Vestibular Disorders - Causes, Symptoms, Diagnosis, and Management

Introduction:

The ear is a complex organ consisting of bone and cartilage. Within the ear, there are canals called semicircular canals, which are filled with fluid. A change in position causes the movement of these fluids. This fluid movement is sensed by sensory receptors of the ear, and the information is sent to the brain to control the balance. This harmony between the ear and brain makes the vestibular system work efficiently. Any disorder or damage to the ear can affect this vestibular system. Various balancing vestibular disorders are:

1. Acoustic Neuroma: It is a serious, non-cancerous tumor that develops on the vestibulocochlear nerve sheath, which transmits both sound and balance information to the brain. As the tumor enlarges, it compresses the acoustic nerve and results in tinnitus, dizziness, deafness, and imbalance between the ear and brain.

2. Benign Paroxysmal Positional Vertigo (BPPV): It is a disorder of the vestibule caused by dizziness, vertigo, and accumulation of debris (also called “ear rocks'') in the inner ear. As the head posture changes, these ear rocks move, resulting in producing false signals to the brain.

3. Vestibular Neuritis: It occurs due to inflammation of the vestibular branch of the eighth cranial nerve (vestibulocochlear nerve) that connects the ear to the brain, leading to vertigo and dizziness. It does not cause any hearing loss.

4. Labyrinthitis: It occurs due to swelling of both vestibular and cochlear branches of the eighth cranial nerve, leading to dizziness and vertigo, accompanied by hearing loss.

5. Meniere Disease: The exact cause of the disease is not known. It causes fluid accumulation in the inner ear, resulting in a ringing sensation in the ear, vertigo, and pressure in the ear.

6. Ototoxicity: It is a poisoning of the ear that occurs due to side effects of drugs and chemicals that damage the eighth cranial nerve, leading to loss of balance and hearing.

What Causes Vestibular Disorders?

Various causes of vestibular disorders are:

• Medicinal side effects.

• Ear infections.

• Traumatic brain injury can damage the vestibular system.

• Accumulation of debris in the ear canals.

• Nerve disorders, like an acoustic neuroma.

• Cancerous or non-cancerous growth in the inner ear.

What Are the Signs and Symptoms of Vestibular Disorders?

The signs and symptoms of vestibular disorders are as follows:

• The feeling of spinning of the head (vertigo).

• Ringing sensation in ears.

• Psychological changes like concentration and memory problems.

• Anxiety and depression.

• Hearing problems.

• Loss of coordination and balance.

• Dizziness.

• Disturbance in vision.

• Disorientation.

• Nausea and vomiting.

• Abnormal heart rhythms.

What Are the Diagnostic Methods for Vestibular Disorders?

Appropriate diagnosis of vestibular disorders can be made based on both tests and careful clinical examination. Various diagnostic aids are:

• Rotary Chair Test: In this test, a patient is made to sit on a computerized rotary chair that moves from side to side at a controlled rate, and the eye movement of the patient with the side of chair movement is examined simultaneously.

• Magnetic Resonance Imaging (MRI): Magnetic resonance imaging for the brain is done to check for any cancerous or non-cancerous soft tissue growth leading to symptoms of vertigo.

• Electrocochleography (ECOG): This is done to evaluate the response to sound from the nervous system. An earphone is used to play sounds in the ear, and an electrode measures the response.

• An Otoacoustic Emission (OAE): This test is used to measure the response of hair cells in the cochlea to the sound produced in the ear canal by a mini speaker.

• Auditory Brainstem Response (ABR): This test is used, especially for those patients in whom imaging procedures are not possible because of implants in the brain, like metal plates and screws. The response of the nervous system to sound is measured, which helps in identifying the auditory pathway defects and any nerve disorder, like an acoustic neuroma.

• Audiometry (Hearing Test): This test is to check the vestibular functions of hearing as well as balance. It is done in a sound-treated room. Earphones are used to present the tone at different pitches, and a response is requested when these sounds are heard.

• Electronystagmography (ENOG): It is a method of detecting and recording nystagmus (involuntary eye movements), which are spontaneous or induced by the caloric, positional, rotational, or optokinetic stimulus.

• Caloric Test: The basis of this test is to induce nystagmus by thermal stimulation of the vestibular system. The advantage of the test is that each labyrinth can be tested separately.

• Clinical Test of Cerebellar Dysfunction: All cases of giddiness should be tested for cerebellar disorders.

What Is the Treatment of Vestibular Disorders?

The treatment modality depends on the cause and extent of vestibular disorders. Some of the treatment methods are:

• Identify and Treat Underlying Cause: In cases of ear infections, the first line of treatment is to identify the cause and start with antibiotics as necessary.

• Lifestyle Changes: Avoid smoking and keep the ears clean and dry.

• Diet Changes: Avoid too much salt intake, especially in cases of high blood pressure and excessive caffeine intake.

• Increase Fluid Intake: If blood pressure drops suddenly while standing (orthostatic hypertension) or changes posture, increase intake of fluids.

• Rehabilitation Therapy: In the case of brain and ear disorders, practice balance exercises like eye or ear head-turning, walking, meditation, and focusing exercises from the therapist in the vestibular rehabilitation centers.

• Epley Maneuver (Canalith Repositioning Procedure): These are the specialized movements of the head and trunk to relocate the particles in the ear canal where they do not trigger the symptoms.

• Surgery: If the conservative treatment fails to resolve the symptoms, surgical management is done to treat the underlying cause and get rid of the ear infection. The purpose of surgery is to correct the deformity of the inner ear.

• Radiotherapy: It is done for patients with tumors involving the nerve sheath (acoustic neuroma) of the eighth cranial nerve to avoid excision and decrease or destroy the tumor to relieve the pressure on the nerve responsible for balancing and hearing disorders.

What Are the Complications Associated With Vestibular Disorders?

The complications associated with vestibular disorders are as follows:

• Trauma due to falls in cases of dizziness.

• Lifestyle disturbance due to anxiety and mental confusion.

• Discomfort, due to loss of balance and hearing.

Conclusion:

The balance of the body depends on the peripheral sources, that is, the eyes, muscles, and vestibular organs. The vestibular system is a sensory system that maintains harmony between the inner ear and the brain by sending signals from the ear to the brain in the form of nerve impulses. Any disturbance to the vestibular system severely affects posture, balance, eye movements, and hearing. Any symptoms like vertigo, dizziness, blurred vision, and hearing changes should be observed and managed by visiting the doctor immediately to treat the underlying cause of the balance disorder.