Auditory Brain Stem Implants
Brain Stem
Evoked Potentials, Auditory, Brain Stem
Auditory Brain Stem Implantation
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Inferior colliculus responses to multichannel microstimulation of the ventral cochlear nucleus: implications for auditory brain stem implants. (1/10)
Multichannel techniques were used to assess the frequency specificity of activation in the central nucleus of the inferior colliculus (CIC) produced by electrical stimulation of localized regions within the ventral cochlear nucleus (VCN). Data were recorded in response to pure tones from 141 and 193 multiunit clusters in the rat VCN and the CIC, respectively. Of 141 VCN sites, 126 were individually stimulated while recording responses in the CIC. A variety of CIC response types were seen with an increase in both electrical and acoustic stimulation levels. The majority of sites exhibited monotonic rate-level types acoustically, whereas spike rate saturation was achieved predominantly with electrical stimulation. In 20.6% of the 364 characteristic frequency aligned VCN-CIC pairs, the CIC sites did not respond to stimulation. In 26% of the 193 CIC sites, a high correlation was observed between acoustic tuning and electrical tuning obtained through VCN stimulation. A high degree of frequency specificity was found in 58% of the 118 lowest threshold VCN-CIC pairs. This was dependent on electrode placement within the VCN because a higher degree of frequency specificity was achieved with stimulation of medial, central, and posterolateral VCN regions than more anterolateral regions. Broadness of acoustic tuning in the CIC played a role in frequency-specific activation. Narrowly tuned CIC sites showed the lowest degree of frequency specificity on stimulation of the anterolateral VCN regions. These data provide significant implications for auditory brain stem implant electrode placement, current localization, power requirements, and facilitation of information transfer to higher brain centers. (+info)Electrical stimulation of the midbrain for hearing restoration: insight into the functional organization of the human central auditory system. (2/10)
The cochlear implant can restore speech perception in patients with sensorineural hearing loss. However, it is ineffective for those without an implantable cochlea or a functional auditory nerve. These patients can be implanted with the auditory brainstem implant (ABI), which stimulates the surface of the cochlear nucleus. Unfortunately, the ABI has achieved limited success in its main patient group [i.e., those with neurofibromatosis type 2 (NF2)] and requires a difficult surgical procedure. These limitations have motivated us to develop a new hearing prosthesis that stimulates the midbrain with a penetrating electrode array. We recently implanted three patients with the auditory midbrain implant (AMI), and it has proven to be safe with minimal movement over time. The AMI provides loudness, pitch, temporal, and directional cues, features that have shown to be important for speech perception and more complex sound processing. Thus far, all three patients obtain enhancements in lip reading capabilities and environmental awareness and some improvements in speech perception comparable with that of NF2 ABI patients. Considering that our midbrain target is more surgically exposable than the cochlear nucleus, this argues for the use of the AMI as an alternative to the ABI. Fortunately, we were able to stimulate different midbrain regions in our patients and investigate the functional organization of the human central auditory system. These findings provide some insight into how we may need to stimulate the midbrain to improve hearing performance with the AMI. (+info)Accuracy of image-guided surgical systems at the lateral skull base as clinically assessed using bone-anchored hearing aid posts as surgical targets. (3/10)
(+info)Auditory Brainstem Implant: surgical technique and early audiological results in patients with neurofibromatosis type 2. (4/10)
(+info)Consensus recommendations to accelerate clinical trials for neurofibromatosis type 2. (5/10)
(+info)Histopathological analysis of a 15-year user of an auditory brainstem implant. (6/10)
(+info)An in vivo investigation of inferior colliculus single neuron responses to cochlear nucleus pulse train stimulation. (7/10)
(+info)Auditory brainstem implants: how do they work? (8/10)
(+info)An auditory brainstem implant (ABI) is a surgically placed device that provides a sense of sound to individuals who have severe hearing loss and cannot benefit from cochlear implants. Unlike cochlear implants, which stimulate the auditory nerve directly, ABIs transmit electrical signals directly to the brainstem, bypassing the inner ear entirely.
The ABI consists of a microphone, processor, and a series of electrodes that are surgically placed on the surface of the brainstem. The microphone picks up sounds from the environment, and the processor converts them into electrical signals. These signals are then sent to the electrodes, which stimulate the nearby nerve cells in the brainstem.
The brain interprets these stimuli as sound, allowing the individual to perceive some level of hearing. While ABIs do not provide the same level of hearing as cochlear implants, they can help individuals with profound hearing loss to communicate more effectively and improve their quality of life.
It's important to note that ABIs are typically reserved for individuals who have severe hearing loss due to damage to the inner ear or auditory nerve, and who are not candidates for cochlear implants. The procedure is complex and carries risks, so it is only recommended in cases where the potential benefits outweigh the risks.
The brainstem is the lower part of the brain that connects to the spinal cord. It consists of the midbrain, pons, and medulla oblongata. The brainstem controls many vital functions such as heart rate, breathing, and blood pressure. It also serves as a relay center for sensory and motor information between the cerebral cortex and the rest of the body. Additionally, several cranial nerves originate from the brainstem, including those that control eye movements, facial movements, and hearing.
Auditory brainstem evoked potentials (ABEPs or BAEPs) are medical tests that measure the electrical activity in the auditory pathway of the brain in response to sound stimulation. The test involves placing electrodes on the scalp and recording the tiny electrical signals generated by the nerve cells in the brainstem as they respond to clicks or tone bursts presented through earphones.
The resulting waveform is analyzed for latency (the time it takes for the signal to travel from the ear to the brain) and amplitude (the strength of the signal). Abnormalities in the waveform can indicate damage to the auditory nerve or brainstem, and are often used in the diagnosis of various neurological conditions such as multiple sclerosis, acoustic neuroma, and brainstem tumors.
The test is non-invasive, painless, and takes only a few minutes to perform. It provides valuable information about the functioning of the auditory pathway and can help guide treatment decisions for patients with hearing or balance disorders.
An auditory brainstem implant (ABI) is a surgically placed device that provides a sense of sound to individuals who have severe hearing loss and are unable to benefit from cochlear implants. Unlike cochlear implants, which stimulate the auditory nerve directly, ABIs stimulate the cochlear nucleus, a region in the brainstem responsible for processing sound.
During the ABI procedure, an electrode array is placed on the surface of the cochlear nucleus, and electrical signals are used to bypass damaged structures in the inner ear and auditory nerve. These signals are then transmitted to the brain, where they are interpreted as sound. The success of ABIs varies from person to person, but many individuals report improved ability to understand speech and recognize environmental sounds.
ABIs are typically recommended for people with hearing loss caused by damage to the auditory nerve or inner ear, such as those with neurofibromatosis type 2 (NF2), a genetic disorder that causes tumors to grow on the nerves responsible for hearing and balance. ABIs may also be considered for individuals who have had unsuccessful cochlear implantation due to damaged or absent auditory nerves.
Audiology is a branch of science that deals with the study of hearing, balance disorders, and related conditions. It involves the assessment, diagnosis, and treatment of hearing and balance problems using various tests, techniques, and devices. Audiologists are healthcare professionals who specialize in this field and provide services such as hearing evaluations, fitting of hearing aids, and counseling for people with hearing loss or tinnitus (ringing in the ears). They also work closely with other medical professionals to manage complex cases and provide rehabilitation services.
An encyclopedia is a comprehensive reference work containing articles on various topics, usually arranged in alphabetical order. In the context of medicine, a medical encyclopedia is a collection of articles that provide information about a wide range of medical topics, including diseases and conditions, treatments, tests, procedures, and anatomy and physiology. Medical encyclopedias may be published in print or electronic formats and are often used as a starting point for researching medical topics. They can provide reliable and accurate information on medical subjects, making them useful resources for healthcare professionals, students, and patients alike. Some well-known examples of medical encyclopedias include the Merck Manual and the Stedman's Medical Dictionary.
I'm sorry for any confusion, but the term "humanities" is not typically used in a medical context as it relates to fields such as literature, philosophy, arts, and languages. The humanities are academic disciplines that study human culture, including language, history, philosophy, and the creation of art. They provide valuable insights into human nature, behavior, and experience, which can certainly have applications in various fields, including healthcare. However, a specific medical definition of "humanities" would not be applicable.
I apologize for any confusion, but "books" is a general term that refers to bound sets of pages that are printed or written with text, illustrations, or signs, and are meant to be read, studied, or consulted. It does not have a specific medical definition. If you're looking for information about a specific medical term or concept, please let me know and I'd be happy to help!
I'm sorry for any confusion, but "Social Sciences" is a broad term that refers to academic disciplines that study human society and social relationships. It includes fields such as anthropology, sociology, psychology, political science, and economics. These subjects are considered part of the liberal arts and humanities, not medical sciences.
However, aspects of social sciences can intersect with medical studies in areas like medical anthropology, health psychology, sociology of health and illness, and psychiatry. For instance, medical anthropologists might study how cultural factors influence healthcare practices, while health psychologists examine the role of behavior and mental processes in health and illness.
If you're looking for a definition related to medical sciences, perhaps there was some confusion with the term. Could you please clarify or provide more context?
I'm sorry for any confusion, but "Internet" is a term that pertains to the global network of interconnected computers and servers that enable the transmission and reception of data via the internet protocol (IP). It is not a medical term and does not have a specific medical definition. If you have any questions related to medicine or health, I'd be happy to try to help answer them for you!
I'm sorry for any confusion, but "Science" is a broad field that refers to a systematic and logical process used to discover how things in the universe work. It's not typically used as a medical term. However, within the context of medicine, "science" often refers to evidence-based practices, which are treatments and preventions that have been scientifically researched and proven to be effective. This could include areas like pharmacology (the study of drugs), pathophysiology (the study of changes in the body due to disease), or clinical trials (studies used to test new treatments). If you're looking for a specific medical term, could you please provide more context?