Surgical therapy for medically intractable epilepsy

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.

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.


1994 ◽  
Vol 80 (5) ◽  
pp. 820-825 ◽  
Author(s):  
Daniel L. Silbergeld ◽  
John W. Miller

✓ 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.


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.


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.


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.


1996 ◽  
Vol 85 (6) ◽  
pp. 1000-1004 ◽  
Author(s):  
Atsushi Koike ◽  
Hiroyuki Shimizu ◽  
Ichiro Suzuki ◽  
Buichi Ishijima ◽  
Morihiro Sugishita

✓ It has been widely accepted that the right temporal lobe plays a major role in the processing of music. One of the main lines of evidence was derived from Milner's study, published in 1962, which reported that right temporal lobectomy led to a decline in patient scores on four of the six subtests (Tonal Memory, Timbre, Loudness, and Time subtests) of the Seashore Measures of Musical Talents. That finding had led some surgeons and patients to hesitate in choosing right temporal lobectomy as a treatment for intractable epilepsy. The authors examined performance on the Seashore Measures before and after operations in 20 patients with right temporal lobectomy and nine patients with left temporal lobectomy. No disturbances in the Seashore Measures were detected after temporal lobectomy on either side. The extent of these temporal lobectomies was smaller than that of the temporal lobectomies in Milner's study, as measured along the sylvian fissure (1.5–4 cm; mean 2.7 cm, standard deviation (SD) 0.92 cm) and the base of the temporal lobe (3.5–5.5 cm; mean 4.7 cm, SD 0.63 cm). These findings indicate that the region resected on right temporal lobectomy in the present study is not essential for basic musical processing.


2002 ◽  
Vol 97 ◽  
pp. 542-550 ◽  
Author(s):  
Marc Levivier ◽  
David Wikler ◽  
Nicolas Massager ◽  
Philippe David ◽  
Daniel Devriendt ◽  
...  

Object. The authors review their experience with the clinical development and routine use of positron emission tomography (PET) during stereotactic procedures, including the use of PET-guided gamma knife radiosurgery (GKS). Methods. Techniques have been developed for the routine use of stereotactic PET, and accumulated experience using PET-guided stereotactic procedures over the past 10 years includes more than 150 stereotactic biopsies, 43 neuronavigation procedures, and 34 cases treated with GKS. Positron emission tomography—guided GKS was performed in 24 patients with primary brain tumors (four pilocytic astrocytomas, five low-grade astrocytomas or oligodendrogliomas, seven anaplastic astrocytomas or ependymomas, five glioblastomas, and three neurocytomas), five patients with metastases (single or multiple lesions), and five patients with pituitary adenomas. Conclusions. Data obtained with PET scanning can be integrated with GKS treatment planning, enabling access to metabolic information with high spatial accuracy. Positron emission tomography data can be successfully combined with magnetic resonance imaging data to provide specific information for defining the target volume for the radiosurgical treatment in patients with recurrent brain tumors, such as glioma, metastasis, and pituitary adenoma. This approach is particularly useful for optimizing target selection for infiltrating or ill-defined brain lesions. The use of PET scanning contributed data in 31 cases (93%) and information that was specifically utilized to adapt the target volume in 25 cases (74%). It would seem that the integration of PET data into GKS treatment planning may represent an important step toward further developments in radiosurgery: this approach provides additional information that may open new perspectives for the optimization of the treatment of brain tumors.


1978 ◽  
Vol 48 (4) ◽  
pp. 622-627 ◽  
Author(s):  
Richard L. Sogg ◽  
Sarah S. Donaldson ◽  
Craig H. Yorke

✓ A 9-year-old schoolgirl received 6007 rads to the suprasellar region for craniopharyngioma. Five years later, a malignant astrocytoma developed in the right temporal lobe. We cite clinical and experimental evidence to support our suspicion that the glioma may have been induced by radiation.


1991 ◽  
Vol 75 (5) ◽  
pp. 715-722 ◽  
Author(s):  
Timothy B. Garner ◽  
O. Del Curling ◽  
David L. Kelly ◽  
D. Wayne Laster

✓ Cerebral venous angiomas are congenital anomalies of the intracranial venous drainage. Many believe that they are associated with a high risk of hemorrhage and neurological dysfunction, but newer neurodiagnostic imaging techniques are showing not only that they are more common than previously known but also that many have no associated symptoms. In this retrospective study, the natural history of venous angiomas was examined in 100 patients (48 males and 52 females) with radiographically identifiable lesions treated over a 14-year period. Information on the natural history of the lesion was obtained from clinical records and follow-up data. Imaging studies included angiography, computerized tomography, and magnetic resonance imaging. Angioma locations were classified as frontal (42 cases), parietal (24 cases), occipital (4 cases), temporal (2 cases), basal or ventricular (11 cases), cerebellar (14 cases), or brain stem (3 cases); 47 lesions were on the left side. Headache as a presenting symptom was common (36 patients) and often led to other radiographic studies, but this appeared to be related to the vascular lesion in only four patients. Other possibly related complications were hemorrhage in one patient, seizures in five, and transient focal deficits in eight. Fifteen patients had no neurological signs or symptoms. The mean patient age at last contact was 45.3 years (range 3 to 94 years). All patients have been managed without surgery. It is concluded that significant complications secondary to venous angiomas are infrequent and that surgical resection of these lesions and of surrounding brain is rarely indicated.


2000 ◽  
Vol 92 (6) ◽  
pp. 1009-1015 ◽  
Author(s):  
Seiji Yamamoto ◽  
Weiyu Teng ◽  
Shigeru Nishizawa ◽  
Takeharu Kakiuchi ◽  
Hideo Tsukada

Object. The hydroxyl radical scavenger (±)-N,N′-propylenedinicotinamide (AVS) has been shown to ameliorate the occurrence of vasospasm following experimental subarachnoid hemorrhage (SAH) and to reduce the incidence of delayed ischemic neurological deficits (DINDs) in patients with SAH. The authors investigated whether prophylactic administration of AVS could improve cerebral blood flow (CBF) and cerebral glucose utilization (CGU) following SAH in rats.Methods. Anesthetized rats were subjected to intracisternal injection of blood (SAH group) or saline (control group). Either AVS (1 mg/kg/min) or saline (vehicle group) was continuously injected into the rat femoral vein. Forty-eight hours later, positron emission tomography scanning was used with the tracers 15O-H2O and 18F-2-fluoro-d-glucose to analyze quantitatively CBF and CGU, respectively, in the frontoparietal and occipital regions (12 regions of interest/group).In SAH rats receiving only vehicle, CBF decreased significantly (p < 0.05, Tukey's test) and CGU tended to decrease, compared with values obtained in control (non-SAH) rats receiving vehicle. In rats that were subjected to SAH, administration of AVS significantly (p < 0.05, Tukey's test) improved CBF and CGU in both the frontoparietal and occipital regions compared with administration of vehicle alone.Conclusions. Prophylactic administration of AVS improves CBF and CGU in the rat brain subjected to SAH, and can be a good pharmacological treatment for the prevention of DINDs following SAH.


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