Vocal fold abductor paralysis as a solitary and fatal manifestation of multiple system atrophy.

A patient is presented who had bilateral abductor vocal fold paralysis pathologically proven to be due to multiple system atrophy (MSA) in the absence of other neurological features. MSA is a degenerative neurological condition that includes olivopontocerebellar atrophy, Shy-Drager syndrome and striatonigral degeneration. The usual predominant features of MSA are cerebellar ataxia, autonomic dysfunction and Parkinsonism. Stridor is present in over one third of patients and has been reported previously as a presenting symptom in MSA: however previously reported patients have always gone on to develop other neurological symptoms. The usual investigations of bilateral abductor vocal fold paralysis caused by MSA will not reveal the pathological process and we believe that magnetic resonance imaging (MRI) of the medulla and brain stem and autonomic function tests are probably the investigations of choice. It is a worthwhile exercise attempting to identify MSA as the cause of stridor as the prognosis is good in the medium term if appropriate support is offered.