Which sign is most characteristic of Parkinson’s disease and often used as a key diagnostic clue?

Which sign is most characteristic of Parkinson’s disease and often used as a key diagnostic clue?

• A. Unsteady gait
• B. Muscle rigidity
• C. Hyperactive reflexes
• D. Bradykinesia

Answer: (D)

Bradykinesia, or slowness of movement, is the defining feature of Parkinson’s disease and a primary diagnostic clue. In Parkinson’s, loss of dopamine in the nigrostriatal pathway disrupts the balance of basal ganglia circuits, making it hard to initiate and execute movements quickly and smoothly. This shows up as slowed finger tapping, reduced arm swing when walking, a slow, shuffling gait, and often a quiet or masked facial expression. Strength is usually preserved, but the speed and amplitude of movements are reduced, which is why bradykinesia stands out as the most characteristic sign. Other signs like unsteady gait can appear as the disease progresses due to postural instability, and rigidity is common but less specific than bradykinesia. Hyperactive reflexes are not typical of Parkinson’s disease. Tremor at rest can occur, but bradykinesia is the feature most closely tied to the motor impairment that defines the condition.

Bradykinesia, or slowness of movement, is the defining feature of Parkinson’s disease and a primary diagnostic clue. In Parkinson’s, loss of dopamine in the nigrostriatal pathway disrupts the balance of basal ganglia circuits, making it hard to initiate and execute movements quickly and smoothly. This shows up as slowed finger tapping, reduced arm swing when walking, a slow, shuffling gait, and often a quiet or masked facial expression. Strength is usually preserved, but the speed and amplitude of movements are reduced, which is why bradykinesia stands out as the most characteristic sign.

Other signs like unsteady gait can appear as the disease progresses due to postural instability, and rigidity is common but less specific than bradykinesia. Hyperactive reflexes are not typical of Parkinson’s disease. Tremor at rest can occur, but bradykinesia is the feature most closely tied to the motor impairment that defines the condition.