Dramatic Response to Pramipexole in Delayed-Onset Parkinsonism from Osmotic Demyelinating Syndrome

Delayed parkinsonism and dystonia are recognized phenomena in osmotic demyelinating syndrome (ODS). Dopamine receptor agonists and levodopa have been reported to benefit select patients. We report a patient with ODS with severe pseudobulbar deficits, parkinsonism and dystonia, poorly responsive to levodopa, who experienced a remarkable improvement with pramipexole. A marked response to pramipexole with lack of response to levodopa suggests a pre-synaptic source for his deficits coupled with injuries to non-nigral compensatory structures. This case highlights a dramatic response of osmotic demyelination-induced parkinsonism/dystonia to pramipexole. A lack of response to levodopa suggests deficits in the pre-synaptic nigral as well as non-nigral compensatory structures.