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Spatial plasticity of the auditory cortex in single‐sided deafness
Author(s) -
Chang Jolie L.,
Pross Seth E.,
Findlay Anne M.,
Mizuiri Danielle,
HendersonSabes Jennifer,
Garrett Coleman,
Nagarajan Srikantan S.,
Cheung Steven W.
Publication year - 2016
Publication title -
the laryngoscope
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.181
H-Index - 148
eISSN - 1531-4995
pISSN - 0023-852X
DOI - 10.1002/lary.25961
Subject(s) - auditory cortex , plasticity , cortex (anatomy) , neuroscience , neuroplasticity , psychology , audiology , medicine , physics , thermodynamics
Objectives/Hypothesis To evaluate spatial plasticity of the auditory cortex in single‐sided deafness (SSD). Study Design Cross‐sectional study comparing a cohort with adult‐onset, idiopathic SSD to a cohort with normal hearing. Methods Demographic, audiometric, magnetoencephalographic imaging, and magnetic resonance imaging data were collected for 13 SSD adult subjects and 13 normal‐hearing controls. Locations of peak activation corresponding to the M100 response in auditory cortices ipsilateral and contralateral to tonal stimuli (0.5 kHz and 4 kHz) were extracted from advanced biomagnetic source imaging analyses. Spatial extent of frequency representation across the 0.5 kHz to 4 kHz zone was computed for the two hemispheres. Results Spatial separation distance between peak locations for 0.5 kHz and 4 kHz stimuli in SSD showed increased activation spread distance in the hemisphere contralateral to the only hearing ear and decreased distance in the ipsilateral hemisphere. In contrast, normal hearing controls had nearly the same activation spread distance in the two hemispheres for ipsilateral and contralateral inputs. The difference between interhemispheric activation spread distance in SSD is significantly increased to 6.5 mm, when compared to 1.7 mm in normal controls ( P < .05). Conclusions Loss of unilateral peripheral input in SSD is associated with spatial reorganization of the auditory cortex in both hemispheres. This change in central auditory functional organization may in turn lead to higher order hearing deficits that rely on interhemispheric processing. Hearing optimization in the only hearing ear may require remediation of both spatial and temporal central auditory changes in SSD. Level of Evidence NA Laryngoscope , 126:2785–2791, 2016