Posterior spinocerebellar tract

The posterior spinocerebellar tract is an ascending sensory pathway that conveys unconscious proprioceptive input from 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 first-order sensory neurons originate in the dorsal root ganglia, with their axons entering the posterior gray horns of spinal cord via the posterior nerve rootlets. These fibers synapse with second-order neurons in the nucleus dorsalis (Clarke’s column), located in the lateral intermediate substance (lamina VII or the base) of posterior horns of spinal segments C8–L3. Proprioceptive fibers entering from levels outside C8–L3 (upper cervical or lower lumbar and sacral spinal nerves) ascend or descend in the cord to reach Clarke’s column.

The second-order sensory axons from the nucleus dorsalis, ascend in the lateral funiculus, ascending ipsilaterally as the posterior spinocerebellar tract. These fibers reach the medulla oblongata and enter the cerebellum via the inferior cerebellar peduncle, terminating in the cerebellar cortex.

Lesions in lateral spinal cord, affecting the spinocerebellar tracts, can disrupt coordination, leading to motor deficits such as nystagmus, dysmetria, dysdiadochokinesia, and gait imbalance, typically ipsilateral to the lesion.