Which motor symptom typically shows the most dramatic improvement with L-DOPA/Carbidopa treatment?

Bradykinesia (Slowness).

The combination therapy of L-DOPA and Carbidopa targets the most debilitating movement deficits experienced by individuals with Parkinson’s disease, offering significant relief in several areas. Among the hallmark symptoms—bradykinesia (slowness), rigidity (stiffness), and tremor—bradykinesia is often cited as the symptom showing the most profound positive response. Difficulty in initiating and executing movement, which is the core characteristic of bradykinesia, frequently lessens considerably upon successful restoration of dopamine levels. While rigidity typically lessens and tremor can respond to treatment, the text specifically emphasizes that the improvement in slowness of movement is often the most dramatically observed effect.