Babinski sign assesses which neural pathway?

Babinski sign assesses which neural pathway?

• A. Corticospinal tract
• B. Dorsal columns
• C. Spinothalamic tract
• D. Cerebellar pathways

Answer: (A)

The Babinski sign points to dysfunction of the corticospinal (pyramidal) tract. This pathway normally suppresses primitive reflexes and coordinates voluntary movement. When the corticospinal tract is damaged—such as from a stroke, tumor, or demyelinating disease—the inhibitory control over the spinal reflexes is lost. Stroking the lateral sole then triggers an abnormal extension of the big toe with the other toes fanning outward, instead of the normal curling response. That extensor plantar response is a hallmark of an upper motor neuron lesion affecting the corticospinal tract. The other tracts listed handle different functions—dorsal columns for fine touch and proprioception, spinothalamic for pain and temperature, and cerebellar pathways for coordination—and their disruption does not produce the Babinski response. In adults, a positive sign signals UMN involvement; in infants it can be normal due to immature myelination.

The Babinski sign points to dysfunction of the corticospinal (pyramidal) tract. This pathway normally suppresses primitive reflexes and coordinates voluntary movement. When the corticospinal tract is damaged—such as from a stroke, tumor, or demyelinating disease—the inhibitory control over the spinal reflexes is lost. Stroking the lateral sole then triggers an abnormal extension of the big toe with the other toes fanning outward, instead of the normal curling response. That extensor plantar response is a hallmark of an upper motor neuron lesion affecting the corticospinal tract. The other tracts listed handle different functions—dorsal columns for fine touch and proprioception, spinothalamic for pain and temperature, and cerebellar pathways for coordination—and their disruption does not produce the Babinski response. In adults, a positive sign signals UMN involvement; in infants it can be normal due to immature myelination.