Neurological Surgery 脳神経外科46巻1号

2018年01月発行

連載 機能的脳神経外科最新の動向【新連載】

（1）EEG-fMRIを用いた焦点診断

著者： 前澤聡¹² エピファニオバガリナオ¹ 中坪大輔² 若林俊彦²

所属機関： ¹名古屋大学脳とこころの研究センター ²名古屋大学大学院医学系研究科脳神経外科

ページ範囲：P.67 - P.79

Ⅰ．はじめに—EEG-fMRIの概念と意義—
　てんかんの有病率は人口1,000人あたり4〜8人であり，中枢神経系疾患の中では頻度の高い疾患の1つであるが，その約30%では薬剤治療による発作抑制が得られない．このような薬剤抵抗性の難治性てんかんに対しては外科治療を考慮するが，成功の鍵となるのが焦点診断である．
　焦点診断に重要なのは，第1に症候学であるが，検査項目として最初に挙げられるのは依然として脳波（electroencephalography：EEG）である．てんかんは脳内の過剰な，もしくは同期した異常神経活動に基づく一過性の徴候・症状と定義され，大脳皮質の神経活動の評価は必須である．脳波で得られる神経活動は，大脳皮質の主に第5・6層にある錐体細胞の尖頂樹状突起に数多く形成されているシナプスの，興奮性シナプス後電位の総和であり，これを記録し電気生理学的に評価する脳波の重要性は，さまざまなモダリティが利用可能となった現在でも揺るぎない．脳波に次いで挙げられる重要な検査は，MRIであろう．その高い空間分解能と著しい画像解析技術の進歩は，単に解剖学的構造を高解像度で可視化するのみではなく，その血流変化，代謝，そして機能を反映した画像，つまり機能的MRI画像（functional MRI：fMRI）を取得することを可能としている．

参考文献

1) Allen PJ, Josephs O, Turner R：A method for removing imaging artifact from continuous EEG recorded during functional MRI. Neuroimage 12：230-239, 2000

2) An D, Fahoum F, Hall J, Olivier A, Gotman J, Dubeau F：Electroencephalography/functional magnetic resonance imaging responses help predict surgical outcome in focal epilepsy. Epilepsia 54：2184-2194, 2013

3) Bagshaw AP, Aghakhani Y, Bénar CG, Kobayashi E, Hawco C, Dubeau F, Pike GB, Gotman J：EEG-fMRI of focal epileptic spikes：analysis with multiple haemodynamic functions and comparison with gadolinium-enhanced MR angiograms. Hum Brain Mapp 22：179-192, 2004

4) Bénar CG, Gross DW, Wang Y, Petre V, Pike B, Dubeau F, Gotman J：The BOLD response to interictal epileptiform discharges. Neuroimage 17：1182-1192, 2002

5) Berg AT, Vickrey BG, Langfitt JT, Sperling MR, Walczak TS, Shinnar S, Bazil CW, Pacia SV, Spencer SS：The multicenter study of epilepsy surgery：recruitment and selection for surgery. Epilepsia 44：1425-1433, 2003

6) Cardinale F, Cossu M：SEEG has the lowest rate of complications. J Neurosurg 122：475-477, 2015

7) Coan AC, Chaudhary UJ, Grouiller F, Campos BM, Perani S, De Ciantis A, Vulliemoz S, Diehl B, Beltramini GC, Carmichael DW, Thornton RC, Covolan RJ, Cendes F, Lemieux L：EEG-fMRI in the presurgical evaluation of temporal lobe epilepsy. J Neurol Neurosurg Psychiatry 87：642-649, 2016

8) Englot DJ, Konrad PE, Morgan VL：Regional and global connectivity disturbances in focal epilepsy, related neurocognitive sequelae, and potential mechanistic underpinnings. Epilepsia 57：1546-1557, 2016

9) Flanagan D, Abbott DF, Jackson GD：How wrong can we be? The effect of inaccurate mark-up of EEG/fMRI studies in epilepsy. Clin Neurophysiol 120：1637-1647, 2009

10) Glover GH：Deconvolution of impulse response in event-related BOLD fMRI. Neuroimage 9：416-429, 1999

11) Gotman J, Grova C, Bagshaw A, Kobayashi E, Aghakhani Y, Dubeau F：Generalized epileptic discharges show thalamocortical activation and suspension of the default state of the brain. Proc Natl Acad Sci U S A 102：15236-15240, 2005

12) Grouiller F, Vercueil L, Krainik A, Segebarth C, Kahane P, David O：Characterization of the hemodynamic modes associated with interictal epileptic activity using a deformable model-based analysis of combined EEG and functional MRI recordings. Hum Brain Mapp 31：1157-1173, 2010

13) Grouiller F, Thornton RC, Groening K, Spinelli L, Duncan JS, Schaller K, Siniatchkin M, Lemieux L, Seeck M, Michel CM, Vulliemoz S：With or without spikes：localization of focal epileptic activity by simultaneous electroencephalography and functional magnetic resonance imaging. Brain 134（Pt 10）：2867-2886, 2011

14) Ives JR, Warach S, Schmitt F, Edelman RR, Schomer DL：Monitoring the patient's EEG during echo planar MRI. Electroencephalogr Clin Neurophysiol 87：417-420, 1993

15) Jacobs J, Kobayashi E, Boor R, Muhle H, Stephan W, Hawco C, Dubeau F, Jansen O, Stephani U, Gotman J, Siniatchkin M：Hemodynamic responses to interictal epileptiform discharges in children with symptomatic epilepsy. Epilepsia 48：2068-2078, 2007

16) Jacobs J, Levan P, Moeller F, Boor R, Stephani U, Gotman J, Siniatchkin M：Hemodynamic changes preceding the interictal EEG spike in patients with focal epilepsy investigated using simultaneous EEG-fMRI. Neuroimage 45：1220-1231, 2009

17) Matsuda K, Mihara T, Tottori T, Otubo T, Usui N, Baba K, Matsuyama N, Yagi K：Neuroradiologic findings in focal cortical dysplasia：histologic correlation with surgically resected specimens. Epilepsia 42（Suppl 6）：29-36, 2001

18) Muthukumaraswamy SD, Evans CJ, Edden RA, Wise RG, Singh KD：Individual variability in the shape and amplitude of the BOLD-HRF correlates with endogenous GABAergic inhibition. Hum Brain Mapp 33：455-465, 2012

19) Newton MR, Austin MC, Chan JG, McKay WJ, Rowe CC, Berkovic SF：Ictal SPECT using technetium-99m-HMPAO：methods for rapid preparation and optimal deployment of tracer during spontaneous seizures. J Nucl Med 34：666-670, 1993

20) Pittau F, Fahoum F, Zelmann R, Dubeau F, Gotman J：Negative BOLD response to interictal epileptic discharges in focal epilepsy. Brain Topogr 26：627-640, 2013

21) Pittau F, Ferri L, Fahoum F, Dubeau F, Gotman J：Contributions of EEG-fMRI to assessing the epileptogenicity of focal cortical dysplasia. Front Comput Neurosci 11：8, 2017. doi：10.3389/fncom.2017.00008

22) Raichle ME, MacLeod AM, Snyder AZ, Powers WJ, Gusnard DA, Shulman GL：A default mode of brain function. Proc Natl Acad Sci U S A 98：676-682, 2001

23) Tanaka N, Stufflebeam SM：Clinical application of spatiotemporal distributed source analysis in presurgical evaluation of epilepsy. Front Hum Neurosci 8：62, 2014. doi：10.3389/fnhum.2014.00062

24) Thornton R, Laufs H, Rodionov R, Cannadathu S, Carmichael DW, Vulliemoz S, Salek-Haddadi A, McEvoy AW, Smith SM, Lhatoo S, Elwes RD, Guye M, Walker MC, Lemieux L, Duncan JS：EEG correlated functional MRI and postoperative outcome in focal epilepsy. J Neurol Neurosurg Psychiatry 81：922-927, 2010

25) Thornton R, Vulliemoz S, Rodionov R, Carmichael DW, Chaudhary UJ, Diehl B, Laufs H, Vollmar C, McEvoy AW, Walker MC, Bartolomei F, Guye M, Chauvel P, Duncan JS, Lemieux L：Epileptic networks in focal cortical dysplasia revealed using electroencephalography-functional magnetic resonance imaging. Ann Neurol 70：822-837, 2011

26) van Houdt PJ, de Munck JC, Leijten FS, Huiskamp GJ, Colon AJ, Boon PA, Ossenblok PP：EEG-fMRI correlation patterns in the presurgical evaluation of focal epilepsy：a comparison with electrocorticographic data and surgical outcome measures. Neuroimage 75：238-248, 2013

27) Varotto G, Tassi L, Franceschetti S, Spreafico R, Panzica F：Epileptogenic networks of type II focal cortical dysplasia：a stereo-EEG study. Neuroimage 61：591-598, 2012

28) Vulliemoz S, Carmichael DW, Rosenkranz K, Diehl B, Rodionov R, Walker MC, McEvoy AW, Lemieux L：Simultaneous intracranial EEG and fMRI of interictal epileptic discharges in humans. Neuroimage 54：182-190, 2011

29) Walz JM, Pedersen M, Omidvarnia A, Semmelroch M, Jackson GD：Spatiotemporal mapping of epileptic spikes using simultaneous EEG-functional MRI. Brain 140：998-1010, 2017

30) Zijlmans M, Huiskamp G, Hersevoort M, Seppenwoolde JH, van Huffelen AC, Leijten FS：EEG-fMRI in the preoperative work-up for epilepsy surgery. Brain 130（Pt 9）：2343-2353, 2007