During a cerebellar examination, a patient shows past-pointing and intention tremor on the same side as the lesion. Which cerebellar structure, when damaged, most characteristically produces ipsilateral limb ataxia?

• A Flocculonodular lobe
• B Vermis
• C Anterior lobe
• D Lateral hemisphere (neocerebellum) ✓

Explanation

The lateral cerebellar hemispheres (neocerebellum) receive input from the cerebral cortex via the pontine nuclei and project back via the dentate nucleus and thalamus to the motor cortex. Because the cerebellar outflow decussates twice before reaching the spinal cord, a unilateral hemispheric lesion produces ipsilateral limb incoordination. The vermis mediates truncal balance, and the flocculonodular lobe governs vestibulo-ocular coordination.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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