Surgical management of epilepsy associated with cerebral arteriovenous malformations

1990 ◽  
Vol 72 (2) ◽  
pp. 216-223 ◽  
Author(s):  
Hwa-Shain Yeh ◽  
Shiro Kashiwagi ◽  
John M. Tew ◽  
Thomas S. Berger

✓ Between 1982 and 1986, 27 patients with seizure disorders due to cerebral arteriovenous malformation (AVM) were surgically treated by the authors. These patients had no history or clinical manifestation of intracranial hemorrhage. All were treated with anticonvulsant agents by their neurologists but became disabled due to inadequate control of seizures by medication, side effects of the anticonvulsant drugs, or the effects on their professional lives of even infrequent seizures. The age of the patients ranged from 13 to 61 years. There were 13 males and 14 females. The AVM's were smaller than 2 cm in four patients, between 2 and 4 cm in five, and larger than 4 cm in 18. The most frequent location of the AVM's was in the temporal lobe, followed by the frontal, parietal, and occipital lobes. All patients had preoperative electroencephalography (EEG) and intraoperative electrocorticography. Intraoperative recording of the amygdala and the hippocampus by depth electrodes was performed if the AVM's were located in the temporal lobe. Superficial or posterior temporal lobe AVM's often have remote seizure foci that involve the amygdala and hippocampus. All patients underwent craniotomy and total excision of their AVM's. Surgery was carried out under local anesthesia to allow localization by electrical stimulation if the AVM involved the speech area or the sensorimotor cortex. Based on the EEG findings, excision of the epileptogenic lesion in addition to the AVM was performed in 18 patients. In seven patients with AVM's located in the temporal lobe, remote seizure foci were identified and excised. The remote epileptic activity was particularly prominent in AVM's in the temporal lobe and usually involved mesial temporal structures. Microscopic study of excised seizure foci showed gliosis in 26 cases, hemosiderin deposits in 10, and focal hemorrhage in four. There were no operative deaths. Two patients developed a hemiparesis and three suffered temporary dysphasia after surgery. Two patients had visual field deficits. The results of postoperative seizure control during the average follow-up period of 3 years 11 months were excellent in 21 patients, good in three, fair in two, and poor in one. The latter patient, whose epileptic lesion was not completely excised because of its location in the motor cortex, had poor seizure control postoperatively. Another patient required a second operation to remove a remote seizure focus. In this series, proposed mechanisms of seizure associated with cerebral AVM include focal cerebral ischemia secondary to arteriovenous shunting, gliosis of the surrounding brain, and a secondary epileptogenesis in the temporal lobe. Successful seizure control can be obtained with wide excision of the epileptogenic foci surrounding the AVM's. In some circumstances, seizure foci remote from the vascular malformation must be excised.

1984 ◽  
Vol 60 (3) ◽  
pp. 457-466 ◽  
Author(s):  
Sidney Goldring ◽  
Erik M. Gregorie

✓ 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.


1987 ◽  
Vol 66 (4) ◽  
pp. 489-499 ◽  
Author(s):  
George A. Ojemann

✓ 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.


1975 ◽  
Vol 43 (5) ◽  
pp. 596-607 ◽  
Author(s):  
John M. Van Buren ◽  
Cosimo Ajmone Marsan ◽  
Naomi Mutsuga

✓ 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.


1998 ◽  
Vol 89 (2) ◽  
pp. 177-182 ◽  
Author(s):  
Bhaskara Rao Malla ◽  
Terence J. O'Brien ◽  
Gregory D. Cascino ◽  
Elson L. So ◽  
Kurupath Radhakrishnan ◽  
...  

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.


1999 ◽  
Vol 91 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Josef Zentner ◽  
Helmut K. Wolf ◽  
Christof Helmstaedter ◽  
Thomas Grunwald ◽  
Ales F. Aliashkevich ◽  
...  

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.


2000 ◽  
Vol 93 (1) ◽  
pp. 44-52 ◽  
Author(s):  
Guy M. McKhann ◽  
Julie Schoenfeld-McNeill ◽  
Donald E. Born ◽  
Michael M. Haglund ◽  
George A. Ojemann

Object. Among the variety of surgical procedures that are performed for the treatment of medically refractory mesial temporal lobe epilepsy (TLE), no consensus exists as to how much of the hippocampus should be removed. Whether all patients require a maximal hippocampal resection has not yet been determined.Methods. At the University of Washington, all TLE operations are performed in a tailored fashion, guided by electrocorticography (ECoG). The amount of hippocampal resection is determined intraoperatively by the extent of interictal epileptiform abnormalities on ECoG recorded from that structure, resulting in a hippocampal resection that is individualized for each patient. Using this approach, the authors prospectively observed 140 consecutive patients who underwent surgery for mesial TLE with pathological diagnoses of either mesial temporal sclerosis with neuronal loss (MTS group) or mild gliosis without neuronal loss (non-MTS group) to determine whether the extent of hippocampal resection correlates with outcome when a tailored approach is used. Additionally, the authors analyzed whether the presence of residual interictal epileptiform activity on ECoG following mesial temporal resection predicts poorer seizure control.With at least 18 months of clinical follow up, 67% of the 140 patients were seizure free or had only a single postoperative seizure. There was no correlation between the size of the hippocampal resection and seizure control in the group as a whole or when stratified by pathological subtype. Using an intraoperatively tailored strategy, individuals with a larger hippocampal resection (> 2.5 cm) were not more likely to have seizure-free outcomes than patients with smaller resections (p = 0.9). Additionally, both MTS and non-MTS patients, in whom postoperative ECoG detected residual epileptiform hippocampal (but not cortical or parahippocampal) interictal activity following surgical resection, had significantly worse seizure outcomes (p = 0.01 in the MTS group; p = 0.002 in the non-MTS group).Conclusions. Intraoperative hippocampal ECoG can predict how much hippocampus should be removed to maximize seizure-free outcome, allowing for sparing of possibly functionally important hippocampus.


2000 ◽  
Vol 93 (3) ◽  
pp. 402-409 ◽  
Author(s):  
Shenandoah Robinson ◽  
T. S. Park ◽  
Lynn B. Blackburn ◽  
Blaise F. D. Bourgeois ◽  
Susan T. Arnold ◽  
...  

Object. Unilateral resection of the hippocampus and amygdala can be used to treat medically intractable mesial temporal lobe seizures. To date seizure outcome and the extent of cognitive morbidity have been unknown in children following the transparahippocampal variation of selective amygdalohippocampectomy (TSA), which prompted the present prospective study.Methods. Preoperative examinations and outcomes in 22 consecutive children and adolescents who underwent TSA were studied. Cognitive and psychological morbidity were assessed using standard neuropsychological instruments. The authors evaluated relationships between seizure control and cognitive morbidity and 13 and nine clinical variables, respectively.Seizure control was achieved in 11 (65%) of 17 patients (> 2 years follow up). Among 13 clinical variables, the only preoperative finding that had a significant bearing on seizure control was the presence of unilateral hypometabolism, which could be observed on [18F]fluorodeoxyglucose—positron emission tomography scans (p < 0.001). Patients with seizure control showed significant improvements in verbal and full scale intelligence quotients (both p = 0.05). Patients with longer preoperative durations of seizures exhibited more cognitive impairment that persisted postoperatively. Cognitive outcome analysis based on nine clinical factors revealed no significant difference in cognitive parameters postoperatively, except that significant improvement occurred in rote verbal memory scores among patients who underwent right-sided TSA (p = 0.01). Individually, 81% of the children achieved significant improvement in at least one of seven cognitive parameters, and 52% had stable or improved scores in all parameters.Conclusions. The results indicate that TSA is a safe effective approach for the treatment of medically intractable mesial temporal lobe seizures in children with minimum effect on cognitive morbidity. Given that the literature suggests that children suffer progressive cognitive morbidity from persistent seizures, the results of this study support early surgical intervention for this group of children.


1994 ◽  
Vol 81 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Isabelle M. Germano ◽  
Nicole Poulin ◽  
André Olivier

✓ The indications for and the risks and outcome of reoperation for medically refractory temporal lobe epilepsy have not been well documented. A retrospective review is presented of 40 patients who underwent reoperation on the temporal lobe for recurrent seizures. The mean patient age at the first operation was 22 ± 7 years (± standard deviation). Electrocorticography during the first operation showed interictal epileptic abnormalities from surface electrodes in 97% of the cases and from depth electrodes in the mesiotemporal structures in 38%. The seizures recurred with the same pattern within 6 months after the first operation in 60% of patients and within 2 years in 90%. Postoperative neuroimaging studies showed residual mesiotemporal structures in all cases. The mean time between the two operations was 5.5 ± 5 years and the mean patient age at the second operation was 28 ± 8 years. The second operation involved focal resection of the mesiotemporal structures in 30 cases. The mean postoperative follow-up period was 4.8 ± 2.7 years (range 2 to 11 years). After the second operation, 63% of the patients were seizure-free or had rare seizures (one or two per year). There were no permanent neurological complications. Patients who did not benefit from reoperation had electroencephalographic abnormalities in multiple brain areas. Reoperation for temporal lobe epilepsy effectively controls seizures in the majority of patients, and the procedure is safe if rigorous technical rules are observed. More complete resection of mesiotemporal structures during the first operation, even in the absence of intraoperative electrographic abnormalities, could prevent the need for reoperation in defined cases.


1993 ◽  
Vol 79 (1) ◽  
pp. 62-69 ◽  
Author(s):  
Mitchel S. Berger ◽  
Saadi Ghatan ◽  
Michael M. Haglund ◽  
Jill Dobbins ◽  
George A. Ojemann

✓ Adults and children with low-grade gliomas often present with medically refractory epilepsy. Currently, controversy exists regarding the need for intraoperative electrocorticography (ECoG) to identify and, separately, resect seizure foci versus tumor removal alone to yield maximum seizure control in this patient population. Forty-five patients with low-grade gliomas and intractable epilepsy were retrospectively analyzed with respect to preoperative seizure frequency and duration, number of antiepileptic drugs, intraoperative ECoG data (single versus multiple foci), histology of resected seizure foci, and postoperative control of seizures with or without antiepileptic drugs. Multiple versus single seizure foci were more likely to be associated with a longer preoperative duration of epilepsy. Of the 45 patients studied, 24 were no longer taking antiepileptic drugs and were seizure-free (mean follow-up interval 54 months). Seventeen patients, who all had complete control of their seizures, remained on antiepileptic drugs at lower doses (mean follow-up interval 44 months); seven of these patients were seizure-free postoperatively, yet the referring physician was reluctant to taper the antiepileptic drugs. Four patients continued to have seizures while receiving antiepileptic drugs, although at a reduced frequency and severity. In this series 41% of the adults versus 85% of the children were seizure-free while no longer receiving antiepileptic drugs, with mean postoperative follow-up periods of 50 and 56 months, respectively. This difference was statistically significant (p = 0.016). Therefore, based on this experience and in comparison with numerous retrospective studies involving similar patients, ECoG is advocated, especially in children and in any patient with a long-standing seizure disorder, to maximize seizure control while minimizing or abolishing the need for postoperative antiepileptic drugs.


2002 ◽  
Vol 97 (5) ◽  
pp. 1142-1151 ◽  
Author(s):  
Aviva Abosch ◽  
Neda Bernasconi ◽  
Warren Boling ◽  
Marilyn Jones-Gotman ◽  
Nicole Poulin ◽  
...  

Object. Selective amygdalohippocampectomy (SelAH) is used in the treatment of mesial temporal lobe epilepsy (MTLE). The goal of this study was to determine factors predictive of poor postoperative seizure control (Engel Class III or IV) following SelAH. Methods. A retrospective study was conducted of 27 patients with poor seizure control postoperatively (Engel III/IV group), in comparison with 27 patients who were free from seizures after surgery (Engel I/II group). The results of electroencephalography, magnetic resonance (MR) imaging, and pathological studies were reviewed, and volumetric MR image analysis was used to compare the extent of the mesial structures that had been resected. In 56% of patients in the Engel III/IV group, significant bitemporal abnormalities were displayed on preoperative EEG studies, compared with 24% of patients in the Engel I/II group (p < 0.05). An analysis of preoperative MR images disclosed five patients (19%) in the Engel III/IV group and no patient in the Engel I/II group with normal hippocampal volumes bilaterally. Thirteen patients in the Engel III/IV group subsequently underwent either extension of the SelAH (six cases) or a corticoamygdalohippocampectomy (seven patients). Three patients from the former and one patient from the latter subgroup subsequently became seizure free (four patients total [34%]). The remaining nine patients did not improve, despite the fact that they had undergone near-total resection of mesial structures. Conclusions. The majority of patients receiving suboptimal seizure control following SelAH did not meet the criteria for unilateral MTLE, based on EEG, MR imaging, and/or histopathological studies. These patients were therefore unlikely to benefit from additional resection of mesial structures. With the benefits of modern imaging, and by strict adherence to selection criteria, SelAH can be predicted to yield excellent postoperative seizure control for nearly all patients with unilateral MTLE. There remains a subpopulation, however, that meets the criteria for MTLE, but does not become free from seizure following SelAH.


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