Parkinsonian Disorders and Pure Autonomic Failure

INTRODUCTION Disorders of bladder, bowel and sexual function are common problems in Parkinson’s disease (PD), multiple system atrophy (MSA) and pure autonomic failure (PAF). Although the pathology of PD and MSA is quite different and distinct, the differential diagnosis of the conditions in life, particularly in the early stages, may be difficult and the presence of autonomic failure, as indicated by postural hypotension, may assist in the differential diagnosis. Figure 1 shows the major clinical features of these various disorders and the relationship between them [1]. However, it should be noted that the pathophysiological cause of postural hypotension does not necessarily also cause bladder, bowel and sexual dysfunction in these diseases and pelvic organ disorders may occur without postural hypotension. In patients with PD, pelvic organ dysfunction usually occurs late in the course of the disease and is not associated with postural hypotension. MSA is commonly misdiagnosed as PD, but pelvic organ dysfunction usually occurs early in the course of the disease, before the onset of symptoms of hypotension and it is often the prominent complaints of bladder and sexual dysfunction which raise the suspicion of the correct diagnosis. Although the commonest presentation of MSA is as a parkinsonian syndrome (striatonigral degeneration: SND) (Case 1), cerebellar syndrome (olivopontocerebellar atrophy: OPCA) and autonomic disorder (Shy-Drager syndrome) (Case 2) may also occur. PAF is a sporadic disorder characterized by widespread autonomic failure without other neurological features. It usually occurs in older age and has a less rapidly progressive course than MSA. In all these disorders, complaints of bladder, bowel and sexual dysfunction may add considerably to the patients’ disabilities. The neurologist needs to be aware of the possible diagnostic significance of such symptoms as well as the various treatments available for the conditions.