Spatiotemporal EEG analysis and distributed source estimation in presurgical epilepsy evaluation

Journal of Clinical Neurophysiology

Volumn 16, Issue 3, 1999, Pages 239-266

  Michel, Christoph M ^a   De Peralta, Rolando Grave ^b   Lantz, Göran ^b   Andino, Sara Gonzalez ^b   Spinelli, Laurent ^b   Blanke, Olaf ^b   Landis, Theodor ^b   Seeck, Margitta ^b  

^a Faculty of Medicine   (Switzerland)

^b NONE

Author keywords

EEG segmentation; EEG source reconstruction; Epilepsy; Frequency analysis; Functional magnetic resonance imaging; Linear inverse solutions

Indexed keywords

BRAIN ELECTROPHYSIOLOGY; CLINICAL ARTICLE; ELECTROENCEPHALOGRAM; EPILEPSY; EPILEPTIC FOCUS; FREQUENCY ANALYSIS; HUMAN; IMAGE RECONSTRUCTION; INTERMETHOD COMPARISON; LINEAR SYSTEM; MATHEMATICAL ANALYSIS; NUCLEAR MAGNETIC RESONANCE; POWER SPECTRUM; REVIEW; SPIKE WAVE; THREE DIMENSIONAL IMAGING;

EID: 0032982799     PISSN: 07360258     EISSN: None     Source Type: Journal    
DOI: 10.1097/00004691-199905000-00005     Document Type: Review

References (127)

1. Achim A, Richer F, Saint-Hilaire J. Methodological considerations for the evaluation of spatio-temporal source models. Electroenceph Clin Neurophysiol 1991;79:227-40.
2. Alarcon G, Binnie CD, Elwes RDC, Polkey CE. Power spectrum and intracranial EEG patterns at seizure onset in partial epilepsy. Electroenceph Clin Neurophysiol 1995;94:326-37.
3. Alarcon G, Guy CN, Binnie CD, Walker SR, Elwes RDC, Polkey CE. Intracerebral propagation of interictal activity in partial epilepsy: implications for source localisation. J Neurol Neurosurg Psychiatry 1994;57:435-49.
4. Babiloni F, Babiloni C, Carducci F, Fattorini C, Anello L, Onorati P, Urbano A. A high resolution EEG: a new model-dependent spatial deblurring method using a realistically-shaped MR-constructed subject's head mo del. Electroenceph Clin Neurophysiol 1997; 102:69-80.
5. Backus GE, Gilbert JF. Numerical applications of a formalism for geophysical inverse problems. Geophys J Roy Astron Soc 1967; 13:247-76.
6. Backus GE, Gilbert JF. The resolving power of gross earth data. Geophys J Roy Astron Soc 1968;16:169-205.
7. Backus GE, Gilbert JF. Uniqueness in the inversion of gross earth data. Phil Trans R Soc 1970;266:123-92.
8. Barr RC, Pilkington TC, Boineau JP, Rogers CL. An inverse electrocardiographic solution with an on-off model. IEEE Trans Biomed Eng 1970; 17:49-57.
9. Barth DS, Sutherling W Engel J, Beatty J. Neuromagnetic localization of epileptiform spike activity in the human brain. Science 1982; 218:891-94.
10. Baumgartner C, Lidinger G, Ebner A, Aull S, Series W, Olbrich A, Luger S, Czech T, Burgess R, Lüders H. Propagation of interictal epileptic activity in temporal lobe epilepsy. Neurology 1995;45: 118-22.
11. Bertero M, De Mol C, Pike ER. Linear inverse problems with discrete data. I: General formulation and singular system analysis. Inverse Problem 1985;1:301-30.
12. Bertero M, De Mol C, Pike ER. Linear inverse problems with discrete data. II. Stability and regularization. Inverse Problem 1988;4:573-94.
13. Blanke O, Seeck M, Landis T, Michel CM. Temporal and spatial seizure onset localization using frequency-domain source localization [abstract]. J Clin Neurophysiol 1997;14:452.
14. Blume WT, Young GB, Lemieux JF. EEG morphology of partial epileptic seizures. Electroenceph Clin Neurophysiol 1984;57:295-302.
15. Brandeis D, Lehmann, D. Event-related potentials of the brain and cognitive processes: approaches and applications. Neuropsychologia 1986;24:151-68.
16. Brandeis D, Lehmann D. Segments of ERP map series reveal landscape changes with visual attention and subjective contours. Electroenceph Clin Neurophysiol 1989;73:507-19.
17. Bullmore ET, Brammer MJ, Bourlon P, Alarcon G, Polkey CE, Elwes R, and Binnie CD. Fractal analysis of electroencephalographic signals intracerebrally recorded during 35 epileptic seizures: evaluation of a new method for synoptic visualisation of ictal events. Electroenceph Clin Neurophysiol 1994;91:337-45.
18. Cabrera Fernandez, D, Grave de Peralta R, Gonzalez Andino S. Some limitations of spatio temporal source models. Brain Topography 1995;7:233-43.
19. Dale AM, Sereno MI. Improved localization of cortical activity by combining EEG and MEG with MRI cortical surface reconstruction: A linear approach. J Cogn Neurosci 1993;5:162-76.
20. Darcey TM, Williamson PD. Spatio-temporal EEG measures and their application to human intracranially recorded epileptic seizures. Electroenceph Clin Neurophysiol 1985;61:573-87.
21. Davies AR. Optimality in regularization. In: Pike ER, ed. Inverse problems in scattering and imaging. Bristol: Adam Hilger, 1991: 393-409.
22. Detre JA, Sirven JI, Alsop DC, O'Connor MJ, French JA. Localization of subclinical ictal activity by functional magnetic resonance imaging: correlation with invasive monitoring. Ann Neurol 1995; 38:618-24.
23. Dieckmann V, Becker W, Jürgens R, Kleiser B, Richter HP, Wollinsky KH. Localisation of epileptic foci with electric, magnetic and combined electromagnetic models. Electroenceph Clin Neurophysiol 1998;106:297-313.
24. Dierks T, Engelhardt W, Maurer K. Equivalent dipoles of FFT data visualize drug interaction at benzodiazepine receptors. Electroencephalogr Clin Neurophysiol 1993;86:231-37.
25. Duffy FH, Burchfiel JL, Lombroso CT. Brain electrical activity mapping (BEAM): A method for extending the clinical utility of EEG and evoked potential data. Ann Neurol 1979;5:309-21.
26. Ebersole JS. EEG dipole modelling in complex partial epilepsy. Brain Topography 1991;4:113-23.
27. Ebersole JS. Equivalent dipole modelling - a new EEG method for localisation of epileptogenic foci. In: Pedley TA, Meldrum BS, eds. Recent Advances in Epilepsy, Vol. 5, London: Churchill Livingston, 1992: 51-71.
28. Ebersole JS. Non-invasive localization of the epileptogenic focus by EEG dipole modelling. Acta Neurol Scand 1994;(suppl 152):20-28.
29. Ebersole JS, Pacia SV. Localization of temporal lobe foci by ictal EEG patterns. Epilepsia 1996; 37:386-99.
30. Ebersole JS, Wade PB. Spike voltage topography identifies two types of frontotemporal epileptic foci. Neurology, 1991;41:1425-33.
31. Fender DH. Source localization of brain electrical activity. In: Gevins AS, Remond A, eds. Handbook of electroencephalography and clinical neurophysiology, vol. 1: Methods of analysis of brain electrical and magnetic signals. Amsterdam: Elsevier, 1987:355-399.
32. Gath I, Feuerstein C, Pham DT, Rondouin G. On the tracking of rapid dynamic changes in seizure EEG. IEEE Trans Biomed Eng 1992; 39:952-58.
33. Gath I, Lehmann D, Bar-On E. Fuzzy clustering of EEG signals and vigilance performance. Int J Neurosc 1983;20:303-12.
34. Gath I, Michaeli A, Feuerstein C. A model for dual channel segmentation of the EEG signal. Biol Cybern 1991;64:225-30.
35. Geiger LR, Harner RN. EEG patterns at the time of focal seizure onset. Arch Neurol 1978;35:276-86.
36. Gevins A, Le J, Martin N, Brickett P, Desmond J, Reutter B. High resolution EEG: 124-channel recording, spatial deblurring and MRI integration methods. Electroenceph clin neurophysiol 1994; 90:337-58.
37. Gorodnitsky IF, George JS, Rao BD. Neuromagnetic source imaging with FOCUSS: a recursive weighted minimum norm algorithm. Electroenceph Clin Neurophysiol 1995;95:231-51.
38. Gotman J, Levtova V, Farine B. Graphic representation of the EEG during epileptic seizures. Electroenceph Clin Neurophysiol 1993; 87:206-14.
39. Grave de Peralta Menendez R, Gonzalez Andino SL. A critical analysis of linear inverse solutions. IEEE Trans Biomed Eng 1998a;4:440-48.
40. Grave de Peralta Menendez R, Gonzalez Andino SL. Distributed source models: standard solutions and new developments. In: Uhl C, ed. Analysis of neurophysiological brain functioning. Heidelberg: Springer Verlag, 1999a; 176-201.
41. th annual international conference of the IEEE-EMBS. Hong Kong, 1998b; 2143-6.
42. Grave de Peralta Menendez R, Gonzalez Andino SL. The Backus and Gilbert method for vector fields. Human Brain Mapping 1999b; 7:161-5.
43. Grave de Peralta Menendez R, Hauk O, Gonzalez Andino S, Vogt H, Michel. CM. Linear inverse solutions with optimal resolution kernels applied to the electromagnetic tomography. Human Brain Mapping 1997a; 5:454-67.
44. Grave de Peralta Menendez R, Gonzalez Andino S, Hauk O, Spinelli L, Michel CM. A linear inverse solution with optimal resolution properties: WROP. Biomedizinische Technik 1997b; 42:53-6.
45. Grave de Peralta Menendez R, Gonzalez Andino S, Lütkenhöner B. Figures of merit to compare linear distributed inverse solutions. Brain Topography 1996;9:117-24.
46. Greenblatt RE. Probabilistic reconstruction of multiple sources in the neuroelectromagnetic inverse problem. Inverse Problems 1993;9: 271-84.
47. Hämäläinen MS, Ilmoniemi RJ. Interpreting measured magnetic fields of the brain: Estimates of current distributions. Technical report TKK-F-A559. Helsinski University of Technology, 1984.
48. Hjorth B EEG analysis based on time domain properties. Electroenceph Clin Neurophysiol 1970;29:306-10.
49. Horan LG, Flowers NC. Simulation of the sequence of ventricular activation and the choice of an inverse solution. Med Res Eng 1967;7:28-35.
50. Huiskamp G, van Oosterom A. The depolarization sequence of the human heart surface computed from measured body surface potentials. IEEE Trans Biomed Eng 1988;35:1047-58.
51. Itil, TM, Shapiro, DM, Herrman, WM, Schulz, W, Morgan, V. HZI systems for EEG parametrization and classification of psychotropic drugs. Pharmacopsychiatria 1979;12:4-19.
52. Ives JR, Warach S, Schmitt F, Edelman RR, Schomer DL. Monitoring the patient's EEG during echo planar MRI. Electroenceph Clin Neurophysiol 1993;87:417-20.
53. Jackson GD, Connelly A, Cross JH, Gordon I, Gadian DG. Functional magnetic resonance imaging of focal seizures. Neurology 1994; 44:850-56.
54. John ER, Prichep LS, Easton P. Normative data banks and neurometrics. Basic concepts, methods and results of norm constructions. In: Gevins AS, Rémond A, eds. Handbook of electroencephalography and clinical neurophysiology. Volume I: methods of analysis of brain electrical and magnetic signals. Amsterdam: Elsevier, 1987:449-496.
55. Kinoshita T, Michel CM, Yagyu T, Lehmann D, Saito M. Diazepam and sulpiride effects on frequency domain EEG source localisations. Neuropsychobiol 1994;30:126-31.
56. Koenig T, Lehmann D. Microstates in language-related brain potential maps show noun-verb differences. Brain Lang 1996; 53:169-82.
57. Koukkou M, Lehmann D, Federspiel A, Merlo MCG. EEG reactivity and EEG activity in schizophrenia measured with spectral analysis and dimensional complexity. J Neural Transm (Gen Sect) 1995; 99:98-102.
58. Lachaux J-P, Pezard L, Garnero L, Pelte C, Renault B, Varela FJ, Martinerie J. Spatial extension of brain activity fools the single-channel reconstruction of EEG dynamics. Hum Brain Mapping 1997;5:26-47.
59. Lantz G, Holub M, Ryding E, Rosén I. Simultaneous intracranial and extracranial recording of interictal epileptiform activity in patients with drug resistant partial epilepsy: patterns of conduction and results from dipole reconstruction. Electroenceph Clin Neurophysiol 1996;99:69-78.
60. Lantz G, Michel CM, Pascual-Marqui RD, Spinelli L, Seeck M, Seri S, Landis T. Rosen I. Extracranial localization of intracranial interictal epileptiform activity using LORETA (Low Resolution Electromagnetic Tomography). Electroenceph Clin Neurophysiol 1997;102:414-422.
61. Lantz G, Michel CM, Rosén I. Characterization of epileptiform EEG-activity during epileptic seizures, using segmentation and 3-dimensional source reconstruction [abstract]. Epilepsy Res 1999a; 34:S4.
62. Lantz G, Michel CM, Seeck M, Rosén I. Frequency domain EEG source localization of ictal epileptiform activity in patients with partial complex epilepsy of temporal lobe origin. Electroencephalogr Clin Neurophysiol 1999b;110:176-84.
63. Lantz G, Ryding E, Rosén I. Three-dimensional localization of interictal epileptiform activity with dipole analysis: comparison with intracranial recordings and SPECT findings. J Epilepsy 1994;7: 117-129.
64. Lawson CL, Hanson RJ. Solving least squares problems. Englewood Cliffs, NJ: Prentice Hall, 1974.
65. Lehmann D. Principles of spatial analysis. In: Gevins AS, Rémond A, eds. Handbook of electroencephalography and clinical neurophysiology. Volume I: methods of analysis of brain electrical and magnetic signals. Amsterdam: Elsevier 1987:309-54.
66. Lehmann D, Henggeler B, Koukkou M, Michel CM. Source localization of brain electric field frequency bands during conscious, spontaneous visual imagery and abstract thoughts. Cognitive Brain Res 1993;1:203-10.
67. Lehmann D, Michel CM. Intracerebral dipole source localization for FFT power maps. Electroenceph Clin Neurophysiol 1990;76: 271-6.
68. Lehmann D, Ozaki H, Pal I. EEG alpha map series: brain micro-states by space-oriented adaptive segmentation. Electroenceph Clin Neurophysiol, 1987;67:271-88.
69. Lehmann D, Skrandies W. Reference-free identification of components of checkerboard-evoked multichannel potential fields. Electroenceph Clin Neurophysiol 1980;48:609-21.
70. Lehmann D, Skrandies W. Spatial analysis of evoked potentials in man - a review. Progr Neurobiol 1984;23:227-50.
71. Lehnertz K, Elger CE. Spatio-temporal dynamics of the primary epileptogenic area in temporal lobe epilepsy characterized by neuronal complexity loss. Electroenceph Clin Neurophysiol 1995; 95:108-17.
72. Liu AK, Belliveau JW, Dale AM. Spatiotemporal imaging of human brain activity using functional MRI constrained magnetoencephalography data: Monte Carlo simulations. Proc Natl Acad Sci USA 1998;95:8945-50.
73. Lütkenhöner B. Frequency-domain localization of intracerebral dipolar sources. Electroencephalogr Clin Neurophysiol 1992;82:112-8.
74. Lütkenhöner B, Grave de Peralta Menendez R. The resolution field concept. Electroenceph Clin Neurophysiol 1997;102:326-34.
75. Lynn MS, Barnard ACL, Holt JH, Sheffield LT. A proposed method for the inverse problem in electrocardiography. Biophys J 1968; 7:925-45.
76. Lopes da Silva FH, Mars NJI. Parametric methods in EEG analysis. In: Gevins AS, Rémond A, eds. Handbook of electroencephalography and clinical neurophysiology. Volume I: methods of analysis of brain electrical and magnetic signals. Amsterdam: Elsevier, 1987:243-60.
77. Menke W. Geophysical data analysis: discrete inverse theory. San Diego, Academic Press, 1989; Sect 5.8.
78. Merlet I, Garcia-Larrea L, Ryvlin P, Isnard J, Sindou M, Mauguière F. Topographical reliability of mesio-temporal sources of interictal spikes in temporal lobe epilepsy. Electroenceph Clin Neurophysiol 1998;107:206-12.
79. Merrin EL, Meek P, Floyd TC, Callaway E. Topographic segmentation of waking EEG in medication-fre schizophrenic patients, Int J Psychophysiol 1990;9:231-6.
80. Michael D, Houchin J. Automatic EEG analysis: a segmentation procedure based on the autocorrelation function. Electroenceph Clin Neurophysiol 1979;46:232-35.
81. Michel CM, Henggeler B, Lehmann D. 42-channel potential map series to visual contrast and stereo stimuli: perceptual and cognitive event-related segments. Int J Psychophysiol 1992a;12:133-45.
82. Michel CM, Lehmann D, Henggeler B, Brandeis D. Localization of the sources of EEG delta, theta, alpha and beta frequency bands using the FFT dipole approximation. Electroencephalogr Clin Neurophysiol 1992b;82:38-44.
83. Michel CM, Lehmann D. Single doses of Piracetam affect event-related potential microstates during cognitive information processing. Neuropsychohiology 1993;28:212-21.
84. Michel CM, Pascual-Marqui RD, Strik WK, Koenig T, Lehmann D. Frequency domain source localization shows state dependent diazepam effects in 47-channel EEG. J Neural Transm Gen Sect 1995;99:157-71.
85. Michel CM, Koukkou M, Lehmann, D. EEG reactivity in high and low symptomatic schizophrenics, using source modeling in the frequency domain. Brain Topogr 1993;5:389-94.
86. Mosher JC, Lewis, PS, Leahy L. Multiple dipole modeling and localization from spatio temporal MEG data. IEEE Trans Biomed Eng 1992;39:541-57.
87. Mosher JC, Leahy RM. Recursively applied MUSIC: A framework for EEG and MEG source localization. IEEE Trans Biomed Eng 1999a (in press).
88. Mosher JC, Leahy RM. Source localization using recursively applied and projected (RAP) MUSIC. IEEE Trans Signal Proc 1999 (in press).
89. Nakasato N, Levesque MP, Barth DS, Baumgartner C, Rogers RL, Sutherling WW. Comparisons of MEG, EEG, ECoG source localization in neocortical epilepsy in humans. Electroenceph Clin Neurophysiol 1994; 91:171-72.
90. Pacia SV, Ebersole JS. Intracranial EEG substrates of scalp ictal patterns from temporal lobe foci. Epilepsia 1997;38:642-54.
91. Pascual-Marqui RD, Michel CM, Lehmann D. Low resolution electromagnetic tomography: a new method for localizing electrical activity in the brain. Int J Psychophysiol 1995a;18:49-65.
92. Pascual-Marqui RD, Michel CM, Lehmann D. Segmentation of brain electrical activity into microstates: model estimation and validation. IEEE Trans Biomed Eng 1995b;42:658-65.
93. Pegna AJ, Khateb A, Spinelli L, Seeck M, Landis T, Michel CM. Unraveling the cerebral dynamics of mental imagery. Hum Brain Mapping 1997;5:410-21.
94. Penrose R. A generalized inverse for matrices. Proc Cambridge Philos Soc 1955;51:406-13.
95. Pilkington T. Electrocardiographic Leads. In: Pilkington T, Plonsey R, eds. Engineering contributions to biophysical electrocardiography. IEEE Press, 1989:70-73.
96. Plonsey R. The nature of the sources of bioelectric and biomagnetic fields. J Biophys 1982;39:309-12.
97. Risinger MW, Engel J, Van Ness PC, Henry TR, Crandall PH. Ictal localization of temporal lobe seizures with scalp/sphenoidal recordings. Neurology 1989;39:1288-93.
98. Robinson S, Rose D. Current source image estimation by spatially filtered MEG. In: Hoke M, Erne S, Okada Y, Romani G, eds. Biomagnetism: clinical aspects. Amsterdam: Excerpta Medica, 1992:761-5.
99. Rogers CL, Pilkington TC. Free-moment current dipoles in inverse electrocardiography. IEEE Trans Biomed Eng 1968;15:312-23.
100. Sanderson AC, Segen J, Richey E Hierarchical modelling of EEG signals. IEEE Trans Pattern Anal Machine Intel 1980;2:405-15.
101. Scherg M, Von Cramon D. A new interpretation of the generators of BAEP waves I-V: Results of spatio-temporal dipole model. Electroenceph Clin Neurophysiol 1985;62:290-9.
102. Scherg M, Von Cramon D. Two bilateral sources of the late AEP as identified by a saptio-temporal dipole model. Electroenceph Clin Neurophysiol 1986;65:344-60.
103. Scherg M, Von Cramon D. Dipole source potentials of the auditory cortex in normal subjects and patients with temporal lobe lesions. In: Grandori F, Hoke M, Romani, GL, eds. Auditory evoked magnetic fields and electric potentials. Basel: Karger, 1990:165-93.
104. Seeck M, Lazeyras F, Michel CM, Blanke O, Gericke C, Delavelle J, Ives J, Landis T, de Tribolet N. Epileptic focus localization with EEG-triggered fMRI and 3D-electric source analysis [abstract]. J Clin Neurophysiol 1998a;14:444.
105. Seeck M, Lazeyras F, Michel CM, Blanke O, Gericke CA, Ives J, Delavelle J, Golay X, Haenggeli CA, de Tribolet N, Landis T. Non-invasive epileptic focus localization using EEG-triggered functional MRI and electromagnetic tomography. Electroenceph Clin Neurophysiol 1998b;106:508-12.
106. Sekihara K, Poeppel D, Marantz A, Koizumi H, Miyashita Y. Noise covariance incorporated MEG-Music algorithms: A method for multiple dipole estimation tolerant of the influence of Background Brain activity. IEEE Trans Biomed Eng 1997.
107. Sekihara K, Scholz B. Average-intensity reconstruction and Wiener reconstruction of bioelectric current distribution based on its estimated covariance matrix. IEEE Trans Biomed Eng 1995;42: 149-57.
108. Sekihara K, Scholz B. Generalized wiener estimation of three dimensional current distribution from biomagnetic measurements. IEEE Trans Biomed Eng 1996;43:281-91.
109. Seri S, Cerquiglini A, Pisani F, Michel CM, Pascual-Marqui RD, Curatolo P. Frontal lobe epilepsy associated with tuberous sclerosis: EEG-MRI fusioning. J Child Neurol 1998;13:33-8.
110. Shindo K, Ikeda A, Musha T, Terada K, Fukuyama H, Taki W, Kimura J, Shibasaki H. Clinical usefulness of the dipole tracing method for localizing interictal spikes in partial epilepsy. Epilepsia 1998; 39:371-9.
111. So N, Gloor P, Quesney LF, Jones-Gotman M, Olivier A, Andermann F. Depth electrode investigation in patients with bitemporal epileptiform abnormalities. Ann Neurol 1989;25:423-31.
112. Spencer SS, Guimaraes P, Katz A, Kim J, Spencer D. Morphological patterns of seizures recorded intracranially. Epilepsia 1992;33: 537-45.
113. Stefan H, Schneider S, Feistel H, Pawlik G, Schuler P, Abraham-Fuchs K, Schlegel T, Neubauer U, Huk WJ. Ictal and interictal activity in partial epilepsy recorded with multichannel magnetoencephalography: correlation with electroencephalography/electro-corticography, magnetic resonance imaging, single photon emission computed tomography and positron emission tomography findings. Epilepsia 1992;33:874-87.
114. Stefan H, Schuler P, Abraham-Fuchs K, Schneider S, Gebhardt M, Neubauer U, Hummel C, Huk WJ, Thierauf P. Magnetic source localization and morphological changes in temporal lobe epilepsies: comparison of MEG/EEG, ECoG and volumetric MRI in presurgical evaluation of operated patients. Acta Neurol Scand 1994;152(suppl):83-8.
115. Strik WK, Lehmann D. Data-determined window size and space-oriented segmentation of spontaneous EEG map series. Electroenceph Clin Neurophysiol 1993;87:169-74.
116. Takens F. Detecting strange attractors in fluid turbulence. Springer Lect Notes Math 1981;898:366-81.
117. Tarantola A. Inverse Problem Theory. Amsterdam: Elsevier, 1987.
118. Tesche C, Kajola M. A comparison of the localization of spontaneous neuromagnetic activity in the frequency and time domains. Electroenceph Clin Neurophysiol 1993;87:408-16.
119. Thut G, Hauert C-A, Morand S, Seeck M, Landis T, Michel CM. Evidence for interhemispheric motor-level transfer in a simple reaction time task: An EEG study. Exp Brain Res 1999 (in press).
120. Valdes P, Bosch J, Grave R, Hernandez J, Riera J, Pascual R, Biscay R. Frequency domain models of the EEG. Brain Topogr, 1992;4: 309-19.
121. Villier G. Statistical inversion methods. In: Pike ER, ed. Inverse problems in scattering and imaging. Adam Hilger, 1991; 371-392.
122. Wackermann J, Lehmann D, Michel CM. Global dimensional complexity of multichannel EEG indicates change of human brain functional state after single dose of a nootropic drug. Electroenceph Clin Neurophysiol 1993a; 86:193-8.
123. Wackermann J, Lehmann D, Michel CM, Strik WK. Adaptive segmentation of spontaneous EEG map series into spatially defined microstates. Int J Psychophysiol 1993b;14:269-83.
124. Warach S, Ives JR, Schlaug G, Patel MR, Darby DG, Thangaraj V, Edelman RR, Schomer DL. EEG-triggered echo-planar functional MRI in epilepsy. Neurology 1996;47:89-93
125. Wendling F, Badier JM, Chauvel P, Coatrieux JL. A method to quantify invariant information in depth-recorded epileptic seizures. Electroenceph Clin Neurophysiol 1997;102:472-85
126. Wong PKH. Source modelling of the rolandic focus. Brain Topogr 1991;4:105-12.
127. Wu L, Gotman J. Segmentation and classification of EEG during epileptic seizures. Electroenceph Clin Neurophysiol 1998; 106: 344-56