A Look Into the Physiology of Tinnitus

A Look Into the Physiology of Tinnitus

People have been trying to understand the ringing in our years as far back as the Egyptians. One would think, with all the technological advances of science, we would have found a way to describe, explain, and cure tinnitus. That’s not the case when it comes to that annoying buzzing, whooshing, ringing, or whatever other noise you hear.

After all these years, we still don’t fully understand tinnitus. We understand some of the possible causes such as hearing loss for subjective tinnitus, and turbulent blood flow for objective tinnitus, but we don’t fully understand why the auditory system reacts the way it does.

There are existing and experimental treatments on the horizon for tinnitus but that doesn’t mean we’ve cracked the code. Some supplements claim they can help tinnitus such as Tinnitus 911. There is also tinnitus retraining therapy, which carries the potential to retrain how the brain works to assimilate to your condition.

But before you start fretting about how that ringing will never stop, it’s beneficial to first look inside the body to discover some of the possible explanations for tinnitus.

Characteristics of Tinnitus

Tinnitus can present a wide range of symptoms such as ringing, roaring, whistling, or hissing in the ear. It is sometimes variable and sometimes constant. Subjective and objective tinnitus are two different conditions. Subjective tinnitus has no discernible source. Objective tinnitus is usually pulsatile and synchronous with your heartbeat. It can also be intermittent.

Tinnitus is the most noticeable in quiet environments and in the absence of distracting stimuli. Therefore, it can worsen at bedtime. Continuous tinnitus typically causes more disruptions in patients due to its incessant nature, though patients can adapt to its presence. Depression is a common result of this condition.

Pathophysiology of Tinnitus

The pathophysiology of tinnitus depends on whether it is subjective or objective.

For patients who suffer from subjective tinnitus, it is usually caused by abnormal neuronal activity in the auditory cortex. The activity begins when various disruptions modify input from the auditory pathway. This pathway contains the cochlea, auditory nerve, brain stem nuclei, and auditory complex and the disruptions occurring within this pathway can suppress intrinsic cortical activity and create new neural connections.

The resulting phenomenon can be compared to what happens when the brain experiences the sensation of a phantom limb after an amputation. Conductive hearing loss can also be associated with subjective tinnitus.

Objective tinnitus represents actual noise generated by physiologic phenomena occurring near the middle ear. This noise typically emanates from blood vessels, either normal vessels in conditions of increased turbulent flow or abnormal vessels such as tumors or vascular malformations. Muscle spasms or myoclonus of palatal muscles in the middle ear can also cause clicking sounds.

Etiology of Tinnitus

Causes of tinnitus should be separated into subjective and objective tinnitus causes. Subjective tinnitus can occur with nearly any disorder that affects the auditory pathways. The most common cause of tinnitus is sensorineural hearing loss. Acoustic trauma is an example of this sensorineural hearing loss. Some other causes include:

  • Presbycusis (aging)
  • Ototoxic drugs
  • Meniere disease

Infections and central nervous system lesions can also affect the auditory pathways. Disorders that cause hearing loss might also affect tinnitus. Issues such as the obstruction of the ear canal by cerumen, foreign objects, otitis media, barotrauma, and eustachian tube dysfunction might also be associated with tinnitus.

Objective Tinnitus

Objective tinnitus typically involves noise from vascular flow, causing an audible pulsating sound synchronous with pulse. Causes of objective tinnitus include:

  • Turbulent flow through the carotid artery or jugular vein
  • Highly vascular middle ear tumors
  • Dural arteriovenous malformations

Muscle spasms or myoclonus of palatal muscles or those in the middle ear can cause perceptible noise such as rhythmic clicking.

Evaluation of Tinnitus

To evaluate tinnitus, doctors must administer a few different tests. The first of these tests examines the history of present illness within the patient. This test diagnoses whether the tinnitus is intermittent, in one or both ears, and whether it is objective or subjective. It will pair the patients current symptoms with their medical history and try to identify any exacerbating conditions.

After this initial diagnosing stage, your doctor should examine the possible other symptoms including diplopia and difficulty swallowing or speaking. They should pair this with focal weakness and any sensory changes that might be caused by disorders in the peripheral nervous system. The doctor should also examine the effect of tinnitus on the patient during this time and check for any mental health disorders or struggles caused by the tinnitus.

After diagnosing the cause of the patient’s tinnitus, the doctor should prescribe a program tailored to their case. The prescriptions should take into consideration the various effects the patient feels from their tinnitus such as anxiety and depression and the severity of these conditions. Treatment programs typically combine psychological therapy with auditory therapy.

Key Takeaways

The physiological causes of tinnitus are still not fully understood. We understand some of what happens in the auditory cortex, but we don’t understand why. Until we understand why various causes of tinnitus affect the auditory system the way they do, we are limited with the types of treatment we can provide those who suffer from tinnitus. 

The physiological aspects of tinnitus unfortunately don’t explain how to cure the condition. But even though we don’t have a cure for the phenomena, there are various proactive measures people can take to avoid experiencing tinnitus such as avoiding loud environments that cause hearing damage. There are also treatments available to treat the condition itself.

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About the Author: Barry Lachey

Barry Lachey is a Professional Editor at Zobuz. Previously He has also worked for Moxly Sports and Network Resources "Joe Joe." he is a graduate of the Kings College at the University of Thames Valley London. You can reach Barry via email or by phone.