II. Indications
- Brainstem function testing in coma
III. Mechanism
- Afferent limb: Touch stimulates the V1 branch of the Trigeminal Nerve (Cranial Nerve 5)
- Reflex center: Pons in the Brainstem
- Efferent limb: Temporal and zygomatic arches of the Facial Nerve (Cranial Nerve 7) close the Eyelids
IV. Technique
- Touch Cornea, lid or Conjunctiva with cotton whisp
- Alternative: Instill 5-10 cc Normal Saline by syringe over the surface of the Cornea
V. Interpretation: Expected response (normal)
- Results in a rapid, Blink Reflex in the exposed eye as well as the other eye (consensual response)
- Diminished reflex in those who use Contact Lenses
- Intact reflex suggests intact Brainstem function
VI. Resources
VII. References
- Degowin (1987) Diagnostic Examination, 5th ed, MacMillan Publishing Company, p. 810