Congenital hearing loss
Encyclopedia
Congenital hearing loss implies that the hearing loss is present at birth
. It can include hereditary hearing loss or hearing loss due to other factors present either in utero (prenatal) or at the time of birth.
).
There are some genetic syndromes, in which hearing loss is one of the known characteristics. Some examples are Down syndrome
(abnormality on a gene), Usher syndrome
(autosomal recessive), Treacher Collins syndrome
(autosomal dominant), Crouzon syndrome
(autosomal dominant), and Alport syndrome
(X-linked).
In the United States of America, because of a Federal law (the Individuals with Disabilities Education Act
), children with a hearing loss between birth and 3 years of age have the right to receive interdisciplinary assessment and early intervention services at little or no cost. After age 3, early intervention and special education programs are provided through the public school system.
There are a number of treatment options available, and parents will need to decide which are most appropriate for their child. They will need to consider the child’s age, developmental level and personality, the severity of the hearing loss, as well as their own preferences. Ideally a team of experts including the child’s primary care provider, an otolaryngologist, a speech-language pathologist, audiologist and an educator will work closely with the parents to create an Individualized Family Service Plan. Treatment plans can be changed as the child gets older.
Children as young as 4 weeks of age can benefit from a hearing aid
. These devices amplify sound, making it possible for many children to hear spoken words and develop language. However, some children with severe to profound hearing loss may not be able to hear enough sound, even with a hearing aid, to make speech audible. A behind-the-ear hearing aid is often recommended for young children because it is safer and more easily fitted and adjusted as the child grows as compared to one that fits within the ear.
Parents also will need to decide how their family and child are going to communicate. If the child is going to communicate orally (speech), s/he may need assistance learning listening skills and lip reading skills to help her/him understand what others are saying. Many children with hearing loss also need speech or language therapy.
A child also can learn to communicate using a form of sign language. In the United States of America, the type preferred by most deaf adults is American Sign Language
(ASL), which has rules and grammar that is distinct from English. There are also several variations of sign language that can be used along with spoken English which are standard in English-speaking countries outside the United States.
Surgery may be recommended if a child has a permanent conductive hearing loss caused by malformations of the outer or middle ear, or by repeated ear infections. Although fluid in the middle ear usually results in only temporary hearing loss, chronic ear infection can cause a child to fall behind in language skills. In some cases, a doctor may suggest inserting a tube through the eardrum to allow the middle ear to drain. This procedure generally does not require an overnight hospital stay.
Surgery also may be an option for some children with severe to profound sensorineural hearing loss
. A device called a cochlear implant
can be surgically inserted in the inner ear of children as young as 12 months of age to stimulate hearing. The surgery requires a hospital stay of one to several days. With additional language and speech therapy, children with cochlear implants may learn to understand speech and speak reasonably well, but the amount of improvement is variable.
Once a child is diagnosed, the immediate and anticipated reaction of the parents and immediate family is one of the denial. Doctors or the audiologists need to counsel the family, help them cope with the situation and encourage them to look forward to solutions to overcome the problem. Often when the family is told about the excellent options available for a hearing impaired child, the chances of acceptance are much better. Once the family accepts the handicap, half the battle is over and rehabilitation can begin.
The type of intervention required depends on several factors. Chief among these is the degree of impairment. When a child has a fair degree of residual hearing, the correct intervention would be fitting "optimised" hearing aids. "Optimisation" means fitting the child with a hearing aid appropriate to its degree of deafness.
Today a variety of good quality hearing aids are available - analog or digital body worn (for small children) or ear level for older children. When fitting a hearing aid, a competent audiologist has to assess the child's residual hearing, look at the hearing aid's performance and fit the child with an appropriate instrument. Equally important is the ear mould, which has to be custom made to suit the shape of the child's ear.
If a child has profound or even total deafness, it has very little or virtually no residual hearing. In such a case hearing aids do not make scientific sense. Such a child needs a different kind of treatment called Cochlear Implants which are a sets of electrodes implanted surgically into the inner ear.
Birth
Birth is the act or process of bearing or bringing forth offspring. The offspring is brought forth from the mother. The time of human birth is defined as the time at which the fetus comes out of the mother's womb into the world...
. It can include hereditary hearing loss or hearing loss due to other factors present either in utero (prenatal) or at the time of birth.
Genetic factors
Genetic factors are thought to cause more than 50% of all incidents of congenital hearing loss. Genetic hearing loss may be autosomal dominant, autosomal recessive, or X-linked (related to the sex chromosomeChromosome
A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...
).
Autosomal dominant hearing loss
In autosomal dominant hearing loss, one parent who carries the dominant gene for hearing loss and typically has a hearing loss passes it on to the child. In this case there is at least a 50% probability that the child will also have a hearing loss. The probability is higher if both parents have the dominant gene (and typically both have a hearing loss) or if both grandparents on one side of the family have hearing loss due to genetic causes. Because at least one parent usually has a hearing loss, there is prior expectation that the child may have a hearing loss.Autosomal recessive hearing loss
In autosomal recessive hearing loss, both parents who typically have normal hearing, carry a recessive gene. In this case the probability of the child having a hearing loss is 25%. Because both parents usually have normal hearing, and because no other family members have hearing loss, there is no prior expectation that the child may have a hearing loss.X-linked hearing loss
In X-linked hearing loss, the mother carries the recessive trait for hearing loss on the sex chromosome. She can pass on the trait to males and female children, but usually only male children are affected.There are some genetic syndromes, in which hearing loss is one of the known characteristics. Some examples are Down syndrome
Down syndrome
Down syndrome, or Down's syndrome, trisomy 21, is a chromosomal condition caused by the presence of all or part of an extra 21st chromosome. It is named after John Langdon Down, the British physician who described the syndrome in 1866. The condition was clinically described earlier in the 19th...
(abnormality on a gene), Usher syndrome
Usher syndrome
Usher syndrome is a relatively rare genetic disorder that is a leading cause of deafblindness and that is associated with a mutation in any one of 10 genes. Other names for Usher syndrome include Hallgren syndrome, Usher-Hallgren syndrome, rp-dysacusis syndrome and dystrophia retinae dysacusis...
(autosomal recessive), Treacher Collins syndrome
Treacher Collins syndrome
Treacher Collins syndrome , also known as Treacher Collins–Franceschetti syndrome, or mandibulofacial dysostosis is a rare autosomal dominant congenital disorder characterized by craniofacial deformities, such as absent cheekbones. Treacher Collins syndrome is found in about 1 in 10,000 births, ....
(autosomal dominant), Crouzon syndrome
Crouzon syndrome
Crouzon syndrome is a genetic disorder known as a branchial arch syndrome. Specifically, this syndrome affects the first branchial arch, which is the precursor of the maxilla and mandible...
(autosomal dominant), and Alport syndrome
Alport syndrome
Alport syndrome or hereditary nephritis is a genetic disorder characterized by glomerulonephritis, endstage kidney disease, and hearing loss. Alport syndrome can also affect the eyes . The presence of blood in the urine is almost always found in this condition.It was first identified in a British...
(X-linked).
Other causes of congenital hearing loss
Other causes of congenital hearing loss that are not hereditary in nature include prenatal infections, illnesses, toxins consumed by the mother during pregnancy or other conditions occurring at the time of birth or shortly thereafter. These conditions typically cause sensorineural hearing loss ranging from mild to profound in degree. Examples include:- Intrauterine infections including rubella (German measles), cytomegalovirus, and herpes simplex virus
- Complications associated with the Rh factor in the blood
- Prematurity
- Lack of oxygen (anoxia)
- Hyperbilirubinemia
- Maternal alcohol/drug use
Treatment
A child with a congenital hearing loss should begin receiving treatment before 6 months of age. Studies suggest that children treated this early are usually able to develop communication skills (using spoken or sign language) that are as good as those of hearing peers.In the United States of America, because of a Federal law (the Individuals with Disabilities Education Act
Individuals with Disabilities Education Act
The Individuals with Disabilities Education Act is a United States federal law that governs how states and public agencies provide early intervention, special education, and related services to children with disabilities...
), children with a hearing loss between birth and 3 years of age have the right to receive interdisciplinary assessment and early intervention services at little or no cost. After age 3, early intervention and special education programs are provided through the public school system.
There are a number of treatment options available, and parents will need to decide which are most appropriate for their child. They will need to consider the child’s age, developmental level and personality, the severity of the hearing loss, as well as their own preferences. Ideally a team of experts including the child’s primary care provider, an otolaryngologist, a speech-language pathologist, audiologist and an educator will work closely with the parents to create an Individualized Family Service Plan. Treatment plans can be changed as the child gets older.
Children as young as 4 weeks of age can benefit from a hearing aid
Hearing aid
A hearing aid is an electroacoustic device which typically fits in or behind the wearer's ear, and is designed to amplify and modulate sound for the wearer. Earlier devices, known as "ear trumpets" or "ear horns", were passive funnel-like amplification cones designed to gather sound energy and...
. These devices amplify sound, making it possible for many children to hear spoken words and develop language. However, some children with severe to profound hearing loss may not be able to hear enough sound, even with a hearing aid, to make speech audible. A behind-the-ear hearing aid is often recommended for young children because it is safer and more easily fitted and adjusted as the child grows as compared to one that fits within the ear.
Parents also will need to decide how their family and child are going to communicate. If the child is going to communicate orally (speech), s/he may need assistance learning listening skills and lip reading skills to help her/him understand what others are saying. Many children with hearing loss also need speech or language therapy.
A child also can learn to communicate using a form of sign language. In the United States of America, the type preferred by most deaf adults is American Sign Language
American Sign Language
American Sign Language, or ASL, for a time also called Ameslan, is the dominant sign language of Deaf Americans, including deaf communities in the United States, in the English-speaking parts of Canada, and in some regions of Mexico...
(ASL), which has rules and grammar that is distinct from English. There are also several variations of sign language that can be used along with spoken English which are standard in English-speaking countries outside the United States.
Surgery may be recommended if a child has a permanent conductive hearing loss caused by malformations of the outer or middle ear, or by repeated ear infections. Although fluid in the middle ear usually results in only temporary hearing loss, chronic ear infection can cause a child to fall behind in language skills. In some cases, a doctor may suggest inserting a tube through the eardrum to allow the middle ear to drain. This procedure generally does not require an overnight hospital stay.
Surgery also may be an option for some children with severe to profound sensorineural hearing loss
Sensorineural hearing loss
Sensorineural hearing loss is a type of hearing loss in which the root cause lies in the vestibulocochlear nerve , the inner ear, or central processing centers of the brain....
. A device called a cochlear implant
Cochlear implant
A cochlear implant is a surgically implanted electronic device that provides a sense of sound to a person who is profoundly deaf or severely hard of hearing...
can be surgically inserted in the inner ear of children as young as 12 months of age to stimulate hearing. The surgery requires a hospital stay of one to several days. With additional language and speech therapy, children with cochlear implants may learn to understand speech and speak reasonably well, but the amount of improvement is variable.
Once a child is diagnosed, the immediate and anticipated reaction of the parents and immediate family is one of the denial. Doctors or the audiologists need to counsel the family, help them cope with the situation and encourage them to look forward to solutions to overcome the problem. Often when the family is told about the excellent options available for a hearing impaired child, the chances of acceptance are much better. Once the family accepts the handicap, half the battle is over and rehabilitation can begin.
The type of intervention required depends on several factors. Chief among these is the degree of impairment. When a child has a fair degree of residual hearing, the correct intervention would be fitting "optimised" hearing aids. "Optimisation" means fitting the child with a hearing aid appropriate to its degree of deafness.
Today a variety of good quality hearing aids are available - analog or digital body worn (for small children) or ear level for older children. When fitting a hearing aid, a competent audiologist has to assess the child's residual hearing, look at the hearing aid's performance and fit the child with an appropriate instrument. Equally important is the ear mould, which has to be custom made to suit the shape of the child's ear.
If a child has profound or even total deafness, it has very little or virtually no residual hearing. In such a case hearing aids do not make scientific sense. Such a child needs a different kind of treatment called Cochlear Implants which are a sets of electrodes implanted surgically into the inner ear.