Surgical management of epilepsy using epidural recordings to localize the seizure focus

1984 ◽  
Vol 60 (3) ◽  
pp. 457-466 ◽  
Author(s):  
Sidney Goldring ◽  
Erik M. Gregorie
Keyword(s):  
Temporal Lobe ◽  
Focal Epilepsy ◽  
Temporal Lobectomy ◽  
Epileptogenic Focus ◽  
Electrode Arrays ◽  
Content Type ◽  
Seizure Focus ◽  
Depth Electrodes ◽  
Sensory Evoked ◽  
Fine Print

✓ One hundred patients with focal epilepsy (44 were children) were evaluated with extraoperative electrocorticography via epidural electrode arrays. Localization of the epileptogenic focus was derived predominantly from recordings made during spontaneously occurring seizures. All resection procedures were carried out under general anesthesia. During anesthesia, the recording of sensory evoked responses made it possible to readily identify the sensorimotor region. Of the 100 patients, 72 underwent resection of an epileptogenic focus, and 33 of these were children. Those who did not have a resection either exhibited a diffuse seizure focus, failed to show an electrical seizure discharge in association with the clinical seizure, failed to have a seizure during the period of monitoring, or failed to exhibit conclusive changes for identifying a focus in the interictal record. Fifty-seven patients (29 children and 28 adults) who had a resection have been followed for between 1 and 12 years. Eighteen (62%) of the 29 children and 18 (64%) of the 28 adults enjoyed a good result. Twenty of the 100 patients reported here had temporal lobe epilepsy. They were candidates for recordings with depth electrodes to identify their focus, but they were evaluated instead with epidural recordings; the method is described. In 15 of them, a unilateral focus was identified and they underwent an anterior temporal lobectomy. Pathological changes were found in every case and, in 11 patients, the epidural recordings distinguished between a medial and a lateral focus. Ten of these patients have been followed for 9 months to 3½ years, and seven have had a good result. The observations suggest that epidural electrodes may be used in lieu of depth electrodes for identifying the symptomatic temporal lobe.

Significance of surgery for temporal lobe epilepsy in childhood and adolescence

1970 ◽  
Vol 33 (3) ◽  
pp. 233-252 ◽  
Author(s):  
Murray A. Falconer
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Temporal Lobectomy ◽  
Mesial Temporal Sclerosis ◽  
Childhood And Adolescence ◽  
Content Type ◽  
Pathological Lesion ◽  
Fine Print

✓ The problem of childhood temporal lobe epilepsy is reviewed and illustrated from three cases in which the patients were freed from fits by temporal lobectomy. The pathological lesion (mesial temporal sclerosis) is discussed and the likelihood that many adult cases have gone unrecognized in childhood is emphasized.

Preoperative predictors of anterior temporal language areas

1998 ◽  
Vol 89 (6) ◽  
pp. 962-970 ◽  
Author(s):  
Theodore H. Schwartz ◽  
Orrin Devinsky ◽  
Werner Doyle ◽  
Kenneth Perrine
Keyword(s):  
Temporal Lobe ◽  
Right Hemisphere ◽  
Temporal Lobectomy ◽  
Seizure Onset ◽  
Anterior Temporal Lobe ◽  
Verbal Iq ◽  
Content Type ◽  
Language Areas ◽  
Fine Print

Object. Although it is known that 5 to 10% of patients have language areas anterior to the rolandic cortex, many surgeons still perform standard anterior temporal lobectomies for epilepsy of mesial onset and report minimal long-term dysphasia. The authors examined the importance of language mapping before anterior temporal lobectomy. Methods. The authors mapped naming, reading, and speech arrest in a series of 67 patients via stimulation of long-term implanted subdural grids before resective epilepsy surgery and correlated the presence of language areas in the anterior temporal lobe with preoperative demographic and neuropsychometric data. Naming (p < 0.03) and reading (p < 0.05) errors were more common than speech arrest in patients undergoing surgery in the anterior temporal lobe. In the approximate region of a standard anterior temporal lobectomy, including 2.5 cm of the superior temporal gyrus and 4.5 cm of both the middle and inferior temporal gyrus, the authors identified language areas in 14.5% of patients tested. Between 1.5 and 3.5 cm from the temporal tip, patients who had seizure onset before 6 years of age had more naming (p < 0.02) and reading (p < 0.01) areas than those in whom seizure onset occurred after age 6 years. Patients with a verbal intelligence quotient (IQ) lower than 90 had more naming (p < 0.05) and reading (p < 0.02) areas than those with an IQ higher than 90. Finally, patients who were either left handed or right hemisphere memory dominant had more naming (p < 0.05) and reading (p < 0.02) areas than right-handed patients with bilateral or left hemisphere memory lateralization. Postoperative neuropsychometric testing showed a trend toward a greater decline in naming ability in patients who were least likely to have anterior language areas, that is, those with higher verbal IQ and later seizure onset. Conclusions. Preoperative identification of markers of left hemisphere damage, such as early seizure onset, poor verbal IQ, left handedness, and right hemisphere memory dominance should alert neurosurgeons to the possibility of encountering essential language areas in the anterior temporal lobe (1.5–3.5 cm from the temporal tip). Naming and reading tasks are required to identify these areas. Whether removal of these areas necessarily induces long-term impairment in verbal abilities is unknown; however, in patients with a low verbal IQ and early seizure onset, these areas appear to be less critical for language processing.

Surgical therapy for medically intractable epilepsy

1987 ◽  
Vol 66 (4) ◽  
pp. 489-499 ◽  
Author(s):  
George A. Ojemann
Keyword(s):  
Temporal Lobe ◽  
Surgical Therapy ◽  
Imaging Techniques ◽  
Intractable Epilepsy ◽  
Content Type ◽  
Human Epilepsy ◽  
Depth Electrodes ◽  
Positron Emission ◽  
Intraoperative Management ◽  
Fine Print

✓ There has been a recent renewal of interest in surgical therapy for medically intractable epilepsies. Cortical resection and callosotomy are the most widely accepted modes of surgical management. The indications for each of these approaches are reviewed. Although there has been much interest in imaging techniques, including positron emission tomography, to identify epileptogenic zones, identification still depends primarily on the electroencephalogram (EEG). There are several approaches to the evaluation and intraoperative management of patients undergoing cortical resection for temporal lobe epileptogenic zones. These range from selection based on scalp interictal EEG criteria, with resections guided by electrocorticography and functional mapping, to selection based on the location of ictal onset as recorded by chronically implanted depth electrodes, with an anatomically standard resection of the temporal lobe or resection limited to amygdalohippocampectomy. No one approach provides the optimum balance of benefits to risks and costs for all patients. The relative value of the different approaches for various populations of patients with medically intractable partial complex seizures is reviewed. Techniques for minimizing the morbidity of these operations, especially in regard to language and memory, are also discussed, as are the contributions to an understanding of the neurobiology of human epilepsy and human higher functions derived from the surgical therapy of epilepsy.

Prospective analysis of diplopia after anterior temporal lobectomy for mesial temporal lobe sclerosis

2003 ◽  
Vol 99 (3) ◽  
pp. 496-499 ◽  
Author(s):  
Aaron A. Cohen-Gadol ◽  
Jacqueline A. Leavitt ◽  
James J. Lynch ◽  
W. Richard Marsh ◽  
Gregory D. Cascino
Keyword(s):  
Temporal Lobe ◽  
Temporal Lobectomy ◽  
Palpebral Fissure ◽  
Ophthalmological Examination ◽  
Trochlear Nerve ◽  
Anterior Temporal Lobectomy ◽  
Content Type ◽  
Nerve Dysfunction ◽  
Mesial Temporal Lobe ◽  
Fine Print

Object. In this prospective study the authors investigated the incidence and natural history of postoperative diplopia in patients undergoing anterior temporal lobectomy (ATL) and amygdalohippocampectomy for medically intractable mesial temporal lobe epilepsy. Methods. Forty-seven patients scheduled for ATL for medically refractory seizures were examined preoperatively, 2 to 7 days postoperatively, and 3 to 6 months postoperatively. Ophthalmological examination including pupillary measurements, stereoacuity measurements, palpebral fissure measurements, vertical fusional amplitudes, Lancaster red green testing, visual field testing, and alternate cover testing was performed. Antiepileptic drug levels were monitored. Nine (19%) of 47 patients developed diplopia postoperatively. The diplopia was caused by trochlear nerve palsy in every case. No oculomotor nerve dysfunction was documented. Trochlear nerve function recovered completely in all patients within 3 to 6 months postoperatively. Conclusions. Postoperative diplopia following ATL occurs more often than previously thought and is primarily due to trochlear nerve dysfunction. Awareness of this transient complication is important in preoperative patient counseling.

Temporal-lobe seizures with additional foci treated by resection

1975 ◽  
Vol 43 (5) ◽  
pp. 596-607 ◽  
Author(s):  
John M. Van Buren ◽  
Cosimo Ajmone Marsan ◽  
Naomi Mutsuga
Keyword(s):  
Temporal Lobe ◽  
Epileptiform Activity ◽  
Epileptic Activity ◽  
Temporal Lobectomy ◽  
Seizure Type ◽  
Content Type ◽  
Implanted Electrodes ◽  
Number Of Patients ◽  
Fine Print

✓ The authors describe the use of temporal lobectomy following careful and repeated electroencephalogram (EEG) evaluation (with implanted electrodes in otherwise unresolvable cases) in the epileptic group characterized by automatisms (psychomotor seizures) with temporal epileptiform activity complicated by EEG foci in the opposite temporal lobe or by extratemporal activity. They found that this can render a significant number of patients (between 25% and 50%) either seizure-free or with significant and useful reduction in their seizure frequency. The cure and improvement rates of cases followed up after temporal resection with or without prior study with implanted electrodes were approximately equal. However, the implanted electrodes permitted surgical treatment of certain cases which would have been rejected on the basis of evidence derived from the scalp recordings alone. Of 28 of these 34 patients with persisting EEG epileptiform activity in the postoperative period, only one had such activity in a different location in a follow-up period of 6 years. No evidence of spreading epileptic activity or appearance of “mirror foci” was seen during a follow-up period averaging 8.2 years. Seizure remission up to 15 years with eventual recurrence of the original seizure type may occur following surgical therapy. Follow-up studies of surgical epileptic treatment of less than 3 to 5 years are of doubtful value.

Extravascular collagen in the human epileptic brain: a potential substrate for aberrant cell migration in cases of temporal lobe epilepsy

2002 ◽  
Vol 97 (5) ◽  
pp. 1125-1130 ◽  
Author(s):  
Erol Veznedaroglu ◽  
Elisabeth J. Van Bockstaele ◽  
Michael J. O'Connor
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Granule Cells ◽  
Light And Electron Microscopy ◽  
Cellular Migration ◽  
Temporal Lobectomy ◽  
Electron Microscopic ◽  
Content Type ◽  
Microscopic Evaluation ◽  
Fine Print

Object. Several lines of evidence have demonstrated a number of cellular changes that occur within the hippocampus in patients with temporal lobe epilepsy (TLE). These include aberrant migration of granule cells and sprouting of mossy fibers, processes that have been linked to the hyperexcitability phenomenon observed in cases of TLE. In the present study the authors examined brain tissues obtained in patients undergoing temporal lobectomy surgery and in patients at autopsy (normal human control specimens), and compared the subcellular composition of regions of the hippocampus containing dispersed granule cells. Methods. Six human hippocampi were obtained in patients undergoing temporal lobectomies for intractable seizures. The patients ranged in age from 24 to 50 years. Two of the six patients had a history of head trauma and one had experienced a febrile seizure during childhood. Immediately following excision from the brain, the tissue was placed in an acrolein—paraformaldehyde fixative. The hippocampi were processed along with six human brain control specimens obtained at autopsy for light and electron microscopic evaluation. The tissues were then labeled for collagen types I through IV. Positive collagen labeling was identified, with the aid of both light and electron microscopy, in the parenchyma of all patients with TLE but not in the control tissues. Conclusions. The authors report the first localization of collagen outside of the vasculature and meninges in the brains of patients with TLE. Recent evidence of collagen's chemoattractant properties and its role in epileptogenesis in animal models suggests that collagen may play a role in cellular migration and seizure activity in a subset of patients. Further studies with a larger series of patients are warranted.

Acute postoperative seizures following anterior temporal lobectomy for intractable partial epilepsy

1998 ◽  
Vol 89 (2) ◽  
pp. 177-182 ◽  
Author(s):  
Bhaskara Rao Malla ◽  
Terence J. O'Brien ◽  
Gregory D. Cascino ◽  
Elson L. So ◽  
Kurupath Radhakrishnan ◽  
...  
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Seizure Control ◽  
Temporal Lobectomy ◽  
Mesial Temporal Sclerosis ◽  
Anterior Temporal Lobectomy ◽  
Content Type ◽  
Excellent Outcome ◽  
Prognostic Importance ◽  
Fine Print

Object. Recurrence of seizures immediately following epilepsy surgery can be emotionally devastating, and raises concerns about the chances of successfully attaining long-term seizure control. The goals of this study were to investigate the frequency of acute postoperative seizures (APOS) occurring in the 1st postoperative week following anterior temporal lobectomy (ATL) to identify potential risk factors and to determine their prognostic significance. Methods. One hundred sixty consecutive patients who underwent an ATL for intractable nonlesional temporal lobe epilepsy were retrospectively studied. Acute postoperative seizures occurred in 32 patients (20%). None of the following factors were shown to be significantly associated with the occurrence of APOS: age at surgery, duration of epilepsy, side of surgery, extent of neocortical resection, electrocorticography findings, presence of mesial temporal sclerosis, and hippocampal volume measurements (p > 0.05). Patients who suffered from APOS overall had a lower rate of favorable outcome with respect to seizure control at the last follow-up examination than patients without APOS (62.5% compared with 83.6%, p < 0.05). The type of APOS was of prognostic importance, with patients whose APOS were similar to their preoperative habitual seizures having a significantly worse outcome than those whose APOS were auras or were focal motor and/or generalized tonic—clonic seizures (excellent outcome: 14.3%, 77.8%, and 75%, respectively, p < 0.05). Only patients who had APOS similar to preoperative habitual seizures were less likely to have an excellent outcome than patients without APOS (14.3% compared with 75%, p < 0.05). Timing of the APOS and identification of a precipitating factor were of no prognostic importance. Conclusions. The findings of this study may be useful in counseling patients who suffer from APOS following ATL for temporal lobe epilepsy.

Fentanyl-induced electrocorticographic seizures in patients with complex partial epilepsy

1992 ◽  
Vol 77 (2) ◽  
pp. 201-208 ◽  
Author(s):  
René Tempelhoff ◽  
Paul A. Modica ◽  
Kerry L. Bernardo ◽  
Isaac Edwards
Keyword(s):  
Temporal Lobe ◽  
Seizure Activity ◽  
Epileptiform Activity ◽  
Temporal Lobectomy ◽  
Electrode Arrays ◽  
Complex Partial Seizures ◽  
Content Type ◽  
Temporal Lobe Seizures ◽  
Eeg Recordings ◽  
The Right

✓ Although electrical seizure activity in response to opioids such as fentanyl has been well described in animals, scalp electroencephalographic (EEG) recordings have failed to demonstrate epileptiform activity following narcotic administration in humans. The purpose of this study was to determine whether fentanyl is capable of evoking electrical seizure activity in patients with complex partial (temporal lobe) seizures. Nine patients were studied in whom recording electrode arrays had been placed in the bitemporal epidural space several days earlier to determine which temporal lobe gave rise to their seizures. The symptomatic temporal lobe was localized by correlating clinical and electrical seizure activity obtained during continuous simultaneous videotape and epidural EEG monitoring. In each patient, clinical seizures and electrical seizure activity were consistently demonstrated to arise unilaterally from one temporal lobe (four on the right, five on the left). During fentanyl induction of anesthesia in preparation for secondary craniotomy for anterior temporal lobectomy, eight of the nine patients exhibited electrical seizure activity at fentanyl doses ranging from 17.7 to 35.71 µg · kg−1 (mean 25.75 µg · kg−1). More importantly, four of these eight seizures occurred initially in the “healthy” temporal lobe contralateral to the surgically resected lobe from which the clinical seizures had been shown to arise. These findings indicate that, in patients with complex partial seizures, moderate doses of fentanyl can evoke electrical seizure activity. The results of this study could have important implications for neurosurgical centers where electrocorticography is used during surgery for the purpose of determining the extent of the resection.

Resective surgery for medically intractable epilepsy associated with schizencephaly

1994 ◽  
Vol 80 (5) ◽  
pp. 820-825 ◽  
Author(s):  
Daniel L. Silbergeld ◽  
John W. Miller
Keyword(s):  
Temporal Lobe ◽  
Intractable Epilepsy ◽  
The Other ◽  
Temporal Lobectomy ◽  
Eeg Monitoring ◽  
Resonance Imaging ◽  
Ipsilateral Hemisphere ◽  
Content Type ◽  
Intracranial Electrodes ◽  
Fine Print

✓ Four adults with unilateral (three cases) or bilateral (one case) closed schizencephaly, medically intractable epilepsy, and otherwise normal neurological examinations are presented. Three were examined preoperatively with magnetic resonance imaging and one with computerized tomography. Scalp electroencephalographic (EEG) studies in all four patients and electrocorticography via intracranial electrodes in two showed seizure origin in the cleft regions in two patients and in the ipsilateral temporal lobe in the other two. Temporal lobectomy was performed in the two patients with temporal lobe foci. Resection of superficial pachygyria around the cleft was performed in one patient. The authors conclude that the abnormal cortical mantle lining schizencephalic clefts may be epileptogenic. Alternatively, temporal allocortex may become the source of seizures. Therefore, these patients require careful EEG monitoring of the entire ipsilateral hemisphere as well as the cleft region.

Clinical relevance of amygdala sclerosis in temporal lobe epilepsy

1999 ◽  
Vol 91 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Josef Zentner ◽  
Helmut K. Wolf ◽  
Christof Helmstaedter ◽  
Thomas Grunwald ◽  
Ales F. Aliashkevich ◽  
...  
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Verbal Memory ◽  
Computer Assisted ◽  
Amygdaloid Nucleus ◽  
Image Analysis System ◽  
Short Term ◽  
Content Type ◽  
Depth Electrodes ◽  
Fine Print

Object. The goal of this study was to define the incidence and clinical significance of amygdala sclerosis (AS) in patients with temporal lobe epilepsy (TLE).Methods. Surgical specimens of the lateral amygdaloid nucleus and the hippocampus excised from 71 patients who were treated for medically intractable TLE were quantitatively evaluated using a computer-assisted image-analysis system and compared with 10 normal autopsy specimens. Densities of neurons and reactive astrocytes in the patients with TLE were correlated with clinical, neuropsychological, and depth-electroencephalography data. The neuron counts of the lateral amygdaloid nucleus did not correlate with various presumed etiological factors of TLE including hereditary seizures, birth complications, febrile convulsions, traumatic brain injury, infections, seizure semiology, and epileptological outcome. However, patient age at surgery was significantly higher (mean difference 10 years) when AS was present, as compared with patients without AS (p < 0.01). Seizure origin, as determined by using amygdalohippocampal depth electrodes, did not correlate with the presence or absence of AS. Neuropsychologically, there was a significant correlation between the neuronal densities of the lateral amygdaloid nucleus and both preoperative visual recognition and postoperative deterioration of short-term verbal memory performance (p < 0.05).Conclusions. Except for the relatively long history of epilepsy, the presence of AS is not associated with specific clinical or electrocorticographic features of mesial TLE. However, patients without AS are particularly at risk for deterioration of short-term verbal memory following amygdalohippocampectomy.

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