Snapshot A 63-year-old male is brought to the physician by his wife for the evaluation of a tremor. The tremor is worse at rest, and decreases in severity with purposeful movement. The patient reports to having difficulty with initiating voluntary movement, and his wife states that the patient’s movements have been slow. On exam, there is seborrheic dermatosis on the nasolabial folds. There is a “pill-rolling” resting tremor accentuated when the patient is asked to perform mental calculations. Resistance to passive movement at the elbow joint is noted. On gait testing, there was difficulty with initiating gait, as well as the patient taking short steps when walking forward. Introduction Neurodegenerative progressive movement disorder cardinal manifestations tremor resting, "pill-rolling" bradykinesia muscle rigidity postural instability associated with lewy bodies Pathophysiology neurodegeneration of dopaminergic neurons e.g., substantia nigra pars compacta leads to bradykinesia due to distruption of basal ganglia circuit may be related to failure of α-synuclein degeneration major component of lewy bodies intracellular eosinophillic inclusion Secondary parkinsonism loss or interference with the action of dopamine in the basal ganglia due to idiopathic degenerative diseases, drugs, or exogenous toxins drugs methyl-phenyl-tetrahydropyridine (MPTP) antipsychotics reserpine metoclopramide diseases frontotemporal dementia Lewy body dementia others carbon monoxide poisoning Presentation Symptoms motor involvement resting pill-rolling tremor bradykinesia muscle rigidity cogwheel rigidity postural instability shuffling gait mask-like facies depression dementia usually a late finding Evaluation Clinical diagnosis Histology loss of pigmented neurons in the substantia nigra Lewy bodies round eosinophilic inclusions of α-synuclein Differential Lewy body dementia Alzheimer's disease Essential tremor Parkinson-plus syndromes multiple system atrophy (Shy-Drager syndrome) olivopontocerebellar atrophy supranuclear palsy Drug-induced parkinsonism Treatment Pharmacologic treatment levodopa-carbidopa dopamine agonist pramipexole bromocriptine ropinirole monoamine-oxidase type B (MAO-B) inhibitors selegiline amantadine anticholinergics benztropine trihexyphenidyl Surgical treatment deep brain stimulation thalamotomy pallidotomy Prognosis, Prevention, and Complications Prognosis a chronic progressive disorder treatment improves quality of life and function Prevention currently not a preventable disease Complications dementia depression psychosis/hallucinations pneumonia most common cause of death