neurologic disorders
Parkinson Disease
Key Points
Parkinson disease is a synucleinopathy and thus can overlap with other synucleinopathies (eg, dementia with Lewy bodies, multiple system atrophy). Suspect Parkinson disease based on characteristic features: resting tremor, muscle rigidity, slow and decreased movement, and postural and gait instability. Distinguish Parkinson disease from disorders that cause similar symptoms based mainly on the history and physical examination results, but also test responsiveness tolevodopa; sometimes neuroimaging is useful. Typically, uselevodopa/carbidopa(the mainstay of treatment), but other drugs (amantadine,dopamineagonists, MAO-B inhibitors, COMT inhibitors) may be used before and/or withlevodopa/carbidopa. Consider surgical procedures, such as deep brain stimulation, if patients have symptoms refractory to optimal drug therapy and do not have cognitive impairment or a psychiatric disorder. 