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Oculovestibular Testing
Aka: Oculovestibular Testing, Cold Calorics
- Technique
- Patient supine with head at 30 degrees elevation
- Isolates input of horizontal semicircular canals
- Instill 10-20 ml iced saline into auditory canal
- Use 20 cc syringe
- Use butterfly tubing with needle cut off
- Cools mastoid bone and alters endolymphatic flow
- Stimulates vestibular nuclei as if head turned
- rapidly to opposite side
- Interpretation
- Nystagmus both eyes slow toward cold, fast to midline
- Not comatose
- Both eyes tonically deviate toward cold water
- Coma with intact Brainstem
- No eye movement
- Brainstem injury
- Movement only of eye on side of stimulus
- Internuclear ophthalmoplegia
- Suggests Brainstem structural lesion