Papers - ENATSU Rei

海馬・後帯状皮質間の機能的連絡 皮質間誘発電位(CCEP)研究(The functional connectivity between hippocampus and posterior cingulate: A Corticocortical evoked potentials (CCEP) study)

久保田 有一, 江夏 怜, Nair Dileep, Najm Imad

臨床神経生理学 ( (一社)日本臨床神経生理学会 )  39 ( 5 ) 427 - 427  2011.10

脳機能を有するてんかん原性皮質形成異常に対する覚醒下手術

三國 信啓, 西田 南海子, 多喜 純也, 江夏 怜, 橋本 信夫, 池田 昭夫, 松本 理器, 早瀬 ヨネ子, 天野 殖

てんかん研究 ( (一社)日本てんかん学会 )  28 ( 3 ) 436 - 436  2011.01

内側側頭葉てんかんでのmagnetometer、gradiometer同時記録によるMEG spike検出の有用性

江夏 怜, 三國 信啓, 多喜 純也, 西田 南海子, 橋本 信夫, 松本 理器, 池田 昭夫, 松林 潤, Begum Tahamina, 臼井 桂子, 長峯 隆, 福山 秀直

てんかん研究 ( (一社)日本てんかん学会 )  28 ( 3 ) 442 - 442  2011.01

Accentuated cortico-cortical evoked potentials in neocortical epilepsy in areas of ictal onset.

Masaki Iwasaki, Rei Enatsu, Riki Matsumoto, Eric Novak, Baburaj Thankappen, Zhe Piao, Tim O'Connor, Karl Horning, William Bingaman, Dileep Nair

Epileptic disorders : international epilepsy journal with videotape   12 ( 4 ) 292 - 302  2010.12  [International journal]

　View Summary

OBJECTIVE: To determine whether patients with neocortical epilepsy show evidence for increased excitability measured by cortico-cortical evoked potentials (CCEPs) in ictal-onset regions. METHODS: In patients undergoing intracranial recordings with subdural electrodes for epilepsy surgery, we measured amplitudes, latencies, and stimulus thresholds of CCEPs near ictal onset zones (iCCEPs), and compared with adjacent neocortex not associated with ictal EEG (nCCEP). CCEP amplitude and latency measurements were made with each stimulation site, using graded stimulation intensities. RESULTS: Ten patients were included in this study. CCEPs were recorded in eight of 10 patients. The first negative (N1) iCCEP amplitude was higher than that of nCCEP in seven of the eight patients. In the group analysis, this difference was statistically significant. In three of these patients, the difference was individually significant. In one patient, the amplitude was higher in nCCEP than iCCEP and the area selected as nCCEP was within primary eloquent cortex. There was no significant difference seen in latency changes or stimulus threshold. CONCLUSIONS: Accentuated CCEP amplitudes near ictal onset zones could reflect an increased excitability of the cortex associated with the epileptogenic zone in some patients with neocortical epilepsy. The response of the neocortex to low-frequency stimulation may vary depending on the presence or absence of intrinsic epileptogenicity.

DOI PubMed

Somatosensory evoked magnetic fields following electric tongue stimulation using pin electrodes.

Hitoshi Maezawa, Kazuya Yoshida, Takashi Nagamine, Jun Matsubayashi, Rei Enatsu, Kazuhisa Bessho, Hidenao Fukuyama

Neuroscience research   62 ( 2 ) 131 - 9  2008.10  [International journal]

　View Summary

Quantitative evaluation of the sensory disturbance of the tongue is important clinically. However, because the conventional electrophysiological approach to the peripheral nerve cannot be used in the mandible owing to the deep route of the lingual nerve, we applied evoked potentials in the central nervous system. Somatosensory evoked magnetic fields (SEFs) following electric stimulation were recorded in 10 healthy subjects by means of pin electrodes placed on the tongue mucosa. Three or four components (P25m, P40m, P60m, and P80m) were identified over the contralateral hemisphere with unilateral stimulation. Because none of the components were consistently detected in all subjects, we evaluated the root mean square (RMS) of 18 channels over the contralateral hemisphere. To estimate the activated cortical response, we calculated the difference in mean RMS amplitude between 10 and 150 ms and that of the baseline period (aRMS=RMS[10, 150]-RMS[-50, -5]). The aRMS values for right-sided and left-sided stimulation were 10.18+/-7.92 and 10.99+/-8.98 fT/cm, respectively, and the mean laterality index, expressed by [(left-right)/(left+right)] was 0.025+/-0.104. This parameter can be useful for evaluating patients with unilateral sensory abnormality of the tongue.

DOI PubMed

大脳内側部病変に対する開頭手術の工夫と注意点

平井 収, 松本 眞人, 朝日 稔, 江夏 怜

日本脳神経外科学会総会CD-ROM抄録集 ( (一社)日本脳神経外科学会 )  67回   2B - 07  2008.10

Usefulness of MEG magnetometer for spike detection in patients with mesial temporal epileptic focus.

R Enatsu, N Mikuni, K Usui, J Matsubayashi, J Taki, T Begum, R Matsumoto, A Ikeda, T Nagamine, H Fukuyama, N Hashimoto

NeuroImage   41 ( 4 ) 1206 - 19  2008.07  [International journal]

　View Summary

The present study investigated the sensitivity of magnetoencephalography (MEG) for spikes depending on sensor type in patients with mesial temporal epileptic focus. We recorded MEG in 6 patients with mesial temporal epileptic focus using two sensor types (magnetometer and gradiometer) simultaneously. The number of spikes detected and the corresponding equivalent current dipole (ECD) parameters (distance from the coordinated head center (radius), and dipole moment) were evaluated with respect to sensor type. Among 426 MEG 'consensus spikes' determined by 3 reviewers, 378 spikes satisfied the predetermined criteria for source localization. Comparing ECD parameters, spikes detected by magnetometer alone displayed a smaller radius and larger dipole moment than those detected by gradiometer alone. Spikes estimated in the mesial temporal area were more frequently detected by magnetometer alone (38.5%) than by gradiometer alone (11.5%), whereas spikes in the lateral temporal area were detected less by magnetometer alone (3.7%) than by gradiometer alone (53.9%). The present results suggest that a magnetometer is advantageous for spike detection in patients with mesial temporal epileptic focus. This also implies the higher sensitivity of magnetometer for deep sources.

DOI PubMed

特発性脊髄硬膜外血腫の2例

朝日 稔, 平井 収, 松本 眞人, 江夏 怜

脊髄外科 ( (一社)日本脊髄外科学会 )  22 ( 1 ) 49 - 49  2008.06

脳梗塞との鑑別を要した胸部大動脈解離の一例

松本 眞人, 平井 収, 朝日 稔, 江夏 怜

日本脳神経外科救急学会プログラム・抄録集 ( (NPO)日本脳神経外科救急学会 )  13回   84 - 84  2008.01

慢性硬膜下血腫における最近の動向と再手術について

江夏 怜, 松本 眞人, 平井 収

日本脳神経外科学会総会CD-ROM抄録集 ( (一社)日本脳神経外科学会 )  66回   3K - 9  2007.10

Clinical significance of preoperative fibre-tracking to preserve the affected pyramidal tracts during resection of brain tumours in patients with preoperative motor weakness.

Nobuhiro Mikuni, Tsutomu Okada, Rei Enatsu, Yukio Miki, Shin-ichi Urayama, Jun A Takahashi, Kazuhiko Nozaki, Hidenao Fukuyama, Nobuo Hashimoto

Journal of neurology, neurosurgery, and psychiatry   78 ( 7 ) 716 - 21  2007.07  [International journal]

　View Summary

OBJECTIVE: To clarify the clinical usefulness of preoperative fibre-tracking in affected pyramidal tracts for intraoperative monitoring during the removal of brain tumours from patients with motor weakness. METHODS: We operated on 10 patients with mild to moderate motor weakness caused by brain tumours located near the pyramidal tracts under local anaesthesia. Before surgery, we performed fibre-tracking imaging of the pyramidal tracts and then transferred this information to the neuronavigation system. During removal of the tumour, motor function was evaluated with motor evoked potentials elicited by cortical/subcortical electrical stimulation and with voluntary movement. RESULTS: In eight patients, the locations of the pyramidal tracts were estimated preoperatively by fibre-tracking; motor evoked potentials were elicited on the motor cortex and subcortex close to the predicted pyramidal tracts. In the remaining two patients, in which fibre-tracking of the pyramidal tracts revealed their disruption surrounding the tumour, cortical/subcortical electrical stimulation did not elicit responses clinically sufficient to monitor motor function. In all cases, voluntary movement with mild to moderate motor weakness was extensively evaluated during surgery and was successfully preserved postoperatively with appropriate tumour resection. CONCLUSIONS: Preoperative fibre-tracking could predict the clinical usefulness of intraoperative electrical stimulation of the motor cortex and subcortical fibres (ie, pyramidal tracts) to preserve affected motor function during removal of brain tumours. In patients for whom fibre-tracking failed preoperatively, awake surgery is more appropriate to evaluate and preserve moderately impaired muscle strength.

PubMed

集学的治療が奏功した大腸癌脳転移の1例

岡本 正吾, 平田 英周, 江夏 怜, 山内 寛子, 小泉 直樹, 山神 和彦, 小柴 孝友, 藤本 康二, 西沢 弘泰, 坂野 茂

日本消化器外科学会雑誌 ( (一社)日本消化器外科学会 )  40 ( 7 ) 1411 - 1411  2007.07

Clinical impact of integrated functional neuronavigation and subcortical electrical stimulation to preserve motor function during resection of brain tumors.

Nobuhiro Mikuni, Tsutomu Okada, Rei Enatsu, Yukio Miki, Takashi Hanakawa, Shin-ichi Urayama, Kenichiro Kikuta, Jun A Takahashi, Kazuhiko Nozaki, Hidenao Fukuyama, Nobuo Hashimoto

Journal of neurosurgery   106 ( 4 ) 593 - 8  2007.04  [International journal]

　View Summary

OBJECT: The authors evaluated the clinical impact of combining functional neuronavigation with subcortical electrical stimulation to preserve motor function following the removal of brain tumors. METHODS: Forty patients underwent surgery for treatment of brain tumors located near pyramidal tracts that had been identified by fiber tracking. The distances between the electrically stimulated white matter and the pyramidal tracts were measured intraoperatively with tractography-integrated functional neuronavigation, and correlated with subcortical motor evoked potentials (MEPs) and clinical symptoms during and after resection of the tumors. Motor function was preserved after appropriate tumor resection in all cases. In 18 of 20 patients, MEPs were elicited from the subcortex within 1 cm of the pyramidal tracts as measured using intraoperative neuronavigation. During resection, improvement of motor weakness was observed in two patients, whereas transient mild motor weakness occurred in two other patients. In 20 patients, the distances between the stimulated subcortex and the estimated pyramidal tracts were more than I cm, and MEPs were detected in only three of these patients following stimulation. CONCLUSIONS: Intraoperative functional neuronavigation and subcortical electrical stimulation are complementary techniques that may facilitate the preservation of pyramidal tracts around 1 cm of resected tumors.

PubMed

Fibers from the dorsal premotor cortex elicit motor-evoked potential in a cortical dysplasia.

Nobuhiro Mikuni, Tsutomu Okada, Junya Taki, Riki Matsumoto, Namiko Nishida, Rei Enatsu, Takashi Hanakawa, Akio Ikeda, Yukio Miki, Shin-ichi Urayama, Hidenao Fukuyama, Nobuo Hashimoto

NeuroImage   34 ( 1 ) 12 - 8  2007.01  [International journal]

　View Summary

OBJECTIVE: To identify the fibers originating from the dorsal premotor cortex (dorsal PMC) that contribute to motor-evoked potentials (MEP), we have applied integrated functional neuronavigation and awake surgery during removal of an epileptic cortical dysplasia located in the right premotor cortex. METHODS: Chronic subdural electrodes were employed for functional mapping during a routine invasive evaluation for intractable epilepsy. After the fibers originating from the dorsal PMC were plotted into the tractography-integrated functional neuronavigation, subcortical MEPs and clinical symptoms were examined during resection of the epileptogenic dorsal PMC. RESULTS: During removal of the epileptogenic area, MEPs were elicited by electrical stimulation of the fibers originating from the dorsal PMC, which were separated from the pyramidal tracts from the precentral gyrus. Resection of the dorsal PMC and its fibers caused a transient dysmetric movement of the left toe without motor weakness. CONCLUSION: Functional corticospinal tract fibers originating from the dorsal PMC can be defined and removed safely under local anesthesia with the aid of integration of functional neuronavigation and subcortical electrical stimulation.

PubMed

Comparison between motor evoked potential recording and fiber tracking for estimating pyramidal tracts near brain tumors.

Nobuhiro Mikuni, Tsutomu Okada, Namiko Nishida, Junya Taki, Rei Enatsu, Akio Ikeda, Yukio Miki, Takashi Hanakawa, Hidenao Fukuyama, Nobuo Hashimoto

Journal of neurosurgery   106 ( 1 ) 128 - 33  2007.01  [International journal]

　View Summary

OBJECT: The utility of subcortical electrical stimulation and fiber tracking were compared to estimate the pyramidal tract near brain tumors. METHODS: In 22 patients, the white matter at the bottom of a tumor was electrically stimulated near the fiber tracking of the pyramidal tract shown on a neuronavigation system. The distance between the center of the fiber tracking of these tracts and the stimulated region was measured and defined as the motor evoked potential (MEP) response. The MEP was consistently produced at distances less than 7 mm (six patients), but was consistently absent at distances more than 13 mm (seven patients) from the fiber tracking of the pyramidal tracts. In the nine patients in whom the distance was between 8 and 12 mm, an MEP was elicited when stimulation was applied at the level of the corona radiata. Motor function was preserved or even improved with appropriate tumor resection in all patients. CONCLUSIONS: The anteroposteriorly running superior longitudinal fasciculus could cause complications in the fiber tracking of upper-extremity motor pathways at the level of the corona radiata. During resection of tumors located near the corona radiata, subcortical electrical stimulation should be applied at some distance from the pyramidal tract, as estimated by fiber tracking.

PubMed

Wada memory test scoreの呈示物間相違

菊池 隆幸, 三國 信啓, 多喜 純也, 江夏 怜, 池田 昭夫, 福山 秀直, 橋本 信夫

臨床神経生理学 ( (一社)日本臨床神経生理学会 )  34 ( 5 ) 494 - 494  2006.10

聴覚刺激によって発生するノンレム睡眠時の長潜時脳磁場成分の電流源の探索

松林 潤, 長峯 隆, 前澤 仁志, 江夏 怜, 臼井 桂子, 立花 直子, 福山 秀直

臨床神経生理学 ( (一社)日本臨床神経生理学会 )  34 ( 5 ) 405 - 405  2006.10

ヒトの難治てんかんにおけるてんかん焦点と2次性焦点間の機能連関 CCEPによる検討

松本 理器, 池田 昭夫, 多喜 純也, 井内 盛遠, 三枝 隆博, 人見 健文, 木下 真幸子, 江夏 怜, 三國 信啓, 福山 秀直, 高橋 良輔

てんかん研究 ( (一社)日本てんかん学会 )  24 ( 3 ) 185 - 185  2006.08

Evidence for a wide distribution of negative motor areas in the perirolandic cortex.

Nobuhiro Mikuni, Shinji Ohara, Akio Ikeda, Naoki Hayashi, Namiko Nishida, Junya Taki, Rei Enatsu, Riki Matsumoto, Hiroshi Shibasaki, Nobuo Hashimoto

Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology   117 ( 1 ) 33 - 40  2006.01  [International journal]

　View Summary

OBJECTIVE: The perirolandic regions were studied by extensive electrical stimulation to clarify the topography and somatotopic distribution of negative motor areas (NMAs) and examine the clinical significance of these areas. METHODS: We evaluated the cortical function elicited by electrical stimulation in 30 patients with tumors or intractable epilepsy. The somatotopic distribution of NMAs was examined by localizing these regions using Talairach's bicommissural reference system. NMAs within the lesions of two patients were removed under local anesthesia. RESULTS: We obtained negative motor responses following the stimulation of 30 electrodes in 15 patients. On the lateral brain surface, the majority of NMAs for the upper extremities were distributed broadly throughout the premotor cortex, while NMAs for the tongue were only found in the inferior frontal gyrus of the dominant hemisphere. During removal of the NMAs within the lesions of two patients, we documented transient hand clumsiness in one patient. CONCLUSIONS: NMAs were widely distributed throughout the perirolandic area, as well as the previously reported regions in the inferior frontal gyrus. These areas likely function in the control of skilled movements; dysfunction of such movements transiently follows resection of these regions, but is subsequently well compensated for after surgery. SIGNIFICANCE: The localization and consequences of resection of NMAs suggests their clinical significance in motor control.

PubMed

Evaluation of adverse effects in intracarotid propofol injection for Wada test.

N Mikuni, M Takayama, T Satow, S Yamada, N Hayashi, N Nishida, J Taki, R Enatsu, A Ikeda, S Miyamoto, N Hashimoto

Neurology   65 ( 11 ) 1813 - 6  2005.12  [International journal]

　View Summary

The authors evaluated adverse effects of intracarotid propofol injection during a Wada test and their risk factors in 58 patients. Nineteen patients had an adverse effect, mostly in patients receiving more than 10 mg. For patients older than age 55 years or those requiring an injection dose greater than 20 mg to produce hemiplegia, propofol should be injected slowly and patients monitored for excitatory movements.

PubMed