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P19-7 Abnormal auditory sensory gating in stuttering: A magnetoencephalographic study
S216
Posters
P19-6 The mismatch negativity and N1 related to gap or omission
P19-8 Brown-Vialetto-Van Laere: five sporadic cases from Iran
S. Tamakoshi1 , A. Yagi2 1 Graduate School of Psychological Science, Kwansei Gakuin University, Nishinomiya, Japan, 2 Department of Integrated Psychological Sciences, Kwansei Gakuin University, Japan
S. Yadegari1 , S. Nafissi1 , A. Soltanzadeh1 , H. Sikaroodi1 , A. Ghorbani1 Shariati Hospital, Depatment of Neurology, Tehran University of Medical Sciences, Tehran, Iran
Objective: Previous studies measured by mismatch negativity (MMN) showed that the auditory information inputted within the temporal window of integration (TWI) was encoded as a single auditory event. The purpose of this study was to investigate the auditory coding in perceptual difference caused by stimuli presentation rates. The lower limits in participants perceived as continuous sound were shorter than 33 ms in SOA. Hence the omission in continuous sound was perceived as a gap event. In contrast, the omission was perceived as an omission event in conditions that were greater than 50 ms in SOA. The MMN and N1 components indicate the omission detection was influenced by the SOA. Methods: Electroencephalogram (EEG) was recorded by using 30 Ag/AgCl electrodes to gap or omission events in sound streams. The stimulus was a burst tone one half of an SOA in duration (rise and fall time 5 ms). Auditory stimuli presented by different conditions of a total of 5 repetition rates (SOA = 12.5, 25, 100, 125 and 200 ms) in separate blocks. The stimulus was omitted once in approximately 2 s randomly from the sound sequence. Results: The large negativity showed at conditions of shorter than 25 ms. There was no negative amplitude in a condition of 200 ms in SOA. The MMN appeared in conditions of 100 ms and 125 ms in SOA. Conclusions: The conditions of sound perceived as continuous low pitch sound elicited large negative amplitude rather than the neural adaptation affected by high presentation rates. This study showed the responses weighted to the right hemisphere regardless of events were omission and gap. It was suggested the same system was activated with the omission and gap. Additionally there was only a difference in saliency indicated by amplitude of a negative component. P19-7 Abnormal auditory sensory gating in stuttering: A magnetoencephalographic study Y. Kikuchi1,2 , K. Ogata2 , T. Umesaki1 , M. Kenjo4 , Y. Hirano3 , S. Komune1 , S. Tobimatsu2 1 Departments of Otolaryngology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, 2 Departments of Clinical Neurophysiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, 3 Departments of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, 4 Department of Special Education, Fukuoka University of Education, Fukuoka, Japan Objective: People who stutter (PWS) can improve stuttering rates while hearing masking noise and listening to a metronome as pacing sounds. This suggests that abnormal speech processing in PWS results from abnormal sound processing. We examined the sound processing system in PWS by using auditory sensory gating. Methods: A 306-channel magnetoencephalograpy was used for functional lateralization of the auditory cortex. We adopted a P50m suppression paradigm as auditory gating in 17 male PWS (aged 21 41 years) and 18 male normal subjects (aged 22 43 years). Two successive clicks (S1 and S2) with a 500-msec interstimulus interval were given to each ear in a separate recording session. The auditory sensory gating was expressed as a ratio P50m dipole moment by S2 (Q2) to that by S1 (Q1) for each hemisphere. Results: Q2/Q1 ratio was significantly smaller in the left hemisphere than in the right hemisphere in controls (p < 0.05). Q2/Q1 in the left hemisphere was significantly higher in PWS than in controls (p < 0.05). In addition, there was no significant side-to-side difference in PWS. The S1-P50m latency in the right hemisphere of PWS was significantly shorter than that of the left hemisphere (p < 0.05). Conclusions: We first demonstrated that auditory sensory gating in the left auditory cortex was impaired in PWS. The disturbed auditory sensory gating in the left hemisphere is an electrophysiological signature of stuttering, which reflects inability to gate out unnecessary auditory information in PWS.
1
Objective: To enhance the information of literature about BrownVialetto-Van Laere syndrome (BVVLS) which is a rare neurological disorder of unknown origin and characterized by bilateral sensorineural deafness and a variety of lower cranial nerve disorders. Method: We report our findings about five patients clinically and electrophysiologically diagnosed as BVVLS. Result: Our cases of BVVLS consisting 5 sporadic patients (4 female and 1 male). The first symptom was bilateral hearing loss. Onset of other cranial nerves involvement varied between 0 15 years. Our patients represent some rare features like bilateral fifth nerve palsy and large fiber sensory loss in one patient and upper motor neuron signs in two patients. One case interestingly showed some clinical improvement. Conclusion: This is the largest series of sporadic cases and the first report of BVVLS from Iran. Sporadic cases may be due to de novo rearrangement of an autosomal recessive gene. P19-9 The brainstem auditory evoked potentials in two cases of Bickerstaff’s brainstem encephalitis J.H. Cho1 , G.S. Kim1 , S.-A. Choi1 , J.H. Lee1 Department of Neurology, National Health Insurance Corporation Ilsan Hospital, Korea
1
Background and Significance: Bickerstaff’s brainstem encephalitis (BBE) is a rare disease and characterized by progressive ophthalmoplegia, ataxia and disturbance of consciousness (or hyper-reflexia). The brainstem auditory evoked potentials (BAEPs) are helpful to evaluate brainstem lesion. We report two patients of BBE whose BAEPs suggest a lesion in the upper brainstem. Case 1: A 70-year old man presented with acute diplopia and bilateral ptosis. Neurological examination revealed total ophthalmoplegia, bilateral ptosis, gait ataxia and hyperreflexia. The anti-GQ1b antibodies were absent and brain MRI showed no lesion of brain parenchyma. The BAEPs showed increased III-V and I-V interpeak latency bilaterally. Case 2: A 35-year old man presented with dysarthria and gait ataxia. He developed total ophthalmoplegia, areflexia and confusion within 5 days. The anti-GQ1b IgG was positive and brain MRI was normal. The BAEPs revealed increased latency of wave V in left side and increased III-V and I-V interpeak latency bilaterally. Conclusion or Comment: The diagnosis of BBE remains based on clinical criteria and exclusion of other etiologies. Abnormal brain MRI can help to support diagnosis of BBE but normal MRI does not exclude the diagnosis. The BAEPs suggestive brainstem lesion may helpful in diagnosis of BBE. P19-10 Influence of cardiac and respiratory artifacts on the relationship between spontaneous EEG and fMRI signals K. Omata1 , T. Hanakawa1 , M. Morimoto1 , M. Honda1 1 Department of Functional Brain Research, National Institute of Neuroscience National Center of Neurology and Psychiatry, Japan Objects: Cardiac beats and respiration affect both BOLD signals of fMRI and EEG signals under simultaneous EEG/fMRI studies. In order to explore the relationship between spontaneous EEG and fMRI signals, the effect of such autonomic artifacts should be clarified. In this study, we investigated the influence of the cardiac and respiratory artifacts on the relationship between fMRI and the spontaneous EEG, especially occipital dominant alpha oscillation. Methods: Healthy subjects were asked to lie still on a scanner bed and to keep their eyes closed. We recorded the EEG and fMRI data simultaneously while measuring the amount of respiration by attaching a belt sensor on the chest or abdomen. Five indexes were used to represent the cardiac beat and respiration: heart beat and its variance, cardiac phase, respiration phase and respiration volume per time. The fMRI data were corrected by using the five indexes in a multiple regression analysis. We compared the brain areas positively correlated with the occipital alpha power of EEG under two conditions; with and without considering the correction of cardiac and respiratory artifacts. Results: The indexes of cardiac and respiration phase were mainly correlated with the BOLD signals in the cerebrospinal fluid and the
Posters
P19-6 The mismatch negativity and N1 related to gap or omission
P19-8 Brown-Vialetto-Van Laere: five sporadic cases from Iran
S. Tamakoshi1 , A. Yagi2 1 Graduate School of Psychological Science, Kwansei Gakuin University, Nishinomiya, Japan, 2 Department of Integrated Psychological Sciences, Kwansei Gakuin University, Japan
S. Yadegari1 , S. Nafissi1 , A. Soltanzadeh1 , H. Sikaroodi1 , A. Ghorbani1 Shariati Hospital, Depatment of Neurology, Tehran University of Medical Sciences, Tehran, Iran
Objective: Previous studies measured by mismatch negativity (MMN) showed that the auditory information inputted within the temporal window of integration (TWI) was encoded as a single auditory event. The purpose of this study was to investigate the auditory coding in perceptual difference caused by stimuli presentation rates. The lower limits in participants perceived as continuous sound were shorter than 33 ms in SOA. Hence the omission in continuous sound was perceived as a gap event. In contrast, the omission was perceived as an omission event in conditions that were greater than 50 ms in SOA. The MMN and N1 components indicate the omission detection was influenced by the SOA. Methods: Electroencephalogram (EEG) was recorded by using 30 Ag/AgCl electrodes to gap or omission events in sound streams. The stimulus was a burst tone one half of an SOA in duration (rise and fall time 5 ms). Auditory stimuli presented by different conditions of a total of 5 repetition rates (SOA = 12.5, 25, 100, 125 and 200 ms) in separate blocks. The stimulus was omitted once in approximately 2 s randomly from the sound sequence. Results: The large negativity showed at conditions of shorter than 25 ms. There was no negative amplitude in a condition of 200 ms in SOA. The MMN appeared in conditions of 100 ms and 125 ms in SOA. Conclusions: The conditions of sound perceived as continuous low pitch sound elicited large negative amplitude rather than the neural adaptation affected by high presentation rates. This study showed the responses weighted to the right hemisphere regardless of events were omission and gap. It was suggested the same system was activated with the omission and gap. Additionally there was only a difference in saliency indicated by amplitude of a negative component. P19-7 Abnormal auditory sensory gating in stuttering: A magnetoencephalographic study Y. Kikuchi1,2 , K. Ogata2 , T. Umesaki1 , M. Kenjo4 , Y. Hirano3 , S. Komune1 , S. Tobimatsu2 1 Departments of Otolaryngology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, 2 Departments of Clinical Neurophysiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, 3 Departments of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, 4 Department of Special Education, Fukuoka University of Education, Fukuoka, Japan Objective: People who stutter (PWS) can improve stuttering rates while hearing masking noise and listening to a metronome as pacing sounds. This suggests that abnormal speech processing in PWS results from abnormal sound processing. We examined the sound processing system in PWS by using auditory sensory gating. Methods: A 306-channel magnetoencephalograpy was used for functional lateralization of the auditory cortex. We adopted a P50m suppression paradigm as auditory gating in 17 male PWS (aged 21 41 years) and 18 male normal subjects (aged 22 43 years). Two successive clicks (S1 and S2) with a 500-msec interstimulus interval were given to each ear in a separate recording session. The auditory sensory gating was expressed as a ratio P50m dipole moment by S2 (Q2) to that by S1 (Q1) for each hemisphere. Results: Q2/Q1 ratio was significantly smaller in the left hemisphere than in the right hemisphere in controls (p < 0.05). Q2/Q1 in the left hemisphere was significantly higher in PWS than in controls (p < 0.05). In addition, there was no significant side-to-side difference in PWS. The S1-P50m latency in the right hemisphere of PWS was significantly shorter than that of the left hemisphere (p < 0.05). Conclusions: We first demonstrated that auditory sensory gating in the left auditory cortex was impaired in PWS. The disturbed auditory sensory gating in the left hemisphere is an electrophysiological signature of stuttering, which reflects inability to gate out unnecessary auditory information in PWS.
1
Objective: To enhance the information of literature about BrownVialetto-Van Laere syndrome (BVVLS) which is a rare neurological disorder of unknown origin and characterized by bilateral sensorineural deafness and a variety of lower cranial nerve disorders. Method: We report our findings about five patients clinically and electrophysiologically diagnosed as BVVLS. Result: Our cases of BVVLS consisting 5 sporadic patients (4 female and 1 male). The first symptom was bilateral hearing loss. Onset of other cranial nerves involvement varied between 0 15 years. Our patients represent some rare features like bilateral fifth nerve palsy and large fiber sensory loss in one patient and upper motor neuron signs in two patients. One case interestingly showed some clinical improvement. Conclusion: This is the largest series of sporadic cases and the first report of BVVLS from Iran. Sporadic cases may be due to de novo rearrangement of an autosomal recessive gene. P19-9 The brainstem auditory evoked potentials in two cases of Bickerstaff’s brainstem encephalitis J.H. Cho1 , G.S. Kim1 , S.-A. Choi1 , J.H. Lee1 Department of Neurology, National Health Insurance Corporation Ilsan Hospital, Korea
1
Background and Significance: Bickerstaff’s brainstem encephalitis (BBE) is a rare disease and characterized by progressive ophthalmoplegia, ataxia and disturbance of consciousness (or hyper-reflexia). The brainstem auditory evoked potentials (BAEPs) are helpful to evaluate brainstem lesion. We report two patients of BBE whose BAEPs suggest a lesion in the upper brainstem. Case 1: A 70-year old man presented with acute diplopia and bilateral ptosis. Neurological examination revealed total ophthalmoplegia, bilateral ptosis, gait ataxia and hyperreflexia. The anti-GQ1b antibodies were absent and brain MRI showed no lesion of brain parenchyma. The BAEPs showed increased III-V and I-V interpeak latency bilaterally. Case 2: A 35-year old man presented with dysarthria and gait ataxia. He developed total ophthalmoplegia, areflexia and confusion within 5 days. The anti-GQ1b IgG was positive and brain MRI was normal. The BAEPs revealed increased latency of wave V in left side and increased III-V and I-V interpeak latency bilaterally. Conclusion or Comment: The diagnosis of BBE remains based on clinical criteria and exclusion of other etiologies. Abnormal brain MRI can help to support diagnosis of BBE but normal MRI does not exclude the diagnosis. The BAEPs suggestive brainstem lesion may helpful in diagnosis of BBE. P19-10 Influence of cardiac and respiratory artifacts on the relationship between spontaneous EEG and fMRI signals K. Omata1 , T. Hanakawa1 , M. Morimoto1 , M. Honda1 1 Department of Functional Brain Research, National Institute of Neuroscience National Center of Neurology and Psychiatry, Japan Objects: Cardiac beats and respiration affect both BOLD signals of fMRI and EEG signals under simultaneous EEG/fMRI studies. In order to explore the relationship between spontaneous EEG and fMRI signals, the effect of such autonomic artifacts should be clarified. In this study, we investigated the influence of the cardiac and respiratory artifacts on the relationship between fMRI and the spontaneous EEG, especially occipital dominant alpha oscillation. Methods: Healthy subjects were asked to lie still on a scanner bed and to keep their eyes closed. We recorded the EEG and fMRI data simultaneously while measuring the amount of respiration by attaching a belt sensor on the chest or abdomen. Five indexes were used to represent the cardiac beat and respiration: heart beat and its variance, cardiac phase, respiration phase and respiration volume per time. The fMRI data were corrected by using the five indexes in a multiple regression analysis. We compared the brain areas positively correlated with the occipital alpha power of EEG under two conditions; with and without considering the correction of cardiac and respiratory artifacts. Results: The indexes of cardiac and respiration phase were mainly correlated with the BOLD signals in the cerebrospinal fluid and the