Abnormal doll's eye reflex may indicate:

• A. Brainstem dysfunction
• B. Optic nerve dysfunction
• C. Trigeminal nerve dysfunction
• D. Cerebellar dysfunction

Answer: (A)

The doll’s eye reflex tests brainstem integrity by evaluating the vestibulo-ocular reflex. When you turn the infant’s head, the eyes should move in the opposite direction to keep the gaze fixed. This response depends on brainstem circuits that coordinate input from the vestibular system with the ocular motor nerves. If the brainstem is damaged, this reflex is absent or abnormal, so abnormal doll’s eye reflex points to brainstem dysfunction.

Optic nerve dysfunction would affect vision and pupillary responses, not the gaze-stabilizing reflex. Trigeminal nerve issues would alter corneal or jaw reflexes, not the eye movements in response to head turning. Cerebellar dysfunction affects coordination and balance but does not primarily disrupt this brainstem-mediated reflex.