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Hearing Disorders: HELP
Articles by Salima Jiwani
Based on 4 articles published since 2010
(Why 4 articles?)
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Between 2010 and 2020, S. Jiwani wrote the following 4 articles about Hearing Disorders.
 
+ Citations + Abstracts
1 Review What is the optimal timing for bilateral cochlear implantation in children? 2011

Gordon, K A / Jiwani, S / Papsin, B C. ·Archie's Cochlear Implant Laboratory, The Hospital for Sick Children, Toronto, ON, Canada. karen.gordon@utoronto.ca ·Cochlear Implants Int · Pubmed #21917210.

ABSTRACT: Bilateral cochlear implants (CIs) have been provided to children who are deaf in both ears with intent to promote binaural hearing. If it is possible to establish binaural hearing with two CIs, these children would be able to make use of interaural level and timing differences to localize sound and to distinguish between sounds separated in space. These skills are central to the ability to attend to one particular sound amidst a number of sound sources. This may be particularly important for children because they are typically learning and interacting in groups. However, the development of binaural processing could be disrupted by effects of bilateral deafness, effects of unilateral CI use, or issues related to the child's age at onset of deafness and age at the time of the first and second cochlear implantation. This research aims to determine whether binaural auditory processing is affected by these variables in an effort to determine the optimal timing for bilateral cochlear implantation in children. It is now clear that the duration of bilateral deafness should be limited in children to restrict reorganization in the auditory thalamo-cortical pathways. It has also been shown that unilateral CI use can halt such reorganization to some extent and promote auditory development. At the same time, however, unilateral input might compromise the development of binaural processing if CIs are provided sequentially. Mismatches in responses from the auditory brainstem and cortex evoked by the first and second CI after a long period of unilateral CI use suggest asymmetry in the bilateral auditory pathways which is significantly more pronounced than in children receiving bilateral implants simultaneously. Moreover, behavioural responses to level and timing differences between implants suggest that these important binaural cues are not being processed normally by children who received a second CI after a long period of unilateral CI use and at older ages. In sum, there may be multiple sensitive periods in the developing auditory system, which must be considered when determining the optimal timing for bilateral cochlear implantation.

2 Article Early unilateral cochlear implantation promotes mature cortical asymmetries in adolescents who are deaf. 2016

Jiwani, Salima / Papsin, Blake C / Gordon, Karen A. ·Institute of Medical Sciences, Faculty of Medicine, University of Toronto, Toronto, Canada, Ontario. · Archie's Cochlear Implant Laboratory, the Hospital for Sick Children, Toronto, Ontario, Canada. · Department of Otolaryngology-Head & Neck Surgery, University of Toronto, Toronto, Ontario, Canada. ·Hum Brain Mapp · Pubmed #26456629.

ABSTRACT: Unilateral cochlear implant (CI) stimulation establishes hearing to children who are deaf but compromises bilateral auditory development if a second implant is not provided within ∼ 1.5 years. In this study we asked: 1) What are the cortical consequences of missing this early sensitive period once children reach adolescence? 2) What are the effects of unilateral deprivation on the pathways from the opposite ear? Cortical responses were recorded from 64-cephalic electrodes within the first week of bilateral CI activation in 34 adolescents who had over 10 years of unilateral right CI experience and in 16 normal hearing peers. Cortical activation underlying the evoked peaks was localized to areas of the brain using beamformer imaging. The first CI evoked activity which was more strongly lateralized to the contralateral left hemisphere than normal, with abnormal recruitment of the left prefrontal cortex (involved in cognition/attention), left temporo-parietal-occipital junction (multi-modal integration), and right precuneus (visual processing) region. CI stimulation in the opposite deprived ear evoked atypical cortical responses with abnormally large and widespread dipole activity across the cortex. Thus, using a unilateral CI to hear beyond the period of cortical maturation causes lasting asymmetries in the auditory system, requires recruitment of additional cortical areas to support hearing, and does little to protect the unstimulated pathways from effects of auditory deprivation. The persistence of this reorganization into maturity could signal a closing of a sensitive period for promoting auditory development on the deprived side.

3 Article Central auditory development after long-term cochlear implant use. 2013

Jiwani, Salima / Papsin, Blake C / Gordon, Karen A. ·Archie's Cochlear Implant Laboratory, Department of Otolaryngology, The Hospital for Sick Children, Toronto, Ontario, Canada. s.jiwani@mail.utoronto.ca ·Clin Neurophysiol · Pubmed #23680008.

ABSTRACT: OBJECTIVE: We aimed to determine whether long-term cortical auditory development is altered or delayed in children using cochlear implants relative to their normal hearing peers. We hypothesized that cortical development in children using unilateral cochlear implants follows a normal trajectory with long-term auditory input when the duration of bilateral auditory deprivation in childhood is limited. METHODS: Electrically-evoked cortical responses were recorded in 79 children who received one cochlear implant within 2.03 ± 1.36 years of bilateral deafness and had up to ∼16 years of time-in-sound experience, and in 58 peers with normal hearing. Amplitude differences between the responses from children using cochlear implants and with normal hearing were calculated between 0 and 300 ms. RESULTS: Responses from cochlear implant users remain different from those of their normal hearing peers. These differences decreased over time, but were not eliminated even after 10 years of time-in-sound. Specifically, the P(1)-N(1)-P(2)-N(2) complex, typical of a normally mature response, began to emerge by 10 years of time-in-sound experience, but the amplitudes of peaks P(2) and N(2) became abnormally large. CONCLUSION: Mature-like cortical responses emerge in children after long-term unilateral cochlear implant use, however, differences from normal persist. SIGNIFICANCE: Maturation of cortical responses with long-term cochlear implant use potentially underlies functional improvements in hearing. Persistent differences from normal could reflect an increase in attention or multi-sensory processing during listening.

4 Article Speech detection in noise and spatial unmasking in children with simultaneous versus sequential bilateral cochlear implants. 2011

Chadha, Neil K / Papsin, Blake C / Jiwani, Salima / Gordon, Karen A. ·Division of Pediatric Otolaryngology - Head and Neck Surgery, BC Children's Hospital, University of British Columbia, Vancouver, Canada. nchadha@cw.bc.ca ·Otol Neurotol · Pubmed #21725259.

ABSTRACT: OBJECTIVES: To measure speech detection in noise performance for children with bilateral cochlear implants (BiCI), to compare performance in children with simultaneous implant versus those with sequential implant, and to compare performance to normal-hearing children. STUDY DESIGN: Prospective cohort study. SETTING: Tertiary academic pediatric center. PATIENTS: Children with early-onset bilateral deafness and 2-year BiCI experience, comprising the "sequential" group (>2 yr interimplantation delay, n = 12) and "simultaneous group" (no interimplantation delay, n = 10) and normal-hearing controls (n = 8). INTERVENTION: Thresholds to speech detection (at 0-degree azimuth) were measured with noise at 0-degree azimuth or ± 90-degree azimuth. MAIN OUTCOME MEASURES: Spatial unmasking (SU) as the noise condition changed from 0-degree azimuth to ± 90-degree azimuth and binaural summation advantage (BSA) of 2 over 1 CI. RESULTS: Speech detection in noise was significantly poorer than controls for both BiCI groups (p < 0.0001). However, the SU in the simultaneous group approached levels found in normal controls (7.2 ± 0.6 versus 8.6 ± 0.6 dB, p > 0.05) and was significantly better than that in the sequential group (3.9 ± 0.4 dB, p < 0.05). Spatial unmasking was unaffected by the side of noise presentation in the simultaneous group but, in the sequential group, was significantly better when noise was moved to the second rather than the first implanted ear (4.8 ± 0.5 versus 3.0 ± 0.4 dB, p < 0.05). This was consistent with a larger BSA from the sequential group's second rather than first CI. CONCLUSION: Children with simultaneously implanted BiCI demonstrated an advantage over children with sequential implant by using spatial cues to improve speech detection in noise.