Seizure outcomes of lesionectomy in pediatric lesional epilepsy with brain tumor – Single institute experience

Purpose

To determine the clinical characteristics, surgical strategy, and outcome in pediatric lesional epilepsy patients younger than 5 years of age undergoing surgery in a single institute.

Method

Retrospective data were collected and analyzed on patients younger than 5 years of age who underwent lesionectomy for lesional epilepsy at single institute from January 2001 to August 2010. Fourteen pediatric lesional epilepsy patients were enrolled in this study. Engel classification was used to classify seizure outcome.

Results

Median preoperative seizure period was 1 month (range, 1–21). Median post-operative follow up period was 35 months (range 13–84). Ten patients who underwent gross total resection of tumor showed Engel class Ia seizure outcome without any antiepileptic drug (AED). Subtotal resection was performed in four patients to avoid eloquent area injury. Two of these four patients with subtotal removal became seizure-free (Engel class Ia) without AED, while two were in Engel class Ib with AED medication. There was no significant surgical morbidity or mortality.

Conclusion

Lesionectomy in children younger than 5 years of age is relatively safe and effective in controlling seizures. Short preoperative seizure periods and total removal of tumor might be associated with good outcome. Therefore, early and complete lesionectomy alone may help allow for seizure freedom and optimal brain development in pediatric patients.     

Gamma knife radiosurgery for intracranial cavernous malformations

Objectives

To analyze and evaluate the role of Gamma knife radiosurgery (GKRS) and clinical outcome in patients with intracranial cavernous malformations.

Patients and methods

The medical records of 96 patients who underwent radiosurgery at our institute were reviewed retrospectively.

Results

After a mean follow-up period of 4.3 years, 33 cases out of 44 (75.0%) with complaint of seizure had cleared or got improved, 9 (20.5%) were not improved and 2 (4.5%) got worse. Of the 100 lesions in the 96 patients, 24 (24.0%) had the lesions shrinkage on the follow-up imagings. One patient (1.6%) with symptom of headache and dizziness got worse and three patients (3.1%) presented with new cranial nerve palsy. We have compared the treatment results between different marginal dose groups and find that low marginal dose can get better therapeutic efficacy but with less complications.

Conclusion

GKRS is an effective and microinvasive treatment option for intracranial cavernous malformations.     

Is seizure detection based on EKG clinically relevant?

Objective

Real-time EKG-based automated seizure detection is emerging as a complement or supplement to that based on cortical signals, but its value is unproven. This study assesses the clinically relevance of EKG-based seizure detection by comparing the information content in EKG and ECoG.

Methods

ECoGs (6935 h; 241 clinical and 4311 sub-clinical seizures) with simultaneous EKG from 81 subjects undergoing surgical evaluation were used in these analyses. Differences, if any, between clinical and sub-clinical seizures in variables such as intensity, duration and their product severity, were investigated with a multi-variate regression model.

Results

Highly statistically significant differences in severity between clinical and sub-clinical seizures were discerned with EKG and ECoG. Furthermore, EKG-based seizure severity was linearly correlated with that estimated using ECoG.

Conclusions

These findings support the notion that EKG-based seizure detection is clinically relevant in certain localization-related epilepsies, providing similar information to that yielded by neuronal electrical signals.

Significance

The information content equivalence between EKG and ECoG would enable automated seizure detection, quantification and therapy delivery, without resorting to cortical monitoring. The considerably higher S/N and ease of acquisition and processing of EKG compared to ECoG/EEG may foster widespread clinical applications of this novel detection approach.     

Neurosurgical considerations on highly eloquent brainstem cavernomas during pregnancy

Objective

Cerebral cavernous malformations (CCMs) and especially cavernous malformations (CMs) in highly eloquent brain areas such as brainstem CMs are rare but possible events during pregnancy. Due to the few published cases in literature clear recommendations regarding the management are rare. In this study we evaluate the proceeding decision in pregnant patients with highly eloquent brainstem CMs.

Methods

In our series 43 patients with CMs in highly eloquent brain areas, including 39 patients with brainstem CMs, were surgically treated by the senior author between July 2007 and July 2010. Out of these, 29 patients were female and three of them presented with a symptomatic brainstem CMs during pregnancy and were included in this study. According to our experiences and to the available literature we analyzed demographic and clinical variables to provide recommendations for the management of pregnant patients with highly eloquent brainstem CMs.

Results

Only one patient was operated during pregnancy the other two patients were surgically treated after delivery, respectively. A thorough review of the literature revealed 12 patients with brainstem cavernomas during pregnancy there of only two patients were operated during pregnancy.

Conclusion

Surgical treatment during pregnancy is rarely required, but needs to be performed right away in life-threatening and rapidly progressive clinical situations. Pregnant women with CMs in highly eloquent brain areas such as brainstem CMs need to be treated in specialized centers to assess the best point of time for surgery. Our study offers a useful tool to support the proceeding decision in this rare but important situation.     

Intramedullary cavernous malformations: Clinical features and surgical technique via hemilaminectomy

Objective

The purpose of this study was to define the clinical features and the surgical technique of unilateral hemilaminectomy for treating intramedullary cavernous malformations.

Materials and methods

Retrospective chart was performed in 16 patients with histologically diagnosed intramedullary cavernous malformations. All patients were treated with unilateral hemilaminectomy and microsurgical resection of the malformations. The pre- and postoperative neurological state was evaluated using Frankel scale.

Results

There were nine females and seven males (mean age 38 years) harbouring symptomatic intramedullary cavernous malformations. The annual retrospective haemorrhage rate was 3.1% per patient/year. All cavernous malformations were completely resected. Twelve of 16 patients experienced the improvement of the neurological state and in four patients, clinical features remained unchanged during the follow-up period. Static and dynamic plain radiograph film showed none of them had spinal deformity or spinal instability.

Conclusion

According to the defined bleeding risk, symptomatic and MRI-morphologically growing intramedullary cavernous malformations should be totally surgically removed, to avoid the recurrence and rebleeding of the residue. A least traumatic myelotomy, as well as a meticulous microsurgical technique and the intraoperative somatosensory evoked potentials monitoring, together with selection of a minimally invasive microsurgical approach (hemilaminectomy), leads to a favourable outcome and prevents additional morbidity.     

Transsulcal approach supported by navigation-guided neurophysiological monitoring for resection of paracentral cavernomas

Objectives

The aim of the study is to evaluate tools that can improve surgical precision and minimize surgical trauma for removal of cavernomas in the paracentral area. Moreover, the surgical strategies for the treatment of symptomatic epilepsy in cavernoma patients are discussed.

Patients and methods

Between June 2000 and July 2007, 17 patients suffering from paracentral cavernoma underwent surgery via a transsulcal approach with the aid of neuronavigation, functional mapping and neurophysiological intraoperative monitoring. To optimize outcome for procedures in the paracentral area, the hemosiderin-stained tissue was removed entirely except for a small proportion on the side of precentral gyrus.

Results

All cavernomas and their adjacent sulci could be precisely located with the aid of ultrasonography-assisted neuronavigation. By combining preoperative fMRI and intraoperative neurophysiological monitoring, including SEP, MEP and cortical mapping, the motor cortex could be defined in all cases. Thus damage to the primary motor area could be avoided during resection of cavernomas. All the lesions located in the paracentral area were removed completely via transsulcal microsurgical approach without neurological deficits. No significant seizures were induced during surgery.

Conclusions

The successful excision of these lesions was effected by the following four key factors: (1) the precise location of the lesion supported by intraoperative neuronavigation; (2) the preservation of the eloquent area with the aid of functional mapping; (3) a minimally invasive transsulcal microsurgical approach; and (4) the entire removal of cavernoma and hemosiderin-stained tissue.     

Intracranially recorded interictal spikes: Relation to seizure onset area and effect of medication and time of day

Objective

The relationship between seizures and interictal spikes remains undetermined. We analyzed intracranial EEG (icEEG) recordings to examine the relationship between the seizure onset area and interictal spikes.

Methods

80 unselected patients were placed into 5 temporal, 4 extratemporal, and one unlocalized groups based on the location of the seizure onset area. We studied 4-h icEEG epochs, removed from seizures, from day-time and night-time during both on- and off-medication periods. Spikes were detected automatically from electrode contacts sampling the hemisphere ipsilateral to the seizure onset area.

Results

There was a widespread occurrence of spikes over the hemisphere ipsilateral to the seizure onset area. The spatial distributions of spike rates for the different patient groups were different (p < 0.0001, chi-square test). The area with the highest spike rate coincided with the seizure onset area only in half of the patients.

Conclusion

The spatial distribution of spike rates is strongly associated with the location of the seizure onset area, suggesting the presence of a distributed spike generation network, which is related to the seizure onset area.

Significance

The spatial distribution of spike rates, but not the area with the highest spike rate, may hold value for the localization of the seizure onset area.     

幕上与癫痫有关的海绵状血管瘤的显微外科治疗

目的 探讨幕上表现于癫痫的颅内海绵状血管瘤外科治疗方法和效果.方法 25例幕上表现于癫痫的颅内海绵状血管瘤患者,根据术前影像学、脑电图表现与运动区的关系分为A、B二组.手术在皮层脑电图(ECoG)监测下进行,包括单纯切除血管瘤、切除血管瘤和切除含铁血黄素层,以及辅助部分皮层痫灶切除、皮层热灼或软膜下横切等.结果 本组海绵状血管瘤均令切除,2例术后有一过性轻度肢体功能障碍,无手术死亡.随访10个月-4.5年,A组9例,Engel Ⅰ级6例;Engel Ⅱ B级2例;Engel Ⅲ级1例.B组16例,均无发作.结论 幕上与癫痫有关的海绵状血管瘤在ECoG监测下做病灶和痫灶切除,是控制术后癫痫发作的有效手段;运动区和附近海绵状血管瘤由于手术没有完全切除致痫灶可能是术后癫痫控制率差的原因.     

Outcome of lesionectomy in medically refractory epilepsy due to non-mesial temporal sclerosis (non-MTS) lesions

Objectives

To analyze the seizure outcome of lesionectomy for refractory epilepsy secondary to non-mesial temporal sclerosis (non-MTS) lesions.

Methods

Sixty-eight patients with non-MTS lesions (M:F = 42:26; age at onset: 11.7 ± 9.6 years; age at surgery: 21.1 ± 9.4 years), who underwent lesionectomy for refractory epilepsy were analyzed. The age at onset, frequency/type of seizure, MRI findings, video-EEG, histopathology and Engel's grading at 1 year/last follow up were recorded.

Results

The duration of epilepsy at surgery was 9.9 ± 6.9 years. The location of lesions were: temporal: 41 (60.3%); frontal: 21 (30.9%); parietal: 6 (8.8%). The type of lesionectomies performed were temporal 41 (60.3%), extra-temporal: 25 (36.8%), temporo-frontal and temporo-parietal: 1 (1.5%) patient each. The histopathological diagnosis were neoplastic: 32 (47.1%), cortical dysplasia: 19 (27.9%), other focal lesions: 17 (25%). At mean follow up of 2.9 ± 2.1 years (median: 2.6 years), outcome was – Engel's class I: 43 (63.2%), IIa: 14 (20.6%), III: 7 (10.3%), IV: 4 (5.9%). Good seizure control (Engel's class I/IIa) was achieved in 57 (83.8%) patients. The good prognostic markers included temporal seizures, extended lesionectomy and AEDs after surgery while poor prognostic marker was gliotic lesion on histopathology.

Conclusion

Following lesionectomy due to non-MTS lesions, seizure freedom (Engel I) was noted in about 63.2% of patients, which is comparable to other series and reiterates the effectiveness of lesionectomy for seizure control.     

Is ictal cognitive dysfunction predictable?

Objective

Accurate prediction of electrographic seizure onset may reduce injuries and improve quality of life in pharmaco-resistant epileptics. However, because sub-clinical, far out-number clinical seizures, indiscriminate issuance of warnings may have a paralyzing effect on these patients. This study investigates the predictability of ictal cognitive dysfunction.

Methods

Latency and percentage of correct responses to a reaction time test triggered by automated seizure detections were compared to those obtained inter-ictally in 14 subjects undergoing surgery evaluation. Since accurate prediction of seizures is elusive, early detection was used, as it indirectly but reliably investigates for the existence of a cognitive pre-ictal state.

Results

Significant differences between ictal and inter-ictal cognitive performance were not uncovered until late into the temporal evolution of “focal” seizures.

Conclusions

These observations suggest that cognitive dysfunction is unpredictable in seizures originating from discrete cortical regions, as the transition into unawareness seems abrupt.

Significance

Prediction of electrographic seizure onsets with worthwhile accuracy would likely result in large numbers of daily warnings, the great majority for sub-clinical seizures. This outcome would considerably increase, without safety justification, patients’ psychological burden inherent to each forecast, thus further diminishing quality of life.     

Clinical and ictal characteristics of infantile seizures: EEG correlation via long-term video EEG monitoring

Purpose

The semiology of infantile seizures often shows different characteristics from that of adults. We performed this study to describe clinical and ictal characteristics of infantile seizures at less than two years of age.

Methods

A retrospective study was done for infants with epilepsy (ages: 1–24 months) who underwent long-term video electroencephalography (EEG) monitoring at Samsung medical center between November 1994 and February 2012. We analyzed the clinical and ictal characteristics of the 56 cases from 51 patients.

Results

In 69% of the patients, the seizure onset was before six months of age and the etiology was symptomatic in one third of the patients. Twelve seizure types were identified; spasms (24%), unilateral motor seizures (18%), and generalized tonic seizures (15%) were the three frequent types of seizure.All partial seizures were well correlated with the partial-onset ictal EEG, however 19.4% (7/36) of clinically generalized seizures revealed partial-onset ictal EEG. About one-thirds (4/11) of generalized tonic seizures had its ictal onset on unilateral or bilateral frontal areas and two out of seven generalized myoclonic seizures showed unilateral frontal rhythmic activities. Hypomotor seizures mainly arose from the temporal areas and hypermotor seizures from the frontal regions.

Conclusions

Even though most of the seizure semiology of infants is well correlated with ictal EEG, some of the generalized tonic seizures or myoclonic seizures revealed partial-onset ictal EEG suggesting localized epileptic focus. Accurate definition of seizures via video EEG monitoring is necessary for proper management of seizures in infancy, especially in some clinically generalized seizures.     

Temporal lobe gangliogliomas associated with chronic epilepsy: Long-term surgical outcomes

Objective

To review the clinical features and surgical outcome in patients with temporal lobe gangliogliomas associated with intractable chronic epilepsy.

Methods

The Rush University Surgical Epilepsy Database was queried to identify patients with chronic intractable epilepsy who underwent resection of temporal lobe gangliogliomas at Rush University Medical Center. Medical records were reviewed for age of seizure onset, delay to referral for surgery, seizure frequency and characteristics, pre-operative MRI results, extent of resection, pathological diagnosis, complications, length of follow-up, and seizure improvement.

Results

Fifteen patients were identified. Average duration between seizure onset and surgery was 14.3 years. Complex partial seizures were the most common presenting symptom. Detailed operative data was available for 11 patients – of these, 90.9% underwent complete resection of the amygdala and either partial or complete resection of the hippocampus, in addition to lesionectomy. Average follow-up was 10.4 years (range 1.6–27.5 years), with 14 patients improving to Engel's class I and one patient to Engel's class III. There were no recurrences, and permanent complications were noted in one patient.

Conclusions

Long-term follow-up of patients with temporal lobe gangliogliomas associated with chronic intractable epilepsy demonstrates excellent results in seizure improvement with surgery and increasingly low incidence of complications with improvements in microsurgical techniques.     

Seizures as a presenting symptom in neurosurgical patients: A retrospective single-institution analysis

Background

In patients with brain lesions, the appropriate management of epileptic seizures is important because recurrent seizures have a negative effect on the clinical course and quality of life. Acute symptomatic seizures are known to be one of the risk factors to develop epilepsy that cause recurrent unprovoked seizures in the later stage. To obtain background information, we performed a retrospective study in which we investigated the incidence of seizures as one of the presenting symptoms in neurosurgical patients admitted to our department during the past 43 years.

Methods

We extracted 4537 consecutive patients from 11,675 records in our inpatient database to calculate the seizure incidence in patients with 19 most common diagnoses. We also studied whether the location of cortical lesions have relation to the seizure incidence.

Results

Among 2342 patients with brain tumors, 9 of 18 (50%) ganglioglioma-, 40 of 87 (46%) oligodendroglioma-, 69 of 207 (33%) low-grade astrocytoma-, 172 of 804 (21%) high-grade astrocytoma- or anaplastic oligodendroglioma-, 84 of 598 (14%) meningioma-, 38 of 313 (12%) metastatic brain tumor-, 7 of 67 (10%) malignant meningioma-, 7 of 79 (9%) ependymoma-, and 11 of 169 (7%) malignant lymphoma patients suffered seizures. There were 1626 patients with vascular lesions, 20 of 80 (25%) with cavernous malformation, 61 of 281 (22%) with arteriovenous malformation, 50 of 666 (8%) with subarachnoid hemorrhage, 26 of 457 (6%) with brain infarcts, and 5 of 142 (4%) with hypertensive brain hemorrhage had seizures. Of the 569 patients with traumatic brain injury, 33 of 168 (20%) with traumatic intracranial hemorrhage, 6 of 31 (19%) with brain concussion, 18 of 96 (19%) with brain contusion, 15 of 244 (6%) with chronic subdural hematoma, and 1 of 30 (3%) with minor head injury suffered seizures. We found that these seizure incidences were significantly higher when the cortical lesion was located in the frontal lobe (p < 0.01, chi square test) but not in parietal, occipital, nor temporal lobes.

Conclusion

We investigated the prevalence rate of seizures at the time of admission in a large number of patients who had been treated in our institution. Our results suggest that seizures are a common feature in patients with slow-growing and frontal intra-parenchymal lesions.     

Effectiveness and tolerability of rufinamide in children and young adults with Lennox–Gastaut syndrome: A single center study in Korea

Purpose

Rufinamide is a novel antiepileptic drug (AED), which is known to be effective in the treatment of partial seizures and drop attacks in patients with Lennox–Gastaut syndrome (LGS). The aim of this study is to evaluate the efficacy and tolerability of rufinamide in those with LGS.

Methods

Patients with LGS who had received rufinamide adjunctive therapy were enrolled in this study. We retrospectively reviewed these patient's baseline clinical characteristics, and the reduction of seizure frequency and adverse events after the use of rufinamide.

Results

Twenty-three patients (15 males and 8 females, ages 4–22 years) were enrolled in the study. All the patients suffered from daily head drops and tonic seizures despite multiple antiepileptic drugs. After one month of rufinamide, one patient (4.3%) achieved freedom from seizures, ten (43.5%) achieved a ≥50% decrease in seizure frequency. After six months of rufinamide, eight patients (34.8%) maintained a satisfactory response (seizure free in one, and greater than 50% seizure reduction in seven). Adverse events were reported in six (26.0%) patients, which were somnolence in three, aggressive behavior in two, and aggravation of seizure in one patient.

Conclusions

Our results suggest that rufinamide is effective and safe in children and young adults with LGS.     

Surgery for perirolandic epilepsy: Epileptogenic cortex resection guided by chronic intracranial electroencephalography and electric cortical stimulation mapping

Subject

The objective of this study was to assess outcome with regard to seizure status and neurological function in patients undergoing resective surgery involving the perirolandic area.

Method

All 15 patients who underwent perirolandic cortical resection between October 2006 and September 2007 at the Comprehensive Epilepsy Centre of Beijing Xuanwu Hospital were included in the study. The locations of functional cortical areas, ictal onset zones and epileptogenic lesions were mapped by chronic intracranial EEG recordings and electric cortical stimulation. Seizure outcome was determined using the modified classification of Engel and colleagues. Motor and sensory deficits were monitored.

Results

At last follow-up 5 patients (33%) were in Engel class I, 4 (27%) were in class II, 3 (20%) were in class III, and 3 (20%) were in class IV. Nine patients suffered immediate functional deficits; 8 of these recovered completely within 2 weeks to 3 months of surgery. One had mild persistent loss of finger motor control.

Conclusion

After accurate presurgical evaluation using invasive recordings and functional brain mapping, epileptogenic cortical resection can give excellent results and few deficits in patients with perirolandic epilepsy.     

Pregabalin in patients with primary brain tumors and seizures: a preliminary observation

Objectives

Patients with brain tumors and seizures should be treated with non-enzyme-inducing antiepileptic drugs (AED). Some of the newer drugs seem particularly suited in these patients.

Methods

Here we describe our experience with pregabalin (PGB); its effectiveness was retrospectively studied in nine consecutive patients with primary brain tumors and seizures.

Results

Six subjects had secondarily generalized and three simple partial seizures. Patients mostly suffered from WHO grade IV gliomas. PGB replaced enzyme inducing, inefficacious or bad tolerated AED, as add-on or monotherapy. Median follow-up was 5 (2–19) months; three patients died of their tumor. Daily median dosage was 300 mg. All subjects experienced at least a 50% seizure reduction, six were seizure-free. Side effects were reported in four patients, leading to PGB discontinuation in two.

Conclusion

PGB appears to have a promising effectiveness in this setting, even as a monotherapy. Based on these results we embarked on a prospective controlled trial.     

Betweenness centrality of intracranial electroencephalography networks and surgical epilepsy outcome

Objective

We sought to determine whether the presence or surgical removal of certain nodes in a connectivity network constructed from intracranial electroencephalography recordings determines postoperative seizure freedom in surgical epilepsy patients.

Prognostic significance of serial postoperative EEG in extratemporal lobe epilepsy surgery

Objective

To assess the prognostic value of postoperative EEG in patients surgically treated for drug-resistant extra-temporal lobe (ET) epilepsy.

Methods

We studied 63 consecutive patients with ET epilepsy who underwent epilepsy surgery and were followed up for at least 2 years (mean duration of follow-up 6.2 ± 2.3 years, range 2–12). Follow-up evaluations were performed 2, 12, and 24 months after surgery, and included standard EEG (at 2 months) and long-term video-EEG monitoring during both wakefulness and sleep (at 12 and 24 months). Seizure outcome was determined at each follow-up evaluation, and then at yearly intervals. Patients who were in Engel Class I at the last contact were classified as having a good outcome.

Results

Seizure outcome was good in 39 patients (62%). The presence of interictal epileptiform discharges (IED) in postoperative EEG at each time point was found to be associated with poor outcome. The strength of this association was greater for awake plus sleep recording as compared with awake recording alone. In a multiple regression model including all pre- and post-operative factors identified as predictors of outcome in univariate analysis, the presence of early (2 months after surgery) EEG epileptiform abnormalities was found to be independently associated with poor seizure outcome.

Conclusions

Postoperative IED may predict long-term outcome in patients undergoing resective surgery for ET epilepsy.

Significance

The increase in risk of unfavourable outcome associated with EEG epileptiform abnormalities detected as early as two months after surgery may have substantial practical importance. Serial postoperative EEGs including sleep recording may add further predictive power and help making decision about antiepileptic drug discontinuation.     

Resultados quirúrgicos a largo plazo en pacientes con epilepsia fármaco-resistente del lóbulo temporal sin anormalidades histológicas

Introduction

Reports on surgical outcomes in patients with drug-resistant temporal lobe epilepsy without histological abnormalities are scarce.

Methods

Retrospective review of data from patients with drug-resistant temporal lobe epilepsy and no histopathological alterations who underwent anterior mesial temporal lobectomy. We analysed the following variables: age, sex, age at seizure onset, age at surgery, time elapsed between diagnosis and the date of the surgery, follow-up time, and classification according to the Engel rating scale.

Results

From a database of 256 temporal lobectomies, 21 were identified as meeting the inclusion criteria. The average age upon diagnosis of epilepsy was 8.3 years and average age at time of surgery was 28.6 years. The mean time elapsed between diagnosis and surgery was 20.2 years. After a mean follow-up of 6.5 years, 90.5% of the patients showed favourable outcomes (classes i and ii) and 42.9% were seizure-free (class IA). Comparative analysis of the variables revealed that average age at seizure onset was the only statistically significant difference between groups, with age at onset being lower in patients with favourable outcomes.

Conclusion

Although long-term surgical outcomes were favourable for a large majority of patients, the percentage of seizure-free patients is lower than in patients with lesional epilepsy and comparable to that previously reported in the literature.