bilateral hypoactive labyrinth

Bilateral Hypoactive Labyrinth: A Condition Affecting Balance and Vestibular Function

Bilateral hypoactive labyrinth, also known as hypoactive bilateral labyrinthine dysfunction, is a condition characterized by reduced or absent function of the vestibular organs in both ears. This can lead to impairments in balance, gait, and vestibulo-ocular reflex (VOR).

Key Features:

• Reduced or absent vestibular function on both sides
• Impairments in balance and gait problems
• Vestibulo-ocular reflex (VOR) is affected, leading to gaze instability and disorientation
• Can cause oscillopsia, a condition characterized by jumpy vision while the head is in motion

Causes and Associations:

• Bilateral vestibular hypofunction can be caused by various factors, including disease affecting the inner ear or the nerves responsible for transmitting balance information to the brain.
• The condition has been associated with vascular myelopathy and autoimmune epilepsy.

Diagnosis:

• Diagnosis is typically made using tests such as videonystagmography (VNG), rotary chair testing, and head impulse testing.
• These tests can show absent or diminished inner ear responses, decreased gain, phase leads, and decreased time constant on the affected side.

References:

• [1] Patients with bilateral vestibular hypofunction are primarily concerned with their balance and gait problems. During the acute stage, they may feel off balance even when lying or sitting down. More typically, however, their balance problems become obvious only when they are standing or walking. (Source: 1)
• [2-3] Both unilateral and bilateral vestibular hypofunction are diagnosed with VNG (showing absent/diminished inner ear responses to thermal changes on one or both sides), rotary chair testing (showing decreased gain, phase leads, and decreased time constant on the affected side), and head impulse testing (showing that the eyes slip off the target ...). (Source: 3)
• [4] This condition causes impairments in the vestibulo-ocular reflex (VOR) and the major functions of the vestibular organs. (Source: 4)
• [5] The osseous labyrinth is a whole series of chambers and ducts that communicate with each other. The walls (otic capsule) are bordered by bone, in the form of a shell. • The membranous labyrinth, upon which the bony labyrinth is molded, is contained by simple epithelial membranes. Within the labyrinth is a viscous fluid called endolymph, whose ... (Source: 5)
• [6] Integrated disease information for Bilateral Hypoactive Labyrinth including associated genes, mutations, phenotypes, pathways, drugs, and more - integrated from 75 data sources. overview Overview. ... Description MGI ID Score Top Affiliating Genes; 1: behavior/neurological: MP:0005386: 9.36: (Source: 6)
• [7] by disease affecting the inner ear or the nerves responsible for transmitting balance information to the brain. (Source: 7)
• [8-12] Bilateral vestibular hypofunction can be caused by various factors, including disease affecting the inner ear or the nerves responsible for transmitting balance information to the brain. The condition has been associated with vascular myelopathy and autoimmune epilepsy. (Source: 8-12)

Bilateral hypoactive labyrinth, also known as bilateral vestibular hypofunction (BVH), can manifest in various ways, affecting an individual's balance, vision, and overall well-being. Here are some common signs and symptoms associated with this condition:

• Imbalance and unsteadiness: People with BVH may experience difficulty walking or maintaining their balance, especially in busy or unfamiliar environments [11].
• Blurred or jumpy vision (oscillopsia): This is a primary complaint among individuals with bilateral vestibulopathy, where the world appears to be bouncing up and down [12].
• Dizziness and vertigo: These symptoms can occur due to the reduced function of the vestibular organs in both ears, leading to feelings of lightheadedness or spinning [8][9].
• Nausea and motion sickness: Some individuals may experience nausea or discomfort when experiencing motion, such as in a car or on a boat [5][8].
• Difficulty with visual tracking: People with BVH may struggle to track moving objects or people, which can affect their daily activities [11].
• Cognitive deficits: In some cases, bilateral vestibulopathy can lead to cognitive impairments, including difficulties with memory and attention [13].

It's essential to note that the severity and specific symptoms of bilateral hypoactive labyrinth can vary from person to person. If you're experiencing any of these symptoms, it's crucial to consult a healthcare professional for proper evaluation and treatment.

Bilateral hypoactive labyrinth, also known as bilateral vestibular hypofunction (BVH), can be diagnosed using various tests that assess the function of the inner ear and balance system.

• Vestibular testing: This includes tests such as the rotational chair test, caloric test, and head impulse test, which evaluate the function of the vestibular system. These tests can show decreased gain, phase leads, and decreased time constant on the affected side [4].
• Electronystagmography (ENG): ENG measures eye movements in response to different stimuli, such as rotation or caloric irrigation. It can help diagnose bilateral hypoactive labyrinth by showing absent or diminished inner ear responses to thermal changes on one or both sides [5].
• Videonystagmography (VNG): VNG is a type of ENG that uses video cameras to record eye movements. It can also show absent or diminished inner ear responses to thermal changes on one or both sides, making it useful for diagnosing bilateral hypoactive labyrinth [6].
• Blood tests: Blood tests may be ordered to rule out other conditions that could be causing the symptoms, such as anemia or electrolyte imbalances.
• Imaging tests of the head and brain: Imaging tests like MRI or CT scans may be used to rule out other conditions that could be causing the symptoms, such as a tumor or stroke.

It's worth noting that the diagnosis of bilateral hypoactive labyrinth can be challenging, and a combination of these tests may be needed to confirm the diagnosis. A healthcare professional should be consulted for an accurate diagnosis and treatment plan.

References: [4] - 4. Both unilateral and bilateral vestibular hypofunction are diagnosed with VNG (showing absent/diminished inner ear responses to thermal changes on one or both sides), rotary chair testing (showing decreased gain, phase leads, and decreased time constant on the affected side), and head impulse testing (showing that the eyes slip off the target ... [5] - 5. by D Starkov · 2021 · Cited by 77 — Regarding stimuli, air-conducted sound (cVEMP) and bone-conducted vibration (oVEMP) are the preferred stimuli to detect vestibular hypofunction, ... [6] - 6. How is Meniere's disease diagnosed?

Based on the available information, it appears that there are several treatment approaches for bilateral vestibular hypofunction (BVW), including drug treatments.

Medications to Avoid

• Medications with the unintended effect of vestibular suppression should be avoided in the treatment of BVW [6].

Treatment Approaches

• Treatment approaches include increasing the function of the remaining vestibular system, inducing the substitution of alternative mechanisms to maintain gaze stability, and using medications to control dizziness and nausea [2].
• Drugs such as meclizine can be used to decrease the excitability of the inner-ear labyrinth and block conduction in inner-ear vestibular-cerebellar pathways [5].

Specific Medications

• Meclizine is a medication that decreases the excitability of the inner-ear labyrinth and blocks conduction in inner-ear vestibular-cerebellar pathways [5].
• Intratympanic gentamicin is a simple, cheap treatment that can be carried out in an outpatient setting, but it should be used with caution as it has ototoxic effects [8].

General Treatment Principles

• Management of patients in the acute phase involves the use

The differential diagnosis of bilateral hypoactive labyrinth, also known as bilateral vestibular hypofunction (BVH), involves identifying the underlying causes of this condition.

Common Causes

According to various studies [10][12], the differential diagnosis of common vestibular disorders includes:

• Benign paroxysmal positional vertigo (BPPV)
• Labyrinthitis or vestibular neuritis
• Ménière's disease
• Bilateral vestibular weakness (BVW)

Other Possible Causes

In addition to these common causes, other possible differential diagnoses for bilateral hypoactive labyrinth include:

• Spinocerebellar ataxia type 3 (SCA 3) (Machado-Joseph disease)
• Friedreich's ataxia (FRDA)
• Multiple system atrophy
• Bilateral vestibulopathy

Diagnostic Clues

Important clues to the diagnosis of bilateral hypoactive labyrinth include:

• Temporal course of symptoms
• Accompanying symptoms
• Precipitating or modulating factors [12]

Quantitative Testing

It's worth noting that unilateral or bilateral vestibular hypofunction often goes undiagnosed due to a lack of standardization of vestibular testing, and quantitative testing is not always performed [14].

References:

[10] Bilateral vestibular hypofunction (BVH) is a heterogeneous chronic condition characterized by a bilateral reduced or absent function of the vestibular organs, the vestibular nerves or a combination of both (1–3).

[12] The differential diagnosis of common vestibular disorders. Important clues to the diagnosis are to be sought in the temporal course of the symptoms, any accompanying symptoms, and precipitating or modulating factors.

[14] Unilateral or bilateral vestibular hypofunction presents most commonly with symptoms of dizziness or postural imbalance and affects a large population. However, it is often missed because no quantitative testing of vestibular function is performed, or misdiagnosed due to a lack of standardization of vestibular testing.