Purpose of review: The different parkinsonian conditions can be challenging to separate clinically. This review highlights the important clinical features that guide the diagnosis of Parkinson disease (PD), progressive supranuclear palsy (PSP), multiple system atrophy (MSA), and corticobasal degeneration (CBD). Strategies for treatment and disease management are also discussed.
Recent findings: Over the past decade there has been an increasing recognition of the broad clinical presentations of the neurodegenerative forms of parkinsonism. Nonmotor symptoms in these diseases, including psychiatric, cognitive, autonomic, and gastrointestinal dysfunction, appear to have a major impact on quality of life and disability. PSP and CBD are now considered pathologic diagnoses, with several different and varied clinical phenotypes, that overlap and share features with PD and frontotemporal dementia syndromes. PD is distinguished by its excellent response to dopaminergic medications that is maintained over many years, in contrast to the response seen in patients with MSA and PSP. New diagnostic criteria have been proposed for CBD. No new therapeutic interventions have emerged for PSP, MSA, or CBD. Infusional therapies and deep brain stimulation surgery are established therapies for advanced PD.
Summary: The "parkinsonian syndromes" encompass a number of nosologic entities that are grouped together on the basis of their shared clinical features but are separated on the basis of their different pathologies. Overall, the consideration of clinical signs, mode of disease onset, and nature of disease progression are all important to make a timely and definitive diagnosis.