An abnormality in point-to-point movements suggests impairment of which brain structure?

• A. Basal ganglia
• B. Thalamus
• C. Cerebellum
• D. Cerebral cortex

Answer: (C)

Point-to-point movements depend on the cerebellum to fine-tune motor commands in real time, ensuring the limb travels along an accurate trajectory to the target. When the cerebellum is impaired, this online error correction fails, producing dysmetria — overshooting or undershooting the target — and often an intention tremor as you approach the target. You may also see dysdiadochokinesia, reflecting difficulty with rapid alternating movements, and ataxic, uncoordinated movement patterns. While the basal ganglia, thalamus, and cerebral cortex contribute to overall movement initiation, planning, and relay of motor signals, the specific impairment in precise point-to-point movements most characteristically points to cerebellar dysfunction.