Read by QxMD icon Read

Brainstem implantation

Kohei Yamahara, Koji Nishimura, Hideaki Ogita, Juichi Ito, Takayuki Nakagawa, Ichiro Furuta, Tomoko Kita, Koichi Omori, Norio Yamamoto
The hybrid or electric-acoustic stimulation cochlear implant is indicated in patients with a residual hearing at low frequencies. It provides electric and acoustic stimulation for compensating for high- and low-frequency sounds, respectively. However, the implantation procedure damages the cochlea, resulting in loss of the residual-hearing and diminished effects of the acoustic-hearing in several patients. To prevent hearing loss after implantation, corticosteroids have been used clinically although their effects are limited...
July 6, 2018: Hearing Research
Yuchen Xu, Chuan Luo, Fan-Gang Zeng, John C Middlebrooks, Harrison W Lin, Zheng You
OBJECTIVE: To improve the existing manually-assembled cochlear implant electrode arrays, a thin film electrode array (TFEA) was micro-fabricated to have a maximum electrode density of 15 sites along an 8-mm length, with each site having a 75 1.8-μm (diameter - height) disk electrode. METHODS: The micro-fabrication method adopted a sequence of photoresist transferring, lift-off, two-step oxygen plasma etching, and fuming nitric acid release to reduce lift-off complexity, protect the metal layer, and increase the release efficiency...
July 10, 2018: IEEE Transactions on Bio-medical Engineering
Christian Wrobel, Alexander Dieter, Antoine Huet, Daniel Keppeler, Carlos J Duque-Afonso, Christian Vogl, Gerhard Hoch, Marcus Jeschke, Tobias Moser
Cochlear implants partially restore hearing via direct electrical stimulation of spiral ganglion neurons (SGNs). However, spread of excitation from each electrode limits spectral coding. We explored the use of optogenetics to deliver spatially restricted and cell-specific excitation in the cochlea of adult Mongolian gerbils. Adeno-associated virus carrying the gene encoding the light-sensitive calcium translocating channelrhodopsin (CatCh) was injected into the cochlea of adult gerbils. SGNs in all cochlea turns showed stable and long-lasting CatCh expression, and electrophysiological recording from single SGNs showed that light stimulation up to few hundred Hertz induced neuronal firing...
July 11, 2018: Science Translational Medicine
Maike Vollmer
Bilateral cochlear implants (CIs) provide benefits for speech perception in noise and directional hearing, but users typically show poor sensitivity to interaural time differences (ITDs). Possible explanations for this deficit are deafness-induced degradations in neural ITD sensitivity, between-ear mismatches in electrode positions or activation sites, or differences in binaural brain circuits activated by electric versus acoustic stimulation. To identify potential limitations of electric ITD coding in the normal-hearing system, responses of single neurons in the dorsal nucleus of the lateral lemniscus and the inferior colliculus to ITDs of electric (biphasic pulses) and acoustic stimuli (noise, clicks, chirps, and tones) were recorded in normal-hearing gerbils of either sex...
June 29, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Noga Lipschitz, Gavriel D Kohlberg, Mario Zuccarello, Ravi N Samy
PURPOSE OF REVIEW: To review the current literature on the extended middle cranial fossa (xMCF) approach and to provide a comprehensive description of the relevant anatomy, indications, surgical technique, results, and complications. RECENT FINDINGS: The xMCF approach expands the surgical exposure provided by the sMCF approach, allowing access to the internal auditory canal, cerebellopontine angle, prepontine cistern, anterior petrous apex, petrous carotid artery, Meckel's cave, cavernous sinus, mid and upper clivus, and posterior lesions approaching the jugular foramen...
June 27, 2018: Current Opinion in Otolaryngology & Head and Neck Surgery
Shyam Sundar Krishnan, Pulak Nigam, Poonam Mohanty, Madabhushi Chakravarthy Vasudevan, Mohan Kameswaran
INTRODUCTION: Auditory brainstem implant (ABI), a standard technique in treatment of profound sensorineural hearing loss in patients with neurofibromatosis 2, is now being increasingly employed in children with congenital bilateral sensorineural hearing loss, as in Michele's deformity. A detailed knowledge of the relevant surgical anatomy of the lateral recess and its anatomical landmarks including the flocculus, the choroid plexus and the root entry zones of facial-vestibulocochlear and glossopharyngeal-vagus nerve complexes and their anatomical variants is mandatory, as it is the conduit for electrode array placement...
June 8, 2018: Child's Nervous System: ChNS: Official Journal of the International Society for Pediatric Neurosurgery
Adrian L James, Peter R Dixon, Robert V Harrison
BACKGROUND: Cochlear nerve aplasia (CNA) may present with features of auditory neuropathy spectrum disorder (ANSD), having detectable otoacoustic emissions (OAE) but profound hearing loss. We propose that some children with CNA have a distinct form of afferent ANSD in which efferent cochlear nerve function can be detected using contralateral suppression of OAE. METHODS: Children were prospectively enrolled with MRI and auditory brainstem response evidence of unilateral CNA, a normal contralateral ear, and detectable OAE bilaterally...
June 22, 2018: Audiology & Neuro-otology
Nastaren Abad, Jens T Rosenberg, David C Hike, Michael G Harrington, Samuel C Grant
Under the hypothesis that increased extracellular sodium induces sustained neuronal excitability with the onset and progression of migraine, this study evaluates dynamic in vivo Na fluxes in the brain of a preclinical rodent analogue of migraine. Ultra-high field Na MRI at 21.1 T has demonstrated potential to quantify sodium concentrations with good spatial and temporal resolution following the onset of central sensitization. Sprague-Dawley male rats with implanted intraperitoneal (IP) lines were studied by MRI before and after an in situ injection of 10 mg/kg of nitroglycerin (NTG) versus vehicle and saline controls...
June 12, 2018: Pain
Nadine Schart-Morén, Karin Hallin, Sumit K Agrawal, Hanif M Ladak, Per-Olof Eriksson, Hao Li, Helge Rask-Andersen
OBJECTIVES: Dehiscence between the cochlear otic capsule and the facial nerve canal is a rare and relatively newly described pathology. In cochlear implantation (CI), this dehiscence may lead to adverse electric facial nerve stimulation (FNS) already at low levels, rendering its use impossible. Here, we describe an assessment technique to foresee this complication. METHODS: Pre- and postoperative computed tomography (CT) scans and intraoperative electrically evoked auditory brainstem response (e-ABR) measurements were analyzed in two patients with cochlear-facial dehiscence (CFD)...
June 7, 2018: Cochlear Implants International
Lukáš Školoudík, Viktor Chrobok, Zuzana Kočí, Jiří Popelář, Josef Syka, Jan Laco, Alžběta Filipová, Eva Syková, Stanislav Filip
Temporal bone reconstruction is a persisting problem following middle ear cholesteatoma surgery. Seeking to advance the clinical transfer of stem cell therapy we attempted the reconstruction of temporal bone using a composite bioartificial graft based on a hydroxyapatite bone scaffold combined with human bone marrow-derived mesenchymal stromal cells (hBM-MSCs). The aim of this study was to evaluate the effect of the combined biomaterial on the healing of postoperative temporal bone defects and the preservation of physiological hearing functions in a guinea pig model...
June 3, 2018: Stem Cell Reviews
Laurent Goetz, Manik Bhattacharjee, Murielle U Ferraye, Valérie Fraix, Carina Maineri, Daniela Nosko, Albert J Fenoy, Brigitte Piallat, Napoléon Torres, Alexandre Krainik, Eric Seigneuret, Olivier David, Martin Parent, André Parent, Pierre Pollak, Alim-Louis Benabid, Bettina Debu, Stéphan Chabardès
BACKGROUND: Experimental studies led to testing of deep brain stimulation (DBS) of the pedunculopontine nucleus (PPN) as a new therapy to treat freezing of gait (FOG) in Parkinson disease (PD). Despite promising initial results fueling a growing interest toward that approach, several clinical studies reported heterogeneity in patient responses. Variation in the position of electrode contacts within the rostral brainstem likely contributes to such heterogeneity. OBJECTIVE: To provide anatomoclinical correlations of the effect of DBS of the caudal mesencephalic reticular formation (cMRF) including the PPN to treat FOG by comparing the normalized positions of the active contacts among a series of 11 patients at 1- and 2-yr follow-up and to provide an optimal target through an open-label study...
May 25, 2018: Neurosurgery
S P Huang, X Y Wang, C Fang, X Y Wang, Q Wu
Objective: To observe the survival and migration ability of CXCR4-BMSCs in guinea pig cochlea with gentamycin induced sensorineural hearing loss, and to explore whether SDF-1/CXCR4 axis can mediate bone marrow mesenchymal stem cells (BMSCs) to cochlear homing. Method: BMSCs were isolated and extracted from guinea pigs. A bone marrow mesenchymal stem cell line with overexpression of CXCR4 was established. The animal model of sensorineural deafness was established by intraperitoneal injection of gentamicin[100 mg/(kg·d)]in 50 healthy guinea pigs...
March 2018: Journal of Clinical Otorhinolaryngology, Head, and Neck Surgery
L B Cai, J Yang
A 46-year-old female with profound sensorineural hearing loss in her left ear from childhood developed tinnitus and fluctuating hearing loss on the right side 8 years ago. Four years later, paroxysmal episodes of rotatory vertigo occurred with gradually increased frequency, lasting from half an hour to 2 hours and accompanied with nausea and vomiting. Audiometric test revealed severe sensorineural hearing loss in both of her ears. The tympanograms showed type A on both sides. The threshold of auditory brainstem response was 97 dBnHL in her right ear while no waves could be educed on her left side...
July 5, 2017: Journal of Clinical Otorhinolaryngology, Head, and Neck Surgery
Juan Manuel Vinas Rios, Martin Sanchez-Aguilar, Thomas Kretschmer, Christian Heinen, Fatima Azucena Medina Govea, Sanchez-Rodriguez Jose Juan, Thomas Schmidt
Background: The predictors of shunt dependency such as amount of subarachnoid blood, acute hydrocephalus (HC), mode of aneurysm repair, clinical grade at admission and cerebro spinal fluid (CSF) drainage in excess of 1500 ml during the 1st week after the subarachnoid hemorrhage (SAH) have been identified as predictors of shunt dependency. Therefore our main objective is to identify predictors of CSF shunt dependency following non-traumatic subarachnoid hemorrhage. Methods: We performed a retrospective study including patients from January 1st 2012 to September 30th 2014 between 16 and 89 years old and had a non-traumatic subarachnoid hemorrhage in cranial computed tomography (CCT)...
2018: Patient Safety in Surgery
Hannah J D North, Simon K W Lloyd
Bilateral vestibular schwannomas are almost pathognomonic of neurofibromatosis type 2 (NF2). As a result of these tumors, hearing loss is the presenting symptom in 60% of adults and 30% of children with NF2. It is often bilateral. The best means of preserving hearing in patients with NF2 is conservative management. Even so at least 28% of patients have progression of hearing loss following diagnosis. The likelihood of progression of hearing loss is, at least in part, determined by the type of mutation. Treatment of vestibular schwannomas often has a detrimental effect on hearing...
2018: Advances in Oto-rhino-laryngology
Simon R Freeman, Levent Sennaroglu
Approximately 2% of congenital profound deafness cases are due to cochlear nerve (CN) deficiency. MRI is essential to confirm if the nerve is deficient, but because of limitations with resolution, especially when the internal auditory canal is narrowed, it is often unable to distinguish between hypoplasia and aplasia. A full audiometric test battery should always be performed, even if the MRI suggests CN aplasia, as there will sometimes be evidence of audition. Electrically evoked auditory brainstem response testing can be carried out transtympanically via the round window or using an intracochlear test electrode to help determine the status of the CN...
2018: Advances in Oto-rhino-laryngology
Hidemi Miyazaki, Per Caye-Thomasen
A new electrophysiological system for intraoperative, continuous, near-real time monitoring of cochlear nerve function through acoustic stimulation in the ear canal and recording of the evoked dorsal cochlear nucleus potentials (DNAPs) by a specially designed DNAP electrode placed directly on the brainstem is described. The system is denominated "(cerebellopontine angle) CPA Master" and is designed for hearing preservation surgery in the cerebello-pontine angle, through the retro-sigmoid or the retro-labyrinthine approach...
2018: Advances in Oto-rhino-laryngology
C Carillo, M Kiening, S Bergheimer, M Kalamarides
Neurofibromatosis type 2 (NF2) confronts patients and their relatives with the dual issue of a progressive disease and disability. Deafness creates a brutal rupture in the patients' course of life, and other disabilities often follow in addition, that further deteriorates their quality of life. Hearing rehabilitation, via a cochlear implant and auditory brainstem implant, attempts to reduce the feeling of isolation and suffering due to communication impairment. A NF2-specific quality of life questionnaire not only helps to evaluate the impact of the disease but it is also useful therapy proposals (treatment, auditory implants)...
May 10, 2018: Neuro-Chirurgie
Laurel H Carney
An important topic in contemporary auditory science is supra-threshold hearing. Difficulty hearing at conversational speech levels in background noise has long been recognized as a problem of sensorineural hearing loss, including that associated with aging (presbyacusis). Such difficulty in listeners with normal thresholds has received more attention recently, especially associated with descriptions of synaptopathy, the loss of auditory nerve (AN) fibers as a result of noise exposure or aging. Synaptopathy has been reported to cause a disproportionate loss of low- and medium-spontaneous rate (L/MSR) AN fibers...
May 9, 2018: Journal of the Association for Research in Otolaryngology: JARO
Laurie S Eisenberg, Dianne Hammes Ganguly, Amy S Martinez, Laurel M Fisher, Margaret E Winter, Jamie L Glater, Debra K Schrader, Janice Loggins, Eric P Wilkinson
The auditory brainstem implant (ABI) is an auditory sensory device that is surgically placed on the cochlear nucleus of the brainstem for individuals who are deaf but unable to benefit from a cochlear implant (CI) due to anatomical abnormalities of the cochlea and/or eighth nerve, specific disease processes, or temporal bone fractures. In the United States, the Food and Drug Administration has authorized a Phase I clinical trial to determine safety and feasibility of the ABI in up to 10 eligible young children who are deaf and either derived no benefit from the CI or were anatomically unable to receive a CI...
July 1, 2018: Journal of Deaf Studies and Deaf Education
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"