Levodopa–carbidopa intestinal gel for multiple system atrophy with motor fluctuations: a case series

Parkinsonism-dominant multiple system atrophy (MSA-P) is typically a progressive disorder with poor responsiveness to levodopa and an unfavorable prognosis. However, in certain cases, the response to levodopa can be as robust as in Parkinson's disease (PD), with severe motor fluctuations developing during treatment. Unlike PD, no established therapy exists to maintain activities of daily living (ADLs) in such patients. We present three cases of young-onset MSA-P who demonstrated sustained levodopa responsiveness and were treated with levodopa-carbidopa intestinal gel (LCIG) following the emergence of disabling motor fluctuations. In all three patients, parkinsonism was the predominant symptom from onset until LCIG initiation, with only mild autonomic or cerebellar symptoms. Prior to LCIG introduction, their motor complications closely resembled those of advanced PD. LCIG therapy successfully reduced "off" time and dyskinesia in all cases. However, long-term follow-up revealed a gradual decline in ADLs due to disease progression. These cases suggest that LCIG may be a valuable treatment option for selected MSA-P patients with preserved levodopa responsiveness.