Clinical Features in a Danish Population-Based Cohort of Probable Multiple System Atrophy Patients

<b><i>Background:</i></b> Multiple system atrophy (MSA) is a rare, sporadic and progressive neurodegenerative disorder. We aimed to describe the clinical features of Danish probable MSA patients, evaluate their initial response to dopaminergic therapy and examine mortality. <b><i>Methods:</i></b> From the Danish National Patient Registry, we identified 782 patients diagnosed with conditions potentially compatible with probable MSA (International Classification of Diseases, version 10 (ICD-10) codes G23.2, G23.8 and G23.9) during 1994-2009. Through medical record review, we narrowed our sample to 115 patients who fulfilled the criteria for probable MSA. We recorded clinical features, examined differences by MSA subtype and used Kaplan-Meier survival analysis to examine mortality. <b><i>Results:</i></b> The mean age at onset of patients with probable MSA was 60.2 years (range 36-75 years) and mean time to wheelchair dependency was 4.7 years (range 0-15 years). One-third of patients experienced a transient improvement in motor symptoms with use of levodopa. Median survival from disease onset was 6.9 years (range 1-16 years, 95% CI 6.3-7.5) with no apparent variation according to gender or subtype. <b><i>Conclusions:</i></b> Our nationwide approach corroborated that MSA is associated with diverse and grave symptoms, only limited response to levodopa, and poor prognosis.