What is oculocephalic reflex used for?
Oculocephalic and oculovestibular reflexes are primarily used to determine whether a patient’s brainstem is intact (e.g. coma or brain death assessment) ensure the C-spine is cleared. the patient’s eyes are held open.
What is a negative oculocephalic reflex?
The examiner observes a negative oculocephalic reflex when the patient’s eyes stay midline and do not move while the examiner rotates the head. A similar examination is performable for vertical eye movements.
What is the pathophysiology of oculocephalic reflexes in a coma?
The eyes should gradually return to the mid-position in a smooth, conjugate movement if the brainstem is intact. Patients with metabolic coma (e.g. hepatic failure) may have exaggerated, brisk oculocephalic reflexes.
Why is it called Doll’s eye reflex?
The oculocephalic reflex is also called the doll’s eye reflex, so named because dolls that have movable eyes exhibit the same eye movement. In a comatose patient, if the head is tilted to one side, the eyes move towards the contralateral side.
Is oculocephalic reflex normal?
A normal response is for the eyes to move in the direction opposite the head movement, such as looking left as you turn her head to the right. The oculocephalic reflex is absent if her eyes move in the same direction as her head or stay fixed at midline.
What is the meaning of oculocephalic reflex?
The oculocephalic reflex (doll's eyes reflex) is an application of the vestibular-ocular reflex (VOR) used for neurologic examination of cranial nerves 3, 6, and 8, the reflex arc including brainstem nuclei, and overall gross brainstem function.
What is a negative dolls eye reflex?
Typically the doll's eyes reflex is elicited by turning the head of the unconscious patient while observing the eyes. The eyes will normally move as if the patient is fixating on a stationary object. If there is a negative doll's eyes reflex then the eyes remain stationary with respect to the head.
What is the DOLL's eye maneuver?
USA. Synonyms. Doll's eye movement; Oculocephalic reflex. Definition. The doll's eye maneuver is executed by quickly turning the patient's head horizontally from side to side or vertically up and down while holding the eyelids open.
What does positive DOLL's eyes mean?
The examiner observes a positive oculocephalic reflex when the patient moves their eyes opposite of the rotation of their head, such that their eyes stay looking forward (like a doll's eyes).
What causes DOLL eyes?
Oculocephalic reflex is caused by quickly turning and briefly holding the patient's head to the right, then to the left, and unbending and bending the neck. In this case, the eyes deviate in the opposite direction (for example, when turning the head to the left, the eyes deviate to the right).
How do you detect brain death?
For a diagnosis of brain death:a person must be unconscious and fail to respond to outside stimulation.a person's heartbeat and breathing can only be maintained using a ventilator.there must be clear evidence that serious brain damage has occurred and it cannot be cured.
What does Disconjugate gaze mean?
Dysconjugate gaze is a failure of the eyes to turn together in the same direction.
What is cold caloric test?
This test stimulates your acoustic nerve by delivering cold or warm water or air into your ear canal. When cold water or air enters your ear and the inner ear changes temperature, it should cause fast, side-to-side eye movements called nystagmus.
What are brain stem reflexes?
Brainstem reflexes are relatively simple motor responses organized by the brainstem and designed to enable the body to adjust rapidly to sudden changes in the environment.
How is the corneal reflex tested?
Approaching his eye from the side, out of his line of vision, lightly touch a thin strand of clean cotton (as from a cotton ball) to his cornea. Observe for blinking and tearing in that eye (direct corneal reflex). At the same time, observe whether his other eye blinks (consensual corneal reflex).
How do you test for vestibulo ocular reflex?
VOR is generally tested by turning the patient's head on their long axis and observing for the doll's eyes response (DOLL). The eyes deviate opposite to the direction of head rotation. A possibly related maneuver has been used in infants as a neurologic test.
Which nerves are involved in the corneal reflex?
The corneal blink reflex is caused by a loop between the trigeminal sensory nerves and the facial motor (VII) nerve innervation of the orbicularis oculi muscles. The reflex activates when a sensory stimulus contacts either free nerve endings or mechanoreceptors within the epithelium of the cornea.
What is the Oculocephalic reflex?
Oculocephalic reflex: ensure the C-spine is cleared. the patient’s eyes are held open. the head is briskly turned from side to side with the head held briefly at the end of each turn. a positive response occurs when the eyes rotate to the opposite side to the direction of head rotation, thus indicating that the brainstem (CN3,6,8) is intact.
How to assess vertical oculovestibular eye response?
Vertical oculovestibular eye responses can be assessed by irrigating both ear s simultaneously.
Why is the head elevated to 30 degrees above horizontal?
the head is elevated to 30 degrees above horizontal so that the lateral semicircular canal is vertical, and so that stimulation with generate a maximal response.
What is the reflex that keeps the eyes looking straight ahead when the head is turned?
This reflex is brainstem mediated and keeps the eyes looking straight ahead when the head is turned, in an unconscious patient. It’s a test to use on the unconscious patient to see if the brainstem is intact.
Which cranial nerves are involved in reflexes?
The reflex is mediated by three cranial nerves VIII, III and VI.
What does it mean when a doll's eyes move with the head?
The old dolls used to have the eyes painted on, so that when you turned the head, the eyes moved with the head. This would indicate that the brainstem was not intact .
What happens when your head is turned to one side?
So when the head is turned to one side, the eyes move in the opposite direction to face the centre. The way to perform this test in the unconscious patient, is to hold the head (assuming no cervical injury), with eyes held open. The head is turned rapidly to one side. The eyes will move in a smooth motion to the centre, i.e.., looking forward.
What is reflex in psychology?
reflex. a reflected action or movement; the sum total of any particular automatic response mediated by the nervous system. A reflex is built into the nervous system and does not need the intervention of conscious thought to take effect. The knee jerk is an example of the simplest type of reflex.
What is conditioned reflex?
A conditioned reflex is one acquired as the result of experience. When an action is done repeatedly the nervous system becomes familiar with the situation and learns to react automatically, and a new reflex is built into the system.
What is the reflex that protects the body from injury called?
A reflex that protects the body from injury, as this one does, is called a nociceptive reflex .
What nerves do the hot stove reflex go to?
Before the hand is pulled away, an impulse must go from the sensory nerve endings in the skin to a center in the spinal cord, from there to a motor center, and then out along the motor nerves to shoulder, arm, and hand muscles.
How many nerves are involved in a simple reflex?
This reflex, or simple reflex arc, involves only two nerves and one synapse. The leg begins to jerk up while the brain is just becoming aware of the tap. Other simple reflexes, the stretch reflexes, help the body maintain its balance. Every time a muscle is stretched, it reacts with a reflex impulse to contract.
What is the Bainbridge reflex?
Bainbridge reflex a rise in pressure in, or increased distension of, the large somatic veins or the right atrium causes acceleration of the heart beat. Called also Bainbridge effect.
What is accelerator reflex?
accelerator reflex an increase in heart rate in response to changes in intrathoracic pressure or respiratory rate; see also Bainbridge reflex and cardiac respiratory reflex.
What is the oculocephalic reflex?
The oculocephalic reflex (doll's eyes reflex) is an application of the vestibular-ocular reflex (VOR) used for neurologic examination of cranial nerves 3, 6, and 8, the reflex arc including brainstem nuclei, and overall gross brainstem function. It is often used to examine patients in the neurologic critical care setting and may have utility ...
How to perform oculocephalic reflex?
The oculocephalic reflex is performed by holding a patient’s eyelids open and moving their head from side to side. The examination should only be performed on patients with a stable cervical spine without c-spine precautions.
What reflex is used to assess retrobulbar anesthesia?
Using the oculocephalic reflex to assess effective retrobulbar anesthesia.
What is the arc of the vestibule?
The vestibulo-ocular reflex (VOR) arc consists of a series of brainstem nuclei and the nerves connecting them as well as the vestibular system and the extra-ocular muscles of the eye.
What are vestibular lesions?
Vestibular lesions - Lesions to the vestibular nerve or vestibular nuclei have been shown to impair the ipsilateral doll's eyes reflex. [7]
What does it mean when an examiner observes a positive oculocephalic reflex?
The examiner observes a positive oculocephalic reflex when the patient moves their eyes opposite of the rotation of their head, such that their eyes stay looking forward (like a doll’s eyes). The examiner observes a negative oculocephalic reflex when the patient’s eyes stay midline and do not move while the examiner rotates the head. ...
When do neonates have reflexes?
Neonates - Most neonates exhibit an unsuppressed doll's eyes reflex before 11.5 weeks; this can serve as a neonatal milestone in neurologic development. [10][2]
How to perform Oculocephalic Reflex?
For a complete test and a maximal stimulus, the following manoeuvres must be performed: Rotate the head to one direction. The eyes should deviate in the opposite direction. This deviation should be smooth and conjugate. Keep the head in that position. The eyes should slowly return to midline.
How to test for eye movement?
Rotate the head to the opposite direction; i.e. if facing to the right, turn the head to face the left. This is the maximal stimulus for this test. Again, the eyes should move smoothly in the opposite direction.
What is the syndrome where both the MLFs are taken out and one of the abducens nuclei?
The result is a situation where only the unaffected side will behave normally in response to cold caloric testing (that's the "half").
Which part of the brain is involved in the ascending arousal system?
These are large, central brainstem regions, which overlap with the ascending arousal system. Thus, it would be highly unlikely that a structural lesion of some sort (like a stroke) has taken out the rest of the brainstem, leaving these regions intact.
Can a coma occur if the oculocephalic reflex is intact?
In other words, if the oculocephalic reflex is intact, the coma is unlikely due to a structural brainstem lesion.
