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John K Niparko

Publications and source records attributed to John K Niparko.

At least 19 recordsLinked to original sources
PubMed2006

Measuring health-related quality of life after pediatric cochlear implantation: a systematic review.

OBJECTIVE: The measurement of health-related quality of life (HRQL) in children presents conceptual and methodological challenges owing to the multidimensionality of the required information and limitations in patient self-report. HRQL results provide a broad measure of treatment impact from the patient and family perspective and are crucial to guiding clinical and policy decisions. The objective of this study was to evaluate how HRQL in children with cochlear implants has been measured in published studies in order to draw conclusions that could inform future investigations of this area of clinical research. METHODS: We searched PubMed, EMBASE, CINAHL, PsychoInfo, and Web of Science databases using a defined search string and hand-searched reference lists of relevant articles and personal files. Retrieved citations were reviewed in two stages, a title and abstract screen followed by review of the full-length article. Inclusion criteria for studies were: (1) original peer-reviewed research article; (2) enrolled subjects <18 years old with cochlear implants; (3) use of a HRQL instrument that incorporated components of physical, mental, and social health; and (4) in English. Data from full-length articles were extracted by a single-investigator. RESULTS: We retrieved 671 citations with our search strategy, and 10 citations were found to be eligible for inclusion. All studies used a cross-sectional design, and three types of HRQL instruments were used: generic questionnaires, ad hoc instruments designed specifically for the purposes of the study, and the parents views and experiences with pediatric CI questionnaire. Heterogeneity in study design and instruments prevented a quantitative, meta-analysis of the data. CONCLUSIONS: Studies that used well-validated, generic HRQL instruments supported conclusions that were less subject to potential bias from the perspective of the clinician investigator. Most studies did not use well-defined cohorts with respect to age at implantation and duration of implant use, and conclusions in these studies were also subject to potential bias. No well-validated, deafness-specific HRQL instruments are currently available. Future research should be done with existing, generic HRQL instruments and with strict study inclusion criteria. Suggested generic HRQL instruments are discussed.

Adolescent↗
PubMed2006

Speech recognition at 1-year follow-up in the childhood development after cochlear implantation study: Methods and preliminary findings.

The Childhood Development after Cochlear Implantation (CDaCI) study is a longitudinal multicenter investigation designed to identify factors influencing spoken language in young deaf children with cochlear implants. Normal-hearing peers serve as controls. As part of a comprehensive evaluation battery, a speech recognition hierarchy was designed to assess how well these children recognize speech stimuli across developmental stages. Data were analyzed for the earliest measures in 42 pairs of children reaching 1 year of follow-up. A number of children in the cochlear implant group who met criteria for testing approached levels of performance similar to the normal-hearing controls, and some could identify sentences in competition. These results demonstrate the responsiveness of the speech recognition hierarchy in tracking emergent skills from a sample of the CDaCI cohort.

Case-Control Studies↗
PubMed2006

Amplification in the rehabilitation of unilateral deafness: speech in noise and directional hearing effects with bone-anchored hearing and contralateral routing of signal amplification.

OBJECTIVE: Vibromechanical stimulation with a semi-implantable bone conductor (Entific BAHA device) overcomes some of the head-shadow effects in unilateral deafness. What specific rehabilitative benefits are observed when the functional ear exhibits normal hearing versus moderate sensorineural hearing loss (SNHL)? DESIGN: The authors conducted a prospective trial of subjects with unilateral deafness in a tertiary care center. PATIENTS: This study comprised adults with unilateral deafness (pure-tone average [PTA] > 90 dB; Sp.D. < 20%) and either normal monaural hearing (n = 18) or moderate SNHL (PTA = 25-50 dB: Sp.D. > 75%) in the contralateral functional ear (n = 5). INTERVENTIONS: Subjects were fit with contralateral routing of signal (CROS) devices for 1 month and tested before (mastoid) implantation, fitting, and testing with a bone-anchored hearing aid (BAHA). OUTCOME MEASURES: Outcome measures were: 1) subjective benefit; 2) source localization tests (Source Azimuth Identification in Noise Test [SAINT]); 3) speech discrimination in quiet and in noise assessed with Hearing In Noise Test (HINT) protocols. RESULTS: There was consistent satisfaction with BAHA amplification and poor acceptance of CROS amplification. General directional hearing decreased with CROS use and was unchanged by BAHA and directional microphone aids. Relative to baseline and CROS, BAHA produced significantly better speech recognition in noise. Twenty-two of 23 subjects followed up in this study continue to use their BAHA device over an average follow-up period of 30.24 months (range, 51-12 months). CONCLUSION: BAHA amplification on the side of a deaf ear yields greater benefit in subjects with monaural hearing than does CROS amplification. Advantages likely related to averting the interference of speech signals delivered to the better ear, as occurs with conventional CROS amplification, while alleviating the negative head-shadow effects of unilateral deafness. The advantages of head-shadow reduction in enhancing speech recognition with noise in the hearing ear outweigh disadvantages inherent in head-shadow reduction that can occur by introducing noise from the deaf side. The level of hearing impairment correlates with incremental benefit provided by the BAHA. Patients with a moderate SNHL in the functioning ear perceived greater increments in benefit, especially in background noise, and demonstrated greater improvements in speech understanding with BAHA amplification.

Adult↗
PubMed2006

Microsatellite analysis of recurrent vestibular schwannoma (acoustic neuroma) following stereotactic radiosurgery.

HYPOTHESIS: Genetic and immunohistochemical studies may provide insight into the mechanisms of vestibular schwannoma (VS) recurrence following radiation therapy. BACKGROUND: Stereotactic radiation therapy is an increasingly common alternative to microsurgical resection for the primary management of sporadic VS. The molecular mechanisms associated with recurrent vestibular schwannoma (VS) following radiation therapy are not known. METHODS: Primary or irradiated VS tumors were fresh-frozen at the time of surgical resection and microdissected to undergo DNA extraction. Lymphocytic control DNA was isolated from blood obtained by venipuncture. Paired normal and tumor DNA specimens were analyzed for allelic loss by PCR amplification of polymorphic dinucleotide repeat sequences. Immunohistochemical studies were performed on paraffin-embedded, irradiated surgical specimens. RESULTS: Using 16 polymorphic microsatellite markers, 20 of 26 non-irradiated VS demonstrated loss of heterozygosity (LOH) in at least one locus of chromosome 22q. In contrast, none of the four irradiated recurrent VS demonstrated LOH on chromosome 22q (p = 0.008). No allelic loss was seen in either the primary or irradiated VS utilizing markers mapping to chromosome 10. Deletions on chromosome 10 are seen in both benign and higher-grade meningiomas and intracranial malignancies associated with radiotherapy. Immunohistochemical studies were performed to detect the protein product of the NF2 gene, merlin, in the four irradiated VS. NF2 staining was not observed. CONCLUSION: This study represents the first microsatellite and immunohistochemical analysis of recurrent VS following radiation therapy. Our preliminary observations suggest an alternative mechanism of NF2 inactivation that may correlate with radioresistance in VS.

Base Sequence↗
PubMed2006

Cochlear implantation in patients with neurofibromatosis type 2 and bilateral vestibular schwannoma.

OBJECTIVE: To investigate the results of cochlear implantation in patients with neurofibromatosis Type 2 (NF2) and bilateral vestibular schwannoma. STUDY DESIGN: Retrospective case review. SETTING: Three academic tertiary referral centers. PATIENTS: Seven patients with NF2 and bilateral vestibular schwannoma who lost hearing in at least one ear after treatment of their tumor (surgery or radiation therapy). INTERVENTION: Cochlear implantation after treatment of their vestibular schwannoma. MAIN OUTCOME MEASURE: Postimplantation audiometric scores (pure-tone average thresholds, consonant-nucleus-consonant (CNC) words/phonemes, Central Institute for the Deaf (CID) sentences, Hearing in Noise Test (HINT) quiet/noise, and Monosyllable, Trochee, Spondee (MTS) recognition/category tests), patient satisfaction, and device use patterns. RESULTS: The average age at implantation was 40 years (range, 16-57 yr). Follow-up ranged from 6 to 88 months after implantation. Three patients were implanted with residual useful hearing in the contralateral ear, whereas four patients had no hearing in the contralateral ear. Hearing loss was due to surgical excision of tumor (n=5) or gamma-knife radiotherapy (n=2). Postactivation pure-tone average thresholds in the implanted ear ranged from 30 to 55 dB (average, 32.5 dB), although speech reception testing varied considerably among subjects. Despite this variability, all patients continue to use the device on a daily basis. CONCLUSION: In selected cases of deafness in patients with NF2 where there has been anatomic preservation of the auditory nerve after acoustic neuroma resection or radiation therapy, cochlear implantation may offer some improvement in communication skills, including the possibility of open-set speech communication in some patients. These results compare favorably to the auditory brainstem implant offering an alternative for hearing rehabilitation in patients with NF2.

Adolescent↗
PubMed2005

Predictive models for cochlear implantation in elderly candidates.

OBJECTIVE: An aging American population carries a high prevalence of profound sensorineural hearing loss. We examined the performance of multichannel cochlear implant recipients in a large database of adult subjects. DESIGN: Nonconcurrent prospective study of a national cohort with multivariate regression analysis of preoperative and postoperative performance variables in multichannel cochlear implant recipients. We applied models of prediction established in previous studies to the observed results. SETTING: Referral centers with active cochlear implant programs. PATIENTS: Adolescents and adults with profound hearing loss (N = 749; age range, 14-91 years). MAIN OUTCOME MEASURE: Postoperative monosyllabic word recognition. RESULTS: The population 65 years and older demonstrated a clinically insignificant 4.6%-smaller postoperative word score compared with the population younger than 65 years. When duration of deafness exceeded 25 years, elderly recipients demonstrated higher word scores than their younger counterparts. A more significant factor affecting outcomes is the ratio of duration of deafness to age at implantation. CONCLUSIONS: Age at implantation carried relatively little predictive value for postoperative performance in subjects 65 years and older. Although a small decrement in mean speech recognition scores was evident, the clinical significance of this difference is questionable when all of the results observed in elderly patients are considered. A shorter percentage of life spent in severe-to-profound sensorineural hearing loss suggests a foundation of acoustic/auditory processing in the elderly cohort that may mitigate potential physiological effects associated with advanced age. This study confirms and extends previous observations that duration of profound deafness and residual speech recognition carry higher predictive value than the age at which an individual receives an implant.

Adolescent↗
PubMed2005

Effects of cytomegalovirus (CMV) related deafness on pediatric cochlear implant outcomes.

OBJECTIVE: Human cytomegalovirus (CMV) is a commonly recognized viral cause of perinatal sensorineural hearing loss. CMV-infected infants are also at risk for developmental neurological deficits. This retrospective study assesses the impact of CMV-induced deafness on pediatric cochlear implant outcomes. STUDY DESIGN AND SETTING: Thirteen patients from the Johns Hopkins pediatric cochlear implant database were identified with CMV-related deafness. A retrospective review of the medical records of the Johns Hopkins Hospital was performed. RESULTS: The mean age at implantation was 5.6 years. Follow-up audiometric data ranged from 6 to 48 months postoperatively. Mean speech perception scores were 4.5 (out of 6) following implantation. CONCLUSION: We have shown that cochlear implants can provide useful speech comprehension to patients with CMV-related deafness. Speech recognition scores were within the range established by our overall pediatric implant population. SIGNIFICANCE: This observation underscores the importance of a multidisciplinary rehabilitation program following implantation in these patients at risk for cognitive delay.

Antibodies, Viral↗
PubMed2005

Cochlear implant outcome is not influenced by the choice of ear.

OBJECTIVES: This study tested the hypothesis that patients with residual hearing in the nonimplanted ear had the same cochlear implant benefit whether the implanted ear had profound or severe hearing loss. DESIGN: A retrospective chart review of adult cochlear implant recipients with postlingual hearing loss. Patients were categorized according to the pure-tone average of the implanted and contralateral ears as (a) bilateral profound, (b) severe-profound, and (c) bilateral severe. The results of a test battery of spoken language measures were compared among patients belonging to these hearing categories at 6, 12, and 24 months after surgery, using a t-test and multivariate regression analyses. RESULTS: The presence of residual hearing in one or both ears was associated with significantly higher postoperative speech perception scores compared with participants with bilateral profound hearing loss. Among participants with similar amounts of residual hearing in the nonimplanted ear, however, there was no difference in speech recognition scores between those with profound and those with severe hearing loss in the implanted ear. CONCLUSIONS: Among participants with asymmetric hearing loss, there is no additional benefit to implanting the better-hearing ear that can be preserved for use with a hearing aid for better speech understanding in noise and sound localization. These results suggest that the additional benefit received by patients with residual hearing is mediated by trophic effects on crossed pathways in the central nervous system and is independent of the preoperative functional status of the implanted ear.

Adult↗
PubMed2005

The vestibulo-ocular reflex response to head impulses rarely decreases after cochlear implantation.

OBJECTIVE: Measure vestibular function using the head impulse test and assess the change in function due to unilateral cochlear implantation. BACKGROUND: Cochlear implantation entails risks to vestibular function in the implanted ear. However, the nature and extent of this risk is not known. The head impulse test uses physiologically relevant stimuli that allow detection of subtle changes in vestibular function of individual semicircular canals. SUBJECTS: Sixteen adults (age, 28-65 years) were recruited for prospective study from the Listening Center at Johns Hopkins. Eleven of these subjects were tested 4 to 6 weeks after cochlear implantation. METHODS: Three-dimensional eye movement recordings were made using the scleral search coil technique. Stimuli were rapid, passive, transient, head-on-body rotations (acceleration approximately 3000 degrees /s) in the direction excitatory for each of the six semicircular canals. RESULTS: Of the 16 subjects measured preoperatively, 6 (36%) had low (< 0.74) VOR gains in one or both of the horizontal canals and 8 (50%) had low (< 0.64) vestibulo-ocular reflex (VOR) gains in one or more of the vertical canals. These preoperative gain deficits were bilateral in six subjects. The VOR gain did not significantly change after implantation in 10 out of the 11 subjects tested postoperatively. The remaining subject suffered a partial loss of function in the implanted ear and was the only subject who experienced transient vertigo and oscillopsia after implantation. CONCLUSIONS: Preoperative vestibular deficits were common among this group of candidates for cochlear implantation; however, significant loss of vestibular function due to cochlear implantation was uncommon.

Acceleration↗