Parkinsonism

Abstract

Parkinsonism is seen in patients with disease of the extrapyramidal system. The key components of parkinsonism are rigidity and bradykinesia. The presence of tremor, asymmetry, cognitive decline, cerebellar abnormalities, and autonomic dysfunction helps to define the cause. Parkinson disease (PD) is the most common of the parkinsonian syndrome, and is defined by asymmetric resting tremor, bradykinesia, and rigidity. Patients with PD respond to levodopa in the early stages of the disease, but become less responsive and develop more drug-related side effects and disability as the disease progresses. Progressive supranuclear palsy usually presents with gait difficulty, and the key diagnostic clue is difficulty with downward saccadic eye movements. Multiple system atrophy may include cerebellar and autonomic features that overshadow the extrapyramidal ones. Corticobasal degeneration is an extrapyramidal disorder with cognitive and behavioral abnormalities including prominent limb apraxia. Parkinsonism may be related to drugs (particularly neuroleptic agents) or cerebrovascular disease.