Vocal cord abductor paralysis in multiple system atrophy: a case report.

Multiple system atrophy (MSA) is a progressive neurodegenerative disease that is characterized by varying degrees of parkinsonism and cerebellar, corticospinal, and autonomic dysfunction. Vocal cord abductor paralysis (VCAP) is considered a sign of a poor prognosis in MSA, because it is a life-threatening complication that may cause nocturnal sudden death. This case report presents a patient who was treated for Parkinson's disease, and complained of dizziness and sleep apnea. We examined VCAP using fiberoptic laryngoscopy as the possible cause of sleep apnea. VCAP usually occurs in the advanced stages of MSA and is accompanied by a worsening of other symptoms. Optokinetic nystagmus was severely impaired and the caloric test response was bilaterally absent. Objective findings such as VCAP and abnormal neuro-otological results led to the diagnosis of MSA.