Influence of unilateral deafness on auditory evoked magnetic field

Fujiki, Nobuya; Naito, Yasushi; Nakagawa, Takashi; Shiomi, Yosaku; Hirano, Shigeru; Honjo, Iwao; Shibasaki, Hiroshi

doi:10.1097/00001756-199810050-00002

Cited by 48 publications

(45 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Additionally, a posttraumatic increase in the efficiency of signal transduction in the remaining fibers or cortical reorganization might have improved the situation. The latter assumption is supported by reports of symmetric activations in both auditory cortices about 4 weeks after unilateral deafening in experimental animals [Fujiki et al, 1998;Scheffler et al, 1998], the modification of synaptic efficiency induced by the transcription of early genes [Kaczmarek and Chaudhuri, 1997], synaptogenesis [Jain et al, 2000], and the recruitment of modified cortical networks [Nudo and Friel, 1999].…”

Section: Deafferented Auditory Cortexmentioning

confidence: 76%

Central Auditory Impairment in Unilateral Diencephalic and Telencephalic Lesions

Biedermann¹,

Bungert²,

Dörrscheidt

et al. 2007

Audiol Neurotol

View full text Add to dashboard Cite

The extent of perceptual impairment following unilateral lesions in the auditory cortex, its thalamic or callosal afferents was studied with psychoacoustic tests. Thresholds for the discrimination of signal frequency, intensity and duration were acquired under three different conditions of headphone stimulation (‘monaural’, ‘interaural’, and ‘dichotic signal/noise tests’) using the three-alternative forced-choice procedure. The different test alternatives generated distinct auditory percepts, which is in accordance with the assumption of specific signal processing at the level of the auditory brainstem and at thalamocortical auditory areas. Twenty-one patients from neurology were studied who suffered from unilateral lesions in the auditory cortex, the auditory thalamus, or the acoustic radiation. Location and extent of the lesions were assessed by magnetic resonance imaging. Monaural tests of either ear revealed no deficits in auditory performance. The patients showed impaired discrimination of signal frequency, intensity and duration in the dichotic signal/noise tests, when the signals were presented to the ear contralateral and the noise ipsilateral to the lesion. With inverted signal and noise stimulation, however, the thresholds were in the range of age-matched controls. All patients were able to master the interaural tests, which indicates the preserved ability to lateralize sound sources to the left and to the right with either one of the auditory cortices left intact. Another 24 patients were studied who had lesions mostly close to but sparing the before-mentioned auditory structures. All of them showed unimpaired performance in all test alternatives. The results indicate the specificity of the dichotic signal/noise tests for the identification of unilateral lesions in thalamocortical auditory structures. In addition, the results also point to the capacity of each telencephalic hemisphere to process the full range of auditory lateralization from left to right.

show abstract

Section: Deafferented Auditory Cortexmentioning

confidence: 76%

Central Auditory Impairment in Unilateral Diencephalic and Telencephalic Lesions

Biedermann¹,

Bungert²,

Dörrscheidt

et al. 2007

Audiol Neurotol

View full text Add to dashboard Cite

show abstract

“…Reorganization in adult humans following unilateral deafness has also been reported in a number of studies (Scheffler et al 1998;Mäkelä 1995, 1997;Vasama et al , 1998Fujuki et al 1998). For example, Scheffler et al (1998) measured activity in the auditory cortex using functional magnetic resonance imaging (fMRI) and reported significantly smaller ipsilateral-contralateral activity differences in unilaterally deaf adults in comparison to normal-hearing adults.…”

Section: Introductionmentioning

confidence: 77%

Differential Ear Effects of Profound Unilateral Deafness on the Adult Human Central Auditory System

Khosla

Ponton

Eggermont

et al. 2003

JARO - Journal of the Association for Research in Otolaryngolog

View full text Add to dashboard Cite

This study investigates the effects of profound acquired unilateral deafness on the adult human central auditory system by analyzing long-latency auditory evoked potentials (AEPs) with dipole source modeling methods. AEPs, elicited by clicks presented to the intact ear in 19 adult subjects with profound unilateral deafness and monaurally to each ear in eight adult normal-hearing controls, were recorded with a 31-channel system. The responses in the 70-210 ms time window, encompassing the N 1b /P 2 and Ta/Tb components of the AEPs, were modeled by a vertically and a laterally oriented dipole source in each hemisphere. Peak latencies and amplitudes of the major components of the dipole waveforms were measured in the hemispheres ipsilateral and contralateral to the stimulated ear. The normal-hearing subjects showed significant ipsilateral-contralateral latency and amplitude differences, with contralateral source activities that were typically larger and peaked earlier than the ipsilateral activities. In addition, the ipsilateralcontralateral amplitude differences from monaural presentation were similar for left and for right ear stimulation. For unilaterally deaf subjects, the previously reported reduction in ipsilateral-contralateral amplitude differences based on scalp waveforms was also observed in the dipole source waveforms. However, analysis of the source dipole activity demonstrated that the reduced inter-hemispheric amplitude differences were ear dependent. Specifically, these changes were found only in those subjects affected by profound left ear unilateral deafness.

show abstract

“…Furthermore, these changes were subsequently found to be reflected primarily by sensors in the central scalp regions. Despite this finding, most studies involving the N1 wave in CAEPs or its MEG equivalent, N1m, have not consistently shown any evidence of plasticity following unilateral deafness in adult humans (Vasama et al, 1995Fujiki et al, 1998;Khosla et al, 2003;Hine et al, 2008;Hanss et al, 2009). The present study was therefore conducted with the aim of clarifying the reasons for the inconsistent findings in EEG/MEG studies of plasticity in adult humans with late onset profound unilateral deafness.…”

Section: Introductionmentioning

confidence: 85%

“…One explanation for these inconsistencies could be methodological factors involving the source modeling techniques most often used to characterize the response of the CAS (Vasama et al, 1995Fujiki et al, 1998;Khosla et al, 2003;Hine et al, 2008). CAEPs such as the N1 (or N1m) are usually characterized in source models by one or more dipoles in each hemisphere.…”

Section: Introductionmentioning

confidence: 99%

Source analysis reveals plasticity in the auditory cortex: Evidence for reduced hemispheric asymmetries following unilateral deafness

Maslin¹,

Munro²,

El‐Deredy³

2013

Clinical Neurophysiology

View full text Add to dashboard Cite

show abstract

Influence of unilateral deafness on auditory evoked magnetic field

Cited by 48 publications

References 1 publication

Central Auditory Impairment in Unilateral Diencephalic and Telencephalic Lesions

Central Auditory Impairment in Unilateral Diencephalic and Telencephalic Lesions

Differential Ear Effects of Profound Unilateral Deafness on the Adult Human Central Auditory System

Source analysis reveals plasticity in the auditory cortex: Evidence for reduced hemispheric asymmetries following unilateral deafness

Contact Info

Product

Resources

About