The Babinski sign is used to assess which neural pathway?

• A. Dorsal column-medial lemniscus
• B. Spinothalamic tract
• C. Corticospinal tract
• D. Spinocerebellar tract

Answer: (C)

Babinski sign assesses the corticospinal (pyramidal) tract, reflecting upper motor neuron integrity. When the sole is stroked, a normal adult response is toe curling downward; an upward extension of the big toe with spreading of the other toes indicates an upper motor neuron lesion along the corticospinal pathway from the motor cortex to the spinal cord. This pathway modulates voluntary movement, and its disruption releases primitive reflexes like the Babinski sign.

The other pathways have different roles: the dorsal column–medial lemniscus carries fine touch, vibration, and proprioception; damage here would produce sensory losses in those modalities rather than an abnormal plantar response. The spinothalamic tract carries pain and temperature sensation, with corresponding sensory deficits rather than a Babinski sign. The spinocerebellar tract conveys unconscious proprioception to the cerebellum, and its damage leads to ataxia rather than an abnormal plantar reflex.