What Causes Vestibular Ocular Reflex Dysfunction?

Medically Reviewed on12/22/2021
what is vestibular-ocular reflex (vor) test?
Vestibular ocular reflex (VOR) is caused by multiple sclerosis, brain stem ischemia, Whipple’s disease, sickness, viral infections, antibiotics, and head injuries.

Vestibularocularreflex also referred to as vestibulo-ocular reflex (VOR), is a vestibular (inner ear) abnormality that can frequently cause vision problems because vestibular and visual systems collaborate to stabilize vision. VOR refers to the “ear to eye” link.

VOR dysfunction is caused by the following:

This condition causes several symptoms that affect most aspects of everyday life.

What is vestibular ocular reflex?

The vestibulo-ocular reflex (VOR) generates eye movements that maintain gaze during head movements by using information from the vestibularlabyrinthof the inner ear.Walkingalong the street without VOR makes it hard to read signs or even identify people.

Inaccurate VOR may cause the visual picture to shift about the photoreceptor cells in the eye, resulting in image blur. VOR responds to rotation and translation by using data from several inner ear receptors.

Even at different speeds and frequencies above 20 Hz, VOR can properly steady the eyes during rotation. This is due to the VOR pathway's short length and its utilization of primarily vestibular sensory input to trigger the motoneurons.

What are the symptoms of vestibular ocular reflex dysfunction?

由于前庭眼反射disord症状er include:

  • Dizziness
  • Trouble balancing the body
  • Spatial disorientation (the person may not be able to determine the body position, motion, and altitude relative to the ground)
  • Vertigo(spinning sensation)
  • Nauseaandvomiting
  • Barotrauma (increased pressure within the ear)
  • Hearingchanges
  • Tinnitus(ringing in the ear)
  • Blurring of vision
  • Cognitive and psychological changes
  • Concentration issues
  • Memory loss

How is vestibular ocular disorder diagnosed?

The vestibular ocular disorder causes several symptoms, which may be consistent with other variousvestibular disorders.

To determine the diagnosis of the vestibulo-ocular reflex (VOR), your doctor may perform different tests, which include:

Head impulse test (HIT)

HIT is more specific in distinguishing peripheral vestibular lesions (inner ear or vestibular nerve) on that side.

  • The examiner instructs the individual to focus on an object while they spin the individual’s head.
  • The individual's head should be rotated slightly past the midline (15° to 20°), and the head should be shoved to the other side using forceful motions.
  • The usual response is to keep one's gaze fixed on the object. When the head moves in one direction, the eyes are drawn away from the objective, followed by eye movements returning to the target. This answer suggests VOR deficiency on the head turn side.
  • Movements should be minimal, the individual's head should not move far to the left or right and the direction of movement should be unexpected.
  • If the individual has a unilateral loss, the abnormal HIT outcome will be toward the lesion's side.
  • If the individual has a bilateral loss, the head thrusts in both directions.

Abnormal HIT is beneficial in differentiating between central and peripheralvertigo.

Rotational chair testing

The goal of rotating chair testing is to establish whether a balance impairment is caused by the vestibular (inner ear) or neurological system.

  • When a person turns their head, thevestibular systemprovides continual impulses to the brain, updating it on the position of the head. This results in extra signals being transmitted to the eye muscles through VOR.
  • Every head movement in one direction is accompanied by an eye movement in the opposing direction. This phenomenon serves as the foundation for rotating chair testing, and hence, this testing should be included in any truly comprehensive balance testing lab.
  • Rotational chair testing can be highly useful in diagnosing bilateral vestibular function loss (no function in both ears) or cerebellar ocular motor disorders. Many people with neurological issues or VOR have been effectively identified using this testing in recent research.

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How to treat vestibular ocular disorder

There is no permanent cure for the vestibular ocular disorder, but symptoms can be managed with certain medications and exercises.

The aim is to treat the cause and provide supportive treatment to alleviate the symptoms. Causes such as infections,multiple sclerosis, nerve degradation, and trauma are treated as follows:

Surgery may be needed to treat the underlying cause if medicines do not help or if there is no role for medications.

  • Rehabilitation:
    • If you have vestibular balance problems, you may benefit from vestibular rehabilitation or balance retraining treatment.
    • This allows you to get through your day without incident.
    • A rehabilitation professional will teach you how to deal withdizzinessin everyday situations.

Exercises to recalibrate vestibular ocular reflex dysfunction

Simple exercise may allow the eye, inner ear, and brain to recalibrate following an injury to the inner ear.

Steps to perform the exercise are as follows:

  1. Sit facing a blank wall and extend your thumb straight in front of you.
  2. You may put up an X symbol on the wall at approximately one meter.
  3. Keep your gaze locked on your thumb or the X you've drawn on the wall at all times during this exercise.
  4. Turn your head to the right and then to the left.
  5. Alternate turning ahead from left to right and back again in a rhythmic pattern.
  6. The left-to-right turn should take about one second.
  7. The movement of your head from left to right should be effortless.
  8. The goal of the exercise is to turn your head while keeping your gaze fixated on one location, such as your thumb or an X on the wall.

Perform this exercise for one to two minutes, three to four times each day for one to two weeks. In most circumstances, you will see a difference within a week.

  • You may experience dizziness while performing this exercise, but you must repeat the activity.
  • You may feel sick or dizzy just after completing this activity. This does not imply that you are performing the exercises incorrectly.Nauseais the body's reaction to inner ear failure. The brain will strive to adjust, which will aid in healing.
  • If you feel ill for more than 30 minutes following the workout, cut down the speed of your head motions and/or turn your head less.
  • If you do not feel dizzy after the workout, you should do it faster or switch to other methods of similar exercise.
  • If your neck is too stiff to move alone, then move your head along with the shoulders.

Follow advanced exercises once you are wellversedwith the above exercise, such as the following:

  • If you were able to complete the exercise without feeling dizzy, move your head faster.
  • If you can complete the exercise comfortably while sitting, try it while standing and while walking.
  • Place your X or thumb against a busy background instead of a blank wall.
  • Turn your head to the left while moving your thumb to the right and vice versa.
  • Begin by sitting, then advance to standing or walking (with or without a busy visual background). If you can accomplish all of them, you have done well because most individuals with regular inner ear problems would struggle to perform these exercises.
  • Rather than moving your head from side to side, move it up and down (nodding).

If you can perform all the above, you are doing extremely well.

Medically Reviewed on12/22/2021
References
Image Source: iStock Images

Current Treatment of Vestibular, Ocular Motor Disorders and Nystagmus: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3002631/#:~:text=The%20three%20most%20common%20causes,internuclear%20ophthalmoplegia%20or%20upbeat%20nystagmus.

Vestibulo-Ocular Reflex: https://www.sciencedirect.com/topics/neuroscience/vestibulo-ocular-reflex

视觉与前庭疾病挑战:https://vestibular.org/article/diagnosis-treatment/vision-hearing/vision-challenges-with-vestibular-disorders/#:~:text=Article%20Summary,eyes%20still%20during%20head%20motion.