Point 18 Intro Pathway Deficit Summary Overview Problems Contents Anatomy

REMEMBER: The cells of origin of fibers of the superior cerebellar peduncle lie in the deep cerebellar nuclei. These nuclei lie deep in the white matter of the cerebellum, under what is called the cortex of the cerebellum. The superior cerebellar peduncle is the principal efferent bundle of the cerebellum, unlike the other two peduncles (inferior or restiform body; middle or brachium pontis) that are conveying information to the cerebellum. The superior cerebellar peduncle crosses at caudal midbrain (inferior colliculus) levels, after which most of the fibers ascend to the red nucleus (rostral midbrain) and dorsal thalamus (ventral lateral and ventral anterior nuclei). The fibers cross (in the caudal midbrain) at the decussation of the superior cerebellar peduncle (brachium conjunctivum). LESIONS OF THE SUPERIOR CEREBELLAR PEDUNCLE BEFORE (CAUDAL) THE DECUSSATION RESULT IN IPSILATERAL DEFICITS IN MOTOR COORDINATION, WHILE INTERRUPTION OF THE FIBERS AFTER (ROSTRAL) TO THE DECUSSATION RESULTS IN CONTRALATERAL DEFICITS.