Teppei Matsubara1, Katsuya Ogata2, Naruhito Hironaga2, Taira Uehara2, Takako Mitsudo2, Hiroshi Shigeto3, Toshihiko Maekawa4, Shozo Tobimatsu2. 1. Department of Clinical Neurophysiology, Neurological Institute, Faculty of Medicine, Graduate School of Medical Sciences, Kyushu University, Japan. Electronic address: teppeim@med.kyushu-u.ac.jp. 2. Department of Clinical Neurophysiology, Neurological Institute, Faculty of Medicine, Graduate School of Medical Sciences, Kyushu University, Japan. 3. Epilepsy and Sleep Center, Fukuoka Sanno Hospital, Fukuoka, Japan. 4. Department of Neuropsychiatry, Amekudai Hospital, Japan.
Abstract
OBJECTIVE: Patients with mesial temporal lobe epilepsy (mTLE) often exhibit central auditory processing (CAP) dysfunction. Monaural 40-Hz auditory steady-state magnetic responses (ASSRs) were recorded to explore the pathophysiology of mTLE. METHODS: Eighteen left mTLE patients, 11 right mTLE patients and 16 healthy controls (HCs) were examined. Monaural clicks were presented at a rate of 40 Hz. Phase-locking factor (PLF) and power values were analyzed within bilateral Heschl's gyri. RESULTS: Monaural 40-Hz ASSR demonstrated temporal frequency dynamics in both PLF and power data. Symmetrical hemispheric contralaterality was revealed in HCs. However, predominant contralaterality was absent in mTLE patients. Specifically, right mTLE patients exhibited a lack of contralaterality in response to left ear but not right ear stimulation, and vice versa in left mTLE patients. CONCLUSION: This is the first study to use monaural 40-Hz ASSR with unilateral mTLE patients to clarify the relationship between CAP and epileptic focus. CAP dysfunction was characterized by a lack of contralaterality corresponding to epileptic focus. SIGNIFICANCE: Monaural 40-Hz ASSR can provide useful information for localizing epileptic focus in mTLE patients.
OBJECTIVE:Patients with mesial temporal lobe epilepsy (mTLE) often exhibit central auditory processing (CAP) dysfunction. Monaural 40-Hz auditory steady-state magnetic responses (ASSRs) were recorded to explore the pathophysiology of mTLE. METHODS: Eighteen left mTLE patients, 11 right mTLE patients and 16 healthy controls (HCs) were examined. Monaural clicks were presented at a rate of 40 Hz. Phase-locking factor (PLF) and power values were analyzed within bilateral Heschl's gyri. RESULTS: Monaural 40-Hz ASSR demonstrated temporal frequency dynamics in both PLF and power data. Symmetrical hemispheric contralaterality was revealed in HCs. However, predominant contralaterality was absent in mTLE patients. Specifically, right mTLE patients exhibited a lack of contralaterality in response to left ear but not right ear stimulation, and vice versa in left mTLE patients. CONCLUSION: This is the first study to use monaural 40-Hz ASSR with unilateral mTLE patients to clarify the relationship between CAP and epileptic focus. CAP dysfunction was characterized by a lack of contralaterality corresponding to epileptic focus. SIGNIFICANCE: Monaural 40-Hz ASSR can provide useful information for localizing epileptic focus in mTLE patients.
Authors: Robert J Quon; Grace A Leslie; Edward J Camp; Stephen Meisenhelter; Sarah A Steimel; Yinchen Song; Alan B Ettinger; Krzysztof A Bujarski; Michael A Casey; Barbara C Jobst Journal: Acta Neurol Scand Date: 2021-04-24 Impact factor: 3.915