Menace reflex

Menace reflex

The menace reflex is one of three forms of blink reflex. It is the reflex blinking that occurs in response to the rapid approach of an object.[1] The reflex comprises blinking of the eyelids, in order to protect the eyes from potential damage, but may also including turning of the head, neck, or even the trunk away from the optical stimulus that triggers the reflex.[2]

Stimulating the menace reflex is used as a diagnostic procedure in veterinary medicine, in order to determine whether an animal's visual system, in particular the cortical nerve, has suffered from nerve damage. Cortical damage, particularly cerebellar lesions, can cause loss of the menace reflex whilst leaving the other blink reflexes, such as the dazzle reflex, unaffected.[3][1] The presence or absence of the menace reflex, in combination with other reflexes, indicates a locus of damage. For examples: An animal with polioencephalomalacia will lack the menace reflex, but will still have the pupillary light reflex. Polioencephalomacia damages the visual cortex, impairing the menace reflex, but leaves the optic nerve, oculomotor nucleus, and oculomotor nerve intact, leaving the pupillary light reflex unaffected. Contrastingly, an animal with ocular hypovitaminosis-A will suffer from degeneration of the optic nerve, affecting both reflexes, and such an animal presents with a lack of both reflexes.[4]

Testing the menace reflex has to be done with care. Waving an object close to an animal's eyes or face does not necessarily demonstrate a functioning menace reflex, in part because the animal can sense such objects and react to them via other senses than sight. Clinical testing of the menace reflex usually involves such precautions as waving an object from behind a sheet of glass, so as to shield the animal from any drafts caused by the motion of the object through the air, which it might otherwise sense. Such reactions to non-visual stimuli are a widespread cause of false positives and false negatives when pet owners test their own animals for the presence of the menace reflex.[3][1]

The neural pathway of the menace reflex comprises the optic (II) and facial (VII) nerves. It is mediated by tectobulbar fibres in the rostral colliculi of the midbrain passing from the optic tract to accessory nuclei, and thence to the spinal cord and lower motor neurones that innervate the head, neck, and body muscles affected by the reflex. The facial nerve is mediated through a corticotectopontocerebellar pathway.[3][1][2]


  1. ^ a b c d Francis Heed Adler (1953). Physiology of the eye: clinical application (2nd ed.). Mosby. pp. 23. 
  2. ^ a b Douglas H. Slatter (2001). Fundamentals of veterinary ophthalmology (3rd ed.). Elsevier Health Sciences. pp. 18. ISBN 0721627056. 
  3. ^ a b c Michael Edward Peterson and Patricia A. Talcott (2006). Small animal toxicology (2nd ed.). Elsevier Health Sciences. pp. 101. ISBN 0721606393. 
  4. ^ O. M. Radostits, J. H. Arundel, and Clive C. Gay (2000). O. M. Radostits. ed. Veterinary medicine: a textbook of the diseases of cattle, sheep, pigs, goats and horses (9th ed.). Elsevier Health Sciences. pp. 512. ISBN 0702026042. 

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Corneal reflex — The corneal reflex, also known as the blink reflex, is an involuntary blinking of the eyelids elicited by stimulation of the cornea (such as by touching or by a foreign body), or bright light, though could result from any peripheral stimulus.… …   Wikipedia

  • Purkinje cell — Infobox neuron neuron name = Purkinje cell image neuron = PurkinjeCell.jpg caption neuron = Drawing of pigeon Purkinje cells (A) by Santiago Ramon y Cajal location = Cerebellum function = inhibitory projection neuron neurotranmitter = GABA… …   Wikipedia

  • Cerebellar abiotrophy — (CA), also referred to as the cerebellar cortical abiotrophy (CCA), which is a genetic neurological disease in animals best known to affect certain breeds of horses and dogs. It develops when the neurons known as Purkinje cells, located in the… …   Wikipedia

  • entendre — [ ɑ̃tɑ̃dr ] v. tr. <conjug. : 41> • 1080; lat. intendere « tendre vers », d où « porter son attention vers » I ♦ 1 ♦ V. tr. ind. Se prêter (à qqch.). ⇒ acquiescer; accepter, approuver, consentir. « Les uns disent que j ai bien fait d… …   Encyclopédie Universelle

  • Seven and the Ragged Tiger — Studio album by Duran Duran Released 21 November 1983 …   Wikipedia

  • AquaNox — Éditeur Fishtank Interactive Développeur Massive Development Date de sortie Ét …   Wikipédia en Français

  • Aquanox — Éditeur Fishtank Interactive Développeur Massive Development Date de sortie …   Wikipédia en Français

  • tomber — 1. tomber [ tɔ̃be ] v. <conjug. : 1> • XV e; tumber XIIe; probablt o. onomat., avec infl. de l a. fr. tumer « gambader, culbuter », frq. °tûmon I ♦ V. intr. (auxil. être) A ♦ Être entraîné à terre en perdant son équilibre ou son assiette. 1 …   Encyclopédie Universelle

  • MAIN — La main, organe de préhension et récepteur sensitif important, est l’apanage des Primates et de l’homme. En vérité, la main humaine possède une signification particulière, car elle se trouve à l’extrémité du membre supérieur qui est libéré des… …   Encyclopédie Universelle

  • voir — [ vwar ] v. <conjug. : 30> • XIIe veoir; vedeir 980; lat. videre I ♦ V. intr. (1080 vedeir) Percevoir les images des objets par le sens de la vue. C est « un postulat bien ancré, qu un nouveau né [...] “ça” ne voit pas » (F. Leboyer). Ne… …   Encyclopédie Universelle

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”