Multichannel auditory brainstem implant: update on performance in 61 patients

2002 ◽  
Vol 96 (6) ◽  
pp. 1063-1071 ◽  
Author(s):  
Steven R. Otto ◽  
Derald E. Brackmann ◽  
William E. Hitselberger ◽  
Robert V. Shannon ◽  
Johannes Kuchta
Keyword(s):  
Cochlear Nucleus ◽  
Electrode Array ◽  
Neurofibromatosis Type ◽  
Auditory Brainstem ◽  
Surgical Removal ◽  
Content Type ◽  
Auditory Brainstem Implant ◽  
Vs Removal ◽  
Fine Print

Object. Neurofibromatosis Type 2 (NF2) has typically resulted in deafness after surgical removal of bilateral vestibular schwannomas (VSs). Cochlear implants are generally ineffective for this kind of deafness because of the loss of continuity in the auditory nerve after tumor removal. The first auditory brainstem implant (ABI) in such a patient was performed in 1979 at the House Ear Institute, and this individual continues to benefit from electrical stimulation of the cochlear nucleus complex. In 1992, an advanced multichannel ABI was developed and a series of patients with NF2 received this implant to study the safety and efficacy of the device. Methods. At the time of first- or second-side VS removal, patients received an eight-electrode array applied to the surface of the cochlear nucleus within the confines of the lateral recess of the fourth ventricle. The device was activated approximately 6 weeks after implantation, and patients were tested every 3 months for the 1st year after the initial stimulation, and annually thereafter. The protocol included a comprehensive battery of psychophysical and speech perception tests. Conclusions. The multichannel ABI proved to be effective and safe in providing useful auditory sensations in most patients with NF2. The ABI improved patients' ability to communicate compared with the lipreading-only condition, it allowed the detection and recognition of many environmental sounds, and in some cases it provided significant ability to understand speech by using just the sound from the ABI (with no lipreading cues). Its performance in most patients has continued to improve for up to 8 years after implantation.

The multichannel auditory brainstem implant: how many electrodes make sense?

2004 ◽  
Vol 100 (1) ◽  
pp. 16-23 ◽  
Author(s):  
Johannes Kuchta ◽  
Steven R. Otto ◽  
Robert V. Shannon ◽  
William E. Hitselberger ◽  
Derald E. Brackmann
Keyword(s):  
Electrode Array ◽  
Neurofibromatosis Type ◽  
Auditory Brainstem ◽  
Sound Effect ◽  
Content Type ◽  
Sentence Recognition ◽  
Auditory Brainstem Implant ◽  
Retrospective Clinical Study ◽  
Wide Range ◽  
Fine Print

Object. Development of multichannel auditory brainstem implant (ABI) systems has been based in part on the assumption that audiological outcome can be optimized by increasing the number of available electrodes. In this paper the authors critically analyze this assumption on the basis of a retrospective clinical study performed using the Nucleus 22 ABI surface electrode array. Methods. The perceptual performances of 61 patients with neurofibromatosis Type 2 were tested approximately 6 weeks after an eight-electrode ABI had been implanted. Of eight implanted electrodes 5.57 ± 2.57 (mean ± standard deviation [SD] provided auditory sensations when stimulated. Electrodes were deactivated when stimulation resulted in significant nonauditory side effects or no auditory sensation at all, and also when they failed to provide distinctive pitch sensations. The mean (± SD) scores for patients with ABIs were the following: sound-only consonant recognition, 20.4 ± 14.3 (range 0–65%); vowel recognition, 28.8 ± 18% (range 0–67%); Monosyllable Trochee Spondee (MTS) word recognition 41.1 ± 25.3% (range 0–100%); and sentence recognition, 5.3 ± 11.4% (range 0–64%). Performance in patients in whom between one and three electrodes provided auditory sensation was significantly poorer than that in patients with between four and eight functional electrodes in the vowel, MTS word, and City University of New York (CUNY) sentence recognition tests. The correlation between performance and electrode number did not reach the 0.05 level of significance with respect to the sound effect, consonant, and MTS stress-pattern recognition tests, probably because a satisfactory performance in these tests can be obtained only with temporal cues, that is, without any information about the frequency of the sounds. In the MTS word and the CUNY sentence recognition tests, performance was optimal in the patients with eight functional electrodes. Although all top performers had more than three functional auditory electrodes, no further improvement (asymptotic performance) was seen in those with five or more active electrodes in the consonant, vowel, and sound effect recognition tests. Conclusions. A minimum of three spectral channels, programmed in the appropriate individual tonotopic order seem to be required for satisfactory speech recognition in most patients with ABI. Due to the limited access to the tonotopic frequency gradient of the cochlear nucleus with surface stimulation, patients with ABI do not receive a wide range of spectral cues (frequency information) with multielectrode (> 5) surface arrays.

Topographic anatomy of the cochlear nuclear region at the floor of the fourth ventricle in humans

1999 ◽  
Vol 91 (3) ◽  
pp. 466-476 ◽  
Author(s):  
Ralf Quester ◽  
Roland Schröder
Keyword(s):  
Surgical Approach ◽  
Cochlear Nucleus ◽  
Fourth Ventricle ◽  
Auditory Brainstem ◽  
Nuclear Surface ◽  
Content Type ◽  
Auditory Brainstem Implant ◽  
Ventral Cochlear Nucleus ◽  
Small Series ◽  
Fine Print

Object. The development of appropriate methods to stimulate the dorsal and ventral cochlear nucleus by means of an auditory brainstem implant in patients with acquired bilateral anacusis requires a detailed topoanatomical knowledge both of the location and extension of the nuclear surface in the fourth ventricle and lateral recess and of its variability. The goal of this study was to provide that information. Anatomically, it is possible to use a midline surgical approach to the fourth ventricle rather than the translabyrinthine and suboccipital routes of access used hitherto. This is especially useful if severe scarring, which occurs as a result of tumor removal in the cerebellopontine angle, make the orientation and placement of an auditory brainstem implant via a lateral surgical approach difficult. There have been only a few studies, involving single cases and small series of patients, in which the focus was the exact extension of the cochlear nuclei, whose microsurgically relevant position in relation to the surface structures is not known in detail.Methods. Landmarks that are important for the placement of an auditory brainstem implant through the fourth ventricle were examined and measured in a large series of 28 formalin-fixed human brainstems. In all cases, these examinations were supplemented by addition of a histological section series. For the first time values of unfixed fresh brainstem tissue were determined. Anatomical features are discussed with regard to their possible neurosurgical relevance, taking into account inter- and intraindividual variability.Conclusions. The midline approach would provide an opportunity to stimulate the whole area of the dorsal as well as the ventral cochlear nucleus with an auditory brainstem implant.

The Auditory Brainstem Implant in Neurofibromatosis Type 2: Experience from the Manchester Programme

Skull Base ◽  
2008 ◽  
Vol 18 (S 01) ◽  
Author(s):  
Simon Freeman ◽  
Richard Ramsden ◽  
Shakeel Saeed ◽  
Martin O'Driscoll ◽  
Deborah Mawman ◽  
...  
Keyword(s):  
Neurofibromatosis Type ◽  
Auditory Brainstem ◽  
Neurofibromatosis Type 2 ◽  
Auditory Brainstem Implant

Age at symptom onset and long-term survival in patients with neurofibromatosis Type 2

2003 ◽  
Vol 99 (3) ◽  
pp. 480-483 ◽  
Author(s):  
Goro Otsuka ◽  
Kiyoshi Saito ◽  
Tetsuya Nagatani ◽  
Jun Yoshida
Keyword(s):  
Symptom Onset ◽  
Survival Rates ◽  
Neurofibromatosis Type ◽  
Neurofibromatosis Type 2 ◽  
Vestibular Schwannomas ◽  
Content Type ◽  
Fine Print

Object. Neurofibromatosis Type 2 (NF2) is an intractable disorder predisposing to multiple, recurrent tumors of the central nervous system (CNS). To clarify the survival rate and characteristics that predict poor survival, we retrospectively reviewed clinical data in cases of NF2. Methods. From among 283 patients with neurofibromatosis who had been registered in a nationwide study in Japan between 1986 and 1987, 74 patients with bilateral vestibular schwannomas were analyzed. The mean duration of follow up after diagnosis was 121 months (range 2–287 months). Results of a Kaplan—Meier product-limit analysis indicated that overall 5-, 10-, and 20-year patient survival rates following diagnosis of NF2 were 85, 67, and 38%, respectively. Early onset of the initial symptom significantly compromised survival; 5-, 10-, and 20-year survival rates in patients with symptom onset at an age younger than 25 years were 80, 60, and 28%, respectively, whereas in patients with symptom onset at an age of 25 years or older the rates were 100, 87, and 62%, respectively. Patients with small vestibular schwannomas at diagnosis (< 2 cm in diameter) had better rates of survival. Other variables such as sex, additional tumors in the CNS, or dermal abnormalities did not significantly affect survival. Conclusions. This first report of long-term follow-up results concerning the survival of patients with NF2 indicates an adverse effect of early symptom onset.

Mechanisms of edema after gamma knife surgery for meningiomas

2005 ◽  
Vol 102 (Special_Supplement) ◽  
pp. 1-3 ◽  
Author(s):  
Amr El Shehaby ◽  
Jeremy C. Ganz ◽  
Wael A. Reda ◽  
Ayman Hafez
Keyword(s):  
Gamma Knife ◽  
Neurofibromatosis Type ◽  
Neurofibromatosis Type 2 ◽  
Gamma Knife Surgery ◽  
Skull Defect ◽  
Brain Swelling ◽  
Content Type ◽  
Multiple Tumors ◽  
Fine Print

✓ The authors describe two patients in whom tumor swelling and brain swelling (and possible tumor swelling), respectively, developed after undergoing gamma knife surgery. One had a skull defect with a palpable parasagittal tumor. One had neurofibromatosis Type 2 with multiple tumors, one of which was parasagittal.

scholarly journals Restoration of Hearing with an Auditory Brainstem Implant in a Patient with Neurofibromatosis Type 2

2000 ◽  
Vol 40 (10) ◽  
pp. 524-527 ◽  
Author(s):  
Yojiro SEKI ◽  
Hiromichi UMEZU ◽  
Masaaki USUI ◽  
Kozo KUMAKAWA ◽  
Fumiai KUMAGAI ◽  
...  
Keyword(s):  
Neurofibromatosis Type ◽  
Auditory Brainstem ◽  
Neurofibromatosis Type 2 ◽  
Auditory Brainstem Implant

Multiple schwannomas: schwannomatosis or neurofibromatosis type 2?

1998 ◽  
Vol 89 (1) ◽  
pp. 36-41 ◽  
Author(s):  
Matti Tapio Seppälä ◽  
Markku Alarik Sainio ◽  
Matti Jouko Johannes Haltia ◽  
Jaakko Jyri Kinnunen ◽  
Kirsi Hannele Setälä ◽  
...  
Keyword(s):  
Clinical Course ◽  
Positive Family History ◽  
Neurofibromatosis Type ◽  
Magnetic Resonance Images ◽  
Neurofibromatosis Type 2 ◽  
Long Term Outcome ◽  
Content Type ◽  
Fine Print

Object. The aim of this study was to clarify the clinical outcome of schwannomatosis, a rare condition characterized by multiple nonvestibular schwannomas in the absence of meningiomas, intraspinal ependymomas, and other clinical signs of neurofibromatosis type 2 (NF2). Methods. Nine patients with schwannomatosis treated at one institution are presented and their clinical course during a median follow-up time of 9.9 years is discussed. The patients were typically middle-aged at the time of their first operation (median 43.5 years), none had a positive family history of schwannomatosis or NF2, and none showed cutaneous or ocular signs of NF2. On histopathological examination the tumors from the patients with schwannomatosis showed a lobular appearance and frequent Verocay bodies, signs indicating NF2, more often than 20 sporadic schwannomas that were investigated as controls. Two patients died of unrelated causes at 3.2 and 9.9 years, respectively, of follow up. Magnetic resonance images of the head and spine were obtained in seven patients at the end of the follow-up period. New spinal schwannomas were detected in one patient and a residual schwannoma in three. No germline mutations of the NF2 gene were found in these seven patients. Two additional patients originally included in the schwannomatosis group who were 8.6 and 11.7 years old at initial surgery had NF2. One was diagnosed at follow-up review and the other developed a fulminant disease that led to death in 4 years. Conclusions. The clinical course, long-term outcome, and genetic mechanism of schwannomatosis differ from that of NF2.

Molecular alterations in the neurofibromatosis Type 2 gene and its protein rarely occurring in meningothelial meningiomas

2001 ◽  
Vol 94 (1) ◽  
pp. 111-117 ◽  
Author(s):  
James J. Evans ◽  
Sin-Soo Jeun ◽  
Joung H. Lee ◽  
Jyoti A. Harwalkar ◽  
Yigal Shoshan ◽  
...  
Keyword(s):  
Protein Expression ◽  
Neurofibromatosis Type ◽  
Neurofibromatosis Type 2 ◽  
Content Type ◽  
Exact Test ◽  
Fisher's Exact Test ◽  
Single Stranded Conformational Polymorphism ◽  
Fisher’S Exact Test ◽  
Fine Print

Object. The neurofibromatosis Type 2 (NF2) gene is the only tumor suppressor gene that has been clearly implicated in the development of benign meningiomas. Interestingly, previous data obtained by the authors indicate that reduced NF2 protein expression seldom occurs in meningothelial meningiomas, the most common histological type of meningioma. The goal of the current study was to explore further the hypothesis of NF2 gene-independent tumorigenesis of meningothelial meningiomas. Methods. The authors performed a mutational analysis of all 17 exons of the NF2 gene by using single-stranded conformational polymorphism (SSCP). In addition, expression levels of the NF2 protein and (µ-calpain, a protease suggested to inactivate the NF2 protein, were determined by immunoblotting analysis of 27 meningiomas (20 meningothelial and seven nonmeningothelial). Mutations of the NF2 gene were found in only one (5%) of 20 meningothelial meningiomas and three (43%) of seven nonmeningothelial tumors (Fisher's exact test, p = 0.042). The levels of NF2 protein were severely reduced in six (28.5%) of 21 meningothelial meningiomas, in contrast to six (86%) of seven nonmeningothelial meningiomas (Fisher's exact test, p = 0.023). Activation of (µ-calpain did not correlate with the status of NF2 protein expression in the meningiomas analyzed, demonstrating that (µ-calpain activation does not account for the loss of NF2 protein in meningiomas with apparently normal NF2 genes. Conclusions. These results clearly demonstrate that NF2 gene mutations and decreased NF2 protein expression rarely occur in meningothelial meningiomas compared with other histological types of meningiomas. The clinical behavior of meningothelial meningiomas, however, is similar to that of other benign meningiomas. It is likely, therefore, that the tumorigenesis of meningothelial meningiomas is the result of deleterious alterations of genes that have final phenotypical effects similar to inactivation of the NF2 gene.

Trigeminal neuralgia resulting from auditory brainstem implant cable compression

2011 ◽  
Vol 114 (1) ◽  
pp. 186-188 ◽  
Author(s):  
Marc S. Schwartz ◽  
Derald E. Brackmann ◽  
Eric P. Wilkinson ◽  
John L. Go ◽  
Felipe Santos
Keyword(s):  
Trigeminal Neuralgia ◽  
Trigeminal Nerve ◽  
Imaging Study ◽  
Neurofibromatosis Type ◽  
Auditory Brainstem ◽  
Fast Imaging ◽  
Neurovascular Compression ◽  
Auditory Brainstem Implant ◽  
Maximal Medical Therapy

The authors report a case of neurofibromatosis Type 2 presenting with symptoms of trigeminal neuralgia refractory to medical management following placement of an auditory brainstem implant (ABI). Physical examination and history revealed trigeminal neuralgia. A 3D FIESTA (fast imaging employing steady-state acquisition) MR imaging study demonstrated compression of the trigeminal nerve by an ABI cable. After maximal medical therapy, a retrosigmoid microscopic decompression of the trigeminal nerve achieved complete symptom resolution. This is the first report of an ABI cable becoming displaced, resulting in neurovascular compression. This case demonstrates that trigeminal neuralgia can result from nonvascular compression of the trigeminal nerve.

scholarly journals Measurements of the local evoked potential from the cochlear nucleus in patients with an auditory brainstem implant and its implication to auditory perception and audio processor programming

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249535
Author(s):  
Lutz Gärtner ◽  
Thomas Lenarz ◽  
Andreas Büchner
Keyword(s):  
Cochlear Nucleus ◽  
Auditory Perception ◽  
False Positive Rate ◽  
Electrode Array ◽  
Compound Action Potential ◽  
Auditory Brainstem ◽  
Auditory Brainstem Implant ◽  
Evoked Compound Action Potential ◽  
Positive Rate ◽  
Fitting In

The measurement of the electrically evoked compound action potential (ECAP) in cochlear implant (CI) patients is widely used to provide evidence of a functioning electrode-nerve interface, to confirm proper location of the electrode array and to program the sound processor. In patients with an auditory brainstem implant (ABI), a likewise versatile measurement would be desirable. The ECAP measurement paradigm “Alternating Polarity” was utilized to record responses via the implanted ABI electrode array placed on the cochlear nucleus. Emphasizing on the different location of stimulation and recording, these responses are called local evoked potentials (LEP). LEP measurements were conducted during the clinical routine in 16 ABI patients (12 children and 4 adults), corresponding to 191 electrode contacts. A retrospective analysis of these data revealed, that LEP responses were observed in 64.9% of all measured electrode contacts. LEP responses predicted auditory perception with a sensitivity of 90.5%. False-positive rate was 33.7%. Objective LEP thresholds were highly significantly (p < 0.001) correlated both to behavioral thresholds (Pearson’s r = 0.697) and behavioral most comfortable levels (r = 0.840). Therefore, LEP measurements have the potential to support fitting in ABI patients.

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