Biomedical subjects

Julian M Nedzelski

Publications and source records attributed to Julian M Nedzelski.

11 recordsLinked to original sources

PubMed2006

A novel method in predicting immediate postoperative facial nerve function post acoustic neuroma excision.

UNLABELLED: To determine whether the percentage calculated by dividing the amplitude of postexcision direct facial nerve stimulus responses (at pontomedullary junction) by the amplitude of distal ipsilateral transcutaneous (stylomastoid region) maximal stimulus responses and response amplitude progression by increasing stimulus intensities have predictive value for determining normal or near-normal (House-Brackmann Grade 1 or 2) immediate postoperative facial nerve function. STUDY DESIGN: Intraoperative recordings of three muscle groups: 1) frontalis, 2) orbicularis oculi, and 3) orbicularis oris. Postexcision direct facial nerve stimulation at the pontomedullary junction and transcutaneous maximal facial nerve stimulation at the ipsilateral stylomastoid region and their associated response amplitudes were recorded. SETTING: Tertiary referral center. PATIENTS AND METHODS: Patients who underwent acoustic neuroma surgery from January 2004 to March 2006 with intraoperative facial nerve monitoring and an intact facial nerve after tumor excision were included. Recordings were available for 38 patients. RESULTS: With a stimulus intensity of 0.3 mA at the root exit zone, there was an 81% positive predictive value in patients that exhibited a compound action potential of greater than 20% of maximum (sensitivity, 81%). This increased to 93% when the compound action potential was greater than 50% of maximum. When the amplitude increase was greater than 5 microV, there was a 77% positive predictive value (sensitivity, 87%). CONCLUSION: The percentage of the response amplitude of direct facial nerve stimulation at the pontomedullary junction when compared with the maximum response amplitude of ipsilateral transcutaneous stimulation at the stylomastoid foramen is a good predictor of normal to near-normal immediate postoperative facial nerve function. Progression of amplitude response also seems to be a good predictor of normal to near-normal immediate postoperative facial nerve function.

Adult↗

PubMed2005

Intratemporal facial nerve schwannoma: a management dilemma.

OBJECTIVE: To report the findings in patients with facial nerve schwannoma in whom surgery was elected at onset versus patients treated expectantly. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Twenty-four patients with a mean age of 44 years (range, 18-65 yr) were followed for an average of 6 years (range, 1-19 yr). INTERVENTION: Eleven patients underwent complete tumor excision and 13 patients were enrolled in ongoing monitoring only. MAIN OUTCOME MEASURES: Facial nerve function and hearing acuity were noted at the time of initial and last visits. Magnetic resonance imaging was used to determine tumor growth in those individuals treated expectantly and as a means of excluding tumor recurrence/persistence in those treated surgically. RESULTS: Of the 11 patients who underwent tumor removal, the facial nerve was spared in 7. Eight had varying degrees of facial nerve dysfunction initially. In this group (mean follow-up, 8 yr), six patients had unchanged nerve function, four had improved nerve function, and one had worsened. No long-term recurrence was noted. Of the 13 patients followed expectantly, three had facial weakness initially. During the follow-up interval (mean, 5 yr), facial function remained unchanged for eight and worsened in five. During this interval, 4 of the 13 patients demonstrated tumor growth and 3 have recently undergone tumor removal. CONCLUSION: Facial nerve schwannomas are extremely slow growing and frequently present without facial dysfunction. It is possible to surgically remove these tumors while sparing the nerve; as a result, postoperative function is correspondingly better. Finally, the decision on how to treat these patients should be individualized and based on initial facial function, growth rate, surgical experience, and informed patient consent.

Adolescent↗

PubMed2004

The status of the contralateral ear in established unilateral Menière's disease.

OBJECTIVES/HYPOTHESIS: To determine the incidence of measurable audiometric changes in the contralateral ear and clinical bilateral Menière's disease in individuals with longstanding established unilateral Menière's disease. STUDY DESIGN: Analysis of data in an ongoing prospective study. METHODS: One hundred and one patients who were treated with intratympanic gentamicin installation for disabling unilateral Menière's disease were followed up for a minimum of 2 years. The mean follow-up time between the initial diagnosis to the last audiogram conducted was 12 +/- 7 (range 2-45) years, and the mean follow-up between the first and last audiograms conducted in our clinic was 5 +/- 3 (range 2-15) years. The incidence of Menière's disease (clinical diagnosis) as compared with audiometric changes in the contralateral ear was analyzed. RESULTS: Compared with several published reports, the development of bilateral Menière's disease in our series within the described observation period was much lower (5%). The incidence of contralateral isolated hearing loss in the low frequencies was 16% (average threshold of .25 and .5 kHz of 25 dB or more). The time interval between the initial diagnosis and the onset of contralateral findings ranged from 0 to 26 years. CONCLUSION: In our experience, individuals with disabling longstanding unilateral disease are not likely to develop bilateral disease. However, a small but significant percentage of patients have audiometric changes in the low frequencies of the contralateral ear (.25, .5 kHz).

Adult↗

PubMed2004

Benefits of cochlear implantation in early-deafened adults: the Toronto experience.

OBJECTIVE: To present the results of a survey administered to a group of early-deafened cochlear implants adults and to report the level of perceived benefit. DESIGN: Prospective. SETTING: Large tertiary referral centre. METHOD: A 47-item questionnaire designed to evaluate cochlear implant use and benefit was sent to 42 early-deafened adult cochlear implant users. The questionnaire can be divided into seven subcategories: time of use, associated symptoms, communication, employment status and function, socialization, perceived benefit, and the impact on quality of life. Responses from 30 patients were received. RESULTS: The majority of our patients use their cochlear implant all of their waking hours. The majority of patients continue to depend on lip-reading and hearing as their main mode of communication, although they reported improved lip-reading skills with their cochlear implant. Twenty-three patients (76.7%) were employed. Eleven patients had a change in employment subsequent to cochlear implantation, nine (81.8%) of whom attributed this to their cochlear implant. Our patients als reported greater independence, a greater sense of safety in their environment, and an improved social life. Twenty-nine patients (96.7%) said that they were satisfied with their implant, 28 (93.3%) said that they would go through the same process again, and 27 (90%) said that they would recommend it to a friend in a similar situation. Twenty-nine patients (96.7%) stated that the cochlear implant has had a positive effect on their quality of life. Family and peer support, prior auditory-verbal therapy, and a positive attitude were the most commonly cited factors in successful cochlear implant use. CONCLUSIONS: Early-deafened adult cochlear implant users perceive significant benefit from cochlear implantation. Importantly, family and peer support, prior auditory-verbal therapy, and a positive attitude are considered important factors in maximizing this benefit.

Adult↗

PubMed2003

Speech coding strategies and revised cochlear implant candidacy: an analysis of post-implant performance.

OBJECTIVE: Technological advances in cochlear implant systems on which a sequence of speech coding strategies have been implemented seem to have resulted in improved speech perception. However, changing selection criteria for implantation have coincided with evolving technology and may confound post-implantation speech perception performance. This study compares speech coding strategy with speech perception performance in severe and profound postlingually deafened adults using one of three successive generations of Nucleus Cochlear Implant speech processors (i.e., Mini Speech Processor, Spectra 22, and SPrint) implementing three speech coding strategies (i.e., MPEAK, SPEAK, and Advanced Combination Encoders; Cochlear Corporation, Englewood, CO, U.S.A.). STUDY DESIGN: Four cohorts of patients were retrospectively reviewed. SETTING: Multicenter, tertiary referral cochlear implant programs in Ontario, Canada. METHODS: Four cohorts of patients (n = 139) were identified based on preimplant audiological measures, duration of deafness, device type, and speech coding strategy. Word and sentence recognition scores at 12 months after implantation were compared using MPEAK with SPEAK22 implemented on the Nucleus 22 speech processors (Mini Speech Processor and Spectra22, respectively) and SPEAK24 as well as Advanced Combination Encoders implemented on the Nucleus 24 SPrint processor. RESULTS: Open-set speech recognition batteries revealed significant improvements in word and sentence scores as advancing technology implemented new speech coding strategies. Subgroup analysis of profoundly deafened patients supported this. Analysis of covariance confirmed that the measured differences could not be accounted for by changing selection criteria for implantation. CONCLUSION: Improvements in performance can be attributed to evolving speech coding strategies and speech processors rather than to differences in preimplant candidacy.

Audiometry, Pure-Tone↗

PubMed2003

Acoustic neuroma surgery: the results of long-term hearing preservation.

OBJECTIVE: To report the long-term outcome hearing results following acoustic neuroma surgery. To determine whether changes, if any, in the thresholds of the operated ear are mirrored in the contralateral unoperated side. In addition, to identify predictive factors, if any, that may predispose individuals to hearing loss in the operated ear in the late post-operative period. STUDY DESIGN: Retrospective patient chart review. SETTING: University Tertiary Referral Centre. PATIENTS: From 1978 to 1997, one hundred and twenty six patients with small acoustic neuromas (less than 2 cm as measured within in the cerebellopontine angle) underwent excision via the suboccipital (retrosigmoid) approach with the patient in the prone position. Hearing preservation was successful in 43 patients (34.1%). The audiometric data of thirty patients with a minimum follow-up interval of 36 months was analyzed. The mean follow-up period was 113.4 months (range 36-264, SD=57.8) and the mean age at surgery was 47.3 years (range 32 to 64, SD = 7.3). OUTCOME MEASURES: Speech Reception Thresholds (SRT), Speech Discrimination Scores (SDS) and Pure-tone Audiometry (PTA, 0.5, 1 & 2 kHz) were noted on the operated and unoperated ears. The AAO Classification according to the Committee on Hearing and Equilibrium guidelines for the evaluation of hearing preservation in acoustic neuroma was used to assess hearing serviceability. RESULTS: Subsequent to including corresponding changes in the unoperated ear, the means of the SRT and PTA in the operated ear between the early and late post-operative periods were statistically significantly different (p=0.0012 & 0.034 respectively). Twelve (40%) patients demonstrated significant deterioration in hearing thresholds over time. Pre-operatively, 96.7% of patients had serviceable hearing (Class A & B). This falls to 76.6% in the early post-operative period and to 56.7% in the late post-operative period. CONCLUSION: Our study highlights the finding that over time a significant number of individuals realize a greater ongoing hearing loss in the post tumour excision ear than the contralateral ear.

Adult↗

PubMed2003

Evaluation of the high-resolution speech coding strategy for the Clarion CII cochlear implant system.

Four postlinguistically deafened adults were implanted with the Clarion CII cochlear implant with the HiFocus II electrode in an evaluation of performance with a new speech coding strategy (high resolution) compared with current speech coding strategies (multiple pulsatile sampler, continuous interleaved sampling, and simultaneous analog stimulation). These strategies were implemented in the Platinum speech processor from Advanced Bionics Corporation (Sylmar, CA). Postoperatively, subjects were fitted with the traditional coding strategies and over the first month were allowed to determine their strategy of choice. This strategy was used to evaluate open-set speech recognition performance at 1 month and 3 months postfitting. At 3 months postfitting, subjects were reprogrammed with the high-resolution strategy. They returned for speech recognition testing at 1 month and 3 months postfitting with this strategy. Performance was significantly better with the high-resolution strategy for all four subjects, particularly when listening to speech in background noise. This finding was in agreement with their strong preference for the high-resolution strategy, and all four patients continue to use the high-resolution strategy.

Adult↗

PubMed2003

Early-deafened adult cochlear implant users: assessment of outcomes.

OBJECTIVE: To determine whether adults deafened in the prelingual and perilingual stages of speech development realize objective and subjective benefits from cochlear implantation. METHOD: Retrospective analysis of the open-set speech recognition and subjective data such as use and quality of life. RESULTS: Between 1989 and 1999, 198 deafened adults underwent cochlear implantation at Sunnybrook and Women's College Health Sciences Centre. Of these, 44 patients were deafened pre- or perilingually. These subjects were implanted with a Nucleus 22, Nucleus 24 (Cochlear Corporation, Denver, Colorado, USA), or Clarion (Advanced Bionics Corporation, Sylmar, California, USA) device. The average age at implantation was 34 years (range 14-62 years). Significant differences in speech perception, as measured by a composite score of open-set word, phoneme, and sentence recognition, were found among groups who differed by type of education and communication training received in childhood. CONCLUSION: By and large, open-set speech recognition in prelingually and perilingually deafened adults is inferior to that achieved in postlingually deafened adults and varies according to the type of communication training they received. However, cochlear implants have significantly improved the overall communication skills and quality of life in all subgroups of patients.

Adolescent↗

PubMed2002

A matched-pair comparison of two cochlear implant systems.

OBJECTIVES: To compare the overall performance of two implant systems based on audiologic outcome, tinnitus handicap, and quality of life using objective and subjective measures. DESIGN: Retrospective cohort study. SETTING: Sunnybrook & Women's College Health Science Centre. METHODS: Two matched groups, with 24 Nucleus 22 SPEAK (Advanced Bionics, Symlar, CA) and 24 Clarion CIS (Cochlear Corporation, Sydney, Australia), were selected. Patients were administered survey forms to evaluate subjective tinnitus and dizziness symptomatology, as well as a 27-item tinnitus handicap questionnaire. Both groups were administered survey forms to assess the frequency of implant use, the subjective benefit derived, and the perceived impact on quality of life. The 36-Item Short-Form (SF-36) Health Survey was administered as a measure of quality of life at 6 months postimplant. Standardized open-set speech recognition parameters were evaluated at 24 months postimplant. Vestibular function was determined by pre-and postimplant electronystagmography with caloric testing. The first author was blinded to implant type during data collection and analysis RESULTS: Cochlear implantation yielded a significant 22% reduction in overall tinnitus handicap (p < .05). There was a 27% reduction in vestibular function that failed to show statistical significance (p = .78). There was no significant reduction in vestibular function postimplant in either group. The average open-set speech perception responses at 24 months postimplant were monosyllabic word recognition 45%, phoneme recognition 65%, and sentence recognition 86.5%. There was no significant difference with respect to implant type. Overall, 76% of implantees reported satisfaction with the amount of subjective benefit they received from their implants. Furthermore, 96% reported an overall positive impact on quality of life. CONCLUSION: Overall, there was no significant difference between the two multichannel devices studied using the present software and hardware configurations.

Adult↗

PubMed2002

Hearing loss following intratympanic instillation of gentamicin for the treatment of unilateral Meniere's disease.

OBJECTIVE: To determine the incidence, extent, and time course of hearing loss following instillation of intratympanic gentamicin using a predetermined fixed protocol for incapacitating unilateral Meniere's disease and to determine whether such loss is associated with any identifiable risk factors. STUDY DESIGN: A retrospective analysis of all patients treated with intratympanic gentamicin between 1988 and 1998 using American Academy of Otolaryngology-Head and Neck Surgery reporting guidelines (1985 and 1995). A predetermined regimen using a fixed dose (gentamicin 26.7 mg/mL administered three times daily for 4 consecutive days) was used. METHODS: The records of patients treated with this particular protocol were reviewed. The relationship between pretreatment hearing acuity, pretreatment bithermal caloric response, duration of symptoms, and previous treatment to post-treatment hearing were analyzed with respect to hearing. RESULTS: Complete vestibular and audiologic data over a minimum 2-year follow-up were available for 85 individuals. Sixty-three patients (74.1%) had unchanged or improved hearing, and 22 patients (25.9%) realized hearing loss. In 80% of the latter, it occurred during the first month post-treatment. When hearing acuity at the 1-month post-treatment interval remained unchanged (91.1%), it was likely to remain so over the next 23 months. A significantly higher incidence of profound hearing loss was noted in patients who developed hearing loss in the first month, as compared with those who developed hearing loss at a later period (p = .0207, relative risk = 1.5). Re-treatment was not associated with hearing loss. The only identifiable risk factor for developing hearing loss was pretreatment hearing acuity stages 3 and 4 (pure-tone average > 40 dB) (p = .022, relative risk = 1.5). CONCLUSION: Hearing loss is a recognized complication of treatment with intratympanic gentamicin, occurring in approximately 26% of individuals. In those individuals in whom hearing acuity has remained unchanged after the first month interval, significant worsening of hearing is unlikely, and patients can be reassured accordingly.

Adult↗

PubMed2002

Estimating the audiogram using multiple auditory steady-state responses.

Multiple auditory steady-state responses were evoked by eight tonal stimuli (four per ear), with each stimulus simultaneously modulated in both amplitude and frequency. The modulation frequencies varied from 80 to 95 Hz and the carrier frequencies were 500, 1000, 2000, and 4000 Hz. For air conduction, the differences between physiologic thresholds for these mixed-modulation (MM) stimuli and behavioral thresholds for pure tones in 31 adult subjects with a sensorineural hearing impairment and 14 adult subjects with normal hearing were 14+/-11, 5+/-9, 5+/-9, and 9+/-10 dB (correlation coefficients .85, .94, .95, and .95) for the 500-, 1000-, 2000-, and 4000-Hz carrier frequencies, respectively. Similar results were obtained in subjects with simulated conductive hearing losses. Responses to stimuli presented through a forehead bone conductor showed physiologic-behavioral threshold differences of 22+/-8, 14+/-5, 5+/-8, and 5+/-10 dB for the 500-, 1000-, 2000-, and 4000-Hz carrier frequencies, respectively. These responses were attenuated by white noise presented concurrently through the bone conductor.

Adult↗