What does TRAP stand for in Parkinson's disease?

• A. Tremor, Rigidity, Akinesia, Paralysis
• B. Tremor, Rigidity, Ataxia, Postural Instability
• C. Tremor, Rebound, Akinesia, Postural Instability
• D. Tremor, Rigidity, Akinesia, Postural Instability

Answer: (D)

The main concept tested is the acronym that sums up the hallmark motor features used to recognize Parkinson’s disease. TRAP stands for Tremor, Rigidity, Akinesia, and Postural Instability. Tremor is typically a resting tremor that often decreases with movement. Rigidity refers to increased muscle tone, sometimes described as cogwheel rigidity. Akinesia here denotes difficulty initiating movement (reflecting the broader concept of bradykinesia in many patients), which contributes to slowness and a paucity of spontaneous movement. Postural Instability is a later sign involving impaired balance and a higher risk of falls.

Why this set fits best: these four features collectively capture the classic motor presentation clinicians look for in PD. Ataxia, for example, signals coordination problems more typical of cerebellar disorders, not the basal ganglia–dopamine pathway disruption seen in PD. Rebound isn’t a standard core PD sign. So the Tremor–Rigidity–Akinesia–Postural Instability combination matches the established tetrad used to describe the motor phenotype in Parkinson’s disease.