- Email: [email protected]
44. Automatic detection of abnormal EEG spikes in the routine photic driving study
Japanese Society of Clinical Neurophysiology / Clinical Neurophysiology 119 (2008) e75–e93
spinal cord during surgery, though it could not evaluate the severe myelopathy cases. To compensate disadvantage, we tried to use muscle-evoked potential after electric stimulation of the brain (Br(E)-MsEP) in combination with Br(E)-SCEP. Both Br(E)MsEP from abductor digit minim and abductor hallucis muscles and Br(E)-SCEP from a bipolar electrode at intra-dural space were recorded in 45 patients. We tried to classify into four groups by a score of clinical motor function of lower extremities (scoring system for cervical myelopathy proposed by the Japanese Orthopedic Association); 4 point (n = 3), 3 point (n = 4), 2 point (n = 16), 1 point (n = 19), zero point (n = 3): unable to walk. As well Br(E)-SCEP wave patterns were classified into three types; type 1 (n = 20): an apparent spike wave, type 2 (n = 18): polyphasic waves without a spike wave, type 3 (n = 7): without apparent wave. And type 3 of each motor function group were 4 point (n = 0), 3 point (n = 2), 2 point (n = 2), 1 point (n = 2), zero point (n = 2). However, Br(E)MsEP could be recorded in type 3 with silent Br(E)-SCEP. (except for two cases).
e85
blood flow single photon emission computed tomography (SPECT) using 123IIMP as a flow tracer. We performed both eyes-closed resting EEG and SPECT on the same day in 8 patients with acute cortical infarction within one month after the onset of stroke. We analyzed frequency band and its topography with sLORETA quantitatively and CBF on SPECT using iSSP ver.3.5 software. In topographical assessment, distribution of delta band correlated with brain MRI lesion, but alpha band was distributed to the opposite site of the brain lesions. Localization of delta band was correlated with hypoperfusion area in cases of brain infarction in the middle cerebral artery territory. However, in cases of occipital infarction or those of extensive lesions there was no correlation between sLORETA analysis and SPECT study. The dissociation between two modalities might reveal pathophysiological differences of individual cases. Therefore the location of stroke and the time following onset of stroke should be taken into account in the evaluation of EEG by sLORETA. doi:10.1016/j.clinph.2008.01.067
doi:10.1016/j.clinph.2008.01.065
41. Circadian rhythm abnormalities of acute cerebral infarction correlate with poor prognosis—Yuko Niijima, Hidehiro Takekawa, Tomohiro Ogawa, Yasuhisa Daimon, Atsuko Ebata, Tomoyuki Miyamoto, Masayuki Miyamoto, Koichi Hirata Dokkyo Medical University, Tochigi, Japan) We investigated the relationship between the core body temperature rhythm in the acute stage of brain infarction and the prognosis at three months after the onset of initial symptoms in 27 patients with severe cerebral infarction. The rectal temperature in the acute stage was measured continuously every 1 min for 48 h. The subjects were divided into two groups: the circadian rhythm (CR) group, in which the patients showed a strong CR, as measured by the maximum entropy method, and the NCR group, in which the patients showed unclear CR. The background factors and modified Ranking Scale at three months after the onset were determined. The NCR group included many patients who had impaired consciousness, and the prognosis at three months was poor. Moreover, many patients in this group died. When the deaths were excluded, there were no differences in background characteristics of the patients between two groups. Similar to overall condition, the prognosis at three months in the NCR group was poor. These findings indicate that the prognosis in the chronic stage could be predicted by evaluating the biological rhythm in the acute stage of cerebral infarction.
43. Evaluation of photic driving EEG responses in migraine patients—Kazuhito Kimoto, Hideaki Tanaka, Yuya Hoshino, Tomohiro Ogawa, Yuka Watanabe, Akinori Hozumi, Koichi Hirata Dokkyo Medical University, Tochigi, Japan) In many migraineurs, photic supersensitivity is an aggravation factor of headache attack and included in the diagnostic criteria. This study is aimed to investigate the mechanism of the brain electric signature of migraineurs, with photic driving EEG responses. We studied 25 patients (6 men, 19 women, age 15–58 years) who had a checkup at outpatient and diagnosed as migraine with aura in 12 patients, and migraine without aura in 13 based on the diagnostic criteria (ICHD-II). We recorded spontaneous eyes-closed resting EEGs from 20 electrodes. Three artifact-free EEG epochs consisting of 2.56 ms during photic stimulation were selected. Stroboscope flashes consisting of 3–5–8–10–13–15–18–20 Hz were used. 17 of 25 patients had photic driving responses, and 13 among them had spread from occipital to frontal lobe. Standardized low resolution electromagnetic tomography (sLORETA), which was used to compute three-dimensional intracerebral distribution of electric activity for each driving response, revealed significant activities related to driving response at not only occipital lobe but also frontal lobe. We conclude that higher rate of photic driving response in migraineurs is presumed to reflect brain hypersensitivity, and it may be related to involvement of anterior cingulate and prefrontal cortex for sensibilization of the limbic system. doi:10.1016/j.clinph.2008.01.068
doi:10.1016/j.clinph.2008.01.066
42. Confirmation study of EEG source by sLORETA with SPECT on acute cerebral cortical infarction—Yuya Hoshino, Hideaki Tanaka, Tomohiro Ogawa, Yuka Watanabe, Akinori Hozumi, Koichi Hirata Dokkyo Medical University, Tochigi, Japan) We evaluated the EEG sources with standardized low-resolution brain electromagnetic tomography (sLORETA) and cerebral
44. Automatic detection of abnormal EEG spikes in the routine photic driving study—Shigeto Nishida, Takenao Sugi, Akio Ikeda, Takashi Nagamine, Hiroshi Shibasaki, Masatoshi Nakamura Fukuoka Institute of Technology, Fukuoka, Japan) A method for detecting spikes in EEG in response to intermittent photic stimulation was proposed as a part of an automatic integrative interpretation system of awake EEG. The spikes were
e86
Japanese Society of Clinical Neurophysiology / Clinical Neurophysiology 119 (2008) e75–e93
detected by considering properties of spike and slow components separately, and their simultaneous emergence in adjacent region of the scalp, by combining a morphological filter with the similarity coefficient. The newly proposed method was tested for the photic driving EEG data containing spikes and also for unique spikes with positive peaks. This was satisfactory for spike detection. By introducing the present method in the automatic integrative interpretation system that has been developed by our colleagues, the new system becomes a more powerful tool for routine EEG evaluation. doi:10.1016/j.clinph.2008.01.069
45. Magnitude of EEG–EMG coherence during isometric contraction in young healthy subjects—Tatsuya Suzuki, Junichi Ushiba, Yoshihisa Masakado Keio University, Kanagawa, Japan) Electroencephalogram (EEG) recorded over the primary motor cortex is known to be coherent with the contralateral electromyogram (EMG) of voluntarily contracted muscles, and coherence analysis can evaluate such linear correlation quantitatively. It has been tacitly known that magnitude of EEG–EMG coherence varies among healthy subjects, but it remains unclear what factors are influencing the relationship. In this study, we recorded EEG close to foot area of the motor cortex and EMG from the right tibialis anterior muscle during moderate isometric ankle dorsiflexion, and calculated EEG–EMG coherence in 102 young healthy subjects (53 males, 49 females, 19–35 age), As a result, sixty-five subjects showed statistically significant magnitudes of coherency, and sixty subjects of them showed the significant EEG–EMG coherence peak in 15–35 Hz bands. No physical factors such as age, gender, and height, correlated with the magnitudes of the significant EEG–EMG coherence, whereas the phase difference of EEG and EMG in the coherent frequency band reflecting the conduction time of the motor command depended on the height. We concluded that the neural activity in the corticospinal tract of young healthy subjects tend to oscillate in 15–35 Hz, independently to their age, gender and height. doi:10.1016/j.clinph.2008.01.070
46. The effect of emotional stimulus using exploratory eye movements on left and right scanning function in schizophrenic patients—Chizuko Kawabe, Hironobu Nakayama, Kiichiro Morita Kurume University, Fukuoka, Japan) To characterize the left and right scanning function and the effect of emotion in schizophrenic patients, exploratory eye movements were recorded as biological marks in 18 schizophrenic patients and 18 age- and sex-matched healthy controls. The total eye scanning length (TESL) and total number of gaze points (TNGPs) in the left and right visual fields of the screen were calculated as the subjects viewed babies’ or mothers’ smiling faces, crying faces, and neutral faces. TESL of patients was shorter than that of controls for all faces. Left TNGPs for all mothers’ faces, for babies’ smiling face and crying face were lower in patients than in controls. Right TNGPs for the babies’ neutral face were
higher in patients than in controls. In patients, left TNGPs for all babies’ faces were lower than right TNGPs for all babies’ faces. In patients, left and right TNGPs for babies’ neutral face were higher than for babies’ smiling face and crying face. Patients’ eye movements in the left visual field of screen and neutral emotion were clearly different from those of controls, suggesting that visual cognitive function is impaired in schizophrenic patients. doi:10.1016/j.clinph.2008.01.071
47. Study of exploratory eye movements in asperger’s syndrome—Chiyomi Egami, Kiichiro Morita, Youhei Ishii, Yushiro Yamashit, Toyojiro Matuishi Kurume University School of Medicine, Fukuoka, Japan) To evaluate the characteristics of visual cognitive functions in patients with asperger’s syndrome, we examined exploratory eye movements in 12 patients and age-matched 12 healthy controls. All subjects and their parents gave written informed consent. The Ethics Committee of Kurume University approved the present study. Subjects were required to view a series of six pictures; picture 1 is simple circles (control), picture 2 smiling faces, picture 3 smiling faces with two lines beside the mouth, picture 4 was the same as picture 3, picture 5 was sight seen, and picture 6 was the same as picture1. Exploratory eye movements were analyzed with regard to three parameters: total number of gazing points (TNGPs), total eye scanning length (TESL) of gazing points, and response search score (RSS) on the right half and the left of the screen. Both TESL and TNGP in the healthy group was significantly longer and larger than those of patients, except for viewing sight seen. RSS of the health group were significantly larger than that of patients. Both left and right RSSs were significantly larger in the health group than in patients. This study indicated that TNGPs, TESL, and RSSs are useful markers of visual cognitive function in patients with asperger’s syndrome. doi:10.1016/j.clinph.2008.01.072
48. Evaluation of behavior inhibition using saccadic eye movement in the children with frontal paroxysmal discharges during awaking state—Yusuke Goto, Yoshimi Kaga, Kazuo Hatakeyama, Hideaki Kanemura, Kakurou Aoyagi, Dai Yamashiro, Hiromi Hosaka, Kanji Sugita, Masao Aihara University of Yamanashi, Yamanashi, Japan) Behavior inhibition, which is ascribed to the frontal cortex, refers to three processes: inhibiting the initial prepotent response: stopping an ongoing response; interference control from disruption, impairments of which lead to secondary executive dysfunctions. The aim of the present study is to investigate the saccadic parameters of reflexive response in the children with frontal paroxysmal discharges (FPDs) presenting with developmental disorders, using memory-guided saccade task (MGST) and antisaccade task. The subjects were 4 patients with FPD during awake state (mean age 11.9 years, range 10–15 years). Fifteen age-matched normal children served as control. Three patients showed more anticipatory errors than controls on the MGST, and two patients more directional errors on the antisaccade task. The patients also
spinal cord during surgery, though it could not evaluate the severe myelopathy cases. To compensate disadvantage, we tried to use muscle-evoked potential after electric stimulation of the brain (Br(E)-MsEP) in combination with Br(E)-SCEP. Both Br(E)MsEP from abductor digit minim and abductor hallucis muscles and Br(E)-SCEP from a bipolar electrode at intra-dural space were recorded in 45 patients. We tried to classify into four groups by a score of clinical motor function of lower extremities (scoring system for cervical myelopathy proposed by the Japanese Orthopedic Association); 4 point (n = 3), 3 point (n = 4), 2 point (n = 16), 1 point (n = 19), zero point (n = 3): unable to walk. As well Br(E)-SCEP wave patterns were classified into three types; type 1 (n = 20): an apparent spike wave, type 2 (n = 18): polyphasic waves without a spike wave, type 3 (n = 7): without apparent wave. And type 3 of each motor function group were 4 point (n = 0), 3 point (n = 2), 2 point (n = 2), 1 point (n = 2), zero point (n = 2). However, Br(E)MsEP could be recorded in type 3 with silent Br(E)-SCEP. (except for two cases).
e85
blood flow single photon emission computed tomography (SPECT) using 123IIMP as a flow tracer. We performed both eyes-closed resting EEG and SPECT on the same day in 8 patients with acute cortical infarction within one month after the onset of stroke. We analyzed frequency band and its topography with sLORETA quantitatively and CBF on SPECT using iSSP ver.3.5 software. In topographical assessment, distribution of delta band correlated with brain MRI lesion, but alpha band was distributed to the opposite site of the brain lesions. Localization of delta band was correlated with hypoperfusion area in cases of brain infarction in the middle cerebral artery territory. However, in cases of occipital infarction or those of extensive lesions there was no correlation between sLORETA analysis and SPECT study. The dissociation between two modalities might reveal pathophysiological differences of individual cases. Therefore the location of stroke and the time following onset of stroke should be taken into account in the evaluation of EEG by sLORETA. doi:10.1016/j.clinph.2008.01.067
doi:10.1016/j.clinph.2008.01.065
41. Circadian rhythm abnormalities of acute cerebral infarction correlate with poor prognosis—Yuko Niijima, Hidehiro Takekawa, Tomohiro Ogawa, Yasuhisa Daimon, Atsuko Ebata, Tomoyuki Miyamoto, Masayuki Miyamoto, Koichi Hirata Dokkyo Medical University, Tochigi, Japan) We investigated the relationship between the core body temperature rhythm in the acute stage of brain infarction and the prognosis at three months after the onset of initial symptoms in 27 patients with severe cerebral infarction. The rectal temperature in the acute stage was measured continuously every 1 min for 48 h. The subjects were divided into two groups: the circadian rhythm (CR) group, in which the patients showed a strong CR, as measured by the maximum entropy method, and the NCR group, in which the patients showed unclear CR. The background factors and modified Ranking Scale at three months after the onset were determined. The NCR group included many patients who had impaired consciousness, and the prognosis at three months was poor. Moreover, many patients in this group died. When the deaths were excluded, there were no differences in background characteristics of the patients between two groups. Similar to overall condition, the prognosis at three months in the NCR group was poor. These findings indicate that the prognosis in the chronic stage could be predicted by evaluating the biological rhythm in the acute stage of cerebral infarction.
43. Evaluation of photic driving EEG responses in migraine patients—Kazuhito Kimoto, Hideaki Tanaka, Yuya Hoshino, Tomohiro Ogawa, Yuka Watanabe, Akinori Hozumi, Koichi Hirata Dokkyo Medical University, Tochigi, Japan) In many migraineurs, photic supersensitivity is an aggravation factor of headache attack and included in the diagnostic criteria. This study is aimed to investigate the mechanism of the brain electric signature of migraineurs, with photic driving EEG responses. We studied 25 patients (6 men, 19 women, age 15–58 years) who had a checkup at outpatient and diagnosed as migraine with aura in 12 patients, and migraine without aura in 13 based on the diagnostic criteria (ICHD-II). We recorded spontaneous eyes-closed resting EEGs from 20 electrodes. Three artifact-free EEG epochs consisting of 2.56 ms during photic stimulation were selected. Stroboscope flashes consisting of 3–5–8–10–13–15–18–20 Hz were used. 17 of 25 patients had photic driving responses, and 13 among them had spread from occipital to frontal lobe. Standardized low resolution electromagnetic tomography (sLORETA), which was used to compute three-dimensional intracerebral distribution of electric activity for each driving response, revealed significant activities related to driving response at not only occipital lobe but also frontal lobe. We conclude that higher rate of photic driving response in migraineurs is presumed to reflect brain hypersensitivity, and it may be related to involvement of anterior cingulate and prefrontal cortex for sensibilization of the limbic system. doi:10.1016/j.clinph.2008.01.068
doi:10.1016/j.clinph.2008.01.066
42. Confirmation study of EEG source by sLORETA with SPECT on acute cerebral cortical infarction—Yuya Hoshino, Hideaki Tanaka, Tomohiro Ogawa, Yuka Watanabe, Akinori Hozumi, Koichi Hirata Dokkyo Medical University, Tochigi, Japan) We evaluated the EEG sources with standardized low-resolution brain electromagnetic tomography (sLORETA) and cerebral
44. Automatic detection of abnormal EEG spikes in the routine photic driving study—Shigeto Nishida, Takenao Sugi, Akio Ikeda, Takashi Nagamine, Hiroshi Shibasaki, Masatoshi Nakamura Fukuoka Institute of Technology, Fukuoka, Japan) A method for detecting spikes in EEG in response to intermittent photic stimulation was proposed as a part of an automatic integrative interpretation system of awake EEG. The spikes were
e86
Japanese Society of Clinical Neurophysiology / Clinical Neurophysiology 119 (2008) e75–e93
detected by considering properties of spike and slow components separately, and their simultaneous emergence in adjacent region of the scalp, by combining a morphological filter with the similarity coefficient. The newly proposed method was tested for the photic driving EEG data containing spikes and also for unique spikes with positive peaks. This was satisfactory for spike detection. By introducing the present method in the automatic integrative interpretation system that has been developed by our colleagues, the new system becomes a more powerful tool for routine EEG evaluation. doi:10.1016/j.clinph.2008.01.069
45. Magnitude of EEG–EMG coherence during isometric contraction in young healthy subjects—Tatsuya Suzuki, Junichi Ushiba, Yoshihisa Masakado Keio University, Kanagawa, Japan) Electroencephalogram (EEG) recorded over the primary motor cortex is known to be coherent with the contralateral electromyogram (EMG) of voluntarily contracted muscles, and coherence analysis can evaluate such linear correlation quantitatively. It has been tacitly known that magnitude of EEG–EMG coherence varies among healthy subjects, but it remains unclear what factors are influencing the relationship. In this study, we recorded EEG close to foot area of the motor cortex and EMG from the right tibialis anterior muscle during moderate isometric ankle dorsiflexion, and calculated EEG–EMG coherence in 102 young healthy subjects (53 males, 49 females, 19–35 age), As a result, sixty-five subjects showed statistically significant magnitudes of coherency, and sixty subjects of them showed the significant EEG–EMG coherence peak in 15–35 Hz bands. No physical factors such as age, gender, and height, correlated with the magnitudes of the significant EEG–EMG coherence, whereas the phase difference of EEG and EMG in the coherent frequency band reflecting the conduction time of the motor command depended on the height. We concluded that the neural activity in the corticospinal tract of young healthy subjects tend to oscillate in 15–35 Hz, independently to their age, gender and height. doi:10.1016/j.clinph.2008.01.070
46. The effect of emotional stimulus using exploratory eye movements on left and right scanning function in schizophrenic patients—Chizuko Kawabe, Hironobu Nakayama, Kiichiro Morita Kurume University, Fukuoka, Japan) To characterize the left and right scanning function and the effect of emotion in schizophrenic patients, exploratory eye movements were recorded as biological marks in 18 schizophrenic patients and 18 age- and sex-matched healthy controls. The total eye scanning length (TESL) and total number of gaze points (TNGPs) in the left and right visual fields of the screen were calculated as the subjects viewed babies’ or mothers’ smiling faces, crying faces, and neutral faces. TESL of patients was shorter than that of controls for all faces. Left TNGPs for all mothers’ faces, for babies’ smiling face and crying face were lower in patients than in controls. Right TNGPs for the babies’ neutral face were
higher in patients than in controls. In patients, left TNGPs for all babies’ faces were lower than right TNGPs for all babies’ faces. In patients, left and right TNGPs for babies’ neutral face were higher than for babies’ smiling face and crying face. Patients’ eye movements in the left visual field of screen and neutral emotion were clearly different from those of controls, suggesting that visual cognitive function is impaired in schizophrenic patients. doi:10.1016/j.clinph.2008.01.071
47. Study of exploratory eye movements in asperger’s syndrome—Chiyomi Egami, Kiichiro Morita, Youhei Ishii, Yushiro Yamashit, Toyojiro Matuishi Kurume University School of Medicine, Fukuoka, Japan) To evaluate the characteristics of visual cognitive functions in patients with asperger’s syndrome, we examined exploratory eye movements in 12 patients and age-matched 12 healthy controls. All subjects and their parents gave written informed consent. The Ethics Committee of Kurume University approved the present study. Subjects were required to view a series of six pictures; picture 1 is simple circles (control), picture 2 smiling faces, picture 3 smiling faces with two lines beside the mouth, picture 4 was the same as picture 3, picture 5 was sight seen, and picture 6 was the same as picture1. Exploratory eye movements were analyzed with regard to three parameters: total number of gazing points (TNGPs), total eye scanning length (TESL) of gazing points, and response search score (RSS) on the right half and the left of the screen. Both TESL and TNGP in the healthy group was significantly longer and larger than those of patients, except for viewing sight seen. RSS of the health group were significantly larger than that of patients. Both left and right RSSs were significantly larger in the health group than in patients. This study indicated that TNGPs, TESL, and RSSs are useful markers of visual cognitive function in patients with asperger’s syndrome. doi:10.1016/j.clinph.2008.01.072
48. Evaluation of behavior inhibition using saccadic eye movement in the children with frontal paroxysmal discharges during awaking state—Yusuke Goto, Yoshimi Kaga, Kazuo Hatakeyama, Hideaki Kanemura, Kakurou Aoyagi, Dai Yamashiro, Hiromi Hosaka, Kanji Sugita, Masao Aihara University of Yamanashi, Yamanashi, Japan) Behavior inhibition, which is ascribed to the frontal cortex, refers to three processes: inhibiting the initial prepotent response: stopping an ongoing response; interference control from disruption, impairments of which lead to secondary executive dysfunctions. The aim of the present study is to investigate the saccadic parameters of reflexive response in the children with frontal paroxysmal discharges (FPDs) presenting with developmental disorders, using memory-guided saccade task (MGST) and antisaccade task. The subjects were 4 patients with FPD during awake state (mean age 11.9 years, range 10–15 years). Fifteen age-matched normal children served as control. Three patients showed more anticipatory errors than controls on the MGST, and two patients more directional errors on the antisaccade task. The patients also