Snapshot A 65-year-old man present with a tremor in his right hand. His tremor is most apparent at rest and improves with movement. His movements are noticeably slower and he has difficulty initiating movement. On physical exam, the patient appears apathetic and has rigidity with passive arm movement. Gait testing is notable for shuffling with a stooped posture. Introduction Definition movement disorder characterized by login to view 4 more bullets Parkinson-plus syndromes multiple system atrophy login to view 7 more bullets progressive supranuclear palsy login to view 2 more bullets corticobasal degeneration (CBD) login to view 2 more bullets Associated conditions dementia depression sleep disorders psychosis Pathogenesis Loss of dopaminergic neurons in the substantia nigra leads to dopamine depletion in the striatum this creates an imbalance between dopamine and acetylcholine resulting in improper muscle movement Impaired degradation of α-synuclein can lead to degradation of dopaminergic striatal neurons Presentation Symptoms/physical exam bradykinesia login to view 1 more bullet muscle rigidity login to view 1 more bullet postural instability login to view 3 more bullets resting tremor login to view 2 more bullets Studies Clinical diagnosis Differential Huntington disease differentiating factor login to view 1 more bullet Essential tremor differentiating factor login to view 1 more bullet Drug-induced Parkinsonism Treatment Medical carbidopa-levodopa login to view 4 more bullets Operative deep brain stimulation login to view 2 more bullets Complications Dementia Sleep disorders Falls