Auditory brainstem implant Health Dictionary

Auditory Brainstem Implant: From 1 Different Sources


a device similar to a *cochlear implant except that the electrode stimulates the auditory parts of the *brainstem rather than the cochlea. It is used to restore hearing of profoundly deaf people who have had damage to both auditory nerves and are hence unsuitable for cochlear implantation. It consists of an electrode that is permanently implanted on the surface of the brainstem. An external device with a microphone and an electronic processing unit pass information to the electrode using radio-frequency waves. The implant is powered by batteries in the external part of the device. It is most commonly used in patients with *neurofibromatosis type II who have had bilateral *vestibular schwannomas.
Health Source: Oxford | Concise Colour Medical Dictionary
Author: Jonathan Law, Elizabeth Martin

Auditory Nerve

See VESTIBULOCOCHLEAR NERVE.... auditory nerve

Implantation

(1) The placing of a substance such as a drug, or an object such as a pacemaker, in a body tissue.

(2) The surgical replacement of injured or unhealthy tissue or organ with healthy tissue or organ (also known as TRANSPLANTATION).

(3) Attachment of the early EMBRYO to the lining of the UTERUS, which occurs around six days after conception; the site where this happens is where the placenta will develop.... implantation

Brainstem

A stalk of nerve tissue that forms the lowest part of the brain and links with the spinal cord. The brainstem acts partly as a highway for messages travelling between other parts of the brain and spinal cord. It also connects with 10 of the 12 pairs of cranial nerves (which emerge directly from the underside of the brain) and controls basic functions such as breathing, vomiting, and eye reflexes. Brainstem activities are below the level of consciousness, and they operate mainly on an automatic basis.

The brainstem is composed of 3 main parts: the midbrain, pons, and medulla. The midbrain contains the nuclei (nervecell centres) of the 3rd and 4th cranial nerves. It also contains cell groups involved in smooth coordination of limb movements. The pons contains nerve fibres that connect with the cerebellum. It also houses the nuclei for the 5th–8th cranial nerves. The medulla contains the nuclei of the 9th–12th cranial nerves. It also contains the “vital centres” (groups of nerve cells that regulate the heartbeat, breathing, blood pressure, and digestion (information on which is relayed via the 10th cranial nerve (see vagus nerve). Nerve-cell groups in the brainstem, known collectively as the reticular formation, alert the higher brain centres to sensory stimuli that may require a conscious response. Our sleep/wake cycle is controlled by the reticular formation.

The brainstem is susceptible to the same disorders that afflict the rest of the central nervous system (see brain, disorders of). Damage to the medulla’s vital centres is rapidly fatal; damage to the reticular formation may cause coma. Damage to specific cranial nerve nuclei can sometimes lead to specific effects. For example, damage to the 7th cranial nerve (the facial nerve) leads to facial palsy. Degeneration of the substantia nigra in the midbrain is thought to be a cause of Parkinson’s disease.... brainstem

Breast Implant

An artificial structure surgically introduced into the breast to increase its size (see mammoplasty).... breast implant

Cochlear Implant

A device used to treat profoundly deaf people who are not helped by hearing aids. A cochlear implant consists of tiny electrodes surgically implanted in the cochlea deep in the inner ear and a receiver that is embedded in the skull just behind and above the ear. A microphone, sound processor, and transmitter are worn externally. A cochlear implant does not restore normal hearing, but it enables patterns of sound to be detected. Combined with lip-reading, it may enable speech to be understood.... cochlear implant

Implant

Any material, either natural or artificial, inserted into the body for medical or cosmetic purposes. For example, artificial joints can replace diseased structures and breast implants can improve appearance. Implants are also used to maintain proper functioning of an internal organ, treat certain disorders, or deliver drugs or hormones.... implant

Lens Implant

A plastic prosthesis used to replace the removed opaque lens in cataract surgery.... lens implant

Cochlear Implants

A cochlear implant is an electronic device, inserted under a general anaesthetic, which stimulates the auditory system, restoring partial hearing in profound sensory deafness. Although there are many types of cochlear implant, they all consist of a microphone, a signal processor, a signal coupler (transmitter and receiver), and an array of electrodes. Most are multi-channel implants. The microphone and signal processor are worn outside the body, like a conventional hearing aid: they receive sound and convert it into an electronic signal which is transmitted through the skin to the receiver. Here the signal is transmitted to the array of electrodes which stimulates the cochlear nerve. Although cochlear implants do not provide normal hearing, most profoundly deaf patients who receive a cochlear implant are able to detect a variety of sounds, including environmental sounds and speech. The duration of hearing-loss and age at implantation are among the many factors which in?uence the results (see DEAFNESS).... cochlear implants

Contraceptive Implant

A hormonal method of contraception in which longacting contraceptive drugs are inserted under the skin.

An implant consists of a small rod that steadily releases a progestogen drug into the bloodstream.... contraceptive implant

Implantation, Egg

Attachment of a fertilized ovum (egg) to the wall of the uterus.

It occurs about 6 days after fertilization, when the blastocyst (early embryo) comes into contact with the wall of the uterus.

As the cells of the developing embryo continue to divide, the outer cell layer penetrates the lining of the uterus to obtain oxygen and nutrients from the mother’s blood; later, this layer develops into the placenta.

The embryo usually implants in the upper part of the uterus; if it implants low down near the cervix, placenta praevia may develop.

Rarely, implantation occurs outside the uterus, possibly in a fallopian tube, resulting in an ectopic pregnancy.... implantation, egg

Implant, Dental

A post, surgically embedded in the jaw for the attachment of a dental prosthesis (an artificial tooth). Titanium or synthetic materials may be used. A dental implant is fitted under local anaesthesia. A hole is drilled in the jaw and a post inserted. Several months later, an attachment that protrudes from the gum is screwed into the post; a few weeks after that, the prosthesis is fitted.... implant, dental

Penile Implant

A prosthesis inserted into the penis to help a man suffering from permanent impotence to achieve intercourse.

The various types include a silicone splint inserted in the tissues of the upper surface of the penis, and an inflatable prosthesis that is inflated by squeezing a small bulb in the scrotum.... penile implant

Titanium Dental Implants

See implants, dental.... titanium dental implants

Auditory

adj. relating to the ear or to the sense of hearing.... auditory

Auditory Brainstem Response Audiometry

(ABR audiometry, brainstem evoked response audiometry, BSER) an objective test of hearing that measures the electrical activity in the auditory nerve and *brainstem following sound stimulation using repeated clicks or brief tones.... auditory brainstem response audiometry

Auditory Canal

(auditory meatus) the canal leading from the pinna to the eardrum.... auditory canal

Auditory Dyssynchrony

see auditory neuropathy spectrum disorder.... auditory dyssynchrony

Auditory Neuropathy Spectrum Disorder

(auditory neuropathy, auditory dyssynchrony) a form of hearing loss characterized by normal cochlear function as measured by *otoacoustic emissions or detection of *cochlear microphonics but abnormal or absent *middle ear reflexes and abnormal *auditory brainstem responses.... auditory neuropathy spectrum disorder

Auditory Processing Disorder

(APD, central auditory processing disorder, CAPD) a series of conditions characterized by difficulty in hearing and processing auditory information, especially in poor acoustic environments, despite normal or near-normal ear function. It may be due to genetic factors, maturational delay in the central nervous system, or focal abnormalities of the central nervous system (such as tumours). Treatments include *hearing therapy, *auditory skills training, educational support, use of *assistive listening devices, and training with computerized therapy tools.... auditory processing disorder

Auditory Skills Training

a method of teaching people to use their hearing to its best potential, undertaken in the treatment of *auditory processing disorder.... auditory skills training

Auditory Steady State Response

(ASSR) an objective test of hearing that measures the electrical activity in the auditory nerve and *brainstem following sound stimulation using a modulated continuous tone.... auditory steady state response

Auditory Verbal Therapy

(AVT) a technique for teaching deaf children to communicate that focuses on speech and residual hearing rather than sign language.... auditory verbal therapy

Brainstem Evoked Response Audiometry

see auditory brainstem response audiometry.... brainstem evoked response audiometry

Central Auditory Processing Disorder

see auditory processing disorder.... central auditory processing disorder

Children’s Auditory Performance Scale

(CHAPS) a questionnaire designed to assess children’s hearing abilities in certain situations. It is used in the diagnosis of *auditory processing disorder.... children’s auditory performance scale

Dental Implant

see implant.... dental implant

Fetal Implant

(fetal graft) the introduction of an ovum, fertilized in vitro and developed to the *blastocyst stage, into the uterus of a postmenopausal woman in order that she may become pregnant. Before this procedure, the woman’s uterus must be prepared, by hormone therapy, to receive and nurture the blastocyst. Hormone treatment is continued throughout the pregnancy.... fetal implant

Implantable Cardiovertor Defibrillator

(ICD) a self-contained device, similar to a *pacemaker, that monitors heart rhythm and delivers an electric shock to correct life-threatening arrhythmia. See also defibrillator.... implantable cardiovertor defibrillator

Implantable Hearing Aid

a form of hearing aid in which a small electrical vibrator is surgically attached to the auditory *ossicles. An external device with a microphone and an electronic processing unit passes information to the implanted device using radio-frequency waves. The external part is located behind the pinna and is powered by batteries.... implantable hearing aid

Implantable Loop Recorder

(ILR) a device, inserted beneath the skin of the chest, to record the heart rhythm for up to two years. It is usually used for the investigation of patients presenting with infrequent syncope (fainting) in whom arrhythmia is the suspected cause. When syncope occurs, the device can be examined using wireless technology to reveal the heart rhythm at the time of the episode.... implantable loop recorder

Molteno Implant

a valved device used in the surgical treatment of some types of glaucoma to control intraocular pressure by allowing fluid to drain from the anterior chamber into the subconjunctival space.... molteno implant

Obscure Auditory Dysfunction

(OAD, King–Kopetzky syndrome) hearing difficulty, especially in noisy environments, in an individual with a normal *audiogram: a form of *auditory processing disorder. Treatment includes *hearing therapy.... obscure auditory dysfunction

Transcatheter Aortic Valve Implantation

(TAVI) replacement of the aortic valve in patients with *aortic stenosis using a catheter-delivered prosthesis rather than open heart surgery. Usually the catheter is passed via the femoral artery, but sometimes it can be passed via the subclavian artery or through the wall of the left ventricle via a localized *thoracotomy.... transcatheter aortic valve implantation



Recent Searches