doll's head sign

doll's head sign

Neurology A clinical sign for evaluating brainstem function in a comatose Pt; in a normal person, as the head is turned rapidly to one side, 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 3^rd cranial nerve, possibly due to tentorial herniation