A neurosurgeon planning stereotactic surgery for tremor in Parkinson's disease targets the ventral intermediate (VIM) nucleus of the thalamus. The VIM nucleus primarily relays signals from which source?
- A Contralateral dentate nucleus of the cerebellum via dentato-rubro-thalamic tract ✓
- B Ipsilateral globus pallidus internus via the ansa lenticularis
- C Contralateral red nucleus receiving cerebellar efferents
- D Ipsilateral substantia nigra pars reticulata via the nigrostriatal pathway
Correct answer: A. Contralateral dentate nucleus of the cerebellum via dentato-rubro-thalamic tract
Explanation
The ventral intermediate (VIM) nucleus of thalamus is the principal thalamic relay for cerebellar output, receiving inputs from the contralateral dentate nucleus via the dentato-rubro-thalamic (cerebellothalamic) tract. VIM thalamotomy or deep brain stimulation effectively abolishes cerebellar-type tremor and is also used for essential tremor. The globus pallidus internus projects via ansa lenticularis to the ventral anterior (VA) and ventral lateral (VLo) thalamic nuclei, which are targets for Parkinson's dyskinesias.
Reference: BD Chaurasia's Human Anatomy, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.