Earlier age of onset in multiple system atrophy with smoking and heavy alcohol use.

•MSA patients with past or present smoking had earlier age of onset compared to MSA patients with no smoking history.•MSA patients with history of heavy alcohol use had earlier age of onset and higher frequency of ataxia.•History of both smoking and heavy alcohol use contributes to earlier onset in MSA of 4.3 years.•Neither smoking history nor heavy alcohol use influenced overall survival in MSA patients.