• Journal of Korean Neurosurgical Society
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• v.29 no.12
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• pp.1650-1656
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• 2000

Objective : Little consensus exists concerning which temporal lobe structures need to be resected or how much resection should be done during hippocampal resection. The purpose of this study is to identify whether the extent of hippocampal resection influences seizure after anterior temporal lobectomy. Materials and Methods : The extent of hippocampal resection was assessed in 96 patients who underwent temporal lobectomy for medically intractable complex partial seizures originating from a unilateral seizure focus in the anteromesial temporal lobe. Patients who had structural lesion were excluded from the study. Postoperative magnetic resonance imaging in the coronal and saggital planes were used to quantify the extent of the hippocampal and lateral cortical resection. The patients were divided into two groups. Patients who underwent hippocampal resection to the level of the cerebral peduncle were included in the partial resection group, and those who had resection to the level of the colliculus were assigned to total resection group. Seizure outcomes were defined according to the Engel classification and compared between the two groups. Neuropsychologic outcomes in the selected cases were reviewed. Results : The over-all seizure-free outcome(Engel classification 1) was accomplished in 75%(72/96) of the patients (mean duration of follow-up, 36.8 months). The total hippocampectomy group had a statistically superior seizure outcome than the partial hippocampectomy group(87.3% versus 58.5% seizure-free, p-value=0.001). Also, younger patients had a more favorable outcome. Other variables such as laterality, the extent of lateral cortical resection, age at onset and gender were not significant. The pre- and postoperative memory functions were evaluated in 24 patients. A worse postoperative memory outcome was associated with partial hippocampectomy. However this was not acceptable due to a former bias. Conclusion : The result of this study conforms that aggressive hippocampectomy resulted in a better seizure outcome.

• Journal of Korean Neurosurgical Society
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• v.30 no.1
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• pp.26-32
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• 2001

Objective : The increasing use of sensitive neuroimaging techniques has demonstrated that significant percentage of patients with intractable complex partial seizures have brain masses, especially in temporal lobe. The optimal surgical solution for these patients is still open to debate. The purpose of our investigation is to evaluate the surgical outcome of patient with lesion-related temporal lobe epilepsy with respect to the types of surgery and the location of lesion. Patients and Methods : From DEC. 1993 to Dec. 1997, 35 patients with intractable epilepsy and space occupying temporal lobe lesion identified in preoperative MRI were included in this study. The types of surgery were lesionectomy, anterior temporal lobectomy with or without hippocampectomy. The location of lesion was divided as anteromedial group and lateral cortical group. The postoperative seizure outcomes according to the type of surgery and location of the lesion were compared. Results : Twenty-six of 34 patients(76.5%) were seizure-free after surgery. The Engel's class was favorable after anterior temporal lobectomy with or without hippocampectomy(p=.044) Conclusion : It is favorable to perform anterior temporal lobectomy for the treatment of intractable epilepsy with space-occipying lesion in temporal lobe. The resection of the hippocampus can be individualized.

• The Korean Journal of Nuclear Medicine
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• v.29 no.3
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• pp.287-293
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• 1995

Anterior temporal lobectomy has become a widely used resective surgery in patients with medically intractable temporal lobe epilepsies. Prerequisites of this resection include the accurate localization of the epileptogenic focus and the determination that the proposed resection would not result in unacceptable postoperative memory or language deficits. The purpose of this study was to evaluate the performance of ictal SPECT compared to MRI findings for localization of epiletogenic foci in this group of patients. 11 patients who had been anterior temporal lobectomy were evaluated with ictal $^{99m}Tc$-HMPAO SPECT and MRI. MRI showed 8/11(73%) concordant lesion to the side of surgery and ictal SPECT also showed 8/11(73%) concordant hyperperfusion. In 3 cases with incorrect or nonlocalizing findings of MRI, ictal SPECT showed concordant hyperperfusion. In 2 cases confirmed by pre-resectional invasive EEG, MRI showed bilateral and contralateral lesion but ictal SPECT showed concordant hyperperfusion. 3 delayed injection of ictal SPECT showed discordant hyperperfusion. Thus, ictal SPECT was a useful method for localizing epileptogenic foci in temporal lobe epilepsis and appeared complementay to MRI.

• Journal of Korean Neurosurgical Society
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• v.67 no.4
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• pp.458-466
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• 2024

Objective : Several clinical studies have explored the feasibility and efficacy of radiosurgical treatment for mesial temporal lobe epilepsy, but the long-term safety of this treatment has not been fully characterized. This study aims to report and describe radiation-induced cavernous malformation as a delayed complication of radiosurgery in epilepsy patients. Methods : The series includes 20 patients with mesial temporal lobe epilepsy who underwent Gamma Knife radiosurgery (GKRS). The majority received a prescribed isodose of 24 Gy as an adjuvant treatment after anterior temporal lobectomy. Results : In this series, we identified radiation-induced cavernous malformation in three patients, resulting in a cumulative incidence of 18.4% (95% confidence interval, 6.3% to 47.0%) at an 8-year follow-up. These late sequelae of vascular malformation occurred between 6.9 and 7.6 years after GKRS, manifesting later than other delayed radiation-induced changes, such as radiation necrosis. Neurological symptoms attributed to intracranial hypertension were present in those three cases involving cavernous malformation. Of these, two cases, which initially exhibited an insufficient response to radiosurgery, ultimately demonstrated seizure remission following the successful microsurgical resection of the cavernous malformation. Conclusion : All things considered, the development of radiation-induced cavernous malformation is not uncommon in this population and should be acknowledged as a potential long-term complication. Microsurgical resection of cavernous malformation can be preferentially considered in cases where the initial seizure outcome after GKRS is unsatisfactory.

• Clinical and Experimental Pediatrics
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• v.56 no.7
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• pp.275-281
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• 2013

Temporal lobe epilepsy (TLE) is the most common type of medically intractable epilepsy in adults and children, and mesial temporal sclerosis is the most common underlying cause of TLE. Unlike in the case of adults, TLE in infants and young children often has etiologies other than mesial temporal sclerosis, such as tumors, cortical dysplasia, trauma, and vascular malformations. Differences in seizure semiology have also been reported. Motor manifestations are prominent in infants and young children, but they become less obvious with increasing age. Further, automatisms tend to become increasingly complex with age. However, in childhood and especially in adolescence, the clinical manifestations are similar to those of the adult population. Selective amygdalohippocampectomy can lead to excellent postoperative seizure outcome in adults, but favorable results have been seen in children as well. Anterior temporal lobectomy may prove to be a more successful surgery than amygdalohippocampectomy in children with intractable TLE. The presence of a focal brain lesion on magnetic resonance imaging is one of the most reliable independent predictors of a good postoperative seizure outcome. Seizure-free status is the most important predictor of improved psychosocial outcome with advanced quality of life and a lower proportion of disability among adults and children. Since the brain is more plastic during infancy and early childhood, recovery is promoted. In contrast, long epilepsy duration is an important risk factor for surgically refractory seizures. Therefore, patients with medically intractable TLE should undergo surgery as early as possible.

• Proceedings of the KSMRM Conference
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• 2001.11a
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• pp.172-172
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• 2001

Purpose： To evaluate compensatory change of opposite hippocampus after temporal lobe surgery in th patient with temporal lobe epilepsy by using single-voxel proton MR spectroscopy. Method： Eighteen patients with intractable temporal lobe epilepsy (TLE) whose MR diagnos was unilateral hippocampal sclerosis (n=11) or localized unilateral anterior temporal lobe lesio (n=7) and who underwent anterior temporal lobectomy were included in the study. Singl proton MRS of opposite hippocampus was carried out on the same day or within 1 week af MR imaging before temporal lobe surgery and after over 1-year post-surgical follow-u Single voxel proton MRS were acquired using GE signa 1.5T scanner and spectrosco system (TR, 1500-2, 000： TE, 136-144). Region of interest (ROI) was placed in a simitar position for all examination to cover the medial temporal lobes including most of the head an body of hippocampus and a part of amygdala, the parahippocampal gyrus. The MR spectr were evaluated with a focus on the metabolite ratio of N-acetylaspartate (NAA choline-containing phospholipids (Cho), creatine (Cr). The metabolite ratios of NAA/ Cr were calculated from the relative peak height measurement. We evaluated change of th intensity ratio NAA/Cr between before and after surgery, to simplify quantification acro patients, because observed decreases in the ratio of NAA/Cr can be interpreted in terms o neuronal or axonal damage.

• Journal of Korean Neurosurgical Society
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• v.47 no.1
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• pp.17-25
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• 2010

Objective: The focus of this study is brain plasticity associated with semantic aspects of language function in patients with medial temporal lobe epilepsy (mTLE) Methods: Using longitudinal functional magnetic resonance imaging (fMRI), patterns of brain activation were observed in twelve left and seven right unilateral mTLE patients during a word-generation task relative to a pseudo-word reading task before and after anterior temporal section surgery. Results: No differences were observed in precentral activations in patients relative to normal controls (n = 12), and surgery did not alter the phonological-associated activations. The two mTLE patient groups showed left inferior prefrontal activations associated with semantic processing (word-generation>pseudo-word reading), as did control subjects. The amount of semantic-associated activation in the left inferior prefrontal region was negatively correlated with epilepsy duration in both patient groups. Following temporal resection, semantic-specific activations in inferior prefrontal region became more bilateral in left mTLE patients, but more left-lateralized in right mTLE patients. The longer the duration of epilepsy in the patients, the larger the increase in the left inferior prefrontal semantic-associated activation after surgery in both patient groups. Semantic activation of the intact hippocampus, which had been negatively correlated with seizure frequency, normalized after the epileptic side was removed. Conclusion: These results indicate alternation of semantic language network related to recruitment of left inferior prefrontal cortex and functional recovery of the hippocampus contralateral to the epileptogenic side, suggesting an intra- and inter-hemispheric reorganization following surgery.

• Journal of Korean Neurosurgical Society
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• v.62 no.3
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• pp.353-360
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• 2019

Epilepsy surgery that eliminates the epileptogenic focus or disconnects the epileptic network has the potential to significantly improve seizure control in patients with medically intractable epilepsy. Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) has been an established option for epilepsy surgery since the US Food and Drug Administration cleared the use of MRgLITT in neurosurgery in 2007. MRgLITT is an ablative stereotactic procedure utilizing heat that is converted from laser energy, and the temperature of the tissue is monitored in real-time by MR thermography. Real-time quantitative thermal monitoring enables titration of laser energy for cellular injury, and it also estimates the extent of tissue damage. MRgLITT is applicable for lesion ablation in cases that the epileptogenic foci are localized and/or deep-seated such as in the mesial temporal lobe epilepsy and hypothalamic hamartoma. Seizure-free outcomes after MRgLITT are comparable to those of open surgery in well-selected patients such as those with mesial temporal sclerosis. Particularly in patients with hypothalamic hamartoma. In addition, MRgLITT can also be applied to ablate multiple discrete lesions of focal cortical dysplasia and tuberous sclerosis complex without the need for multiple craniotomies, as well as disconnection surgery such as corpus callosotomy. Careful planning of the target, the optimal trajectory of the laser probe, and the appropriate parameters for energy delivery are paramount to improve the seizure outcome and to reduce the complication caused by the thermal damage to the surrounding critical structures.

• The Korean Journal of Nuclear Medicine
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• v.33 no.2
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• pp.111-119
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• 1999

Purpose: As mesial temporal lobe epilepsy (TLE) shows hypometabolism of medial and lateral temporal lobe, we investigated whether symmetric uptake of F-18-FDG in medial temporal lobes can differentiate mesial from lateral TLE. Materials and Methods: In 113 patients (83 mesial TLE, 30 lateral TLE) who underwent anterior temporal lobectomy and/or corticectomy with good surgical outcome, we performed F-18-FDG PET and compared F-18-FDG uptake of medial and lateral temporal lobes. All the patients with mesial TLE had hippocampal sclerosis except one congenital abnormal hippocampus. Patients with lateral TLE revealed cerebromalacia, microdysgenesis, arteriovenous malformation, old contusion, and cortical dysplasia. Results: Sensitivity of F-18-FDG PET and MR for mesial TLE was 84% (70/83) and 73% (61/83), respectively. Sensitivity of F-18-FDG PET and MR for lateral TLE was 90% (27/30) and 66% (20/30), respectively. Twelve patients were normal on F-18-FDG PET. 101 patients had hypometabotism of lateral temporal lobe. Among 88 patients who showed hypometabolism of medial temporal lobe as well as lateral temporal lobe, 70 were mesial TLE patients and 18 were lateral TLE on pathologic examination. Positive predictive value of medial temporal hypometabolism for mesial TLE was 80%. Among 13 patients who showed hypometabolism of only lateral temporal lobe, 4 were mesial TLE and 9 were lateral TLE. Positive predictive value of hypometabolism of lateral temporal lobe for the diagnosis of lateral TLE was 69% (9/13). Normal MR findings stood against medial TLE, whose negative predictive value was 66%. Conclusion: Lateral temporal lobe epilepsy should be suspected when there is decreased F-18-FDG uptake in lateral temporal lobe with normal uptake in medial temporal lobe.

• Korean Journal of Radiology
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• v.2 no.2
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• pp.63-67
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• 2001

Objective: Atrophy and a high T2 signal of the hippocampus are known to be the principal MR imaging findings of hippocampal sclerosis. The purpose of this study was to determine whether or not individual MRI findings correlate with surgical outcome in patients with this condition. Materials and Methods: Preoperative MR imaging findings in 57 consecutive patients with pathologically-proven hippocampal sclerosis who underwent anterior temporal lobectomy and were followed-up for 24 months or more were retrospectively reviewed, and the results were compared with the postsurgical outcome (Engel classification). The MR images included routine sagittal T1-weighted and axial T2-weighted spin-echo images, and oblique coronal T1-weighted 3D gradient-echo and T2-weighted 2D fast spin-echo images obtained on either a 1.5 T or 1.0 T unit. The images were visually evaluated by two neuroradiologists blinded to the outcome; their focus was the presence or absence of atrophy and a high T2 hippocampal signal. Results: Hippocampal atrophy was seen in 96% of cases (55/57) [100% (53/53) of the good outcome group (Engel class I and II), and 50% (2/4) of the poor outcome group (class III and IV)]. A high T2 hippocampal signal was seen in 61% of cases (35/57) [62% (33/53) of the good outcome group and 50% (2/4) of the poor outcome group]. All 35 patients with a high T2 signal had hippocampal atrophy. 'Normal' hippocampus, as revealed by MR imaging, occurred in 4% of patients (2/57), both of whom showed a poor outcome (Engel class III). The presence or absence of hippocampal atrophy correlated well with surgical outcome (p<0.01). High T2 signal intensity did not, however, significantly correlate with surgical outcome (p>0.05). Conclusion: Compared with a high T2 hippocampal signal, hippocampal atrophy is more common and correlates better with surgical outcome. For the prediction of this, it thus appears to be the more useful indicator.