Waterjet dissection of the vestibulocochlear nerve: an experimental study

2009 ◽  
Vol 110 (4) ◽  
pp. 656-661 ◽  
Author(s):  
Christoph Tschan ◽  
Michael Robert Gaab ◽  
Joachim Kurt Krauss ◽  
Joachim Oertel
Keyword(s):  
Time Course ◽  
Cranial Nerves ◽  
Auditory Brainstem ◽  
Contralateral Side ◽  
Auditory Brainstem Responses ◽  
Vestibulocochlear Nerve ◽  
Nerve Preservation ◽  
Suboccipital Craniectomy ◽  
And Function ◽  
Waterjet Dissection

Object Waterjet dissection has been shown to protect intracerebral vessels, but no experience exists in applying this modality to the cranial nerves. To evaluate its potential, the authors examined waterjet dissection of the vestibulocochlear nerve in rats. Methods Lateral suboccipital craniectomy and microsurgical preparation of the vestibulocochlear nerve were performed in 42 rats. Water pressures of 2–10 bar were applied, and the effect was microscopically evaluated. Auditory brainstem responses (ABRs) were used to define nerve function compared with preoperative values and the healthy contralateral side. The final anatomical preparation documented the morphological and histological effects of waterjet pressure on the nerve. Results In using up to 6 bar, the cochlear nerve was preserved in all cases. Eight bar moderately damaged the nerve surface. A 10-bar jet markedly damaged or even completely dissected the nerve. Time course analysis of the ABR demonstrated complete functional nerve preservation up to 6 bar after 6 weeks in all rats. Waterjet dissection with 8 bar was associated with a 60% recovery of ABR. In the 10-bar group, no recovery was seen. Conclusions Microsurgical dissection of cranial nerves is possible using waterjet dissection while preserving both morphology and function. The aforementioned jet pressures are known to be effective in neurosurgical treatment of tumors. Thus, waterjet dissection may be useful in skull base surgery including dissection of cranial nerves from tumors. Further studies on this subject are encouraged.

scholarly journals Posterior Approach to Meckel's Cave: Retrosigmoid Craniectomy with Endoscopic Assistance

2019 ◽  
Vol 80 (S 03) ◽  
pp. S331-S332
Author(s):  
Paramita Das ◽  
Hamid Borghei-Razavi ◽  
Nina Z. Moore ◽  
Pablo F. Recinos
Keyword(s):  
Tumor Resection ◽  
Cranial Nerves ◽  
Auditory Brainstem ◽  
Technical Note ◽  
Auditory Brainstem Responses ◽  
Case Review ◽  
Meckel’S Cave ◽  
Meckel's Cave ◽  
Endoscopic Assistance ◽  
Loss Of Hearing

Background Meckel's cave involvement in tumors pose a challenge due to their surrounding neurovascular structure and deep location. Case Review A 24-year-old male presented with progressive headaches and right sided trigeminal neuralgia with a large epidermoid. The tumor extended from the ambient cistern to the cerebellomedullary cistern and involved Meckel's cave (Fig. 1). Technical Note/Video Description A retrosigmoid craniectomy was performed. Cranial nerves 3, 4, 6, 7, and 10, and auditory brainstem responses were monitored. Once the craniectomy was completed the dura was opened and cerebrospinal fluid (CSF) was released from the cisterna magna to allow for the tumor resection to be done without the use of any retractors (Fig. 2). Care was taken to ensure that cranial nerves in the posterior fossa were detethered to prevent any traction injury. Using ring curettes the pearly white epidermoid tumor was able to be debulked. After all the possible tumor was resected with the microscope, the 30-degree endoscope was used to identify the porus trigeminus. Malleable ring curettes and a malleable suction were used to remove the soft tumor from this location. The patient transiently had loss of hearing but this returned within 2 weeks after surgery. Conclusions The retrosigmoid approach is familiar to all neurosurgeons and with the adjunct of an angled endoscope, the posterior Meckel's cave can be easily reached. This is particularly useful for tumors with soft consistency. The assistance of the endoscope allows Meckel's cave visualization without additional drilling while still allowing safe resection of tumor from around the trigeminal nerve.The link to the video can be found at: https://youtu.be/01aqOyUmSW0.

scholarly journals Consecutive Treatment with Brain-Derived Neurotrophic Factor and Electrical Stimulation Has a Protective Effect on Primary Auditory Neurons

2020 ◽  
Vol 10 (8) ◽  
pp. 559 ◽  
Author(s):  
Verena Scheper ◽  
Ira Seidel-Effenberg ◽  
Thomas Lenarz ◽  
Timo Stöver ◽  
Gerrit Paasche
Keyword(s):  
Electrical Stimulation ◽  
Neurotrophic Factor ◽  
Combined Treatment ◽  
Spiral Ganglion ◽  
Brain Derived Neurotrophic Factor ◽  
Auditory Brainstem ◽  
Contralateral Side ◽  
Auditory Brainstem Responses ◽  
Drug Delivery Device ◽  
Ganglion Neurons

Degeneration of neurons, such as the inner ear spiral ganglion neurons (SGN), may be decelerated or even stopped by neurotrophic factor treatment, such as brain-derived neurotrophic factor (BDNF), as well as electrical stimulation (ES). In a clinical setting, drug treatment of the SGN could start directly during implantation of a cochlear implant, whereas electrical stimulation begins days to weeks later. The present study was conducted to determine the effects of consecutive BDNF and ES treatments on SGN density and electrical responsiveness. An electrode drug delivery device was implanted in guinea pigs 3 weeks after deafening and five experimental groups were established: two groups received intracochlear infusion of artificial perilymph (AP) or BDNF; two groups were treated with AP respectively BDNF in addition to ES (AP + ES, BDNF + ES); and one group received BDNF from the day of implantation until day 34 followed by ES (BDNF ⇨ ES). Electrically evoked auditory brainstem responses were recorded. After one month of treatment, the tissue was harvested and the SGN density was assessed. The results show that consecutive treatment with BDNF and ES was as successful as the simultaneous combined treatment in terms of enhanced SGN density compared to the untreated contralateral side but not in regard to the numbers of protected cells.

Safety and Efficacy of Chitosan-Dextran Hydrogel in the Middle Ear in an Animal Model

2016 ◽  
Vol 21 (4) ◽  
pp. 254-260
Author(s):  
Selin Ünsaler ◽  
Bora Başaran ◽  
Şule Öztürk Sarı ◽  
Eyüp Kara ◽  
Kemal Değer ◽  
...  
Keyword(s):  
Middle Ear ◽  
Auditory Brainstem ◽  
Contralateral Side ◽  
Auditory Brainstem Responses ◽  
Control Group ◽  
Ear Surgery ◽  
Significant Difference ◽  
Intratympanic Injection ◽  
Temporal Bones ◽  
Histopathologic Findings

Objectives: To investigate the efficacy of chitosan-dextran hydrogel (CDH) in preventing postoperative adhesions between the tympanic membrane (TM) and intratympanic structures, and to evaluate its ototoxicity in an animal study. Methods: In the first step, ototoxicity was evaluated with 7 male albino guinea pigs (GPs) via auditory brainstem responses (ABR) before and 4 weeks after unilateral intratympanic injection of CDH and saline solution contralaterally. In the second step, 12 GPs underwent bilateral ear surgery. The middle ear (ME) mucosa was abraded, and the cavity was filled with CDH on one side and packed with Gelfoam on the contralateral side. A control group of 6 GPs underwent the same procedure except that no material was applied in the ME. The animals were euthanized at the end of the 7th week, and otomicroscopic findings were noted and the temporal bones harvested for the histologic examination. The findings were scored and compared. Results: There was no statistically significant difference between the pre- and postoperative ABR thresholds. In the otomicroscopic findings, the most prominent difference between the two groups was the presence of retraction of the TM in the Gelfoam group. The histopathologic findings revealed a higher degree of inflammation in the Gelfoam group compared with the CDH group. Conclusion: This study demonstrated that CDH has no ototoxic effects in GPs. Its use as an ME packing material revealed significantly less TM retraction and inflammatory reaction compared with Gelfoam.

scholarly journals Synchronized Progression of Prestin Expression and Auditory Brainstem Response during Postnatal Development in Rats

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Jianfeng Hang ◽  
Wenlu Pan ◽  
Aoshuang Chang ◽  
Shun Li ◽  
Cuixian Li ◽  
...  
Keyword(s):  
Auditory Brainstem Response ◽  
Time Course ◽  
Onset Time ◽  
Auditory Brainstem ◽  
Outer Hair Cells ◽  
Cochlear Amplification ◽  
Brainstem Response ◽  
Temporal And Spatial ◽  
And Function ◽  
Postnatal Rats

Prestin is the motor protein expressed in the cochlear outer hair cells (OHCs) of mammalian inner ear. The electromotility of OHCs driven by prestin is responsible for the cochlear amplification which is required for normal hearing in adult animals. Postnatal expression of prestin and activity of OHCs may contribute to the maturation of hearing in rodents. However, the temporal and spatial expression of prestin in cochlea during the development is not well characterized. In the present study, we examined the expression and function of prestin from the OHCs in apical, middle, and basal turns of the cochleae of postnatal rats. Prestin first appeared at postnatal day 6 (P6) for basal turn, P7 in middle turn, and P9 for apical turn of cochlea. The expression level increased progressively over the next few days and by P14 reached the mature level for all three segments. By comparison with the time course of the development of auditory brainstem response for different frequencies, our data reveal that prestin expression synchronized with the hearing development. The present study suggests that the onset time of hearing may require the expression of prestin and is determined by the mature function of OHCs.

scholarly journals Spheno-Orbital Meningioma with Cavernous Sinus Extension

2021 ◽  
Author(s):  
Rodolfo Figueiredo de Carvalho ◽  
Artur Nóbrega Lima de Morais ◽  
Leonardo Desessards Olijnyk ◽  
Adriana Azeredo Coutinho Abrao ◽  
Claudia Zanatta ◽  
...  
Keyword(s):  
Cavernous Sinus ◽  
Cranial Nerves ◽  
Lateral Wall ◽  
Nerve Preservation ◽  
Secondary Invasion ◽  
Foramen Rotundum ◽  
And Function ◽  
Orbital Meningioma ◽  
Cranial Nerve Preservation ◽  
First Time

AbstractWe present a case of a 37-year-old female, with progressive left eye proptosis and an extensive ipsilateral en plaque spheno-orbital meningioma, with diffuse involvement of the lateral wall of the cavernous sinus and the orbit.A cranio-orbital zygomatic approach was performed to reach all extension of the lesion. We made an extradural clinoidectomy and an extensive bone removal of the orbit, exposition of the superior and lateral walls of the cavernous sinus, unroofing of the optic canal, superior orbital fissure, foramen rotundum, and foramen ovale. We performed the peeling of the lateral wall of cavernous sinus with total removal and preservation of the cranial nerves anatomy and function.In this video, we illustrate the importance of the first time aggressive removal of such tumors. We also demonstrate the concept that secondary invasion of the cavernous sinus are suitable for removal with cranial nerve preservation.The link to the video can be found at https://youtu.be/GJmkqVa6jSs.

scholarly journals Continued Maturation of the Click-Evoked Auditory Brainstem Response in Preschoolers

2015 ◽  
Vol 26 (01) ◽  
pp. 030-035 ◽  
Author(s):  
Emily Spitzer ◽  
Travis White-Schwoch ◽  
Kali Woodruff Carr ◽  
Erika Skoe ◽  
Nina Kraus
Keyword(s):  
Time Course ◽  
Developmental Time ◽  
Auditory Brainstem ◽  
Developmental Trajectory ◽  
Auditory Brainstem Responses ◽  
Cross Sectional ◽  
Data Collection And Analysis ◽  
Brainstem Response ◽  
Cross Sectional Design ◽  
Age Range

Background: Click-evoked auditory brainstem responses (ABRs) are a valuable tool for probing auditory system function and development. Although it has long been thought that the human auditory brainstem is fully mature by age 2 yr, recent evidence indicates a prolonged developmental trajectory. Purpose: The purpose of this study was to determine the time course of ABR maturation in a preschool population and fill a gap in the knowledge of development. Research Design: Using a cross-sectional design, we investigated the effect of age on absolute latencies, interwave latencies, and amplitudes (waves I, III, V) of the click-evoked ABR. Study Sample: A total of 71 preschoolers (ages 3.12–4.99 yr) participated in the study. All had normal peripheral auditory function and IQ. Data Collection and Analysis: ABRs to a rarefaction click stimulus presented at 31/sec and 80 dB SPL (73 dB nHL) were recorded monaurally using clinically-standard recording and filtering procedures while the participant sat watching a movie. Absolute latencies, interwave latencies, and amplitudes were then correlated to age. Results: Developmental changes were restricted to absolute latencies. Wave V latency decreased significantly with age, whereas wave I and III latencies remained stable, even in this restricted age range. Conclusions: The ABR does not remain static after age 2 yr, as seen by a systematic decrease in wave V latency between ages 3 and 5 yr. This finding suggests that the human brainstem has a continued developmental time course during the preschool years. Latency changes in the age 3–5 yr range should be considered when using ABRs as a metric of hearing health.

Auditory Brainstem Responses from Children Three Months to Three Years of Age

1989 ◽  
Vol 32 (2) ◽  
pp. 281-288 ◽  
Author(s):  
Michael P. Gorga ◽  
Jan R. Kaminski ◽  
Kathryn L. Beauchaine ◽  
Walt Jesteadt ◽  
Stephen T. Neely
Keyword(s):  
Time Course ◽  
Age Groups ◽  
Developmental Time ◽  
Auditory Brainstem ◽  
Auditory Brainstem Responses ◽  
Age Appropriate ◽  
Neural Factors ◽  
Interaural Differences ◽  
Interpeak Latency ◽  
Age Range

Auditory brainstem responses (ABR) were measured in 535 children from 3 months to 3 years of age. The latencies reported in this paper should be unaffected by peripheral hearing loss because each child had bilateral wave V responses at 20 dB HL n . Wave V latencies decreased as age increased, at least to 18 months of age, while little or no change was noted in wave I latencies over the same age range. Thus, interpeak latency differences followed the same developmental time course as wave V. The shapes of wave V latency-level functions were comparable across age groups. These results suggest that changes in wave V latency with age are due to central (neural) factors and that age-appropriate norms should be used in evaluations of ABR latencies in children. Interaural differences in absolute wave V latencies and interpeak latency differences were similar to those observed in infants and adults, indicating that response symmetry is independent of age. Statistical analyses suggested that the distributions of absolute and relative latency measurements are normal, making it possible to describe norms in terms of means and standard deviations. A simple model is described that accounts accurately for changes in mean wave V latencies as function of age from preterm through the first three years of life.

The Effect of Kalman-Weighted Averaging and Artifact Rejection on Residual Noise During Auditory Brainstem Response Testing

2019 ◽  
Vol 28 (1) ◽  
pp. 114-124
Author(s):  
Linda W. Norrix ◽  
Julie Thein ◽  
David Velenovsky
Keyword(s):  
Repeated Measures ◽  
Auditory Brainstem ◽  
Weighted Averaging ◽  
Auditory Brainstem Responses ◽  
Residual Noise ◽  
Electrophysiological Recordings ◽  
Artifact Rejection ◽  
Brainstem Response ◽  
Active Motor ◽  
Averaging Time

Purpose Low residual noise (RN) levels are critically important when obtaining electrophysiological recordings of threshold auditory brainstem responses. In this study, we examine the effectiveness and efficiency of Kalman-weighted averaging (KWA) implemented on the Vivosonic Integrity System and artifact rejection (AR) implemented on the Intelligent Hearing Systems SmartEP system for obtaining low RN levels. Method Sixteen adults participated. Electrophysiological measures were obtained using simultaneous recordings by the Vivosonic and Intelligent Hearing Systems for subjects in 2 relaxed conditions and 4 active motor conditions. Three averaging times were used for the relaxed states (1, 1.5, and 3 min) and for the active states (1.5, 3, and 6 min). Repeated-measures analyses of variance were used to examine RN levels as a function of noise reduction strategy (i.e., KWA, AR) and averaging time. Results Lower RN levels were obtained using KWA than AR in both the relaxed and active motor states. Thus, KWA was more effective than was AR under the conditions examined in this study. Using KWA, approximately 3 min of averaging was needed in the relaxed condition to obtain an average RN level of 0.025 μV. In contrast, in the active motor conditions, approximately 6 min of averaging was required using KWA. Mean RN levels of 0.025 μV were not attained using AR. Conclusions When patients are not physiologically quiet, low RN levels are more likely to be obtained and more efficiently obtained using KWA than AR. However, even when using KWA, in active motor states, 6 min of averaging or more may be required to obtain threshold responses. Averaging time needed and whether a low RN level can be attained will depend on the level of motor activity exhibited by the patient.

Effects of Aging on the Subcortical Encoding of Stop Consonants

2020 ◽  
Vol 29 (3) ◽  
pp. 391-403
Author(s):  
Dania Rishiq ◽  
Ashley Harkrider ◽  
Cary Springer ◽  
Mark Hedrick
Keyword(s):  
Older Adults ◽  
Repeated Measures ◽  
Mixed Model ◽  
Auditory Brainstem ◽  
Auditory Brainstem Responses ◽  
Aging Effects ◽  
Formant Frequency ◽  
Place Of Articulation ◽  
Second Formant ◽  
Effects Of Aging

Purpose The main purpose of this study was to evaluate aging effects on the predominantly subcortical (brainstem) encoding of the second-formant frequency transition, an essential acoustic cue for perceiving place of articulation. Method Synthetic consonant–vowel syllables varying in second-formant onset frequency (i.e., /ba/, /da/, and /ga/ stimuli) were used to elicit speech-evoked auditory brainstem responses (speech-ABRs) in 16 young adults ( M age = 21 years) and 11 older adults ( M age = 59 years). Repeated-measures mixed-model analyses of variance were performed on the latencies and amplitudes of the speech-ABR peaks. Fixed factors were phoneme (repeated measures on three levels: /b/ vs. /d/ vs. /g/) and age (two levels: young vs. older). Results Speech-ABR differences were observed between the two groups (young vs. older adults). Specifically, older listeners showed generalized amplitude reductions for onset and major peaks. Significant Phoneme × Group interactions were not observed. Conclusions Results showed aging effects in speech-ABR amplitudes that may reflect diminished subcortical encoding of consonants in older listeners. These aging effects were not phoneme dependent as observed using the statistical methods of this study.

Comparisons of Auditory Brainstem Responses Between a Laboratory and Simulated Home Environment

2020 ◽  
Vol 63 (11) ◽  
pp. 3877-3892
Author(s):  
Ashley Parker ◽  
Candace Slack ◽  
Erika Skoe
Keyword(s):  
Home Environment ◽  
Signal To Noise Ratio ◽  
Auditory Brainstem ◽  
Auditory Brainstem Responses ◽  
Single Family ◽  
Adult Participants ◽  
Simulated Home Environment ◽  
Brainstem Response ◽  
Research Populations ◽  
Response Consistency

Purpose Miniaturization of digital technologies has created new opportunities for remote health care and neuroscientific fieldwork. The current study assesses comparisons between in-home auditory brainstem response (ABR) recordings and recordings obtained in a traditional lab setting. Method Click-evoked and speech-evoked ABRs were recorded in 12 normal-hearing, young adult participants over three test sessions in (a) a shielded sound booth within a research lab, (b) a simulated home environment, and (c) the research lab once more. The same single-family house was used for all home testing. Results Analyses of ABR latencies, a common clinical metric, showed high repeatability between the home and lab environments across both the click-evoked and speech-evoked ABRs. Like ABR latencies, response consistency and signal-to-noise ratio (SNR) were robust both in the lab and in the home and did not show significant differences between locations, although variability between the home and lab was higher than latencies, with two participants influencing this lower repeatability between locations. Response consistency and SNR also patterned together, with a trend for higher SNRs to pair with more consistent responses in both the home and lab environments. Conclusions Our findings demonstrate the feasibility of obtaining high-quality ABR recordings within a simulated home environment that closely approximate those recorded in a more traditional recording environment. This line of work may open doors to greater accessibility to underserved clinical and research populations.

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