Oculocephalic reflex

Oculocephalic reflex

The oculocephalic reflex is a medical sign seen in comatose patients in which the eyes will move opposite the direction the head is turned, thus maintaining a more-or-less steady gaze. It is also called the doll's eye reflex due to the fact that many dolls with movable eyes mimic the reflex.

This reflex is used by physicians to determine if a comatose patient has intact function of the brainstem. Normally in a conscious person, this reflex is suppressed by the cerebral cortex, but such higher-level control is lost when a patient is comatose. If the reflex is present, it means that cortical influence on the brainstem has weakened as expected but the brainstem is intact, leading the physician to assume that the source of unconsciousness lies in the cerebral hemispheres and not the brainstem. If however a patient is comatose and the reflex is "not" present, it suggests damage to the brainstem. [Pillai S, Praharaj SS, Mohanty A, Kolluri VR. Prognostic factors in children with severe diffuse brain injuries: a study of 74 patients. Pediatr Neurosurg. 2001 Feb;34(2):98-103. PMID 11287810.] In the setting of brain injury, an absent oculocephalic reflex carries a very poor prognosis, possibly indicating brain death.

Since the test involves rapid neck movement, it is contraindicated in patients with known or suspected spinal cord injuries. It also can be used to evaluate dizzy patients for vestibular pathologies and yields information similar to testing the vestibulo-ocular reflex. [Harvey SA, Wood DJ. The oculocephalic response in the evaluation of the dizzy patient. Laryngoscope. 1996 Jan;106(1 Pt 1):6-9. PMID 8544630.]

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