During VNG, optokinetic testing is performed using a full-field moving stimulus. A reduced or asymmetric optokinetic nystagmus (OKN) response indicates pathology in which location?
- A Peripheral vestibular system
- B Central parieto-occipital pathways ✓
- C Cerebellum
- D Semicircular canals
Correct answer: B. Central parieto-occipital pathways
Explanation
Optokinetic nystagmus is a central pursuit-following reflex mediated by parieto-occipito-temporal pathways. Asymmetric or reduced OKN indicates central pathology in these cortical or brainstem pathways, not peripheral vestibular disease. The cerebellum modulates but does not generate OKN. Peripheral vestibular lesions do not affect OKN symmetry.
Reference: Cummings Otolaryngology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.