Labyrinthitis
Synonyms and keywords: Otitis interna

# Overview
Labyrinthitis is self-limiting inner ear disorder, often secondary to viral infection. The infection of vestibular neuron and labyrinth primary affects balance and hearing. The condition is commonly called as vestibular neuritis/ vestibular neuronitis. It is basically an inflammatory process of the labyrinth, which is the inner ear, and contains the vestibular system. Thus, it is responsible for sensing the position of the head and body on the whole. It contains fluid-filled channels, which in turn control the balance of the body and hearing. With any movement, the fluid moves in the channels and transmits electrical signals to the brain, thus helping the body to balance. Due to the difference in the transmitted signals from the inflamed and noninflamed ear, derangements can occur, which ultimately makes the person feel dizzy .Along with balance problems, patients often experience hearing loss and tinnitus. Usually caused by a virus, or from bacterial infection,upper respiratory tract infection, labyrinthitis can also occur due to head injury, an allergy or as adverse drug reaction to any medicine. Although rare, all these can cause permanent hearing loss. Labyrinthitis is also known as Vestibular neuritis or acute peripheral vestibulopathy . Mostly, it is a self-limited disorder, with acute short term symptoms like vertigo, nausea, vomiting, and gait impairment, with complete recovery in most patients. Another common condition associated with labyrinthitis is anxiety, which produces tremors, palpitations, panic attacks, and depression. in many cases, panic attacks and anxiety are the first symptoms to be associated with labyrinthitis.

# Classification
- Viral labyrinthitis: This is caused by an viral upper respiratory tract infection, which includes cold or flu. Apart from this, many other viruses like the varicella-zoster virus, and the mumps, measles, and rubella viruses can also cause labyrinthitis . This type of disease is the most prevalent.
- Bacterial labyrinthitis: This is second most common after viral infections, often, occurring as a complication of infection in the middle ear,(otitis media). Often, there is sudden unilateral hearing loss, dizziness, and vertigo. These are more prevalent in children than in adults. The best treatment approach is with antibiotics, which successfully manages the bacterial labyrinthitis and causes full recovery.
- Autoimmune labyrinthitis: This type of labyrinthitis is rare and lesser prevalent than others.
- Conditions causing damage to the cochlea inside your inner ear like meningitis, circulatory problems, or Menieres disease.
- Tympanogenic labyrinthitis: It is secondary to middle ear disease (rare intratemporal complication of otitis media). It is rare due to early diagnosis and treatment of  otitis media with antibiotics now a days.

# Differential diagnosis
Conditions which mimic Labyrinthitis are:
- Meniere's disease
- Migraine headache
- Stroke
- Intracranial hemorrhage (intralabyrinthine hemorrhage)
- Damage to the vascular structures in the neck
- Benign paroxysmal positional vertigo
- Brain tumor(schwannoma)

# Epidemiology and Demographics
- Adults in the age group of 30 to 60 years are most commonly affected. The incidence of labyrinthitis is around 3.5 cases per 100,000.
- Viral labyrinthitis, the most common type, is more prevalent in adults, whereas the other types of infections affect the children on a larger scale. This can be assessed by the fact that children under the age of two are more predisposed to develop bacterial labyrinthitis.
- Bacterial labyrinthitis is overall, less prevalent than other causes.

# Risk Factors
Certain conditions can increase the risk of labyrinthitis:
- Upper respiratory tract infections
- Infections of the middle ear
- Meningitis
- Head injuries
- Respiratory illnesses like bronchitis
- Viral infections, like herpes and measles
- Autoimmune diseases

# Natural History, Complications, and Prognosis
- The symptoms of labyrinthitis usually start suddenly. Occasionally the patient wakes up with these symptoms and they are progressive.
- There is usually a relief in the symptoms after a few days. Often, the loss of balance is restored in a couple of weeks, but in some cases, it can take longer.
- In some severe and rare cases, there can be a permanent loss of hearing.
- Certain factors like cold, previous illnesses, fatigue, menstruation, and respiratory infections can worsen the symptoms.
- Complications following labyrinthitis includes: labyrinthine fistula, meningitis, cerebellar abscess, mastoiditis etc 

## Recovery
The recovery from an attack of labyrinthitis follows the following phases:
- An acute period, which includes symptoms like vertigo, nausea, and vomiting.
- subacute symptoms, which last for a couple of weeks, followed by a rapid recovery
- chronic compensation, which extends over a period of a couple of months or even years.

# Diagnosis

## Diagnostic Study of Choice
Viral labyrinthitis could be a clinical diagnosis. But a variety of diagnostic tests are performed to rule out other diseases. Tests that may rule out other causes of your symptoms include:
- EEG
- Electronystagmography, also known as caloric stimulation.
- CT Scan of the head: to rule out mastoiditis.
- Temporal bone CT scan: diagnostic techniques in patients with cholesteatoma.
- Rinne and Weber hearing tests
- Head MRI
- Eye test
- Blood pressure
- Assessment of balance
- Culture and sensitivity of the middle ear effusions.
- Vestibular-evoked myogenic potentials to assess vestibular activity
- Gadolinium-nuclear magnetic resonance (NMR) imaging

## History and Symptoms
Labyrinthitis can be suspected when bone conduction loss co-exists with otitis media
Labyrinthitis is characterized by the following symptoms and signs including :
- Dizziness
- Vertigo
- Instability of gait
- Nausea or vomiting
- Tinnitus or ringing in the ears
- Hearing loss particularly of the high-frequency range
- Nystagmus

## Laboratory Findings
Labyrinthitis could be a clinical diagnosis. As a result, routine blood tests don't seem to be helpful in making any diagnosis. However, if systemic infection is suspected, FBC and blood cultures are indicated.

# Treatment
Viral labyrinthitis causes a sudden onset of vertigo, nausea, vomiting, and sudden hearing impairment. As we know that the antibiotics are not effective against viruses, we must adopt the symptomatic treatment techniques, including medications for vertigo, antihistaminics, and complete rest. With all these measures, the patient usually feels better in  a week or two. Nevertheless, acute episodes can sometimes last for up to months. Apart from that, most people will have a full recovery after an episode of viral labyrinthitis if proper and timely vestibular rehabilitation exercises are adopted.
Bacterial labyrinthitis can be effectively treated with antibiotics preventing long term complications 

## Certain emergency conditions which warrant immediate medical attention are
- loss of consciousness
- Convulsions or seizures
- Speech abnormalities
- Fever
- Weakness
- Stroke
- Vision disorders like diplopia

## Medical Therapy
Symptomatic patients need treatment with the following:
- Antihistamines, whic include drugs like desloratadine and loratadine
- Antivertigo medications, such as meclizine
- Sometimes we need to give sedatives to the patienst to ensure rest and recovery, such as diazepam
- Corticosteroids, like prednisone
- Prochlorperazine is also commonly prescribed, which helps to alleviate symptoms of vertigo and nausea.
As we know that, sometimes an attack or anxiety or panic attack can aggravate the symptoms of labyrnthitis, it becomes imperative to treat an anxiety disorder and/or depression, simultaneously with the medication for otehr symptoms, to treat any vestibular damage. This can be achieved with benzodiazepines like diazepam (Valium); but caution should be taken to avoid long term usage of these drugs due to associated addiction with this class of drugs and their interference with the vestibular system (Solomon and Shepard, 2002). Likewise the efficacy of corticosteroids such as prednisone, to treat early stages of labyrnthitis has been advocated and they are very frequently used for proper recovery, along with some antiviral medication. It should be understood that the treatment should be started as soon as possible to prevent any permanent damage to the inner ear.

## Interventions
Apart from medical therapy, we can use several lifestyle techniques to relieve vertigo associated with labyrinthitis:
- Avoiding sudden or jerky movements or any sudden changes in body position
- Rest during the attack and avoid any movements
- Smooth and slow movements when trying to get up from lying
- Avoiding prolonged exposure to screens, and abstain from bright lights in lieu of an attack
- Keeping the head still, while sitting in a chair
- Stress management techniques, to mitigate and factors which can aggravate the anxiety or stressors
- Warm compresses can be used to bring relief from the pain
- Avoiding smoking and limiting the intake of alcohol

## Primary Prevention
- Resting in a cool dark place, if experiencing any symptoms like dizziness or vertigo
- Drinking plenty of fluids and adequate hydration
- Avoiding loud noises and exposure to bright lights which can aggravate the symptoms
- Adequate sleep, as lack of sleep can bring on an attack

## Secondary Prevention
- Implementation of therapies to allow rehabilitation and improve balance, like physical and occupational therapy
- Vestibular rehabilitation: This includes various exercises performed under the supervision of a trained physiotherapist, which helps to improve the gait, movements, and functionality. It substantially reduces any residual symptoms from the attack of labyrinthitis. It helps with balancing and makes everyday activities easier.