Anterior white commissure

The anterior white commissure is a bundle of nerve fibers crossing the midline of the spinal cord, located posterior to the anterior median fissure and anterior to the anterior gray commissure and central canal. Major neuronal pathways passing through the anterior white commissure include the sensory spinothalamic tracts and the anterior corticospinal tract.

The spinothalamic tracts (anterior and lateral) carry sensory information such as pain, temperature, touch, and pressure. Their second-order neurons arise in the substantia gelatinosa (lamina II of the posterior gray horn) and cross the midline via the anterior white commissure. This decussation enables transmission of sensory signals to the opposite side of the spinal cord.

Descending fibers of the anterior corticospinal tract, which have not decussated in the medulla oblongata, cross through the anterior white commissure. These fibers synapse with alpha and gamma motor neurons in the anterior horn, enabling contralateral voluntary control of axial muscles.

The blood supply to the anterior white commissure is primarily derived from the anterior spinal artery.

Commissural myelotomy, a neurosurgical procedure targeting the anterior white commissure, may be employed to treat intractable oncogenic pain by disrupting pain transmission in the spinothalamic tracts.