Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Auditory Brain Stem Implants”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1999

Positron emission tomography in cochlear implant and auditory brain stem implant recipients.

OBJECTIVE: The purpose of this study was to determine whether similar cortical regions are activated by speech signals in profoundly deaf patients who have received a multichannel cochlear implant (CI) or auditory brain stem implant (ABI) as in normal-hearing subjects. STUDY DESIGN: Positron emission tomography (PET) studies were performed using a variety of discrete stimulus conditions. Images obtained were superimposed on standard anatomic magnetic resonance imaging (MRI) for the CI subjects. The PET images were superimposed on the ABI subject's own MRI. SETTING: Academic, tertiary referral center. PATIENTS: Five subjects who have received a multichannel CI and one who had received an ABI. INTERVENTION: Multichannel CI and ABI. MAIN OUTCOME MEASURE: PET images. RESULTS: Similar cortical regions are activated by speech stimuli in subjects who have received an auditory prosthesis. CONCLUSIONS: Neuroimaging provides a new approach to the study of speech processing in CI and ABI subjects.

Acoustic Stimulation↗
PubMed1998

The multichannel auditory brain stem implant: performance in twenty patients.

The auditory brain stem implant has been used effectively to provide hearing sensations to individuals deafened by bilateral auditory nerve tumors (neurofibromatosis type 2). During tumor removal, the auditory brain stem implant is implanted into the lateral recess of the fourth ventricle by a translabyrinthine approach and is intended to stimulate auditory neurons of the cochlear nucleus complex. A new eight-electrode multichannel auditory brain stem implant was developed and evaluated in 20 patients who had at least 3 months' experience with the device. Mild nonauditory sensations (primarily tingling in the head or torso) were encountered in some instances but could be managed by changing the stimulus characteristics or excluding electrodes. Testing of perceptual performance indicated significant benefit from the device for communication purposes, including sound-only sentence recognition scores in three patients ranging from 49% to 58% and ability to converse on the telephone. These results indicate that significant auditory benefit can be derived from direct multichannel electrical stimulation of the auditory portion of the human brain stem.

Acoustics↗
PubMed2000

Experimental study following inactive implantation of an auditory brain stem implant in nonhuman primates.

We report changes in the cochlear nuclei (CNs) after 3 months of bilateral auditory deafferentation and simultaneous unilateral implantation of a dummy auditory brain stem implant (ABI) in 6 nonhuman primates (Macaca fascicularis). These specimens were compared to CNs of 9 controls and 7 bilaterally deafferented animals without implantation. The ABI array consists of 3 platinum electrodes mounted on a silicone pad with the back side covered with Dacron. No migration of the ABI was observed. All deafferented animals showed astrocytic reorganization in the CNs. Histologic changes consisted of superficial reactions around the implant, with formation of fibrillar bundles of fusiform cells, and the presence of giant cells close to the Dacron. Other findings were related to surgical trauma. The dummy ABI did not itself provoke serious adverse reactions in the CNs. Our observations support the possibility of ABI reimplantation surgery.

Animals↗
PubMed1995

A simple CT method for location of auditory brain stem implant electrodes.

A method for locating auditory brain stem implant electrodes that have been placed in the lateral recess of the fourth ventricle is described. CT bone window images are "inverted" to black on white, then manually superimposed onto soft-tissue window images to enable identification of electrodes in relation to soft-tissue structures.

Brain Stem↗
PubMed1998

[Oto-neuro-surgical approach and accessibility to the cochlear nuclei. Significance in auditory brain stem implant].

The auditory brainstem implant (ABI) is now used to stimulate the cochlear nucleus to obtain auditory perception in patients with type 2 neurofibromatosis. Only electrical stimulation of the cochlear nucleus complex, in the lateral recess of the fourth ventricle, can achieve auditory rehabilitation of these profound bilateral retrocochlear deafness. With 20 standard translabyrinthine approaches, our personal anatomical study propose to describe surgical landmarks of the cochlear nuclear complex and surgical accessibility of the lateral recess of the fourth ventricle. The root of vestibulocochlear nerve, the glossopharyngeal nerve and the choroid plexus of the fourth ventricle might have surgical significance because of their reliability.

Brain Stem↗
PubMed2005

Optimizing the clinical fit of auditory brain stem implants.

OBJECTIVE: To develop and implement a new audiological fitting procedure for auditory brain stem implants (ABIs), based on an efficient algorithm, and to compare it with two procedures presently used in clinical practice. DESIGN: First, the different procedures were compared by using computer models and simulations with normal-hearing subjects (N = 4). This allows for an analysis of the accuracy of the procedures in a way that is not possible when testing ABI users. The root-mean-square error between the order estimated by the procedure and the true order was calculated. In addition, ABI users (N = 2) were tested with the new procedure to see if it could be successfully applied in clinic. The degree of variability of their results across runs and sessions was analyzed. RESULTS: The tests of the normal-hearing subjects showed that our proposed procedure required significantly fewer trials (22 on average) than procedures presently used in clinic (with 76 and 234 trials on average for the two other procedures tested) to produce the same degree of accuracy. Computer modeling also demonstrated this advantage. Additional testing showed this advantage was maintained under a variety of conditions relevant to the clinic. The two patients tested were able to use this procedure with success, even though they were poor at discriminating the pitch of electrodes. The patients showed results consistent with having about 4 to 5 discriminable groups of electrodes with the 12 to 14 electrodes tested. CONCLUSIONS: The proposed procedure requires fewer trials to produce a clinically useful result and is well tolerated in the clinic. An additional advantage is that it allows testing to be broken down into several "blocks," each containing a small number of trials. If the variability between blocks is small, information can be combined across blocks to increase the accuracy of the result. If the variability is large, perhaps between blocks on different days, this may reflect a significant change in the percepts generated by the implant, and signal to the clinician that a significant alteration in the fitting is required. We recommend its use in ABI user fitting and in cochlear implant fitting when pitch ranking is problematic.

Adult↗
PubMed1990

Auditory brain stem implant: effect of tumor size and preoperative hearing level on function.

The auditory brain stem implant is an investigational device designed to provide hearing sensations to patients without functioning auditory nerves. We analyzed results from 17 implants in 15 patients to determine if tumor size or preoperative hearing level might be related to proper device function. We found no significant correlation between preoperative hearing level or tumor size and device function. We also found no significant correlation between preoperative hearing level and tumor size in these 15 patients.

Adolescent↗
PubMed1995

Nucleus 20-channel and 21-channel auditory brain stem implants: first European experiences.

Central electrical stimulation of the auditory pathway can allow hearing in patients suffering from deafness localized in the auditory nerve. Developments in a multichannel auditory brain stem implant based on the Nucleus Mini 22 cochlear implant with transcutaneous signal transmission is discussed. The device has been implanted in seven European patients who suffered from neurofibromatosis type 2. Preliminary speech perception results and patient satisfaction are encouraging, and the data presented include some limited open-set speech recognition.

Auditory Threshold↗
PubMed1995

Multichannel auditory brain stem implant: case studies comparing fitting strategies and results.

A new 8-electrode prosthesis has been developed for individuals deafened by bilateral auditory nerve tumors (neurofibromatosis-2). Twelve patients have received the multichannel auditory brain stem implant at House Ear Institute since 1992, 11 of whom receive useful auditory sensations. Processor fitting includes scaling and ranking of electrode-specific pitch sensations, and determination of any nonauditory sensations. Two representative patients differing in experience and number of usable electrodes are compared in terms of range of auditory sensations and speech perception performance. An inexperienced patient with two electrodes using a new speech-processing strategy (Speak) performed comparably to an experienced patient with six electrodes using an earlier feature-extraction processor.

Adult↗
PubMed2000

Advantages of the retrosigmoid approach in auditory brain stem implantation.

From April 1997 to December 1999, six patients (five men and one woman), ranging in age from 22 to 37 years with neurofibromatosis type 2 (NF2) were operated on via the classic retrosigmoid-transmental (RS-TM) approach for removal of a vestibular schwannoma (VS) (tumor size from 12 to 40 mm) and for auditory brain stem implantation (ABI). After tumor removal, the floor of the lateral recess of the fourth ventricle and the convolution of the dorsal cochlear nucleos were reached, and the ABI was inserted. More recently, an ABI was implanted via the retrosigmoid approach in a 4-year-old boy with a cochlear malformation (common cavity) associated with cochlear nerve aplasia. Electrically evoked auditory brain stem responses (EABRs) and neural response telemetry (NRT) were performed to verify the correct positioning of the inserted electrodes. No major complications related to ABI were observed. ABI has been activated to date in five of the NF2 patients. Auditory sensations with various numbers of electrodes were evoked in all patients. We consider the RS-TM approach the route of choice for ABI insertion in patients with NF2 and good hearing, offering a chance of hearing preservation, and in patients with complete cochlear ossification, severe head trauma and cochlear fracture, or nerve disruption, or a combination of these. A new indication for ABI implantation via the RS approach is presented by patients with bilateral cochlear nerve aplasia.

Journal Article↗
PubMed2002

[Use of auditory brain stem implant in a patient with bilateral vestibular schwannoma (type 2 neurofibromatosis].

Surgical technique and functional results of implantation of the acoustic implant of the brain stem (BS) are described for a 16-year-old patient with bilateral vestibular shvannoma (neurofibromatosis of type 2). Initially, a large (IV degree) tumor was removed from the left cerebellopontile angle using the translabyrinthine-transcochlear approach. The function of the facial nerve recovered completely. The BS implant was implanted a year later in the course of removing shvannoma from the right cerebellopontile angle using the above approach. The patient received 22-channel implant Nucleus-CI22M. Speech intelligibility improved by 90-100%. BS implantation is today the only effective method of reestablishment of acoustic sensations in patients with bilateral destruction of the acoustic nerves due to bilateral vestibular shvannoma.

Adolescent↗