Movement Disorders Practice Test

Bradykinesia, or slowness of movement, is the essential motor feature of parkinsonism, and it must be present together with at least one other characteristic sign: resting tremor or rigidity. In practice, the diagnosis rests on this combination because bradykinesia reflects the underlying dopaminergic deficit affecting movement initiation and speed, while resting tremor and rigidity are the accompanying signs that help distinguish parkinsonism from other movement disorders. Tremor alone can occur in other conditions such as essential tremor, and slowness alone can result from non–parkinsonian issues, so neither on its own is sufficient. If there is tremor and rigidity without bradykinesia, the criterion for parkinsonism isn’t met. Therefore, bradykinesia plus resting tremor, rigidity, or both best fit the diagnostic criteria.