Doll's Head Reflex

A clinical sign for evaluating brainstem function in a comatose patient; in a normal person, as the head is turned rapidly to one side—contraindicated if there is a possibility of brainstem injury—the eyes conjugately deviate in the direction opposite to the head’s movement; loss of this reflex implies dysfunction of brainstem or oculomotor nerves; inferolateral deviation of the eyes in combination with pupillary dilation implies dysfunction of the third cranial nerve, possibly due to tentorial herniation
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