Understanding the Pathophysiology, Diagnosis, and Treatment of Meniere's Disease

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In my last post, I discussed Eustachian Tube Dysfunction, and to do that, I did my best to give a little summary about the Ear. In my last post, I discussed the Outer ear, the Middle Ear, and the Inner Ear. I explained that the outer was made up of the visible part of the ear, and the external acoustic meatus that connects the pinna to the eardrum which differentiates the outer ear from the middle ear. I further explained that the middle ear stating that it starts immediately after the eardrum (tympanic membrane). I explained that the middle ear was made up of three small bones, known as the ossicle. The middle ear is made up of the Malleus, the Incus, and the Stapes. I explained how sound travels from the ear canal reaching the tympanic membrane and vibrating the ossicles which then transmit the sound waves from the outer ear to the inner ear. I then talked about the inner ear being made up of the cochlear, and the vestibule. The cochlear is responsible for hearing, while the vestibule is responsible for balancing. I talked about the cochlear having a shape of a snail, filled with fluid, and lined with hair cells that vibrate when sound waves from the middle ear coming from the oval window hits the cochlear. which then vibrates the hair cells, sending signals to the brain through the auditory nerve. The vestibule on the other hand is meant for balancing. That said, today, I will be looking at another ear disorder, known as Meniere's disease.

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Meniere's disease also known as Idiopathic Endolymphatic Hydrops is a disorder of the inner ear that causes recurrent attacks of vertigo, Tinnitus, hearing loss, and a feeling of fullness in the ear.

Quick one, Vertigo is a sensation of dizziness that could lead to disorientation and difficulty in maintaining balance. Vertigo can be caused by a variety of inner ear disorders such as Vestibular Neuronitis, paroxysmal positional vertigo, and Meniere's disease.

Tinnitus which is perceived sounds where there isn't an external source of the sound. People who suffer from tinnitus tend to hear buzzing, humming noise in the ear or in their head.

Pathophysiology of Meniere's disease

The Etiology is not entirely known currently, but the disease is a result of the excessive buildup of endolymph in the labyrinth of the inner ear, causing a higher hydraulic pressure in the Labyrinth, thereby disrupting the sensory signals. The labyrinth is the chamber in the inner ear, made up of the cochlear and the vestibule. Responsible for maintaining balance and converting sound waves into electrical signals to be sent to the brain. The abnormal accumulation of the endolymph leads to a condition known as Endolymphatic hydrops.

Quick one, Endolymphs are fluid produced by vestibular hair cells found in the inner ear. The fluid is found both in the cochlear and the vestibule.

The prevalence of Meniere's disease is usually common in older people between the age of 40 - 50 years, having unilateral episodes of Vertigo, hearing loss, and tinnitus. The Vertigo episodes can last for 20 minutes to several hours, and the episodes can be in clusters for a prolonged period of time. The hearing loss is a sensorineural hearing loss, which starts by fluctuating and then gradually becomes permanent, affecting the lower frequencies first. The tinnitus also becomes permanent as the case worsens. Remember I said it is usually Unilateral, but in some cases, it can affect both ears (bilateral). Meniere's disease affects about 3.5 to 500 people per 100,000 people.

Risk Factors for Meniere's disease

Risk factors for Meniere's disease would include;

Genetic predisposition, as it is more likely to occur within family members with a history of Meniere's disease. It can be dominant or recessive.
Patients with Autoimmune Conditions are more likely to have Meniere's disease. Conditions such as Lupus, and Ankylosing spondylitis are likely to have Meniere's disease.
Patients who suffer from Migraine headaches are likely to have Meniere's disease

Signs, Symptoms and Triggers of Meniere's disease

The Signs and symptoms of Meniere's disease usually start with the patients experiencing Vertigo attacks which then progress. Symptoms include;

Vertigo (recurrent and spontaneous episodes lasting for more than 20 minutes, followed by nystagmus)
Tinnitus (Ringing and Buzzing)
Hearing Reduction and Hearing Loss (Unilateral but in some cases bilateral)
Aural Fullness
Severe Nausea and Vomiting
Sudden falls or drops (No loss of consciousness)
Migraines

Meniere's disease can be triggered by high salt intake, caffeine, alcohol, smoking, psychological stressors, and chocolate.

Diagnosis of Meniere's disease

Diagnosis of Meniere's disease includes;

A minimum of 2 episodes of recurrent and spontaneous Vertigo, lasting from 20 minutes to 12 hours.
Objective measurement of low-to-medium frequency hearing, or cases of hearing loss in one ear or both during and after the episodes of vertigo.
Signs of Aural fullness, tinnitus, and hearing loss

Laboratory tests such as Thyroid Stimulating Hormone level test (TSH), Blood Glucose Level test, CBC, ANA, VDRL, Urinalysis, and Dix-Hallpike positional test.

Treatment and Precaution of Meniere's disease

It is important to treat the underlying disease cause in cases of Meniere's syndrome. Pharmacological treatments such as meclizine, diazepam, and prochlorperazine. Diuretics such as Hydrochlorothiazide, Acetazolamide, and Methazolamide, can be utilized to reduce the risk of an attack by reducing Endolymphatic fluid. Surgical procedures can be used for cases refractory to lifestyle modification such as the Meniett device, using Intratympanic gentamycin injections such as gentamycin.

Precaution includes taking low-Sodium diets will help reduce recurrent attack risk. Avoiding triggers such as Smoking, caffeine, and chocolates.

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