Characterizing responses from auditory cortex in young people with several years of cochlear implant experience

Gordon, Karen A.; Tanaka, Sho; Wong, Daniel; Papsin, Blake C.

doi:10.1016/j.clinph.2008.06.013

Cited by 45 publications

(35 citation statements)

References 42 publications

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“…Responses recorded over the first 2 years of cochlear implant use were characterized by a dominant negative peak which preceded a later positive peak and showed no sign of change over time. This type of response has been associated with poorer speech perception after cochlear implantation (Gordon et al 2005b(Gordon et al , 2008 outcomes of cochlear implantation and perhaps to provide more focused hearing and/or communication therapy for that child. Given that electrophysiological responses provide the most feasible method for imaging auditory activity in children using cochlear implants, we have focused on using these responses to locate where in the brain these responses are generated.…”

Section: Future Work: Cortical Network Evoked By Cochlear Implant Stmentioning

confidence: 96%

“…Later latency cortical responses (*50-300 ms) are often evoked by longer stimuli which can obscure the waveform of interest. This effect can be minimized by restricting the duration of the electrical pulse/pulse train (e.g., (Gordon et al 2008) or by moving the reference electrode to other locations on the head (Gilley et al 2006). Another suggestion has been to eliminate the auditory response using a forward masking technique (as described above) and then subtract this measure, which contains the stimulus artefact alone, from the original response (Friesen and Picton 2010).…”

Section: Recording Evoked Potential Responses In Children Using Cochlmentioning

confidence: 98%

“…Another suggestion has been to eliminate the auditory response using a forward masking technique (as described above) and then subtract this measure, which contains the stimulus artefact alone, from the original response (Friesen and Picton 2010). If the response is recorded from multiple electrodes on the head, principal or independent component analyses can be used to isolate the artefact and remove it from the response (Gilley et al 2006;Gordon et al 2008). We have reported the use of a novel beamformer which can be applied to cortical responses collected from 64 cephalic locations to remove cochlear implant stimulus artefact (Wong and Gordon 2009).…”

Section: Recording Evoked Potential Responses In Children Using Cochlmentioning

confidence: 99%

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Use It or Lose It? Lessons Learned from the Developing Brains of Children Who are Deaf and Use Cochlear Implants to Hear

et al. 2011

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In the present paper, we review what is currently known about the effects of deafness on the developing human auditory system and ask: Without use, does the immature auditory system lose the ability to normally function and mature? Any change to the structure or function of the auditory pathways resulting from a lack of activity will have important implications for future use through an auditory prosthesis such as a cochlear implant. Data to date show that deafness in children arrests and disrupts normal auditory development. Multiple changes to the auditory pathways occur during the period of deafness with the extent and type of change being dependent upon the age and stage of auditory development at onset of deafness, the cause or type of deafness, and the length of time the immature auditory pathways are left without significant input. Structural changes to the auditory nerve, brainstem, and cortex have been described in animal models of deafness as well in humans who are deaf. Functional changes in deaf auditory pathways have been evaluated by using a cochlear implant to stimulate the auditory nerve with electrical pulses. Studies of electrically evoked activity in the immature deaf auditory system have demonstrated that auditory brainstem development is arrested and that thalamo-cortical areas are vulnerable to being taken over by other competitive inputs (cross-modal plasticity). Indeed, enhanced peripheral sight and detection of visual movement in congenitally deaf cats and adults have been linked to activity in specific areas of what would normally be auditory cortex. Cochlear implants can stimulate developmental plasticity in the auditory brainstem even after many years of deafness in childhood but changes in the auditory cortex are limited, at least in part, by the degree of reorganization which occurred during the period of deafness. Consequently, we must identify hearing loss rapidly (i.e., at birth for congenital deficits) and provide cochlear implants to appropriate candidates as soon as possible. Doing so has facilitated auditory development in the thalamo-cortex and allowed children who are deaf to perceive and use spoken language.

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Section: Future Work: Cortical Network Evoked By Cochlear Implant Stmentioning

confidence: 96%

Section: Recording Evoked Potential Responses In Children Using Cochlmentioning

confidence: 98%

Section: Recording Evoked Potential Responses In Children Using Cochlmentioning

confidence: 99%

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Use It or Lose It? Lessons Learned from the Developing Brains of Children Who are Deaf and Use Cochlear Implants to Hear

et al. 2011

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“…In those studies, the time of device use and aspects related to the family and auditory rehabilitation are shown to have an impact on the benefits obtained through cochlear implants (24)(25)(26)(27) . Previous studies have described the correlation between the P1 component and an individual's performance in tests of auditory abilities, characterizing this component as a predictor of the development of speech auditory perception (16)(17)(18)28,29) . In this study, there was significant improvement in the individuals' auditory abilities with the use of cochlear implants, assessed through the IT-MAIS questionnaire (Table 3), but no significant correlation with the latency and amplitude of the P1 component (Table 4).…”

Section: Discussionmentioning

confidence: 99%

“…Children who receive cochlear implants after the sensitive period can present abnormal cortical auditory responses, even after many years of auditory stimulation (9,14,15) . Moreover, individuals with poorer speech perception present atypical records concerning these potentials (16)(17)(18) , thus reflecting abnormal or immature patterns in cortical activity (16) . Therefore, by studying the maturational process of the auditory system, with a focus on CAEP in children who received cochlear implants, it is possible to obtain important information that can aid in understanding the differences in the speech perception development observed among users of cochlear implants, and, consequently, reflect upon the process of referring individuals to this implantation, especially with regard to a child's age at the time of the procedure.…”

Section: Introductionmentioning

confidence: 99%

Identification of risk groups for oropharyngeal dysphagia in hospitalized patients in a university hospital

Bassi

Furkim

Silva

et al. 2014

CoDAS

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Purpose: To identify risk groups for oropharyngeal dysphagia in hospitalized patients in a university hospital. Methods: The study was design as an exploratory cross-sectional with quantitative data analysis. The researched population consisted of 32 patients admitted to the medical clinic at the university hospital. Patient history data were collected, followed by a universal swallowing screening which included functional feeding assessment, to observe clinical signs and symptoms of dysphagia, and assessment of nutritional status through anthropometric data and laboratory tests. Results: Of the total sample, the majority of patients was male over 60 years. The most common comorbidities related to patients with signs and symptoms of dysphagia were chronic obstructive pulmonary disease, systemic arterial hypertension, congestive heart failure, diabetes mellitus and acute myocardial infarction. The food consistency that showed higher presence of clinical signs of aspiration was pudding and the predominant sign was wet voice. Conclusion: There is a high incidence of risk for oropharyngeal dysphagia in hospitalized patients and an even higher rate of hospitalized patients with nutritional deficits or already malnourished. Hospitalized patients with respiratory diseases, chronic obstructive pulmonary disease, congestive heart failure and patients with xerostomia were indicated as risk group for oropharyngeal dysphagia.

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Early unilateral cochlear implantation promotes mature cortical asymmetries in adolescents who are deaf

2015

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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.

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Characterizing responses from auditory cortex in young people with several years of cochlear implant experience

Cited by 45 publications

References 42 publications

Use It or Lose It? Lessons Learned from the Developing Brains of Children Who are Deaf and Use Cochlear Implants to Hear

Use It or Lose It? Lessons Learned from the Developing Brains of Children Who are Deaf and Use Cochlear Implants to Hear

Identification of risk groups for oropharyngeal dysphagia in hospitalized patients in a university hospital

Early unilateral cochlear implantation promotes mature cortical asymmetries in adolescents who are deaf

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