Point 5 Intro Pathway Deficit Note Summary Overview Problems Contents Anatomy

This leads to two of the most important "rules" of neurology. That is, CEREBELLAR PROBLEMS=IPSI., CEREBRAL PROBLEMS=CONTRA. The accessory cuneate nucleus projects to the IPSILATERAL CEREBELLAR HEMISPHERE (via the inferior cerebellar peduncle, along with the dorsal spinocerebellar fibers). Therefore lesions of the accessory cuneate nucleus, like the cerebellum, result in IPSILATERAL deficits. For example, the LEFT accessory cuneate nucleus receives input from Ia, Ib and type II fibers of dorsal root ganglia above C8 on the LEFT. The LEFT accessory cuneate nucleus projects to the LEFT cerebellar hemisphere. Finally the information leaves the cerebellum to eventually influence the LEFT arm. Therefore, a lesion of the LEFT accessory cuneate nucleus would result in "bad" information reaching the LEFT cerebellar hemisphere, and in turn motor incoordination of the LEFT arm. There is NO paralysis or atrophy of these muscles. REMEMBER, for our problem solving questions involving the accessory cuneate nucleus let's just focus on INCOORDINATION OF THE IPSILATERAL ARM.