blink reflex


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blink response

a response elicited during nerve conduction studies, consisting of muscle action potentials evoked from orbicularis oculi muscles after brief electric or mechanical stimuli to the cutaneous area supplied by the ophthalmic branch of the trigeminal nerve. Characteristically, there is an early response (approximately 10 msec after stimulus) ipsilateral to the stimulation site (labeled R1) and bilateral late responses (approximately 30 msec after stimulus; labeled R2); the latter are responsible for the visible twitch of the orbicularis oculi muscles.

blink reflex

Etymology: ME, blenken + L, reflectere, to bend back
the automatic closure of the eyelid when an object is perceived to be rapidly approaching the eye.

blink re·sponse

, blink reflex (blingk rĕ-spons', rē'fleks)
A response elicited during nerve conduction studies, consisting of muscle action potentials evoked from orbicularis oculi muscles after brief electric or mechanical stimuli to the cutaneous area supplied by the ophthalmic branch of the trigeminal nerve. Characteristically, there is an early response (approximately 10 msec after stimulus) ipsilateral to the stimulation site (labeled R1) and bilateral late responses (approximately 30 msec after stimulus; labeled R2); the latter are responsible for the visible twitch of the orbicularis oculi muscles.

blink

the involuntary movement of one or both eyelids of both eyes simultaneously. The frequency varies between species. Cats blink the least, with the possible exception of owls. In birds it is the lower eyelid which is moved up to meet the upper lid. In mammals the upper eyelid is moved down to meet the lower lid. The blink is a part of several reflexes including the palpebral, conjunctival and menace reflexes.

blink reflex
see blink response.
blink response
absent in lesions of the ophthalmic branch of the trigeminal nerve. Called also blink reflex.
References in periodicals archive ?
Untreated animals completely recovered the eye blink reflex in a mean of 17.
In these studies, daily, low-frequency ES hastened the onset of recovery of the eye blink reflex by reducing the initial delay in sprout formation rather than by increasing the rate of axonal regeneration, indicating that ES acts primarily on events in the early stages of recovery [5-7].
Decreased habituation of the R2 component of the blink reflex in migraine patients.
The effects of shounousui on the three responses of the blink reflex in man.
Selective inhibition of ipsilateral and contralateral R3 of the blink reflex by capsaicin.
The blink reflex can be modified by presenting a stimulus (of any sensory modality) in close temporal proximity to the blink-eliciting stimulus.
The results obtained by testing the blink reflex in patients with headaches have been very heterogeneous.
Reduced control of light entering eye Blepharospasm Involuntary blinking, Imbalance of blink reflex squeezing or closure of eyelids Buphthalmos Epiphora, blepharospasm Multiple causes enlarged cornea Coloboma Variable, vision normal Reduction in control of to poor light entering eye Stimulation of trigeminal nerve Corneal Pain, foreign-body Direct irritation of abrasion sensation, reflex tears trigeminal afferents Corneal ulcer Pain, tearing, poor Direct irritation of vision, red eye trigeminal afferents Corneal Low vision, pain, Deposition of lipids in dystrophy hyperaemia cornea.
The data of one subject were unavailable for startle blink reflex (n = 44), heart-rate data of one subject were discarded from statistical analysis due to intractable recording artifacts (n = 44), and SCR data of one subject were discarded due to a low rate of responses (< 2; n = 44).
Blink reflex responses were recorded over the orbicularis oculi (O.