Neocortical temporal lobe epilepsy: intracranial EEG features and surgical outcome.

Patients with neocortical temporal lobe epilepsy (NTLE) may have less favorable outcome with anterior temporal lobectomy than those with mesial temporal foci. The authors analyzed ictal intracranial electroencephalograms (EEGs) in patients with NTLE to identify features that predict surgical outcome. The following intracranial ictal EEG features in 31 consecutive medically intractable NTLE patients were studied: Frequency (i.e., low-voltage fast [>20 Hz], recruiting ictal-onset spikes, ictal-onset rhythms less than 5 Hz, ictal-onset rhythms with repetitive sharp waves between 5 and 20 Hz); extent of ictal onset (focal, sublobar, and lobar); localization within the temporal lobe (anterior, posterior, or regional); and the time to seizure spread outside the temporal lobe (rapid, intermediate, and slow). The average follow-up period was 36.7 months (range, 18 to 60 months). Findings between two outcome groups were compared: class I group (seizure-free) and class II to IV group (persistent seizures). Twenty-one (66.7%) of 31 patients with NTLE were seizure-free. Intracranial EEG features which were significantly associated with seizure-free outcome were focal or sublobar onset, anterior temporal onset, and slow propagation time (P < 0.05). There was a trend for patients with ictal onset morphologies of slow ictal-onset rhythm and repetitive sharp waves to be seizure-free (P = 0.07). Intracranial EEG is helpful in predicting surgical outcome in NTLE patients.

[1]  O. Devinsky,et al.  Left temporal neocortex mediation of verbal memory , 1994, Neurology.

[2]  T S Walczak,et al.  Neocortical Temporal Lobe Epilepsy: Characterizing the Syndrome , 1995, Epilepsia.

[3]  J. Ebersole,et al.  Intracranial EEG Substrates of Scalp Ictal Patterns from Temporal Lobe Foci , 1997, Epilepsia.

[4]  T. Babb,et al.  A Comparison of EEG Seizure Patterns Recorded with Surface and Depth Electrodes in Patients with Temporal Lobe Epilepsy , 1976, Epilepsia.

[5]  A. Friedman,et al.  Predictors of Outcome of Epilepsy Surgery: Multivariate Analysis with Validation , 1996, Epilepsia.

[6]  S. Pacia,et al.  Clinical features of neocoritcal temporal lobe epilepsy , 1996, Annals of neurology.

[7]  H G Wieser,et al.  Mesiobasal versus lateral temporal lobe epilepsy , 1993, Neurology.

[8]  R. Kuzniecky,et al.  Predictive value of magnetic resonance imaging in temporal lobe epilepsy surgery. , 1993, Archives of neurology.

[9]  H. Lüders,et al.  Can Sharp Waves Localized at the Sphenoidal Electrode Accurately Identify a Mesio‐temporal Epileptogenic Focus? , 1989, Epilepsia.

[10]  P H Crandall,et al.  Ictal localization of temporal lobe seizures with scalp/sphenoidal recordings , 1989, Neurology.

[11]  T. Burke,et al.  Temporal Neocorticectomy in Management of Intractable Epilepsy: Long‐Term Outcome and Predictive Factors , 1992, Epilepsia.

[12]  A. Saykin,et al.  Comparison of Mesial Versus Neocortical Onset Temporal Lobe Seizures: Neurodiagnostic Findings and Surgical Outcome , 1995, Epilepsia.

[13]  T L Babb,et al.  Interhemispheric Propagation Time of Human Hippocampal Seizures , 1986, Epilepsia.

[14]  J. Ebersole,et al.  Localization of Temporal Lobe Foci by Ictal EEG Patterns , 1996, Epilepsia.

[15]  S. Spencer,et al.  Combined depth and subdural electrode investigation in uncontrolled epilepsy , 1990, Neurology.

[16]  M. O’Connor,et al.  Presurgical electroencephalographic patterns and outcome from anterior temporal lobectomy. , 1992, Archives of neurology.

[17]  R. Worth,et al.  Clinical characteristics and predictive factors in 98 patients with complex partial seizures treated with temporal resection. , 1994, Archives of neurology.

[18]  W. Blume,et al.  EEG morphology of partial epileptic seizures. , 1984, Electroencephalography and clinical neurophysiology.

[19]  W. J. Brown,et al.  Neuropathological Findings Following Temporal Lobectomy Related to Surface and Deep EEG Patterns , 1981, Epilepsia.

[20]  S. Spencer,et al.  Morphological Patterns of Seizures Recorded Intracranially , 1992, Epilepsia.

[21]  C. Adam,et al.  Temporal and Spatial Characteristics of Intracerebral Seizure Propagation: Predictive Value in Surgery for Temporal Lobe Epilepsy , 1994, Epilepsia.

[22]  C. Jack,et al.  Routine EEG and Temporal Lobe Epilepsy: Relation to Long‐Term EEG Monitoring, Quantitative MRI, and Operative Outcome , 1996, Epilepsia.

[23]  D. C. Hurst,et al.  Ictal EEG wave forms from epidural electrodes predictive of seizure control after temporal lobectomy. , 1992, Electroencephalography and clinical neurophysiology.

[24]  D. Dinner,et al.  Presurgical evaluation of temporal lobe epilepsy using interictal temporal spikes and positron emission tomography. , 1993, Archives of neurology.