Labyrinthine - Wounds
Labyrinthine syndrome, see Ménière disease
An inflammation of the labyrinth within the inner ear; also called otitis interna. Symptoms include nausea, vomiting, tinnitus, vertigo and deafness. Usually caused by either a bacterial or viral infection entering the inner ear from the middle ear. Infection can come from a cholesteatoma (q.v.), head trauma (q.v.), or contamination from a stapes operation or mastoidectomy. A possible complication is spread of the infection to the meninges, causing meningitis (q.v.). A form in infants caused by syphilis in the mother is called syphilitic labyrinthitis (see syphilis). EDHD2 p.123.
Laurence-Moon-Bardet-Biedl syndrome (LMBBS), see Bardet-Biedl syndrome
Also known as multiple lentigines syndrome, multiple lentiginosis, or cardio-cutaneous syndrome. A very rare syndrome in which the prominent features are LEntigines (small dark-brown skin spots), Ocular defects, Pulmonary infundibular stenosis, Abnormal genitalia, growth Retardation, and Deafness. The name also reflects the small brown spots all over the face and skin, reminiscent of the markings of a leopard. Affects both sexes; about 1/4 to 1/3 of the cases also include congenital sensorineural deafness. Autosomal dominant inheritance. Lentigines may be present at birth or appear gradually over the first three or four years of life. DSID p.190-192; EGDBD p.229-230.
A rare syndrome resembling Ménière disease. Increasing deafness and tinnitus, interrupted by sudden vertigo during which hearing improves.
Lobstein syndrome, see Osteogenesis imperfecta
Macular dystrophy, see Almaric syndrome
Genetic condition caused by a mutation on gene TCOF1; incidence rate unknown, though recurrence in families throughout several generations has been recorded and studied. Characterized by coloboma or notch of the lower eyelid, malformation of facial bones, low-set malformed external ears, atypical hair growth, occasional pits or clefts between the mouth and ear. Called Franceschetti syndrome if complete or near-complete, Treacher Collins syndrome if limited to orbit and malar areas. About half of Treacher Collins cases also have conductive hearing impairment from small and malformed external ears and auditory canal and/or an abnormally developed middle ear. DSID p.308-310; EGDBD p.313.
This is surgical removal of an infected or damaged mastoid portion of the temporal bone, located behind the external ear. Most mastoidectomies do not in themselves result in hearing loss, but a form called a radical mastoidectomy removes the eardrum and most of the contents of a seriously infected middle ear, necessarily causing a permanent conductive hearing loss of up to 50 dB. EDHD2 p.131-132.
Progressive cerebellar ataxia, myoclonic seizures and sensorineural hearing loss.
Measles, see Roseola; Rubella
Ménière disease or Ménière syndrome
Inner ear disorder of unknown origin, affecting over 1 million Americans. Initial stages include unilateral hearing loss of the fluctuating inner ear type, affecting first only low tones, then both low and high. Tinnitus first low pitched, then high pitched tones. Sudden appearance of violent and often incapacitating vertigo. Cochlear Ménière disease is an atypical form in which the hearing impairment, dizziness and trinities are present, but not the vertigo. Vestibular Ménière disease causes the vertigo without the hearing loss. EDHD2 p.55, 133-135; EDHD p.121-122; GEDPD v.1 p.112, 344-345, v.2 p.30.
An inflammation of the outer membranes surrounding the brain and/or the spinal cord, usually from a bacterial infection and almost always a complication from another bacterial infection. Less commonly, meningitis can also be caused by a viral infection, though the viral form is normally mild and without permanent consequences. If bacterial meningitis is caught and treated early, the prognosis is good and complications rare; however, delayed treatment or no treatment can be very severe (70%-100% death rate if untreated). Prolonged inflammation may spread and suddenly destroy some nerve cells, including those associated with hearing (about 6% or more of child cases). About 15% of children deafened by meningitis also suffer mental retardation. EDHD2 p.135; EDHD p.122-123.
Mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS)
A genetic (mitochondrial) condition caused by a mutation and often characterized by short stature; approximately 30% of affected persons also have hearing loss. EGDBD p.221.
- Kearns-Sayre syndrome
- Myoclonic epilepsy and ragged red fibers
- Mitochondrial encephalopathy
- Diabetes mellitius type II
Möbius syndrome or Möbius sequence
Also spelled Moebius.... Congenital facial diplegia (paralysis), usually associated with other neurological disorders, sometimes including deafness. EGDBD p.222.
Mohr syndrome, see Oral-facial-digital syndrome, type II
A developmental abnormality of the inner ear. Characterized by bony and membranous anomalies of the inner ear exhibiting a wide range of morphological and functional abnormalities. Severe forms show no hearing or vestibular response. EDHD2 p.140.
Mongolism, see Down syndrome
A viral infection that can cause sudden deafness in one ear.
Also known as Morquio-Ullrich syndrome, Brailsford syndrome, or mucopolysaccharidosis 4. Autosomal recessive inheritance. Caused by a genetic defect in the metabolism of the complex sugars; the enzyme for metabolizing keratin sulfate is lacking (see also Hurler syndrome, Hunter syndrome, and Sanfilippo syndrome). Affects both sexes in about 1 out of 100,000 births. Normal appearance at birth, but onset begins in early childhood. Skeletal deformities accompanied by weak extremities and waddling gait. Absence of corneal capacity and typical "gargoyle" face and hepatosplenomegaly. Short stature, short neck, kyphosis, large swelling at the knee, clouding of the corneas, protruding abdomen. Deafness is common, resulting directly from the accumulation of the unmetabolized complex sugar involved. More severe cases usually die in their twenties, though those with the milder type of the syndrome have a longer life expectancy. DSID p.203-206; EGDBD p.226.
Mucopolysaccharidosis 1-H, see Hurler syndrome
Mucopolysaccharidosis 2, see Hunter syndrome
Mucopolysaccharidosis 3, see Sanfilippo syndrome
Mucopolysaccharidosis 4, see Morquio syndrome
Multiple lentigines syndrome, see LEOPARD syndrome
Multiple sclerosis (MS)
A chronic autoimmune disorder of unknown causes that destroys the myelin insulation covering the nerve fibers (neurons) in the brain and spinal chord. MS can cause permanent deafness if it affects the part of the brain that performs hearing. Most victims are female, and onset is usually between 20 and 40 years of age. Estimates of the population go as high as 1 in 1000 individuals in the U.S., as many as 250,000. How many of these are also deaf is not known. EGDBD p.230-231.
A viral illness that is a common cause of severe one-sided deafness, usually sudden in onset but often not noticed for many days or even years before being identified. Usually occurring in childhood; destroys the inner ear, though without affecting the balance mechanism. EDHD2 p.141-142; EDHD p.129.
A group of hereditary disorders characterized by progressive muscle weakness and wasting. Most MD does not affect the ears or hearing, but one form, facio-scapulo-humeral dystrophy (the third most common form of MD) begins during the teens in the muscles of the face, shoulders and upper arms before spreading to the trunk and leg muscles. Hearing loss is one frequent consequence of this variation. EGDBD p.231-232.
Myoclonic epilepsy and ragged red fibers (MERRF)
A genetic (mitochondrial) condition characterized by myoclonus, epilepsy, and ataxia. Sensorineural deafness, blindness, and/or mental impairment often, though not always, occur. Arises as a result of mutations. EGDBD p.221.
Also called von Recklinghausen disease. An inherited developmental disorder of the nervous system, muscles, bones and skin, in which soft tumors (neurofibromas) and café-au-lait spots (flat, darkened skin areas) grow. NF type 2 (bilateral acoustic neurofibromatosis) is the more severe form. Its neurofibromas may cause various neurological, skeletal, endocrinal, and skin problems, and gradual deafness occurs in many NF type 2 victims by growing nodes on the hearing nerve. NF type 2 occurs in about 1 of 50,000 births. Present at birth, but symptoms generally appear during adolescence or in the 20s. 50% risk of passing NF on to a child. Autosomal dominant inheritance; the defective gene has been mapped to gene 22q. DSID p.211-215; EGDBD p.238-239.
Nicotine, see Smoking
Noise-induced hearing loss, see Acoustic trauma
Low-set ears, antimongoloid slant to eyes, mental retardation, and stunted growth. In males, differentiation of male genitalia or complete absence or disappearance; in females, from normal sexual development to absent development and primary amenorrhea; occasionally, mild deafness. Symptoms are similar to that of Turner syndrome, though deafness, if present, is less severe in Noonan syndrome. DSID p.220-223.
A rare X-linked genetic condition occurring only in males. Classic symptoms include various specific pathologies of the eye, including blindness; most affected patients also have mental retardation and many also have severe progressive sensorineural hearing loss that appears as they grow older. EGDBD p.243.
Oculoauriculoverteral dysplasia, see Goldenhar syndrome
Oculovestibuloauditory syndrome, see Cogan syndrome
Ondine's curse, see Congenital central hypoventilation syndrome
Oral-facial-digital syndrome, type II (OFD II)
OFD is a group of genetic disorders with varying origins and unknown basic cause; nine variants are recognized. They have in common deformities and anomalies of the mouth, face, fingers and toes. Of the nine variants, OFD II, an autosomal recessive trait also called Mohr syndrome, frequently includes deafness due to a defect in the incus (one of the middle ear bones). EGDBD p.246-247.
A blow to the head, or an infection of the middle ear, can cause separation of two or all three ossicles (inner ear bones) that carry sound vibrations from the eardrum to the inner ear, causing a conductive deafness. The degree of separation determines the amount of hearing loss. This condition is readily correctible by surgery. EDHD2 p.160; EDHD p.146.
Osteitis deformans, see Paget disease
Also called brittle bone disease or Lobstein syndrome. A rare genetic disease (3 to 4 cases per 100,000 live births), afflicting boys and girls equally; hereditary (autosomal dominant) plus some new mutations; four distinct types. A defect in the production of one of the precursors of collagen, a substance closely involved in skeletal makeup, causes the bones to be brittle and fragile. Hearing is sometimes impaired due to deformity in the middle ear bones. DSID p.227-230; EGDBD p.248-249.
An infection of the outer ear canal, often occurring after swimming in dirty or heavily chlorinated water (hence the common name swimmer's ear). About 5 out of 10,000 people contract it; it is more common among diabetics and in individuals with immune systems weakened by diseases or medication. In more extreme cases, pus can block the ear, causing temporary conductive deafness. A much less-common extreme form is called malignant oititis externa, in which infection from the outer ear can spread, causing inflammation and eventual permanent damage to the bones and cartilage at the base of the skull and to the cranial nerves, the brain, or other parts of the body. EDHD2 p.129; EDHD p.180.
An infection of the middle ear, in which a buildup of fluid or pus can cause a conductive hearing impairment by muffling or immobilizing the middle ear bones and/or the eardrum. Deafness is usually not permanent unless chronic severe cases cause middle ear damage, resulting in the collapse of the eardrum and its adherence to the ossicles; this is known as adhesive otitis media. Serous otitis media, also called secretory otitis media or glue ear, is a form in which the middle ear fills with a thin and watery fluid which causes a conductive hearing loss. Although of unclear and possible multiple causes, serous otitis media is the most common current cause of hearing problems in childhood. It may arise from allergy or viral infection of the middle ear, barotrauma (q.v.), blockage of the eustachian tube, or use of antibiotics without adequate drainage to treat other forms of otitis media. A form characterized by thick fluid in the middle ear, damping the motions of the ossicles and eardrum, is called mucous otitis media. EDHD2 p.5, 141,160-161, 187.
A genetic disorder affecting only males (female carriers with both copies of the gene may show mild expression of the disorder, but never full OPD). Cleft palate and hearing loss combined with abnormalities of the thumbs and toes, frequently with mental impairment. Two forms, OPD-I (Taybi syndrome) and OPD-II (Andre syndrome) are distinguished from each other by their severity and mode of inheritance. OPD-1 is generally the milder form and is X-linked recessive. OPD-II is also X-linked and generally includes microcephaly, wide-set eyes and a small mouth, significant development delays, deformations of the fingers and bowing of the long leg and forearm bones. Most OPD-II victims are stillborn or die before 5 months of age from respiratory problems. EGDBD p.249.
Also called otospongiosis. A disease in which spongy bone overgrows the stapes in the middle ear, immobilizing it and causing a conductive hearing loss. Usually bilateral, more common among women than men, and begins in early adulthood (between 20 and 30 years of age). A tendency to otosclerosis seems to be inherited as autosomal dominant (gene 15q, affecting 25 to 50% of those who inherit the gene), though apparently it is not genetic in all cases. Prevalence is 0.2 to 1% in whites (making it the single most common cause of hearing impairment), about one in 3,300 for blacks, and about one in 33,000 for Asians. The usual treatment is a stapedectomy. EDHD2 p.162-163; EDHD p.148-149; EGDBD p.249-250.
Otospongiosis, see Otosclerosis
Ototoxic drugs and other substances
Some drugs, chemicals and other substances can affect the function of the inner ear by poisoning the delicate hair cells and other nerve cells in that area, or by interfering with the proper development of the ear or hearing system. Damage may occur during fetal development or at any time after birth. A wide variety of drugs are known or believed to be damaging, either alone or in combination with others; the drug families involved include antibiotics, loop diuretics, excess use of salicylates (aspirins), and quinine derivatives. Most of these have permanent effects, though aspirin's and quinine's effects usually disappear within days after discontinuation of use. Aminoglycosides (kanaycin, neomycin, gentamicin, tobramycin and amikacin), streptomycin, and thalidomide have all also been implicated as casing ear malformation or deafness in fetuses. High levels of alcohol (see fetal alcohol syndrome), nicotine, and caffeine sometimes also produce deafness in fetuses and may cause temporary deafness in children and adults. The overuse of certain pain-relieving narcotics (hyocodone and acetaminophen) in combination is also known to cause a rapid and permanent total deafness. Ground contamination by heavy metals and related byproducts, in the vicinity of some mines, has also been blamed for hearing loss in children growing up in those areas. EDHD2 p.17-18, 127-128, 143, 163-165, 172, 175; EDHD p.155-156.
Also called osteitis deformans. A common genetic disease usually appearing in middle age. It weakens the bones of the skull, pelvis, collarbone, and long bones of the leg. Changes in the skull can cause distortion and damage to the inner ear, resulting in tinnitus, vertigo, and sensorineural hearing loss. EDHD2 p.167; EDHD p.151.
Patau syndrome, see Trisomy 13 syndrome
A genetic condition (on the PDS gene), characterized by congenital sensorineural deafness with familial goiter (enlarged thyroid gland). Affects both sexes equally. Various degrees of bilateral deafness from birth (perceptive in type, in some cases associated with defective vestibular function), more complete loss for high than low tones. Autosomal recessive inheritance. Prevalence estimated at between 1 in 12,500 and 1 in 100,000 live births. EDHD2 p.167-168; EDHD p.152; GEDPD v.2 p.21; EGDBD p.255.
A hole, tear or rupture of the eardrum causes a conductive hearing loss. The perforation can be from a variety of causes, including rupture from otitis media (q.v.), barotrauma (q.v.), skull fracture (see temporal bone fracture) or other physical traumas (q.v.), the insertion of sharp or narrow objects into the ear canal, growth of a tumor, etc. EDHD2 p.69.
Peroneal muscular atrophy, see Charcot-Marie-Tooth disease
"Poisoned blood", see Toxemia
Approximately 5% of prematurely born infants have sensorineural hearing loss due to an abnormally short gestational period. GEDPD v.2 p.25.
A type of sensorineural hearing loss usually found among older people, starting usually after age 50; it affects over 10 million Americans. The cochlea begins to lose nerve cells, especially those that respond to high-frequency sounds and then progressing to middle and eventually lower frequencies. It is not clear how much of this loss is from physiological aging, and how much from cumulative exposure to noise throughout the person's life. Approximately one in three persons over age 65 have presbycusis, rising to nearly one in two persons over age 75. EDHD2 p.6-7, 173; EDHD p.4-5, 156-157.
Psychogenic hearing loss, see Functional hearing loss
Ramsay Hunt syndrome, see Hunt syndrome
Recessive spinocerebellar degeneration, see Friedrich ataxia
Refsum syndrome or Refsum disease
Also known as heredopathia atactica polyneuritoformis. This rare genetic condition develops between ages 4 to 7. It is caused by a defect in catabolism of phytanic acid in the diet. Phytanic acid is normally excreted harmlessly, but if it builds up in the body, it becomes ototoxic. Children develop this rare genetic condition between ages 4 and 7. Progressive sensorineural deafness, concentric constriction of visual fields, night blindness, chronic polyneuropathy involving motor and sensory nerves, cerebellar ataxia, loss of sense of smell. Autosomal recessive inheritance, on chromosome 10. Infantile Refsum disease (q.v.) is actually a different condition. EDHD2 p.177-178; EGDBD p.277-278.
Retinitis pigmentosa, see Usher Syndrome
During head colds, allergy attacks, or infections in the back of the nose and throat, the eustachian tube is forced closed so that no air can enter the middle ear. When the air pressure inside the middle ear then drops relative to the pressure in the external ear canal, the eardrum gets pressed into the inner ear. In extreme cases, the flexed eardrum can push aside the ossicles or even touch the cochlea, causing varying degrees of conductive hearing loss. EDHD2 p.179-180.
A lesion located on the auditory nerve itself can cause a sensorineural hearing impairment. EDHD2 p.180.
Rh incompatibility disease
Also called Rh factor incompatibility and erythroblastosis fetalis. If a pregnant mother has an Rh negative blood type, and the fetus has an Rh positive blood type, and if any fetal blood cells cross the placental wall into the mother's blood stream, her body will react by manufacturing antibodies against the fetus' blood. This is not a problem for first pregnancies, but later pregnancies may be affected by the antibodies remaining in the mother's blood from the first one. If those antibodies cross the placental wall in the other direction, they may attack the fetus' blood, causing fetal anemia. Rh incompatibility disease does not directly cause deafness, but afflicted babies who survive pregnancy may develop kernicterus (see hyperbilurbinemia), which in turn can lead to cerebral palsy, mental retardation, speech problems, and/or deafness. EDHD2 p.180; EGDBD p.161.
Also called sixth disease (obsolete), exanthema infantum or exanthema subitum. This type of measles often causes permanent sensorineural deafness due to persistent high fever temperatures that damage the hair cells in the cochlea. As its name implies, it usually strikes infants. Its immediate cause is human herpesvirus 6. EDHD2 p.132-133.
Also known as Gregg syndrome and popularly called German measles. Affects primarily newborns from mothers exposed to the rubella virus during the first trimester of pregnancy, but can occur in either of the other two trimesters, and indeed after birth at any age. Not the measles itself but rather complications from it, including ear infections and encephalitis (q.v.), are responsible for causing deafness in many victims. Symptoms in infants and young children include hepatosplenomegaly, instetitial pneumonia, congenital heart defects, low birth weight, congenital cataracts, purpura, hearing loss (in the cochlea), inguinal hernias, mental retardation, and failure to thrive. Hearing loss affects up to 50 percent of exposed infants. Rubella used to run in minor epidemic cycles 6-9 years apart and major cycles approximately every 20-30 years. The last major epidemic was in 1964-1965, causing nearly 12,000 infants to be born deaf. The 1969 development of an effective rubella vaccine has stopped all major epidemics, though limited outbreaks still occur in settings where large groups of unvaccinated individuals are in close contact with each other, such as schools. EDHD2 p.132-133, 181; GEDPD v.2 p.23; EGDBD p.311.
A form of craniosynostosis, a group of disorders caused by premature closing of the sutures separating the cranial bones, causing an abnormal shape of the skull. Typical characteristics evident at birth include lopsided face, wide-set eyes, beaked nose, low hairline, digital abnormalities, ears low-set and rotated somewhat backward, and sometimes mild to moderate mental retardation. Vision problems and mild hearing loss may also be present. Autosomal dominant inheritance from a gene located on 7p. New mutations may also occur, attributed to increased paternal age. EGDBD p.286.
Also known as mucopolysaccharidosis 3. A genetic defect in the metabolism of the complex sugars; an enzyme is lacking (see also Hurler syndrome, Morquio syndrome, and Hunter syndrome). About 1 in 25,000 live births are affected, both sexes equally. An autosomal recessive genetic defect with four identified subtypes, Sanfilippo A being most common. Symptoms are normal at birth, but at age 2 or 3, or even later, a rapid mental and physical decline become apparent, plus stiffening of the joints, coarsening of facial features and enlargement of the head. Conductive deafness may show up later in childhood, probably caused by the repeated upper respiratory tract infections that are also characteristic of this syndrome. Life expectancy is low, usually ending before age 20. DSID p.259-261; EGDBD p.226.
Also called scarletina. An acute infectious disease caused by streptococcus bacteria. Deafness may arise from complications that include sinus infections, followed by abscesses of the ear and then mastoiditis. Symptoms arise 2-7 days after exposure, and include fever, sore throat, headache, and (in children) vomiting. 2-3 days later, a rash appears in the neck, armpit, groin and chest, plus red spots on the tongue. Once common, scarlet fever is not often seen any more in the U.S. EDHD2 p.183.
A collection of birth anomalies involving the kidneys, heart, brain and skeleton, accompanied by a characteristic flat face. Short lower limbs, nose is short and low, eyes wide-set, and ears low-set, frequently with hearing, vision and mental difficulties. EGDBD p.287.
Shingles, see Hunt syndrome
An inflammation of the lining of the sinuses (air chambers in the facial bones around the nose). It can cause a temporary conductive hearing loss if it causes swelling of the eustachian tube, the blockage of which then interferes with the functioning of the middle ear. EDHD2 p.192.
Sixth disease, see Roseola infantum
Nicotine is known to constrict blood vessels in smokers, which in the long term can cause degeneration of some delicate tissues, including those in and around the ear. In addition to tinnitus and hearing loss, studies indicate that nicotine is connected with a higher failure rate following myringoplasty (a surgical reconstruction of the eardrum made necessary by other causes). Other research shows an increased risk of ear infections in the children of women who smoked while pregnant, up to three times the rate of children whose mothers did not smoke. The chances of the children having to undergo ear surgery before age 5 are also tripled. EDHD2 p.151, 193.
Spinal meningitis, see Meningitis
A form of short-trunk dwarfism that has three forms. In all forms, the cartilage of the vertebrae is gradually replaced by bone as the infant develops and grows, stopping the growth of the spine. Mutations in the gene for type II collagen, COL2A on 12q. S.d. congenita is present at birth, inherited as an autosomal dominant trait. Lack of muscle tone, flat face, "floppy infant" appearance, possibly cleft palate, clubfoot, vision impairment and/or a moderate hearing loss. S.d. tarda is a delayed form appearing only in males, and appears in autosomal recessive and a rare autosomal dominant form, both X-linked. Hunched shoulders, enlarged chest, osteoarthritis of the spine and hip bones, but usually no deafness. EGDBD p.296-297.
Also known as hereditary progressive arthro-ophthalmopathy. An autosomal dominant genetic disease caused by mutations on genes COL2A1, COL11A2, or COL11A1 (chromosome 12). Symptoms include progressive myopia, vitreoretinal degeneration, premature joint degeneration, cleft palate deformity, and sometimes variable sensorineural hearing loss. DSID p.289-291; EGDBD p.298-299.
May cause permanent deafness by damaging the part of the brain that performs hearing.
Surdocardiac syndrome, see Jervell and Lange-Nielson syndrome
Swimmer's ear, see Otitis externa
Many pregnant women having this disease transmit it to their fetuses, and about a third of the infected children will eventually become deaf. The disease affects the neural portion of the auditory system, but the hearing loss usually does not manifest itself until well into childhood or even in adulthood. If syphilis is contracted in adulthood, deafness from untreated syphilis appears gradually, either as a hearing loss or as a fluctuation in hearing intensity. Rarely, congenital syphilis can also cause syphilitic labyrinthitis, which often results in a sudden, flat sensorineural deafness, or a sudden, increasingly fluctuating sensorineural deafness. EDHD2 p.199; GEDPD v.2 p.23; EDHD p.181; EGDBD p.302.
Many infections, such as measles, scarlet fever, tuberculosis, and typhoid fever can cause a bilateral sensorineural deafness.
Taybi syndrome, see Oto-palato-digital syndrome
Temporal bone fracture
A type of head trauma with skull fracture involving the two temporal bones, often damaging the middle ear and causing a conductive hearing loss. If the fracture is traverse, it can also injure the inner ear or internal auditory meatus, causing a sensorineural hearing loss, vertigo, tinnitus, and facial nerve paralysis. See also Trauma. EDHD2 p.204; EDHD p.184.
Temporomandibular joint syndrome (TMJ)
Believed to be caused by improper function of the jaw joints and their muscles and ligaments. Symptoms include severe pain in the jaw, face, and head, especially around the ears; clicking or popping in the jaw and ears; "locking" of the jaws, and pain in opening the mouth. Hearing loss often also occurs, apparently from muscle spasms including the muscles of the middle ear. Hearing usually returns after treatment of the TMJ.
Deafness is associated with three types of thyroid disorders: Pendred syndrome (q.v.), adult myxedema and endemic cretinism. However, the causal link between the hearing deficit and the thyroid disorder has not been established. EGDBD p.255.
Tinnitus-Deafness-Vertigo syndrome, see Lermoyez syndrome
In mainstream medicine, toxemia is the presence of excess toxic bacterial products in the bloodstream. In "alternate medicine" and in much quackery, toxemia is equated to "poisoned blood" and blamed for a very wide variety of ailments, including deafness. However, mainstream medicine rarely, if ever, accepts toxemia as a cause of deafness.
A parasitic infection that hits about 0.2% of pregnant women; a third of these pass it on to their infants, and a small percentage of infected infants have hearing loss. Infection commonly occurs from pregnant women eating or handling raw meat, or from coming in contact with the feces of infected cats. Outdoor cats that hunt are more likely to have the infection; the risk from cats kept strictly indoors and fed regular cat food is low. EDHD2 p.208; GEDPD v.2 p.23; EDHD p.188; EGDBD p.310-311.
Autosomal dominant trait, first described in 1972, caused by a mutation in the SALL1 gene on 16q. Over 50 cases reported; symptoms include an imperforate anus, malformed ears, and mental retardation; most cases also have malformation of the thumb and other digits, and mild to moderate deafness. EGDBD p.312-313.
Trauma is any physical damage caused by a physical blow or impact, as from a serious fall, automobile accident, gunshot wound, etc. Deafness may result from damage to the eardrum, inner ear mechanism, and/or nerves. Its permanence or temporariness depends on the extent of injury, what is damaged, the medical attention given, age, and a variety of other factors. For example, a ruptured eardrum will usually heal, but damage to the inner ear bones is usually irreversible. See also Acoustic trauma and Temporal bone fracture. EDHD2 p.97-98, 138.
Treacher Collins syndrome¸ see Mandibulofacial dystosis
Trigeminal nerve abnormality
A developmental abnormality of the fifth cranial nerve, which divides into three branches, responsible for supplying sensation from the face, scalp, nose, teeth, mouth lining, upper eyelid, sinuses, and the front part of the tongue. Abnormalities of this nerve are often associated with malformation of the ear, and up to 60% of that population has a sensorineural hearing loss. EDHD p.188.
Trisomy 13 syndrome
Also called Patau syndrome. Caused by the presence of an extra chromosome 13. Severe mental retardation, microcephaly, polydactyly, cleft lip or palate; over 30 signs in all. Infants are blind and deaf. Usually fatal within weeks or months; in rare cases they may survive past 3 years. EGDBD p.252-253; EGDBD p.252-253.
Trisomy 21 syndrome, see Down syndrome
Trisomy D1 syndrome, see Trisomy 13 syndrome
Middle ear tumors, which are rare and can be either malignant or benign, cause conductive hearing loss by blocking the middle ear and auditory canal, destroying the ossicles, and/or interfering with the eardrum. Malignant tumors may also protrude into the inner ear and cause an sensorineural hearing impairment. The most common types of malignant tumors found are squamous cell carcinoma (especially in middle age) and globus tumor. Symptoms, especially in women, may include tinnitus, vertigo, and facial paralysis. Also see Choristoma. For tumors that form on hearing-related nerves, see Neurofibramatosis. EDHD2 p.139, 208-209; EDHD p.189.
Also known as chromosome 45/X syndrome or Ullrich-Turner syndrome. A sex-linked genetic disorder that affects only females. In Turner syndrome, about 1 out of every 2500 live female births have a missing X chromosome, leaving only 45 chromosomes instead of the usual 46. Characteristic symptoms include short stature, infertility, heart and eye problems, and others; girls with this syndrome often have frequent otitis media (q.v.), which can lead to a conductive hearing loss. DSID p.314-318; EGDBD p.316-317.
A chronic middle ear infection can cause the growth of new bony tissue along the lining of the middle ear. If this calcification occurs on the tympanum (eardrum), it can cause conductive deafness. EDHD2 p.210.
An infectious disease spread through food or water contaminated by contact with food handled by an infected person, flies, or feces from infected persons. This carries the bacterium Salmonella typhosis, which passes from the victim's intestines into the blood, then the spleen and liver, eventually accumulating in the gall bladder until re-released into the intestine. Symptoms include a mild headache, fever, loss of appetite and malaise, sometimes accompanied by delirium. Constipation develops, then changes to diarrhea; during the second week of illness, a rash appears on the chest and abdomen. Complications sometimes include a sensorineural hearing loss. EDHD2 p.210.
Ullrich-Turner syndrome, see Turner syndrome
A genetic condition consisting of congenital hearing impairment plus progressive retinitis pigmentosa. Prevalences vary; the worldwide average seems to be about 5 in every 100,000, but much higher incidences are known in Finland, Norway, and parts of the U.S. In the U.S., the average is between one in 15,000 and one in 30,000 live births, accounting for 3% to 6% of all American deaf children and possibly an equivalent percentage of hard of hearing children. Males and females are affected in equal numbers. Genes involved are MYO7A, USH2A, and several others still unidentified. Inheritance is autosomal recessive. 90% of Usher syndrome victims are born with sensorineural deafness. Classified into three types: Type I has congenital profound hearing loss, no vestibular response, and onset in the first decade. Type II exhibits a sloping audiogram for congenital hearing loss plus normal vestibular response and onset in first or second decade. Type III has progressive hearing loss, variable vestibular response, and onset is variable. General characteristics of all type include family history of poor night vision, blue-green color blindness, or total blindness. During childhood, progressive hearing loss (evident at age 4-6) and secondary lack of speech development. Usually a few years later (average age 9), progressive poor night vision, degeneration of peripheral visual fields, tunnel vision, blindness. Profound degrees of deafness and blindness develop by early adulthood. A few cases of Usher syndrome occur with mental instability and/or mental retardation and are termed Hallgren syndrome. DSID p.319-322; EDHD p.192; GEDPD v.1 p.237-238; EGDBD p.321-322.
Van der Hoeve syndrome
Also called Adair-Dighton syndrome. About half of patients with osteogeneis imperfecta, a bone disorder causing the entire skeleton to have brittle bones that may fracture before or during birth and postnatally following minor trauma, plus short stature, also have van der Hoeve syndrome. This adds blue sclera (a blue tinge to the whites of the eyes) and conductive hearing loss to the symptoms. Bilateral deafness starts at about age 20 due to otosclerosis. Onset of manifestations apparent at birth or early childhood. EDHD2 p.160.
A common and mild childhood infectious viral disease; its outward symptoms are commonly called chicken pox. After recovery, the victim has lifelong immunity to a reoccurrence, but the virus remains dormant and may erupt in later life as herpes zoster (see Hunt syndrome). Children with varicella zoster usually have only a slight fever and are generally left unharmed, but adults may become very ill, with complications including encephalitis (q.v.) which can lead to deafness, usually just in one ear. Women in late pregnancy are particularly vulnerable and may pass on the disease to their infants, who may have severe cases. EDHD2 p.45; EDHD p.43; EGDBD p.323-324.
Von Recklinghausen disease, see Neurofibromatosis
Genetic (known genes involved are PAX3, MITF, EDNRB, EDN3, and SOX10); no sex preference and reported in all ethnological groups. Autosomal dominant inheritance, though in a few families having a specific variant of the syndrome, inheritance appears to be recessive. Occurs in between 1 in every 20,000 and 1 in every 40,000 live births. No sex preference and reported in all ethnological groups. Among children who are deaf from birth, 3 in every 100 have Waardenburg syndrome. Sensorineural deafness is present from birth in 20%, 25%, or up to 50% of cases (sources differ). Divided into two types (I and II) based on the presence (Type I) or absence (Type II) of dystopia canthorum. Type I combined with upper limb abnormalities is called WS Type III or Klein-Waardenburg syndrome, and Type II plus Hirschsprung disease is called WS Type IV or Waardenburg-Shah syndrome. Visible characteristics of WS include a white forelock in most cases, and smaller number of cases may show different color in each eye, a small nose, and/or confluent eyebrows. DSID p.328-331; EDHD2 p.219; EDHD p.195; GEDPD v.2 p.22; EGDBD p.328-329.
Consists of the Klippel-Feil deformity of the spine with eyeball retraction, lateral gaze, weakness, and hearing loss. Short neck and paralysis of external ocular muscles. Conductive hearing loss, as well as the more frequently occurring sensorineural hearing loss, is caused by dysplasia of the inner ear. Occurs mostly in females. GEDPD v.2 p.23.
Wolfram syndrome 1
Identified in 2001 as a genetic cause of hereditary low-frequency hearing loss.
Wounds, see Trauma