Overview. Problems. Contents. Anatomy. Point: 18. Superior cerebellar peduncle. Function: Principle efferent (out of) pathway of the cerebellum. Plays a major role in the coordination of the IPSI. arm and leg.esion of the superior cerebellar peduncle CAUDAL to the decussation will result in motor incoordination on the IPSI. side of the body, whereas a lesion that occurs ROSTRAL to the decussation results in CONTRA. motor incoordination of the arm and leg. Other Note: REMEMBER THAT CEREBELLAR LESIONS RESULT IN IPSI.