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  • Print publication year: 2019
  • Online publication date: October 2019

Chapter 16 - Intracranial EEG Monitoring


More than 3 million individuals in the United States have epilepsy, and over 50 million worldwide. One million in the United States continue to suffer from seizures, despite medication. Their mortality is twice that of the general population, i.e., about 2% mortality per year.1,2 Surgery for epilepsy has a favorable outcome. Among well-selected patients, 70% are seizure-free after surgery. Many of the remaining patients have seizure frequency greatly reduced, e.g., from twice weekly to twice yearly. Surgical outcome avoids mortality risk, morbidity, and costs of medically refractory seizures, and greatly enhances the patient’s quality of life. Yet only 2000 patients per year undergo resective surgery. Surgery for epilepsy is very underutilized.3

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1.Devinsky, O, Friedman, D, Cheng, JY, et al. Underestimation of sudden deaths among patients with seizures and epilepsy. Neurology. 2017;89(9):886892.
2.Fazel, S, Wolf, A, Langstrom, N, Newton, CR, Lichtenstein, P. Premature mortality in epilepsy and the role of psychiatric comorbidity: a total population study. Lancet. 2013;382(9905):16461654.
3.Engel, J Jr. What can we do for people with drug-resistant epilepsy? The 2016 Wartenberg Lecture. Neurology. 2016;87(23):24832489.
4.Rosenow, F, Luders, H. Presurgical evaluation of epilepsy. Brain. 2001;124(Pt 9):16831700.
5.Carne, RP, O’Brien, TJ, Kilpatrick, CJ, et al. MRI-negative PET-positive temporal lobe epilepsy: a distinct surgically remediable syndrome. Brain. 2004;127(Pt 10):22762285.
6.Sperling, MR. Clinical challenges in invasive monitoring in epilepsy surgery. Epilepsia. 1997;38(Suppl 4):S612.
7.Engel, J Jr. Respiration-linked ‘limbic spindles’: vibration artifact recorded from nasopharyngeal and intracerebral electrodes. Electroencephalogr Clin Neurophysiol. 1980;49(3–4):366372.
8.Van Buren, JM. Complications of surgical procedures in the diagnosis and treatment of epilepsy. In: Engel, J Jr. ed., Surgical Treatment of the Epilepsies. New York: Raven Press; 1987:465475.
9.Sansur, CA, Frysinger, RC, Pouratian, N, et al. Incidence of symptomatic hemorrhage after stereotactic electrode placement. J Neurosurg. 2007;107(5):9981003.
10.Tanriverdi, T, Ajlan, A, Poulin, N, Olivier, A. Morbidity in epilepsy surgery: an experience based on 2449 epilepsy surgery procedures from a single institution. J Neurosurg. 2009;110(6):11111123.
11.Sperling, MR. Intracranial Electroencephalography. New York: Elsevier; 1993.
12.Spencer, SS, Sperling, MR, Shewmon, DA, Kahane, P. Inracranial electrodes. In: Engel, J Jr. Pedley, TA, eds., Epilepsy: A Comprehensive Textbook 2nd edn. Philadelphia: Lippincott Williams & Wilkins; 2008:17911815.
13.Spencer, SS, Spencer, DD. Entorhinal-hippocampal interactions in medial temporal lobe epilepsy. Epilepsia. 1994;35(4):721727.
14.Spencer, SS. Substrates of localization-related epilepsies: biologic implications of localizing findings in humans. Epilepsia. 1998;39(2):114123.
15.Velasco, AL, Wilson, CL, Babb, TL, Engel, J Jr. Functional and anatomic correlates of two frequently observed temporal lobe seizure-onset patterns. Neural Plast. 2000;7(1–2):4963.
16.Schuh, LA, Henry, TR, Ross, DA, et al. Ictal spiking patterns recorded from temporal depth electrodes predict good outcome after anterior temporal lobectomy. Epilepsia. 2000;41(3):316319.
17.Spencer, SS, Marks, D, Katz, A, Kim, J, Spencer, DD. Anatomic correlates of interhippocampal seizure propagation time. Epilepsia. 1992;33(5):862873.
18.Lieb, JP, Babb, TL. Interhemispheric propagation time of human hippocampal seizures: II. Relationship to pathology and cell density. Epilepsia. 1986;27(3):294300.
19.Isnard, J, Guenot, M, Sindou, M, Mauguiere, F. Clinical manifestations of insular lobe seizures: a stereo-electroencephalographic study. Epilepsia. 2004;45(9):10791090.
20.Tassi, L, Colombo, N, Cossu, M, et al. Electroclinical, MRI and neuropathological study of 10 patients with nodular heterotopia, with surgical outcomes. Brain. 2005;128(Pt 2):321337.
21.Aghakhani, Y, Kinay, D, Gotman, J, et al. The role of periventricular nodular heterotopia in epileptogenesis. Brain. 2005;128(Pt 3):641651.
22.Francione, S, Kahane, P, Tassi, L, et al. Stereo-EEG of interictal and ictal electrical activity of a histologically proved heterotopic gray matter associated with partial epilepsy. Electroencephalogr Clin Neurophysiol. 1994;90(4):284290.
23.Engel, J Jr. Outcome with respect to epileptic seizures. In: Engel, J Jr., ed., Surgical Treatment of the Epilepsies. New York: Raven Press; 1987:553571.
24.Wyler, AR, Walker, G, Somes, G. The morbidity of long-term seizure monitoring using subdural strip electrodes. J Neurosurg. 1991;74(5):734737.
25.Lee, WS, Lee, JK, Lee, SA, Kang, JK, Ko, TS. Complications and results of subdural grid electrode implantation in epilepsy surgery. Surg Neurol. 2000;54(5):346351.
26.Onal, C, Otsubo, H, Araki, T, et al. Complications of invasive subdural grid monitoring in children with epilepsy. J Neurosurg. 2003;98(5):10171026.
27.Araki, T, Otsubo, H, Makino, Y, et al. Efficacy of dexamathasone on cerebral swelling and seizures during subdural grid EEG recording in children. Epilepsia. 2006;47(1):176180.
28.Sahjpaul, RL, Mahon, J, Wiebe, S. Dexamethasone for morbidity after subdural electrode insertion – a randomized controlled trial. Can J Neurol Sci. 2003;30(4):340348.
29.Wetjen, NM, Marsh, WR, Meyer, FB, et al. Intracranial electroencephalography seizure onset patterns and surgical outcomes in nonlesional extratemporal epilepsy. J Neurosurg. 2009;110(6):11471152.
30.McGonigal, A, Bartolomei, F, Regis, J, et al. Stereoelectroencephalography in presurgical assessment of MRI-negative epilepsy. Brain. 2007;130(Pt 12):31693183.
31.Spencer, SS, Guimaraes, P, Katz, A, Kim, J, Spencer, D. Morphological patterns of seizures recorded intracranially. Epilepsia. 1992;33(3):537545.
32.Fisher, RS, Webber, WR, Lesser, RP, Arroyo, S, Uematsu, S. High-frequency EEG activity at the start of seizures. J Clin Neurophysiol. 1992;9(3):441448.
33.Schiller, Y, Cascino, GD, Busacker, NE, Sharbrough, FW. Characterization and comparison of local onset and remote propagated electrographic seizures recorded with intracranial electrodes. Epilepsia. 1998;39(4):380388.
34.Lee, SA, Spencer, DD, Spencer, SS. Intracranial EEG seizure-onset patterns in neocortical epilepsy. Epilepsia. 2000;41(3):297307.
35.Blumenfeld, H, Rivera, M, McNally, KA, et al. Ictal neocortical slowing in temporal lobe epilepsy. Neurology. 2004;63(6):10151021.
36.Allen, PJ, Fish, DR, Smith, SJ. Very high-frequency rhythmic activity during SEEG suppression in frontal lobe epilepsy. Electroencephalogr Clin Neurophysiol. 1992;82(2):155159.
37.Worrell, GA, Parish, L, Cranstoun, SD, et al. High-frequency oscillations and seizure generation in neocortical epilepsy. Brain. 2004;127(Pt 7):14961506.
38.Eisenschenk, S, Gilmore, RL, Cibula, JE, Roper, SN. Lateralization of temporal lobe foci: depth versus subdural electrodes. Clin Neurophysiol. 2001;112(5):836844.
39.Bragin, A, Engel, J Jr., Wilson, CL, Fried, I, Mathern, GW. Hippocampal and entorhinal cortex high-frequency oscillations (100–500 Hz) in human epileptic brain and in kainic acid--treated rats with chronic seizures. Epilepsia. 1999;40(2):127137.
40.Urrestarazu, E, Chander, R, Dubeau, F, Gotman, J. Interictal high-frequency oscillations (100–500 Hz) in the intracerebral EEG of epileptic patients. Brain. 2007;130(Pt 9):23542366.
41.Staba, RJ, Wilson, CL, Bragin, A, Fried, I, Engel, J Jr. Quantitative analysis of high-frequency oscillations (80-500 Hz) recorded in human epileptic hippocampus and entorhinal cortex. J Neurophysiol. 2002;88(4):17431752.
42.Jirsch, JD, Urrestarazu, E, LeVan, P, et al. High-frequency oscillations during human focal seizures. Brain. 2006;129(Pt 6):15931608.
43.Zijlmans, M, Worrell, GA, Dumpelmann, M, et al. How to record high-frequency oscillations in epilepsy: a practical guideline. Epilepsia. 2017;58(8):13051315.
44.Bragin, A, Wilson, CL, Staba, RJ, et al. Interictal high-frequency oscillations (80–500 Hz) in the human epileptic brain: entorhinal cortex. Ann Neurol. 2002;52(4):407415.
45.Engel, J Jr., Bragin, A, Staba, R, Mody, I. High-frequency oscillations: what is normal and what is not? Epilepsia. 2009;50(4):598604.
46.Staba, RJ, Wilson, CL, Bragin, A, et al. High-frequency oscillations recorded in human medial temporal lobe during sleep. Ann Neurol. 2004;56(1):108115.
47.Khosravani, H, Mehrotra, N, Rigby, M, et al. Spatial localization and time-dependant changes of electrographic high frequency oscillations in human temporal lobe epilepsy. Epilepsia. 2009;50(4):605616.
48.Fernandez, IS, Loddenkemper, T. Electrocorticography for seizure foci mapping in epilepsy surgery. J Clin Neurophysiol. 2013;30(6):554570.
49.Reuber, M, Kral, T, Kurthen, M, Elger, CE. New-onset psychogenic seizures after intracranial neurosurgery. Acta Neurochir (Wien). 2002;144(9):901907; discussion 907.