Anterior spinocerebellar tract

The anterior spinocerebellar tract is an ascending sensory pathway that transmits unconscious proprioceptive information from the muscle spindles, golgi tendon organs and joint receptors, to the cerebellum. This information about the movements of the muscles and joints and the associated tension in the tendons is computed by the cerebellum to coordinate muscle movements and maintain posture and gait.

The axons of first-order neurons arise from the dorsal root ganglion and enter the posterior gray horns of spinal cord via the posterior nerve rootlets. These synapse with second-order sensory neurons in the nucleus dorsalis (or Clarke’s column), located in the lateral intermediate substance in the base of posterior horn (lamina VII), spanning spinal segments C8–L3. Axons entering spinal cord via upper cervical or lower lumber and sacral spinal nerves must descend or ascend a few segments to synapse in the nucleus dorsalis.

The axons of second-order sensory neurons–originating from the nucleus dorsalis–ascend in the lateral funiculus (or lateral white column) as the anterior spinocerebellar tract. Most fibers decussate in the spinal cord and ascend in the contralateral lateral funiculus, while some remain ipsilateral.

• The tract reaches the medulla oblongata and pons, where it passes through the superior cerebellar peduncle to terminate in the cerebellar cortex of the same side.

• Those majority fibers which crossed, re-cross, traverse through the brainstem, to terminate in the ipsilateral cerebellar cortex.

Lesions in lateral spinal cord, affecting the spinocerebellar tracts, may impair motor coordination, causing ipsilateral ataxia, dysmetria, dysdiadochokinesia, nystagmus, and gait instability.