Blink Reflex
An electrodiagnostic test that evaluates the trigeminal and facial nerve pathways by measuring the reflex blink response to electrical stimulation. Used to assess brainstem function and facial nerve disorders.
Full Definition
The blink reflex is a protective reflex involving bilateral eyelid closure in response to stimulation near the eye. Electrodiagnostically, it is elicited by electrical stimulation of the supraorbital nerve (trigeminal nerve branch) while recording from the orbicularis oculi muscles bilaterally. The reflex produces two response components: R1 (early ipsilateral response) and R2 (late bilateral response), which travel through different brainstem pathways. The blink reflex is valuable for evaluating trigeminal neuralgia, facial nerve palsy, multiple sclerosis, and brainstem lesions. Abnormalities can localize lesions to specific anatomical regions of the reflex arc.
Usage
Usage note: Hyphenate when used as an adjective (blink-reflex testing) but not as a noun.
In Context
- "The blink reflex showed delayed R1 responses ipsilateral to the facial weakness." — Electrodiagnostic report
- "Bilateral R2 responses were absent, suggesting a pontine lesion." — Clinical neurophysiology study