A unique case of coincidence of early onset Parkinson's disease and multiple sclerosis.

We report on a patient who developed left arm rest/postural tremor at age 24 and responded well to trihexyphenidyl. One year later spastic paraparesis appeared, and multiple sclerosis was diagnosed on the basis of clinical, radiological, and laboratory evidence. Although paraparesis improved after immunosuppressant therapy, a complete picture of an asymmetric parkinsonian syndrome gradually developed. Excellent response to levodopa, drug-induced dyskinesias, and DaTSCAN revealing pathology congruent with Parkinson's disease (PD) indicate a coincidental etiopathogenetic relationship of both clinical entities: multiple sclerosis and PD. Genetic analyses focusing on autosomal recessive parkinsonism (parkin, DJ1, and PINK1) were negative. To the best of our knowledge, only 15 cases of parkinsonism in association with multiple sclerosis have been reported, and their relationship has been interpreted to be either causal or coincidental. This is the first report of a coincidence of both entities, in which the parkinsonian syndrome developed first and before age 30. (c) 2007 Movement Disorder Society.