Bilateral Vestibulopathy results as the culmination of damage done to both inner ears. Bilateral Vestibulopathy causes problems in vision, hearing and motor coordination.

Treatment differs depending on the cause. Each cause has a different treatment, and may involve either medical treatment, surgery, or therapy. If serious damage has already been done, then the focus of treatment is upon avoidance of vestibular suppressants and ototoxins. It is recommended that you tell your physicians to avoid drugs that end in mycin ( Azithromycin, Erythromycin ) because of possible reactions which could lead to setbacks. Vestibular rehabilitation is important. Your physician will try to keep the administering of drugs to a minimum.

Brain related causes are less commonly associated with isolated vertigo and nystagmus but can still produce signs and symptoms, which mimic peripheral causes. Disequilibrium is often a prominent feature.

- Degenerative: age related decline in balance function

- Infectious: meningitis, encephalitis, epidural abscess, syphilis

- Circulatory: cerebral or cerebellar ischemia or hypoperfusion, stroke, lateral medullary syndrome (Wallenberg's syndrome)

- Autoimmune: Cogan syndrome

- Structural: Arnold-Chiari malformation, hydrocephalus

- Systemic: multiple sclerosis, Parkinson's disease

- Vitamin deficiency: Vitamin B12 deficiency

- CNS or posterior neoplasms, benign or malignant

- Neurological: Vertiginous epilepsy, abasia

- Other – There are a host of other causes of dizziness not related to the ear.

- Mal de debarquement is rare disorder of imbalance caused by being on board a ship. Patients suffering from this condition experience disequilibrium even when they get off the ship. Typically treatments for seasickness are ineffective for this syndrome.

- Motion sickness – a conflict between the input from the various systems involved in balance causes an unpleasant sensation. For this reason, looking out of the window of a moving car is much more pleasant than looking inside the vehicle.

- Migraine-associated vertigo

- Toxins, drugs, medications; it is also a known symptom of carbon monoxide poisoning.

From 3% to 11% of diagnosed dizziness in neuro-otological clinics are due to Meniere's. The annual incidence rate is estimated to be about 15/100,000 and the prevalence rate is about 218/100,000, and around 15% of people with Meniere's disease are older than 65. In around 9% of cases a relative also had MD, signalling that there may be a genetic predisposition in some cases.

The odds of MD are greater for people of white ethnicity, with severe obesity, and women. Several conditions are often comorbid with MD, including arthritis, psoriasis, gastroesophageal reflux disease, irritable bowel syndrome, and migraine.

The gene for Darwin's tubercle was once thought to be inherited in an autosomal dominant pattern with incomplete penetrance, meaning that those who possess the allele (version of a gene) will not necessarily present with the phenotype. However, genetic and family studies have demonstrated that the presence of Darwin's Tubercle may be more likely to be influenced by one's environment or developmental accidents than it is by genetics alone. There is no clear argument for whether the trait has significance in sexual dimorphism studies or age related studies. In some studies, there is clear data that Darwin's tubercle is not associated with sex. In contrast, others indicate that there is a correlation with sexual dimorphism between men and women, where men tend to have the tubercle more than women in some populations. Two studies indicate that older men tend to have greater expression of Darwin's tubercle than do older women.

Causes of dizziness related to the ear are often characterized by vertigo (spinning) and nausea. Nystagmus (flickering of the eye, related to the Vestibulo-ocular reflex [VOR]) is often seen in patients with an acute peripheral cause of dizziness.

- Benign Paroxysmal Positional Vertigo (BPPV) – The most common cause of vertigo. It is typically described as a brief, intense sensation of spinning that occurs when there are changes in the position of the head with respect to gravity. An individual may experience BPPV when rolling over to the left or right, upon getting out of bed in the morning, or when looking up for an object on a high shelf. The cause of BPPV is the presence of normal but misplaced calcium crystals called otoconia, which are normally found in the utricle and saccule (the otolith organs) and are used to sense movement. If they fall from the utricle and become loose in the semicircular canals, they can distort the sense of movement and cause a mismatch between actual head movement and the information sent to the brain by the inner ear, causing a spinning sensation.

- Labyrinthitis - An inner ear infection or inflammation causing both dizziness (vertigo) and hearing loss.

- Vestibular neuronitis - an infection of the vestibular nerve, generally viral, causing vertigo

- Cochlear Neuronitis – an infection of the Cochlear nerve, generally viral, causing sudden deafness but no vertigo

- Trauma – Injury to the skull may cause either a fracture or a concussion to the organ of balance. In either case an acute head injury will often result in dizziness and a sudden loss of vestibular function.

- Surgical trauma to the lateral semicircular canal (LSC) is a rare complication which does not always result in cochlear damage. Vestibular symptoms are pronounced. Dizziness and instability usually persist for several months and sometimes for a year or more.

- Ménière's disease - an inner ear fluid balance disorder that causes lasting episodes of vertigo, fluctuating hearing loss, tinnitus (a ringing or roaring in the ears), and the sensation of fullness in the ear. The cause of Ménière's disease is unknown.

- Perilymph fistula – a leakage of inner ear fluid from the inner ear. It can occur after head injury, surgery, physical exertion or without a known cause.

- Superior canal dehiscence syndrome – a balance and hearing disorder caused by a gap in the temporal bone, leading to the dysfunction of the superior canal.

- Bilateral vestibulopathy – a condition involving loss of inner ear balance function in both ears. This may be caused by certain antibiotics, anti-cancer, and other drugs or by chemicals such as solvents, heavy metals, etc., which are ototoxic; or by diseases such as syphilis or autoimmune disease; or other causes. In addition, the function of the semicircular canal can be temporarily affected by a number of medications or combinations of medications.

The cause of Ménière's disease is unclear but likely involves both genetic and environmental factors. A number of theories exist including constrictions in blood vessels, viral infections, autoimmune reactions.

The feature is present in approximately 10.4% of the Spanish adult population, 40% of Indian adults, and 58% of Swedish school children. This acuminate nodule represents the point of the mammalian ear. The trait can potentially be bilateral, meaning present on both ears, or unilateral, where it is only present on one ear. There is mixed evidence in regard to whether the bilateral or unilateral expression is related to population, or other factors. Some populations express full bilaterality, while others may express either unilateral or bilaterality. However, bilaterality appears to be more common than unilateral as it pertains to the expression of the trait.

Inverse Marcus Gunn phenomenon is a rare condition that causes the eyelid to fall upon opening of the mouth. In this case, trigeminal innervation to the pterygoid muscles of the jaw is associated with an inhibition of the branch of the oculomotor nerve to the levator palpebrae superioris, as opposed to stimulation in Marcus Gunn jaw-winking.

The prevalence of migraine and vertigo is 1.6 times higher in 200 dizziness clinic patients than in 200 age- and sex-matched controls from an orthopaedic clinic. Among the patients with unclassified or idiopathic vertigo, the prevalence of migraine was shown to be elevated. In another study, migraine patients reported 2.5 times more vertigo and also 2.5 more dizzy spells during headache-free periods than the controls.

MAV may occur at any age with a female:male ratio of between 1.5 and 5:1. Familial occurrence is not uncommon. In most patients, migraine headaches begin earlier in life than MAV with years of headache-free periods before MAV manifests.

In a diary study, the 1-month prevalence of MAV was 16%, frequency of MAV was higher and duration longer on days with headache, and MAV was a risk factor for co-morbid anxiety.

Marcus Gunn phenomenon, also known as Marcus Gunn jaw-winking or trigemino-oculomotor synkinesis, is an autosomal dominant condition with incomplete penetrance, in which nursing infants will have rhythmic upward jerking of their upper eyelid. This condition is characterized as a synkinesis: when two or more muscles that are independently innervated have either simultaneous or coordinated movements.

Common physiologic examples of synkineses occur during sucking, chewing, or conjugate eye movements. There are also several abnormal cranial nerve synkineses, both acquired and congenital. Marcus Gunn jaw-winking is an example of a pathologic congenital synkinesis.

First described by the ophthalmologist Marcus Gunn in 1883, this condition presents in approximately 5% of neonates with congenital ptosis. This condition has been associated with amblyopia (in 54% of cases), anisometropia (26%), and strabismus (56%).

Affected individuals are typically 20 to 50 years old. The female to male ratio is 2:1. By definition, there is no history of either surgical or accidental ocular trauma. VKH is more common in Asians, Latinos, Middle Easterners, American Indians, and Mexican Mestizos; it is much less common in Caucasians and in blacks from sub-Saharan Africa.

VKH is associated with a variety of genetic polymorphisms that relate to immune function. For example, VKH has been associated with human leukocyte antigens (HLA) HLA-DR4 and DRB1/DQA1, copy-number variations (CNV) of complement component 4, a variant IL-23R locus and with various other non-HLA genes. HLA-DRB1*0405 in particular appears to play an important susceptibility role.

Vision improves in almost all cases. In rare cases, a patient may suffer permanent visual loss associated with lesions on their optic nerve.

Rarely, coexisting vasculitis may cause neurological complications. These occurrences can start with mild headaches that steadily worsen in pain and onset, and can include attacks of dysesthesia. This type of deterioration happens usually if the lesions involve the fovea.

Although there is sometimes a preceding viral infection, or skin or eye trauma, the exact underlying initiator of VKH disease remains unknown. However, VKH is attributed to aberrant T-cell-mediated immune response directed against self-antigens found on melanocytes. Stimulated by interleukin 23 (IL-23), T helper 17 cells and cytokines such as interleukin 17 (IL-17) appear to target proteins in the melanocyte.

Spectacles or RGP contact lenses can be used to manage the astigmatism. when the condition worsens, surgical correction may be required.

Terrien marginal degeneration is a noninflammatory, unilateral or asymmetrically bilateral, slowly progressive thinning of the peripheral corneal stroma.

The cause of Terrien marginal degeneration is unknown, its prevalence is roughly equal between males and females, and it usually occurs in the second or third decade of life.

The disorder is caused by injury or dysfunction in the medial longitudinal fasciculus (MLF), a heavily myelinated tract that allows conjugate eye movement by connecting the paramedian pontine reticular formation (PPRF)-abducens nucleus complex of the contralateral side to the oculomotor nucleus of the ipsilateral side.

In young patients with bilateral INO, multiple sclerosis is often the cause. In older patients with one-sided lesions a stroke is a distinct possibility. Other causes are possible.

The cause of the inflammation remains unknown, with various theories of it occurring as an autoimmune response to a mild infection, or the possibility of it being viral because of the preceding flu-like illness that generally accompanies it. It is usually associated with HLA-B7 and HLA-DR2.

The most common cause of cortical blindness is ischemia (oxygen deprivation) to the occipital lobes caused by blockage to one or both of the posterior cerebral arteries. However, other conditions have also been known to cause acquired and transient cortical blindness, including:

- Bilateral lesions of the primary visual cortex

- Side effect of some anti-epilepsy drugs (AEDs)

- Creutzfeldt–Jakob disease, in association with a rapid onset of dementia

- Infection

- Head trauma to the occipital lobe of the brain

- Congenital abnormalities of the occipital lobe

- Eclampsia and, rarely, pre-eclampsia

- Hyperammonemia

The most common causes of congenital cortical blindness are:

- Traumatic brain injury (TBI) to the occipital lobe of the brain

- Congenital abnormalities of the occipital lobe

- Perinatal ischemia

- Encephalitis

- Meningitis

Dysmorphopsia, in a broad sense, is a condition which causes the person affected to be unable to correctly perceive objects. It is a visual distortion, used to denote a variant of metamorphopsia in which lines appear wavy. These illusions may be restricted to certain visuals areas, or may affect the entire visual field.

It has been associated with meningioma tumors and bilateral lateral occipital corital damage, e.g. after carbon monoxide poisoning or drug abuse.

A rostral lesion within the midbrain may affect the convergence center thus causing bilateral divergence of the eyes which is known as the WEBINO syndrome (Wall Eyed Bilateral INO) as each eye looks at the opposite "wall".

If the lesion affects the PPRF (or the abducens nucleus) and the MLF on the same side (the MLF having crossed from the opposite side), then the "one and a half syndrome" occurs which, simply put, involves paralysis of all conjugate horizontal eye movements other than abduction of the eye on the opposite side to the lesion.

In general, approximately one-third of congenital cataracts are a component of a more extensive syndrome or disease (e.g., cataract resulting from congenital rubella syndrome), one-third occur as an isolated inherited trait, and one-third result from undetermined causes. Metabolic diseases tend to be more commonly associated with bilateral cataracts.

The cause of this condition is not known. A genetic basis is suspected. More than one case have been reported in three families.

In the United States, the incidence of primary congenital glaucoma is about one in 10,000 live births. Worldwide, the incidence ranges from a low of 1:22,000 in Northern Ireland to a high of 1:2,500 in Saudi Arabia and 1:1,250 in Romania. In about two-thirds of cases, it is bilateral. The distribution between males and females varies with geography. In North America and Europe it is more common in boys, whereas in Japan it is more common in girls.

- Congenital glaucoma

- Incidence: one in every 10000-15000 live births.

- Bilateral in up to 80% of cases.

- Most cases are sporadic (90%). However, in the remaining 10% there appears to be a strong familial component.

In medicine, enophthalmia describes eyes that are abnormally sunken into their sockets. This condition usually affects elderly persons. Surgery can be done to correct it. Bilateral progressive enophthalmos may be the presenting sign of metastatic breast carcinoma even when local symptoms in the breast are absent.