Presurgical Evaluation: Current Role of Invasive EEG

Summary: Our purpose was to review the current role of invasive and semi‐invasive EEG in the presurgical evaluation of candidates for epilepsy surgery. The use of stereotactically implanted intracranial depth (stereo‐EEG), subdural strip and grid, and foramen ovale electrodes, as well as intraoperative electrocorticography and electrical brain stimulation (“functional mapping”) at the Epilepsy Center University Hospital Zurich, from 1984 to 1998, is analyzed. Advantages and disadvantages of the various intracranial EEG techniques are critically discussed. Out of 422 selective amygdalohippocampectomies performed in Zurich, 54% had non‐invasive, 32% had semi‐invasive, and 14% had invasive presurgical EEG evaluation. Because patients currently referred to our center increasingly present with a complex history of disease, i.e., constitute so‐called “difficult cases”, there is trend to combine several invasive and semi‐invasive, pre‐ and intraoperative neurophysiological techniques.

[1]  Trimble,et al.  Forced normalization and alternative psychoses of epilepsy , 1998 .

[2]  H. G. Wieser,et al.  Electroencephalograms in epilepsy: analysis and seizure prediction within the framework of Lyapunov theory , 1999 .

[3]  C. Elger,et al.  Activation of the epileptic focus during intracarotid amobarbital test. Electrocorticographic registration via subdural electrodes. , 1990, Electroencephalography and clinical neurophysiology.

[4]  A. Buck,et al.  The Anterior and Posterior Selective Temporal Lobe Amobarbital Tests: Angiographic, Clinical, Electroencephalographic, PET, SPECT Findings, and Memory Performance , 1997, Brain and Cognition.

[5]  H F Flanigin,et al.  The intracarotid amobarbital procedure as a predictor of memory failure following unilateral temporal lobectomy , 1990, Neurology.

[6]  H. Jasper,et al.  Epilepsy and the functional anatomy of the human brain , 1985 .

[7]  R.N.Dej.,et al.  Epilepsy and the Functional Anatomy of the Human Brain , 1954, Neurology.

[8]  J. Zentner,et al.  Surgical treatment of epilepsies. , 2002, Acta neurochirurgica. Supplement.

[9]  B. J. Alpers.  The diagnosis and treatment of epilepsy. , 1950, Delaware medical journal.

[10]  H. Silfvenius,et al.  Effects of amobarbital and methohexital on epileptic activity in mesial temporal structures in epileptic patients. An EEG study with depth electrodes , 1984, Acta neurologica Scandinavica.

[11]  S S Kollias,et al.  Intraoperative validation of functional magnetic resonance imaging and cortical reorganization patterns in patients with brain tumors involving the primary motor cortex. , 1999, Journal of neurosurgery.

[12]  H. Wieser,et al.  Improved multipolar foramen ovale electrode monitoring , 1988 .

[13]  C E Elger,et al.  The 'foramen ovale electrode': a new recording method for the preoperative evaluation of patients suffering from mesio-basal temporal lobe epilepsy. , 1985, Electroencephalography and clinical neurophysiology.

[14]  L F Quesney,et al.  Localization of epileptic foci. , 1985, Electroencephalography and clinical neurophysiology. Supplement.