Labyrinthitis is inflammation of the

labyrinth In Greek mythology, the Labyrinth () is an elaborate, confusing structure designed and built by the legendary artificer Daedalus for King Minos of Crete at Knossos. Its function was to hold the Minotaur, the monster eventually killed by the h ...

, a maze of fluid-filled channels in the inner ear. Vestibular neuritis is inflammation of the vestibular nerve (the nerve in the ear that sends messages related to motion and position to the brain). Both conditions involve

inflammation Inflammation (from ) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin ''calor'', '' ...

of the

inner ear The inner ear (internal ear, auris interna) is the innermost part of the vertebrate ear. In vertebrates, the inner ear is mainly responsible for sound detection and balance. In mammals, it consists of the bony labyrinth, a hollow cavity in the ...

. Labyrinths that house the

vestibular system The vestibular system, in vertebrates, is a sensory system that creates the sense of balance and spatial orientation for the purpose of coordinating motor coordination, movement with balance. Together with the cochlea, a part of the auditory sys ...

sense changes in the head's position or the head's motion. Inflammation of these inner ear parts results in a

vertigo Vertigo is a condition in which a person has the sensation that they are moving, or that objects around them are moving, when they are not. Often it feels like a spinning or swaying movement. It may be associated with nausea, vomiting, perspira ...

(sensation of the world spinning) and also possible

hearing loss Hearing loss is a partial or total inability to hear. Hearing loss may be present at birth or acquired at any time afterwards. Hearing loss may occur in one or both ears. In children, hearing problems can affect the ability to acquire spo ...

tinnitus Tinnitus is a condition when a person hears a ringing sound or a different variety of sound when no corresponding external sound is present and other people cannot hear it. Nearly everyone experiences faint "normal tinnitus" in a completely ...

(ringing in the ears). It can occur as a single attack, a series of attacks, or a persistent condition that diminishes over three to six weeks. It may be associated with

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. It can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat. Over 30 d ...

vomiting Vomiting (also known as emesis, puking and throwing up) is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose. Vomiting can be the result of ailments like food poisoning, gastroenteritis, pre ...

, and eye nystagmus. The cause is often not clear. It may be due to a

virus A virus is a submicroscopic infectious agent that replicates only inside the living Cell (biology), cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are ...

, but it can also arise from

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

l infection, head injury, extreme stress, an

allergy Allergies, also known as allergic diseases, are various conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include Allergic rhinitis, hay fever, Food allergy, food al ...

, or as a reaction to

medication Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, medicinal drug or simply drug) is a drug used to medical diagnosis, diagnose, cure, treat, or preventive medicine, prevent disease. Drug therapy (pharmaco ...

. 30% of affected people had a common cold prior to developing the disease. Either bacterial or viral labyrinthitis can cause a permanent hearing loss in rare cases. This appears to result from an imbalance of neuronal input between the left and right inner ears.

Signs and symptoms

The main symptoms are severe

and nystagmus. The most common symptom of vestibular neuritis is the onset of vertigo that has formed from an ongoing infection or trauma. The dizziness sensation that is associated with vertigo is thought to be from the inner ear labyrinth. Rapid and undesired eye motion ( nystagmus) often results from the improper indication of rotational motion. Nausea, anxiety, and a general ill feeling are common due to the distorted balance signals that the brain receives from the inner ear system. Other common symptoms include

, ear ache, and a feeling of fullness in the ear.

Causes

Some people will report having an upper respiratory infection (common cold) or flu prior to the onset of the symptoms of vestibular neuritis; others will have no viral symptoms prior to the vertigo attack. Some cases of vestibular neuritis are thought to be caused by an infection of the vestibular ganglion by the

herpes simplex Herpes simplex, often known simply as herpes, is a viral disease, viral infection caused by the herpes simplex virus. Herpes infections are categorized by the area of the body that is infected. The two major types of herpes are Cold sore, ora ...

type 1 virus. However, the cause of this condition is not fully understood, and in fact, many different viruses may be capable of infecting the vestibular nerve. Acute localized

ischemia Ischemia or ischaemia is a restriction in blood supply to any tissue, muscle group, or organ of the body, causing a shortage of oxygen that is needed for cellular metabolism (to keep tissue alive). Ischemia is generally caused by problems ...

of these structures also may be an important cause. Especially in children, vestibular neuritis may be preceded by symptoms of a common cold. However, the causative mechanism remains uncertain. This can also be brought on by pressure changes such as those experienced while flying or

scuba diving Scuba diving is a Diving mode, mode of underwater diving whereby divers use Scuba set, breathing equipment that is completely independent of a surface breathing gas supply, and therefore has a limited but variable endurance. The word ''scub ...

Mechanism

In the vestibular system, there are three canals that are semicircular in shape that input sensory clues. These canals allow the

brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...

to sense rotational motion and linear motion changes. The brain then uses the sensory input clues and the visual input clues from the vestibular system to retain balance. The

vestibulo-ocular reflex The vestibulo-ocular reflex (VOR) is a reflex that acts to stabilize Gaze (physiology), gaze during head movement, with eye movement due to activation of the vestibular system, it is also known as the cervico-ocular reflex. The reflex acts to im ...

retains continuous visual focus during motion which is also the vestibular system's purpose during activity.

Treatment

The treatment for vestibular neuritis depends on the cause. However, symptoms of vertigo can be treated in the same way as other vestibular dysfunctions with vestibular rehabilitation.

Physical therapy

Typical treatments include combinations of head and eye movements, postural changes, and walking exercises. Specifically, exercises that may be prescribed include keeping eyes fixated on a specific target while moving the head, moving the head right to left at two targets at a significant distance apart, walking while keeping eyes fixated on a specific target, and walking while keeping eyes fixated on a specific target while also turning the head in different directions. The main function behind repeating a combination of head and eye movements, postural changes and walking is that through this repetition, compensatory changes for the dysfunctions arising from peripheral vestibular structures may be promoted in the central

(

brainstem The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is conti ...

and

cerebellum The cerebellum (: cerebella or cerebellums; Latin for 'little brain') is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as it or eve ...

). Vestibular rehabilitation therapy is a highly effective way to substantially reduce or eliminate residual dizziness from labyrinthitis. VRT works by causing the brain to use already existing neural mechanisms for adaptation,

neuroplasticity Neuroplasticity, also known as neural plasticity or just plasticity, is the ability of neural networks in the brain to change through neurogenesis, growth and reorganization. Neuroplasticity refers to the brain's ability to reorganize and rewir ...

, and compensation. Vestibular neuritis rehabilitation is an effective and safe management to improve symptoms. The vestibular neuritis rehabilitation can improve symptoms or resolve the symptoms which is dependent on each individual. Rehabilitation strategies most commonly used are: *Gaze stability exercises – moving the head from side to side while fixated on a stationary object (aimed at assisting the eye to fixate during head rotation without the input from the lost canal

). An advanced progression of this exercise would be walking in a straight line while looking side to side by turning the head. *Habituation exercises – movements designed to provoke symptoms and subsequently reduce the negative vestibular response upon repetition. Examples of these include

Brandt–Daroff exercises Benign paroxysmal positional vertigo (BPPV) is a disorder arising from a problem in the inner ear. Symptoms are repeated, brief periods of vertigo (medical), vertigo with movement, characterized by a spinning sensation upon changes in the posit ...

. *Functional retraining – including postural control, relaxation, and balance training. These exercises function by challenging the vestibular system. Progression occurs by increasing the amplitude of the head or focal point movements, increasing the speed of movement, and combining movements such as walking and head turning. One study found that patients who believed their illness was out of their control showed the slowest progression to full recovery, long after the initial vestibular injury had healed. The study revealed that the patient who compensated well was one who, at the psychological level, was not afraid of the symptoms and had some positive control over them. Notably, a reduction in negative beliefs over time was greater in those patients treated with rehabilitation than in those untreated. "Of utmost importance, baseline beliefs were the only significant predictor of change in a handicap at 6 months follow-up."

Medication

Vestibular neuritis is generally a self-limiting disease. Treatment with drugs is neither effective nor necessary. The effect of

glucocorticoid Glucocorticoids (or, less commonly, glucocorticosteroids) are a class of corticosteroids, which are a class of steroid hormones. Glucocorticoids are corticosteroids that bind to the glucocorticoid receptor that is present in almost every vertebra ...

s has been studied, but they have not been found to significantly affect long-term outcome. Symptomatic treatment with antihistaminics such as cinnarizine, however, can be used to suppress the symptoms of vestibular neuritis while it spontaneously regresses. Prochlorperazine is another commonly prescribed medication to help alleviate the symptoms of vertigo and nausea.

Mental disorders

Because mood disorders can hamper recovery from labyrinthitis, treatment may also include any co-occurring

anxiety disorder Anxiety disorders are a group of mental disorders characterized by significant and uncontrollable feelings of anxiety and fear such that a person's social, occupational, and personal functions are significantly impaired. Anxiety may cause phys ...

or depression. Severe anxiety episodes are usually addressed by short-term

benzodiazepine Benzodiazepines (BZD, BDZ, BZs), colloquially known as "benzos", are a class of central nervous system (CNS) depressant, depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed t ...

therapy.

Prognosis

Recovery from acute labyrinthine inflammation generally takes from one to six weeks, but it is not uncommon for residual symptoms such as dysequilibrium and dizziness to last for a couple of months. Recovery from a temporarily damaged inner ear typically follows two phases: # An acute period, which may include severe vertigo and vomiting # approximately two weeks of sub-acute symptoms and rapid recovery

Epidemiology

Labyrinthitis affects approximately 35 million people per year (approximately 3.5 cases per 100,000 people). It typically occurs in those between 30 and 60 years of age, and there are no significant differences between male and female incidence rates. In 95% of cases, sufferers experience a single attack and fully recover. Vestibular rehabilitation showed a statistically significant increase in controlling symptoms over no intervention in people who have vestibular neuritis.

References

External links

{{Hearing and balance Inflammations Diseases of inner ear