Nerve Damage And Ringing Ears: Neuropathy-Related Tinnitus

Your senses – including your hearing ability – rely on a network of nerves that receive information and send electrical signals that your brain can interpret within nanoseconds. This process is incredibly complex and if even a few of these nerves become damaged, they can mis-fire, sending wrong signals or none at all. For some people with neuropathy, severe tinnitus can be a result of one of these potential mis-fired signals. 

What Is Tinnitus?

Tinnitus is defined as the perception of sound when there is no external source. You may hear a phantom sound like a buzzing, chirping, clicking, or ringing in one or both ears. Most people experience this phenomenon at least once in their lifetime, but for about 20% of the population, persistent bothersome tinnitus impacts their day to day life. For people with severe tinnitus, the constant sound can impact their ability to sleep, concentrate, or socialize, and can even lead to anxiety and depression. 

Causes Of Tinnitus

The key to managing bothersome tinnitus is understanding the root cause. Tinnitus is typically caused by: 

• Hearing loss. As many as 90% of people with tinnitus also experience some degree of hearing loss.
• Loud noise exposure. The inner ear hair cells are very fragile and can be damaged by exposure to loud or high-pitched sounds.  
• Injury. Head injuries ranging from concussions to traumatic brain injuries can cause changes in your brain’s ability to interpret sound.
• Other causes like earwax buildup, certain medications, migraines, and even allergies can trigger tinnitus. 

One reason people experience tinnitus is because their auditory nerve is affected in some way. Nerves can signal pain, but tinnitus on its own isn’t painful. However, tinnitus can be related to other conditions that do cause pain. In some cases, tinnitus is related to nerve damage – that is, neuropathy.

What Is Neuropathy?

Neuropathy is a general medical term that refers to nerve damage, which can have a wide-reaching impact on your health and wellbeing.

Your brain receives and interprets signals from billions of nerves that branch out through the entire body. These nerves pick up on external stimuli – touch, sight, smell, taste, and hearing – and send an electrical impulse to the brain. Almost immediately, your brain interprets this stimulus and without even thinking about it, you experience your surroundings. Nerve damage, or neuropathy, impacts your brain’s ability to correctly interpret these sensory signals.

Every nerve has a specific function, but can be bundled into three main classifications:

• Sensory nerves that detect temperature, pain, vibration, or touches to your skin.
• Motor nerves that control your muscle movement
• Autonomic nerves that control your unconscious bodily functions like blood pressure, heart rate, digestion, bladder function, and more.

Types Of Neuropathy

Peripheral neuropathy is the result of damage to the nerves located outside the brain and spinal cord. This condition can cause physical weakness and numbness and pain, especially in the hands and feet. Other bodily functions like digestion and circulation may also be affected. 

Neuropathy that impacts the brain and spinal cord is called central neuropathy. This is generally caused by a stroke, brain tumor, or serious injury to the nervous system.

What Causes Neuropathy?

Nerve damage can have many different causes:

• Autoimmune diseases like lupus or rheumatoid arthritis attack your own body’s tissues – including nerves.
• There are quite a few bacterial or viral infections that are known to cause nerve damage.
• Tumors, both cancerous and noncancerous, can put pressure on nerves and damage them.
• Injuries that damage or sever nerves lead to neuropathy. 
• Alcohol abuse, exposure to heavy metals, and vitamin deficiency can contribute to nerve damage.
• Certain medications (especially those used to treat cancer) can contribute to nerve damage as well.
• Although there are many potential causes, diabetes is the most common cause of neuropathy. Over time, blood sugar levels damage tiny blood vessels throughout your body, which in turn damages nerves.

Symptoms Of Neuropathy

Your perception of neuropathic pain depends on the nerve or nerves that are affected. Symptoms may lessen or even go away over time, but in some cases, the damage is permanent. The most noticeable symptoms of peripheral neuropathy are:

• Numbness, prickling, or tingling, most often in hands or feet. You may notice these sensations in other parts of your body as well.
• Sharp pains or a burning sensation without an obvious external cause.
• Pain during activities that shouldn’t cause pain, like the sensation of clothing touching the skin or other light touches.
• Dulled sensation, like you’re wearing gloves or socks when you’re not.
• Problems with coordination. Gross motor skills like walking, standing, or grasping objects may be more difficult if your nerves are misinterpreting stimuli.

If neuropathy impacts nerves that are related to your hearing ability, it can lead to hearing loss and perceived tinnitus. 

What Is Auditory Neuropathy?

As mentioned, your hearing ability relies on a vast network of nerves that pick up and interpret stimuli. If the nerve cells in your auditory system are damaged and your hearing ability is impacted, you may experience a rare condition called auditory neuropathy (also called neural or nerve deafness).

Auditory neuropathy falls under the category of hearing loss, but it is more complicated than that. Since there are many different ways people can perceive this type of nerve damage, it is generally described as auditory neuropathy spectrum disorder. 

Auditory neuropathy spectrum disorder is caused by disruption of the nerve impulses that travel from the inner ear to the brain. Normally, inner hair cells translate sound vibrations into electrical signals and nerve impulses that signal the brain to interpret sound. With auditory neuropathy, the auditory nerve is able to detect sound, but is unable to correctly transmit the signal to your brain for interpretation. 

Symptoms Of Auditory Neuropathy

People with auditory neuropathy may appear to have normal hearing, or they could experience hearing loss that ranges from mild to severe. But because the auditory nerve’s ability to transmit signals is affected, people with auditory neuropathy have trouble understanding speech, regardless of their degree of hearing loss. Both ears are usually affected. 

The symptoms of auditory neuropathy spectrum disorder typically include: 

• Difficulty understanding speech, even with apparently normal hearing abilities. People with auditory neuropathy may describe this as being able to hear, but not understand.
• Worsened speech perception in noisy environments.
• Sounds fade in and out or seem distorted.
• Inconsistent responses to sound.

What Causes Auditory Neuropathy Spectrum Disorder?

Your nervous system plays an important role in your ear function. Researchers point to several different causes including damage to inner hair cells, which are specialized cells that transmit sound signals to the brain. The connection between these inner hair cells and the auditory nerve may be damaged as well. 

How Is Auditory Neuropathy Related To Severe Tinnitus?

Tinnitus does not cause auditory neuropathy – it can arise as a secondary symptom due to the nerve damage in your ears. Research shows that about half of people with auditory neuropathy experience chronic tinnitus. 

You might assume that neuropathy would “turn off” the auditory nerve, but the damage confuses your brain’s signals and can cause abnormal firing of neurons in response to hearing loss. If you have damage to your ear, tinnitus and phantom sounds may accompany these changes to your hearing.

Treatment Options For Auditory Neuropathy And Tinnitus

The causes of auditory neuropathy are not well understood. Theories range from genetic predisposition to birth injuries. Because researchers are still learning about auditory neuropathy, there is no known cure.

While there is no known cure for auditory neuropathy spectrum disorder, there are treatments that may be effective in improving the ability to understand speech:

• Hearing aids and cochlear implants can help, especially among children. 
• Assistive listening devices like remote microphones can be very helpful for some people. These devices help a listener interpret sounds more effectively, especially in a noisy environment.
• Other people manage auditory neuropathy by learning sign language to communicate with others. 

Working with an audiologist, speech therapist, or another doctor who specializes in hearing disorders can help you manage auditory neuropathy spectrum disorder. 

There are several effective ways of treating tinnitus including sound therapy, hearing aids, cognitive behavioral therapy (CBT), tinnitus retraining therapy (TRT), and making positive lifestyle changes. Talk to the audiologists at Treble Health about treating tinnitus and associated auditory neuropathy so you can get the most out of your hearing.