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Results for “Temporal Lobe Resection”

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PubMed2005

BDNF modulates GABAA receptors microtransplanted from the human epileptic brain to Xenopus oocytes.

Cell membranes isolated from brain tissues, obtained surgically from six patients afflicted with drug-resistant temporal lobe epilepsy and from one nonepileptic patient afflicted with a cerebral oligodendroglioma, were injected into frog oocytes. By using this approach, the oocytes acquire human GABAA receptors, and we have shown previously that the "epileptic receptors" (receptors transplanted from epileptic brains) display a marked run-down during repetitive applications of GABA. It was found that exposure to the neurotrophin BDNF increased the amplitude of the "GABA currents" (currents elicited by GABA) generated by the epileptic receptors and decreased their run-down; both events being blocked by K252A, a neurotrophin tyrosine kinase receptor B inhibitor. These effects of BDNF were not mimicked by nerve growth factor. In contrast, the GABAA receptors transplanted from the nonepileptic human hippocampal uncus (obtained during surgical resection as part of the nontumoral tissue from the oligodendroglioma margins) or receptors expressed by injecting rat recombinant alpha1beta2gamma2 GABAA receptor subunit cDNAs generated GABA currents whose time-course and run-down were not altered by BDNF. Loading the oocytes with the Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetate-acetoxymethyl ester (BAPTA-AM), or treating them with Rp-8-Br-cAMP, an inhibitor of the cAMP-dependent PKA, did not alter the GABA currents. However, staurosporine (a broad spectrum PK inhibitor), bisindolylmaleimide I (a PKC inhibitor), and U73122 (a phospholipase C inhibitor) blocked the BDNF-induced effects on the epileptic GABA currents. Our results indicate that BDNF potentiates the epileptic GABAA currents and antagonizes their use-dependent run-down, thus strengthening GABAergic inhibition, probably by means of activation of tyrosine kinase receptor B receptors and of both PLC and PKC.

Animals↗

PubMed2001

Seizure outcome after temporal lobectomy: current research practice and findings.

PURPOSE: The literature regarding seizure outcome and prognostic factors for outcome after temporal lobectomy is often contradictory. This is problematic, as these data are the basis on which surgical decisions and counseling are founded. We sought to clarify inconsistencies in the literature by critically examining the methods and findings of recent research. METHODS: A systematic review of the 126 articles concerning temporal lobectomy outcome published from 1991 was conducted. RESULTS: Major methodologic issues in the literature were heterogeneous definitions of seizure outcome, a predominance of cross-sectional analyses (83% of studies), and relatively short follow-up in many studies. The range of seizure freedom was wide (33-93%; median, 70%); there was a tendency for better outcome in more recent studies. Of 63 factors analyzed, good outcome appeared to be associated with several factors including preoperative hippocampal sclerosis, anterior temporal localization of interictal epileptiform activity, absence of preoperative generalized seizures, and absence of seizures in the first postoperative week. A number of factors had no association with outcome (e.g., age at onset, preoperative seizure frequency, and extent of lateral resection). CONCLUSIONS: Apparently conflicting results in the literature may be explained by the methodologic issues identified here (e.g., sample size, selection criteria and method of analysis). To obtain a better understanding of patterns of long-term outcome, increased emphasis on longitudinal analytic methods is required. The systematic review of possible risk factors for seizure recurrence provides a basis for planning further research.

Electroencephalography↗

PubMed1995

Intraoperative thermal inactivation of the hippocampus in an effort to prevent global amnesia after temporal lobectomy.

In an effort to assess the risk of amnesia after anterior temporal lobectomy (ATL), we conducted localized thermal inactivation (cooling) of the hippocampus with memory testing. Thirty-three ATL patients whose preoperative evaluation suggested risk for postoperative amnesia underwent hippocampal cooling. Cooling consisted of inserting a catheter in the temporal horn and irrigating it with an iced solution until a stable hippocampal temperature of approximately 20 degrees C was reached. Memory was assessed before and after cooling. In 12 of the 33 patients, memory testing was either aborted or suggested poor contralateral support, and the hippocampus was resected in 2 of these patients. The remaining 21 patients showed evidence of contralateral memory support, and the hippocampus was resected in 18. No patient became amnestic. These results suggest that intraoperative hippocampal cooling may be useful in selected cases. However, even among many patients who could cooperate with testing, discomfort, sedation, attentional deficits, confusion, and anxiety made test interpretation difficult.

Adolescent↗

PubMed2005

The field defects of anterior temporal lobectomy: a quantitative reassessment of Meyer's loop.

Temporal lobectomy is often complicated by superior quadrantanopia. The relation of field loss to sagittal resection length can inform us about the functional anatomy of Meyer's loop, with ramifications for surgical planning. However, the literature has produced highly variable results. We studied 29 patients with anterior temporal lobectomies using Goldmann perimetry. 24 patients had post-operating neuroimaging, with which we assessed resection length relative to each patient's temporo-occipital dimensions. For the field defect we calculated the proportion of area lost for three isopters. We found a significant correlation between resection size and field loss for both nasal and temporal defects. Linear regressions suggested an anterior limit of Meyer's loop at 24 to 28 mm from the anterior temporal pole, and involvement of the lower quadrant when resections reached 70 to 79 mm, with significant inter-subject variability. The nasal defect was 15% greater than the temporal defect for all degrees of quadrantanopia, with no difference between right and left hemispheres. Macular involvement began when field defects reached 61% of quadrant area, corresponding to a resection of about 58 mm. Patterns of field loss showed that the lower margins were most often horizontal or with a slight slope towards fixation, rather than true wedge defects. We conclude that field loss is related to resection length and that Meyer's loop extends more anteriorly than estimated in traditional surgical studies, in agreement with modern MRI and dissection studies. The patterns of field loss support a revised retinotopic model in which the most anterior fibers of Meyer's loop represent the superior field, not the vertical meridian as traditionally proposed.

Adult↗

PubMed1993

Temporal neocortical role in ictal experiential phenomena.

Resection of a left temporal neocortical tumor, preserving the amygdala and hippocampus, permanently abolished ictal illusions in a 20-year-old man, suggesting that neocortical epileptic discharge is essential in the production of the experiential phenomena of seizures. In light of other works demonstrating amygdala and hippocampal participation, we propose that ictal experiential phenomena represent simultaneous epileptic discharge of the temporal neocortex and the limbic system.

Adult↗

PubMed1991

Acute effect of anterior temporal lobectomy on musical processing.

Patients with intractable epilepsy treated by anterior temporal lobectomy (Right, RT, n = 12; Left, LT, n = 9) and healthy controls (n = 12) with no musical training were prospectively evaluated with a standardized battery, including the Musical Aptitude Profile and the Seashore Tonal Memory Test. Before surgery, patients performed below controls (P less than 0.001), but there were no differences between RT and LT patients. After resection (2 weeks), RT patients showed a differential decline on tasks measuring perception of meter (P = 0.005) and tempo (P = 0.008) but not tonal processes. LT, and controls studied at the same time interval, showed no decline. The results support the role of the right hemisphere in specific aspects of musical processing.

Adult↗

PubMed2006

Long-term seizure outcome following surgery for dysembryoplastic neuroepithelial tumor.

OBJECT: Resection of dysembryoplastic neuroepithelial tumor (DNET) is thought to result in favorable seizure outcome, but long-term follow-up data are scarce. The authors present a review of 18 patients who underwent surgical removal of a DNET: 12 via temporal lobectomy and six via lesionectomy. METHODS: The mean long-term follow up was 10.8 years (median 10.4 years, range 7.8 to 14.8 years), and results obtained during this time period were compared with previously reported short-term (mean 2.7 years) seizure outcome data. In the current study, 66.7% patients had an Engel Class I outcome and 55.6% had an Engel Class IA outcome compared with 77.8% and 55.6%, respectively. Temporal lobectomy (Engel Class I, 83.3%; Engel Class IA, 66.7%) led to a better seizure outcome than lesionectomy (Engel Classes I and IA, 33.3%). Two patients (11.1%) required repeated operation and both had an incomplete lesionectomy initially. CONCLUSIONS: Results indicated that complete resection of a DNET leads to a favorable seizure outcome, with epilepsy cure in those who had experienced early postoperative seizure relief. Long-term seizure outcome after surgery is predictable based on the result of short-term follow up.

Adolescent↗

PubMed2003

Successful selection of patients with intractable extratemporal epilepsy using non-invasive investigations.

PURPOSE: Patients with intractable epilepsy, operated for extratemporal epileptogenic foci, have often been found to have poorer surgical outcome compared with those with temporal lobe foci. The objective of this study is to assess the surgical outcome in patients with extratemporal foci, operated at the All India Institute of Medical Sciences (AIIMS), New Delhi. METHODS: Patients of intractable epilepsy with extratemporal foci on detailed investigation constituted the study group. They were evaluated by the 'Comprehensive Epilepsy Care Team' at the AIIMS with detailed clinical assessment, interictal EEGs, video-EEG studies, magnetic resonance imaging (MRI) with special sequences tailored for evaluation of the temporal lobes and for cortical dysplasias and single photon emission computerised tomography (SPECT) studies. Intraoperative electrocorticography was obtained in some patients. Outcome was assessed on follow-up, and graded according to Modified Engel's Grading System. RESULTS: Twenty-five patients (18 males, 7 females) with a mean age of 19.7 years (age range 7-45 years) were operated and assessed during the study period, for surgical outcome with a mean follow-up of 16.8 months (range 3 months to 6.5 years). Twenty patients (87%) were found to have a good outcome (Modified Engel's grades I and II), while three had poor outcome, one died and one was lost to follow-up. CONCLUSION: We found a good seizure outcome in patients who underwent resection of extratemporal epileptogenic foci, one of the reasons being presence of a lesion in all patients. Careful patient selection even with non-invasive investigations can aid in obtaining a good outcome in this group of patients.

Adolescent↗

PubMed2001

Comparison of electroencephalographic dipoles of interictal spikes from prolonged scalp video-electroencephalography and magnetoencephalographic dipoles from short-term recording in children with extratemporal lobe epilepsy.

We retrospectively compared electroencephalographic (EEG) dipoles of interictal spikes from prolonged video-EEG monitoring with magnetoencephalographic dipoles from short-term recording in four children with extratemporal lobe epilepsy. We analyzed both sets of dipoles using individual interictal spikes and single moving dipole modeling and evaluated the profiles of spike appearance, dipole position, and orientation in EEG and magnetoencephalography. We obtained more than 100 magnetoencephalographic spikes in two patients who manifested frequent interictal EEG spikes throughout both day and night but fewer than 40 magnetoencephalographic spikes in two patients who had interictal EEG spikes mainly during sleep. The dipole positions of EEG and magnetoencephalography were in close proximity and included in the surgical resection area. Most of the dipoles between EEG and magnetoencephalography were oriented perpendicularly. A combination of EEG dipole analysis from prolonged video-EEG monitoring and magnetoencephalographic dipole analysis provides complementary information for presurgical evaluation in children with intractable extratemporal lobe epilepsy.

Adolescent↗

PubMed1986

Electrical stimulation of Wernicke's area interferes with comprehension.

Arrays of subdural electrodes were placed over the lateral convexity of the dominant hemisphere for propositional language in four patients with epilepsy as part of an evaluation prior to cortical resections. Stimulation was performed over several days. When we stimulated the posterior temporal language area, reading and comprehension of complex verbal information were impaired, but comprehension of nonverbal and simple verbal data was not affected. Impairment produced by stimulation seemed to be due to language comprehension difficulties, rather than impaired praxis or initial word storage.

Adolescent↗

PubMed1992

Temporal lobectomy for intractable epilepsy in patients over age 45 years.

Surgical management of uncontrolled focal epilepsy is most commonly carried out in young adults with good results, but there has been some doubt about the effectiveness of cortical resection in older individuals. We assessed the outcome of temporal lobectomy done after age 45 years in 20 patients with intractable epilepsy followed for more than 2 years after surgery. During a mean follow-up of 5 years, six patients (30%) were seizure-free following surgery and seven (35%) had greater than 90% reduction in seizure frequency. This compares with an outcome of 40% seizure-free and 44% with greater than 90% seizure reduction in 68 younger patients aged 17 to 45 years; the differences do not achieve statistical significance. The outcome was better for complex partial seizures than for secondarily generalized seizures. Complications were no greater than in the younger patients. The findings indicate that surgery is an effective treatment alternative for intractable temporal lobe epilepsy in older patients since two of three of these patients will obtain satisfactory seizure control.

Age Factors↗

PubMed2003

[Castleman's disease located in the central nervous system].

A 26-year-old woman complained of trijeminal nevralgy and ocular symptoms revealing a paracavernal tumor which had progressed for three months. Histopathological analysis after partial resection led to the diagnosis of Castleman's disease. Six months later, the patient was considered cured after focal adjuvant radiotherapy. Castleman's disease is a lymphoproliferative disorder. Solitary intracranial involvement is unusual. Unlike multifocal disease, localized Castleman's disease has an excellent prognosis.

Adult↗

PubMed1995

Klüver-Bucy syndrome after left anterior temporal resection.

A 70-year-old right-handed woman developed a complete Klüver-Bucy syndrome including psychic blindness, aberrant sexual behavior, hypermetamorphosis, aphasia and visual agnosia following left anterior temporal lobectomy for an anaplasic oligodendroglioma. MRI showed no argument for a contralateral ischemic infarct, tumoral growth or white matter damage. Thus the possibility that a unilateral anterior temporal lesion can cause the whole picture of Klüver-Bucy syndrome must therefore be considered.

Affect↗

PubMed1994

Parvalbumin and calbindin-D28k immunocytochemistry in human neocortical epileptic foci.

Serial sections of cortical resection of 30 patients suffering from drug-resistant epilepsy were processed for parvalbumin and calbindin-D28k immunocytochemistry to determine local circuit neuron populations. Our findings indicate that there is not a simple mechanism to explain neocortical epileptic foci. On the basis of the present results it can be suggested that: (1) reduced percentage of local circuit neurons in the vicinity of neoplasms may account for a decreased intracortical inhibition. (2) Abnormal morphology and distribution of local circuit neurons may result in abnormal cortical inhibition in patients with focal cortical dysplasia, and, probably, in other focal migrational disorders, including neuronal nests in the white matter. (3) Increased percentages of immunoreactive local circuit neurons and fibers in focal neocortical necrosis (cavernous angiomas), diffuse hypoxic encephalopathy, and hippocampus in patients with temporal lobe epilepsy due to mesial sclerosis, may play a role in epilepsy. These neurons can be activated by reduced excitatory inputs, or they may establish abnormal synaptic contacts with other inhibitory neurons. (4) Lack of consistent morphologic abnormalities in the neocortex of patients with temporal lobe epilepsy, and in patients with cryptogenetic frontal lobe epilepsy, suggests that electrically abnormal neocortical foci in these cases are probably epiphenomena.

Adolescent↗

PubMed1996

Basal extension of craniotomy for subtemporal middle fossa approach.

Resection of the root of the zygomatic arch including the glenoid fossa, and the roof of the external ear and the superior third of the mastoid process was seen to improve the basal exposure of the lateral subtemporal middle fossa approach. The exposure was horizontally wide. The enhanced exposure helped in reducing the extent of brain retraction that was necessary and improved the working space for manipulation of the instruments.

Craniotomy↗

PubMed1997

Oscillations of cerebrospinal fluid pressure in nonhydrocephalic persons.

Spontaneous cerebrospinal fluid (CSF) pressure oscillations with a wavelength of 0.5-2/min (B-waves) are used as a criterion for shunt insertion in hydrocephalic patients. We describe CSF pressure oscillations in two nonhydrocephalic patients with normal baseline CSF pressure. Intracranial pressure was recorded via a ventricular drainage in a 54-year-old male who had a lumber CSF leak after surgery for lumbar spinal stenosis and disc herniation after the leak was closed. In the second patient, a 42-year-old male, CSF pressure was monitored via a lumbar drainage which was placed for treatment of a subcutaneous CSF effusion after resection of a recurrent temporal meningioma. CSF pressure oscillations of a wavelength of 0.5-2/min were observed with a relative frequency of 50% (patient 1) and 60% (patient 2) of the recorded time. Also longer waves were observed. Our data suggest that CSF pressure oscillations are not confined to hydrocephalic patients with raised intracranial pressure.

Adult↗

PubMed1988

Neuronal activity in human lateral temporal cortex related to short-term verbal memory, naming and reading.

Extracellular microelectrode recordings were obtained from lateral temporal cortex that was subsequently resected in patients undergoing craniotomies under local anaesthesia for treatment of medically intractable epilepsy. During these recordings patients performed visually presented measures of overt and silent naming and word reading, short-term verbal memory and a control task requiring matching of angles. These measures were designed so that the same visual stimuli elicited language, short-term memory or spatial responses. Statistically significant changes within and between these various measures were identified. Technically satisfactory recordings were obtained from 17 populations reflecting activity predominantly from 1 neuron, in 13 patients. Two populations demonstrated no significant changes in any measured functions. Only 1 population showed changes suggesting a relation to visual perception. Four populations in or adjacent to the superior temporal gyrus altered activity with overt speech. Four other populations in the anterior temporal lobe altered activity during silent, but not overt speech. Some relation to language or memory was established for 13 of the 17 populations: 1 altered activity during reading alone, 6 during memory alone, and 6 to both. Most of the recording sites showing these language and memory changes were not essential for those functions based on surface electrical stimulation mapping. Thus the area of temporal lobe that participates in language and memory, as indicated by changes in neuronal activity, is substantially larger than the areas essential for those functions as determined by stimulation mapping. Within that participatory area, changes related to language were most often an increase in activity sustained throughout the task, a pattern suggestive of mechanisms of selective attention. Changes related to memory most often included a sustained increase in activity at the time of entry of information into memory, and again at retrieval, with decreased activity during the time the memory was stored. A few neuronal populations demonstrated relative inhibition of activity during the memory task, compared with control measures.

Electric Stimulation↗

PubMedDate not supplied

[Radioguided neurosurgery: a novel application of nuclear medicine].

Brain tumours show uptake with Thallium-201 Chloride with high target/background rate and they would benefit from radioguided surgery. We report a patient with a brain tumor that was Thallium positive in a brain SPECT. On the next day in the operating room we injected 50 MBq of Thallium-201. At 40 minutes we confirmed tumour uptake with a gamma-probe and with a biopsy sample. After brain tumor resection was completed by conventional method, we found pathologic activity in tumoral bed with the gamma probe, that showed persistence of increased activity. After a new evaluation, residual tumor tissue was located in the pathological uptake area and was removed. Control CT showed complete resection, although the Thallium SPECT carried out after surgery showed faint uptake in the anterior pole of the surgical bed. Radioguided surgery was evaluated as a useful and promising technique by the neurosurgeon.

Biopsy↗