Spasticity indicates a problem in which neural pathway?

• A. corticospinal tract, basal ganglia
• B. basal ganglia, corticospinal tract
• C. cerebellum, brainstem
• D. frontal lobe, parietal lobe

Answer: (A)

Spasticity is a sign of upper motor neuron pathway dysfunction, specifically the corticospinal tract. When this tract is damaged above the spinal motor neurons, the normal inhibitory control of stretch reflexes is lost, leading to a velocity‑dependent increase in muscle tone, hyperreflexia, and often clonus. The corticospinal (pyramidal) tract is the primary pathway behind this pattern. In contrast, basal ganglia involvement tends to produce rigidity and bradykinesia (extrapyramidal signs) rather than true spasticity, and cerebellar, brainstem, or cortical lesions produce coordination, balance, or higher‑order planning problems rather than the characteristic UMN spasticity. So the pathway most associated with spasticity is the corticospinal tract.