The afferent input for somatosensory evoked potentials (SSEPs) travels through which spinal cord tract?

The afferent input for somatosensory evoked potentials (SSEPs) travels through which spinal cord tract?

• A. Spinocerebellar
• B. Spinothalamic
• C. Dorsal columns
• D. Corticospinal

Answer: (C)

SSEPs reflect the dorsal column–medial lemniscus pathway. When a peripheral nerve is stimulated, the afferent signal travels via large, myelinated fibers up the dorsal columns (fasciculus gracilis and fasciculus cuneatus), ascends to the medulla, decussates, and then continues as the medial lemniscus to the thalamus and on to the cortex. This dorsal-column route carries discriminative touch and proprioception, which is what SSEPs monitor. The other tracts serve different roles: spinothalamic carries pain and temperature, corticospinal is motor, and spinocerebellar conveys unconscious proprioception to the cerebellum.

SSEPs reflect the dorsal column–medial lemniscus pathway. When a peripheral nerve is stimulated, the afferent signal travels via large, myelinated fibers up the dorsal columns (fasciculus gracilis and fasciculus cuneatus), ascends to the medulla, decussates, and then continues as the medial lemniscus to the thalamus and on to the cortex. This dorsal-column route carries discriminative touch and proprioception, which is what SSEPs monitor. The other tracts serve different roles: spinothalamic carries pain and temperature, corticospinal is motor, and spinocerebellar conveys unconscious proprioception to the cerebellum.