethral pressure. Pressure assessment at several levels of the urethra is needed to unravel the mechanisms of bladder-urethra dysfunction. Here, we evaluated the use of multiple sensor pressure transducers to assess bladder-sphincter function in 52 patients with MSA in comparison to patients with Parkinson's disease (PD) who were matched for age and severity in the "off" condition. Urinary dysfunction appeared significantly earlier in MSA (<2 years) than in PD (>5 years). Detrusor under-activity with dysuria was observed in 58% of MSA patients within 4 years and in 76% of patients thereafter. Detrusor-urethral dyssynergia in MSA patients was always better characterized by multiple sensor pressure transducer measurement of bladder and urethral pressure than by a single global measurement. This new approach may prove useful for differential diagnosis of parkinsonian syndromes, and especially MSA.