Understanding Hearing & Balance Disorders

Audiologists do more than just treat hearing loss. They also offer solutions for a range of hearing and balance issues, from dizziness to specific conditions like Meniere's disease. This document provides an overview of how your auditory system can impact your sense of balance.

Discussion of Dizziness

Dizziness is a symptom, not a disease. It's best described as a feeling of unsteadiness, imbalance, or disorientation. The sensation can range from a mild unsteadiness to a severe spinning sensation known as vertigo. Because the balance system operates largely unconsciously, it can be difficult to describe the feeling. A doctor will often perform tests to determine the underlying cause, as dizziness can be a symptom of many different conditions and may or may not be accompanied by hearing impairment.

How the Normal Ear Works

The ear has three main parts: the outer, middle, and inner ear. The outer ear gathers sound and directs it to the eardrum. The middle ear, which includes the eardrum and three tiny bones, transmits these vibrations to the fluid of the inner ear. The inner ear is encased in bone and contains fluid that surrounds the delicate nerve endings for both hearing and balance. Fluid waves in the hearing chamber (the cochlea) stimulate nerve endings, which send electrical impulses to the brain to be interpreted as sound. Likewise, fluid movement in the balance chambers (the vestibule and semicircular canals) sends impulses to the brain, which are interpreted as motion.

How We Maintain Balance

Our balance system relies on four key components: the eyes, the inner ear, the muscles, and the central nervous system. The brain acts as a central processor, receiving a constant stream of information from the eyes, inner ear, and receptors in our muscles and joints (called proprioceptors). All three systems work together to keep the body balanced.

The inner ear's balance mechanism—the vestibular labyrinth—is filled with fluid. When you move your head, this fluid shifts and stimulates nerve endings that send impulses to the brain. If the inner ear isn't functioning correctly, the brain receives unequal impulses, leading to a distorted sense of balance. This can cause the eyes to move uncontrollably (nystagmus), making your surroundings appear to spin.

Types of Dizziness

There are different types of dizziness, often categorized by their origin:

• Ear Dizziness: This is one of the most common types and is caused by issues with the inner ear's fluid pressure, circulation, or nerve function. Symptoms can include whirling sensations (vertigo), unsteadiness, and lightheadedness, which are often aggravated by head motion.
• Central Dizziness: This type of dizziness, often an unsteadiness, is caused by the brain's failure to correctly interpret nerve impulses. It can be linked to emotional stress, alcohol intake, or even more serious issues like tumors.
• Visual Dizziness: Caused by an imbalance in eye muscles or a misinterpretation of visual cues. A common example is car sickness, where the eyes send confused signals about motion to the brain.

Causes & Symptoms of Dizziness

Dizziness can stem from a wide variety of causes, including changes in circulation, fluid pressure, metabolism, or from infections, injuries, or growths. An extensive evaluation, including hearing and balance tests, blood work, and X-rays, is often necessary to pinpoint the exact cause and rule out any serious conditions.

• Circulation Changes: Interference with blood flow to the inner ear can cause dizziness. This can be due to blood vessel spasm, a partial or total blockage (occlusion), or a rupture (hemorrhage).
• Benign Positional Paroxysmal Vertigo (BPPV): A common balance disorder caused by loose calcium deposits (cupuliths) in the inner ear. It leads to brief episodes of vertigo when changing head position, such as when lying down or getting out of bed.
• Meniere’s Disease: A condition characterized by repeated attacks of dizziness, hearing loss, and tinnitus. It's caused by increased fluid pressure (hydrops) in the inner ear.
• Other Causes: Imbalance can also be caused by aging, infections (such as neuritis), tumors, metabolic disorders (like thyroid issues or blood sugar problems), or allergies.

Treatment Options for Dizziness

Dizziness can often be managed or eliminated through medical or surgical treatment, depending on the cause and severity.

• Medical Treatment: This can include anti-dizziness medications, diuretics (water pills) to manage fluid pressure, and lifestyle changes like avoiding caffeine and nicotine. For some conditions like BPPV, a physical therapist may perform a Canalith Repositioning Procedure.
• Surgical Treatment: Surgery is considered when medical treatment fails to control vertigo. Options range from procedures to drain excess fluid (endolymphatic shunt), to selectively cutting the balance nerve (selective vestibular neurectomy), or even destroying the balance and hearing portions of the inner ear (labyrinthectomy).
• Nonsurgical Treatments: Physical therapy, which includes habitual exercises and balance retraining, is a common approach. The goal is to help the brain compensate for the imbalance and decrease symptoms.