Lesions of the dentate nucleus of the cerebellum produce ipsilateral limb ataxia. The dentate nucleus projects primarily through which cerebellar peduncle?

• A Middle cerebellar peduncle (brachium pontis)
• B Inferior cerebellar peduncle (restiform body)
• C All three peduncles equally
• D Superior cerebellar peduncle (brachium conjunctivum) ✓

Explanation

The dentate nucleus (largest and most lateral deep cerebellar nucleus) sends its output fibers through the superior cerebellar peduncle, which decussates in the midbrain tegmentum (decussation of the superior cerebellar peduncle) and projects to the contralateral red nucleus and ventral lateral thalamus. This double crossing (decussation + corticospinal tract decussation) results in ipsilateral cerebellar signs from dentate lesions. The middle peduncle carries afferents (pontocerebellar fibers) and the inferior peduncle carries both afferents and efferents of the vermis.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.