In Parkinson’s disease, which symptom is commonly under-recognized relative to tremor?

• A. Difficulty initiating movement
• B. Rigidity
• C. Postural instability
• D. Bradykinesia

Answer: (A)

Difficulty initiating movement captures a facet of Parkinson’s that is often less noticeable than tremor, yet is a central part of the motor impairment. In Parkinson’s, loss of dopamine in the nigrostriatal pathway disrupts the initiation and scaling of voluntary movements managed by basal ganglia circuits. This leads to akinesia or marked slowness when starting a task, hesitation before moving, or freezing episodes, especially when rising from a chair or taking the first step. Tremor tends to be the most visible and socially salient symptom, so it draws attention while initiation difficulties can be subtle or attributed to fatigue or aging. Recognizing this initiation trouble is important because it can be the more functionally limiting aspect of the motor disorder, even when tremor is mild or absent. Other features like rigidity and postural instability are common, but the specific challenge of starting movement is frequently under-recognized relative to tremor.