How Certain Are You When Making the Diagnosis of Multiple System Atrophy?

Multiple system atrophy (MSA) is a multisystem neurodegenerative disorder affecting adults older than 30 years and presenting with a constellation of symptoms, including parkinsonian features, ataxia, and autonomic disturbances. The pathophysiology of MSA has gradually been unveiled. It is characterized by α-synuclein protein aggregates in neurons and glial cells that are different from those seen in Parkinson disease (PD).¹ MSA is the most common condition, after PD, that has parkinsonism as a cardinal feature, and it is also one of the most common causes of sporadic cerebellar ataxias. Because the clinical presentation is heterogeneous, we as clinicians must always be certain of the probability of an MSA diagnosis for each patient we are facing.