Epilepsy Surgery in Children.

Epilepsy in children continues to present a major medical and economic burden on society. Left untreated, seizures can present the risk of sudden death and severe cognitive impairment. It is understood that primary care providers having concerns about abnormal movements or behaviors in children will make a prompt referral to a trusted pediatric neurologist. The authors present a brief introduction to seizure types, classification, and management with particular focus on what surgery for epilepsy can offer. Improved seizure control and its attendant improvements in quality of life can be achieved with timely referral and intervention.

Clinical features of sleep-related hypermotor epilepsy in relation to the seizure-onset zone: A review of 135 surgically treated cases.

OBJECTIVES: Sleep-related hypermotor epilepsy (SHE), formerly nocturnal frontal lobe epilepsy, is characterized by abrupt and typically sleep-related seizures with motor patterns of variable complexity and duration. They seizures arise more frequently in the frontal lobe than in the extrafrontal regions but identifying the seizure onset-zone (SOZ) may be challenging. In this study, we aimed to describe the clinical features of both frontal and extrafrontal SHE, focusing on ictal semiologic patterns in order to increase diagnostic accuracy. METHODS: We retrospectively analyzed the clinical features of patients with drug-resistant SHE seen in our center for epilepsy surgery. Patients were divided into frontal and extrafrontal SHE (temporal, operculoinsular, and posterior SHE). We classified seizure semiology according to four semiology patterns (SPs): elementary motor signs (SP1), unnatural hypermotor movements (SP2), integrated hypermotor movements (SP3), and gestural behaviors with high emotional content (SP4). Early nonmotor manifestations were also assessed. RESULTS: Our case series consisted of 91 frontal SHE and 44 extrafrontal SHE cases. Frontal and extrafrontal SHE shared many features such as young age at onset, high seizure-frequency rate, high rate of scalp electroencephalography (EEG) and magnetic resonance imaging (MRI) abnormalities, similar histopathologic substrates, and good postsurgical outcome. Within the frontal lobe, SPs were organized in a posteroanterior gradient (SP1-4) with respect to the SOZ. In temporal SHE, SP1 was rare and SP3-4 frequent, whereas in operculoinsular and posterior SHE, SP4 was absent. Nonmotor manifestations were frequent (70%) and some could provide valuable localizing information. SIGNIFICANCE: Our study shows that the presence of certain SP and nonmotor manifestations may provide helpful information to localize seizure onset in patients with SHE.

Prolonged Blood-Brain Barrier Disruption Following Laser Interstitial Ablation in Epilepsy: A Case Series with a Case Report of Postablation Optic Neuritis.

OBJECTIVE: Laser interstitial thermal therapy has become increasingly popular for targeting epileptic foci in a minimally invasive fashion. Despite its use in >1000 patients, the long-term effects of photothermal injury on brain physiology remain poorly understood. METHODS: We prospectively followed clinical and radiographic courses of 13 patients undergoing laser ablation for focal epilepsy by the senior author (N.T.). Only patients with nonenhancing lesions and patients who had a delayed postoperative magnetic resonance imaging (MRI) scan with gadolinium administration approximately 6 months after ablation were considered. Volumetric estimates of the amount of enhancement immediately after ablation and on the delayed MRI scan were made. RESULTS: Median interval between surgery and delayed postoperative MRI scan was 6 months (range, 5-8 months). In 12 of 13 cases, persistent enhancement was seen, consistent with prolonged blood-brain barrier dysfunction. Enhancement, when present, was 9%-67% (mean 30%). There was no correlation between the time from surgery and the relative percentage of postoperative enhancement on MRI. The blood-brain barrier remained compromised to gadolinium contrast for up to 8 months after thermal therapy. There were no adverse events from surgical intervention; however, 1 patient developed delayed optic neuritis. CONCLUSIONS: Prolonged incompetence of the blood-brain barrier produced by thermal ablation may provide a path for delivery of macromolecules into perilesional tissue, which could be exploited for therapeutic benefit, but rarely it may result in autoimmune central nervous system inflammatory conditions.

Derivation and initial validation of a surgical grading scale for the preliminary evaluation of adult patients with drug-resistant focal epilepsy.

OBJECTIVE: Presently, there is no simple method at initial presentation for identifying a patient's likelihood of progressing to surgery and a favorable outcome. The Epilepsy Surgery Grading Scale (ESGS) is a three-tier empirically derived mathematical scale with five categories: magnetic resonance imaging (MRI), electroencephalography (EEG), concordance (between MRI and EEG), semiology, and IQ designed to stratify patients with drug-resistant focal epilepsy based on their likelihood of proceeding to resective epilepsy surgery and achieving seizure freedom. METHODS: In this cross-sectional study, we abstracted data from the charts of all patients admitted to the New York University Langone Medical Center (NYULMC) for presurgical evaluation or presented in surgical multidisciplinary conference (MDC) at the NYU Comprehensive Epilepsy Center (CEC) from 1/1/2007 to 7/31/2008 with focal epilepsy, who met minimal criteria for treatment resistance. We classified patients into ESGS Grade 1 (most favorable), Grade 2 (intermediate), and Grade 3 (least favorable candidates). Three cohorts were evaluated: all patients, patients presented in MDC, and patients who had resective surgery. The primary outcome measure was proceeding to surgery and seizure freedom. RESULTS: Four hundred seven patients met eligibility criteria; 200 (49.1%) were presented in MDC and 113 (27.8%) underwent surgery. A significant difference was observed between Grades 1 and 3, Grades 1 and 2, and Grades 2 and 3 for all presurgical patients, and those presented in MDC, with Grade 1 patients having the highest likelihood of both having surgery and becoming seizure-free. There was no difference between Grades 1 and 2 among patients who had resective surgery. SIGNIFICANCE: These results demonstrate that by systematically using basic information available during initial assessment, patients with drug-resistant epilepsy may be successfully stratified into clinically meaningful groups with varied prognosis. The ESGS may improve communication, facilitate decision making and early referral to a CEC, and allow patients and physicians to better manage expectations.

Seizures with tonic posturing: Semiologic difference between supplementary sensorimotor area (SSMA) origin and extra-SSMA origin.

In seizures with tonic posturing, differentiation of seizures originating in SSMA from seizures originating in cortices other than SSMA and spreading to SSMA has not been previously attempted. Twenty-two patients were studied with intractable focal epilepsy with tonic limb posturing as the most prominent semiology, who underwent resective surgery and obtained favorable postoperative seizure outcomes. These 22 patients were divided into an SSMA group (N = 12) and an extra-SSMA group (N = 10), according to the location of resection. Resection area in the extra-SSMA group was located in the dorsolateral frontal or prefrontal area in four patients, the frontal operculum (insula) in two, the parietal cortex in three, and the temporoparietal cortex in one patient. Video-recorded seizures were carefully reviewed. Tonic posturing characteristics and the presence or absence of accompanying symptoms were compared between groups. Incidence of preservation of consciousness was significantly higher in the SSMA group (p < 0.001). Patients in the SSMA group demonstrated a propensity for having unilateral or bilateral asymmetrical tonic limb posturing. In contrast, patients in the extra-SSMA group had a statistically significantly higher incidence of bilateral symmetrical tonic limb posturing (p < 0.05). These findings may be helpful in identifying seizure origin.

Gamma knife radiosurgery of paracentral epilepsy.

BACKGROUND: In pharmacoresistant focal epilepsies involving the central region, risk of motor deficit generally contraindicates cortical resection. Gamma knife radiosurgery (GK) is an established treatment for mesial temporal epilepsy and epilepsy associated with hypothalamic hamartoma. OBJECTIVES: To explore the safety profile and efficacy of GK in motor cortex epilepsies. METHODS: Four patients (18-31 years) with intractable focal sensorimotor epilepsy seizures arising from the paracentral lobule, demonstrated by stereoelectroencephalography, in whom conventional surgery was contraindicated because of motor deficit risk underwent GK. A marginal dose of 24 Gy was delivered to a focal zone involving the paracentral lobule. Results Volume of treatment ranged from 1.6 to 3.18 cm(3) (median: 2.34). No motor deficit or other adverse effect occurred. Follow-up was available for at least 3 years (range: 36-78 months; median: 49). No complication of GK, including motor deficit, occurred. Two patients achieved an Engel class 1B outcome and 2 were unchanged. Both of the patients who improved had gradual disappearance of objective motor ictal semiology (6-12 months after GK), preceding reduced seizure frequency (12-18 months onwards). Cerebral MRI showed no change. CONCLUSIONS: GK is a potentially useful treatment for focal paracentral epilepsies where conventional surgery would carry an unacceptable risk of motor deficit.

Surgical management of medically refractory epilepsy due to early childhood stroke.

UNLABELLED: OBJECT.: The risk of developing epilepsy after perinatal stroke, hypoxic/ischemic injury, and intracerebral hemorrhage is significant, and seizures may become medically refractory in approximately 25% of these patients. Surgical management can be difficult due to multilobar or bilateral cortical injury, nonfocal or poorly lateralizing video electroencephalography (EEG) findings, and limited functional reserve. In this study the authors describe the surgical approaches, seizure outcomes, and complications in patients with epilepsy due to vascular etiologies in the perinatal period and early infancy. METHODS: The records were analyzed of 19 consecutive children and adults with medically refractory epilepsy and evidence of perinatal arterial branch occlusions, hypoxic/ischemic insult, or hemorrhagic strokes, who underwent surgery at the Comprehensive Epilepsy Center of Beth Israel Medical Center and St. Luke's-Roosevelt Hospital Center. Preoperative findings including MRI, video EEG, functional MRI, and neuropsychological testing were analyzed. The majority of patients underwent staged operations with invasive mapping, and all patients had either extra- or intraoperative functional mapping. RESULTS: In 7 patients with large porencephalic cysts due to major arterial branch occlusions, periinsular functional hemispherotomy was performed in 4 children, and in 3 patients, multilobar resections/disconnections were performed, with 1 patient undergoing additional resections 3 years after initial surgery due to recurrence of seizures. All of these patients have been seizure free (Engel Class IA) after a mean 4.5-year follow-up (range 15-77 months). Another 8 patients had intervascular border-zone ischemic infarcts and encephalomalacia, and in this cohort 2 hemispherotomies, 5 multilobar resections/disconnections, and 1 focal cortical resection were performed. Seven of these patients remain seizure free (Engel Class IA) after a mean 4.5-year follow-up (range 9-94 months), and 1 patient suffered a single seizure after 2.5 years of seizure freedom (Engel Class IB, 33-month follow-up). In the final 4 patients with vascular malformation-associated hemorrhagic or ischemic infarction in the perinatal period, a hemispherotomy was performed in 1 case, multilobar resections in 2 cases, and in 1 patient a partial temporal lobectomy was performed, followed 6 months later by a complete temporal and occipital lobectomy due to ongoing seizures. All of these patients have had seizure freedom (Engel Class IA) with a mean follow-up of 4.5 years (range 10-80 months). Complications included transient monoparesis or hemiparesis in 3 patients, transient mutism in 1 patient, infection in 1 patient, and a single case of permanent distal lower-extremity weakness. Transient mood disorders (depression and anxiety) were observed in 2 patients and required medical/therapeutic intervention. CONCLUSIONS: Epilepsy surgery is effective in controlling medically intractable seizures after perinatal vascular insults. Seizure foci tend to be widespread and rarely limited to the area of injury identified through neuroimaging, with invasive monitoring directing multilobar resections in many cases. Long-term functional outcomes have been good in these patients, with significant improvements in independence, quality of life, cognitive development, and motor skills, despite transient postoperative monoparesis or hemiparesis and occasional mood disorders.

Applicability of nTMS in locating the motor cortical representation areas in patients with epilepsy.

BACKGROUND: Transcranial magnetic stimulation (TMS) is increasingly used for non-invasive functional mapping in preoperative evaluation for brain surgery, and the reliability of navigated TMS (nTMS) motor representation maps has been studied in the healthy population and in brain tumor patients. The lesions behind intractable epilepsy differ from typical brain tumors, ranging from developmental cortical malformations to injuries early in development, and may influence the functional organization of the cortical areas. Moreover, the interictal cortical epileptic activity and antiepileptic medication may affect the nTMS motor threshold. The reliability of the nTMS motor representation localization in epilepsy patients has not been addressed. METHODS: We compared the nTMS motor cortical representation maps of hand and arm muscles with the results of invasive electrical cortical stimulation (ECS) in 13 patients with focal epilepsy. The nTMS maps were projected to the cortical surface segmented from preoperative magnetic resonance images (MRI), and the positions of the subdural electrodes were extracted from the postoperative low-dose computed tomography (CT) images registered with preoperative MRI. RESULTS: The 3D distance between the average nTMS site and average ECS electrode location was 11 ± 4 mm for the hand and 16 ± 7 mm for arm muscle representation areas. In all patients the representation areas defined with nTMS and ECS were located on the same gyrus, also in patients with abundant interictal epileptic activity on the motor gyrus. CONCLUSIONS: nTMS can reliably locate the hand motor cortical representation area with the accuracy needed for pre-surgical evaluation in patients with epilepsy.

Etiology-specific differences in motor function after hemispherectomy.

Prediction of functional motor outcome after hemispherectomy is difficult due to the heterogeneity of motor outcomes observed. We hypothesize that this might be related to differences in plasticity during the onset of the underlying epileptogenic disorder or lesion and try to identify predictors of motor outcome after hemispherectomy. Thirty-five children with different etiologies (developmental, stable acquired or progressive) underwent functional hemispherectomy and motor function assessment before hemispherectomy and 24 months after hemispherectomy. Preoperatively, children with developmental etiologies performed better in terms of distal arm strength and hand function, but not on gross motor function tests. Postoperatively, the three etiology groups performed equally poor in muscle strength and hand function, but gross motor function improved in those with acquired and progressive etiologies. Loss of voluntary hand function and distal arm strength after surgery was associated with etiology, intact insular cortex and intact structural integrity of the ipsilesional corticospinal tract on presurgical MRI scans. In conclusion, postoperative motor function can be predicted more precisely based on etiology and on preoperative MRI. Children with developmental etiology more often lose distal arm strength and hand function and show less improvement in gross motor function, compared to those with acquired pathology.

Surgical treatment of focal inhibitory motor seizures.

The authors describe a rare case of a pediatric patient with focal inhibitory motor seizures (ictal paralysis) with the seizure focus in the primary motor cortex. Seizures were characterized by ictal paralysis of the contralateral limbs without loss of consciousness. The seizure focus and progression were examined using long-term video electroencephalography (EEG) monitoring and MR imaging. Invasive recordings of the ictal EEG revealed spike rhythms arising from the primary motor cortex, suggesting that seizures associated with paralysis can arise from hyperactivity in either positive or negative motor areas. Resection of the cortical area related to ictal onset resulted in a seizure-free status for the last 3 years.

Versive seizures in occipital lobe epilepsy: lateralizing value and pathophysiology.

To clarify the value of versive seizures in lateralizing and localizing the epileptogenic zone in patients with occipital lobe epilepsy, we studied 13 occipital lobe epilepsy patients with at least one versive seizure recorded during preoperative noninvasive video-EEG monitoring, who underwent occipital lobe resection, and were followed postoperatively for more than 2 years with Engel's class I outcome. The videotaped versive seizures were analyzed to compare the direction of version and the side of surgical resection in each patient. Moreover, we examined other motor symptoms (partial somatomotor manifestations such as tonic and/or clonic movements of face and/or limbs, automatisms, and eyelid blinking) associated with version. Forty-nine versive seizures were analyzed. The direction of version was always contralateral to the side of resection except in one patient. Among accompanying motor symptoms, partial somatomotor manifestations were observed in only five patients. In conclusion, versive seizure is a reliable lateralizing sign indicating contralateral epileptogenic zone in occipital lobe epilepsy. Since versive seizures were accompanied by partial somatomotor manifestations in less than half of the patients, it is suggested that the mechanism of version in occipital lobe epilepsy is different from that in frontal lobe epilepsy.

Brain activation patterns of versive, hypermotor, and bilateral asymmetric tonic seizures.

PURPOSE: Patients who have seizure onset from different brain regions can produce seizures that appear clinically indistinguishable from one another. These clinically stereotypic manifestations reflect epileptic activation of specific networks. Several studies have shown that ictal perfusion single photon emission computed tomography (SPECT) can reveal propagated ictal activity. We hypothesize that the pattern of hyperperfusion may reflect neuronal networks that generated specific ictal symptomatology. METHODS: All patients were identified who were injected with (99m)Tc-hexamethyl-propylene-amine-oxime (HMPAO) during versive seizures (n = 5), bilateral asymmetric tonic seizures (BATS; n = 5), and hypermotor seizures (n = 7) in the presurgical epilepsy evaluation between 2001 and 2005. The SPECT ictal­interictal difference image pairs of each subgroup were compared with image pairs of 14 controls using statistical parametric mapping (SPM 2) to identify regions of significant hyperperfusion. Hyperperfused regions with corrected cluster-level significance p < 0.05 were considered significant. RESULTS: We have identified a distinct ictal perfusion pattern in each subgroup. In versive seizure subgroup, prominent hyperperfusion was present in the frontal eye field opposite to the direction of head version. In addition, there was associated caudate and crossed cerebellar hyperperfusion. The BATS subgroup showed pronounced hyperperfusion supplementary sensorimotor area ipsilateral to the epileptogenic region, bilateral basal ganglia, and contralateral cerebellar hemisphere. The hypermotor seizure subgroup demonstrated two clusters of significant hyperperfusion: one involving bilateral frontomesial regions, cingulate gyri, and caudate nuclei, and another involving ipsilateral anteromesial temporal structures, frontoorbital region, insula, and basal ganglia. DISCUSSION: We have identified distinct hyperperfusion patterns for specific ictal symptomatology. Our findings provide further insight into understanding the anatomic basis of seizure semiology.

Surgical treatment of patients with drug-resistant hypermotor seizures.

PURPOSE: To describe the clinical, electrophysiologic, neuroradiologic, and histologic findings in our patients with drug-resistant hypermotor seizures (HMSs) and to evaluate the outcome of their surgical treatment. METHODS: Twenty-three patients were identified by criteria for drug-resistant HMS. Surgical treatment and presurgical evaluation modalities including semiology, magnetic resonance imaging (MRI), interictal/ictal scalp video-EEG (electroencephalography), and intracranial recording were analyzed retrospectively. RESULTS: The common seizure frequency of 60-300 per month was observed among 15 patients. Sixteen patients (69.6%) experienced auras such as fear and palpitation. Marked agitation was observed in 12 patients and mild agitation in 11 patients. Groaning/shouting and asymmetric posturing were common accompanying symptoms. Asymmetric posturing was observed more often in patients with mild agitation than in those with marked agitation (p = 0.027). MRI detected focal abnormalities in six patients. Intracranial recording was conducted in 16 patients. The origins of seizures were localized in mesial frontal cortex in four patients, dorsolateral frontal cortex in four patients, and mesial temporal cortex in two patients. The epileptogenic zones (EZs) were resected from the frontal lobe in 21 patients and from the temporal lobe in 2 patients. The follow-up ranged from 12-60 months. Seventeen patients (73.9%) had been seizure-free, 11 of whom had presented with marked agitation (11 of 12) and 6 with mild agitation (6 of 11) (p = 0.069). Histologic examinations demonstrated focal cortical dysplasia (FCD) in 18 patients. DISCUSSION: The HMSs can originate from both the mesial and dorsolateral frontal cortex, and occasionally from the temporal lobe. Patients with drug-resistant HMSs should be recommended for resective surgical treatment.

A hypermotor seizure with a focal orbital frontal lesion originating in the insula: a case report.

We present herein the case of a patient with a focal orbital frontal lesion on magnetic resonance imaging (MRI), but an insular onset of seizures. A 15-year-old boy suffered from hypermotor seizures for 9 years. In his seizures, he initially had a sensation that sounds were distant, and then his consciousness became impaired. After a short period of tonic activity, violent activities occurred, such as kicking or gripping some objects and shaking. MRI showed a focal cortical abnormality in the right orbital frontal lobe. [(18)F]FDG-PET revealed diffuse hypometabolism in the right frontal lobe, especially in the same site as the cortical lesion on MRI. The seizure onset zone was localized in the right anterior insula by intracranial recording. A resection of the right anterior insula and a partial disconnection of the frontal lobe were performed, rendering the patient seizure-free.

Hypermotor seizures in patients with temporal pole lesions.

Hypermotor seizures are considered to be characteristic of frontal lobe epilepsy, with only rare occurrence in temporal lobe epilepsy. After noting hypermotor seizures in several patients with lesions involving the pole of the temporal lobe, we investigated whether temporal pole lesions were associated with hypermotor seizures. We systematically reviewed medical records, MRI images and pathological findings in consecutive patients who underwent epilepsy surgery over the preceding 10 years in our institution and identified eight patients with temporal pole lesions and intractable complex partial seizures. We analyzed all recorded seizures for semiology, classifying seizures as hypermotor or typical "psychomotor." Four patients exhibited hypermotor seizure semiology and four patients manifested typical psychomotor seizure characteristics. In patients with hypermotor seizures, scalp EEG tended to demonstrate lateral anterior temporal ictal onset, with lesser involvement of the sphenoidal electrode, while the patients with psychomotor seizures had initial inferomesial temporal rhythmic theta activity. Two patients with hypermotor seizures had implanted frontal and temporal subdural grids demonstrating orbitofrontal spread before hypermotor behavior. Patients underwent either anterior temporal lobectomy or lesionectomy. All improved considerably, with six patients seizure-free since surgery. We conclude that hypermotor seizures occur frequently in patients with temporal pole lesions. A search for temporal pole pathology is recommended for patients with hypermotor seizures and temporal epileptiform discharges. Modification of the surgical approach to include this region should be considered in patients who exhibit hypermotor seizures.

[Supplementary sensory-motor seizures--symptomatology, etiology, and surgical management with illustrative case reports]. / A szupplementer szenzomotoros rohamok tünettana, kóreredete és mutéti kezelhetosége, illusztratív esetismertetésekkel.

In the past decade, owing to the advance of epilepsy surgery, growing knowledge has accumulated on the role of the supplementary motor area, described by Penfield and coworkers in the early fifties, in movement regulation and on the characteristics of seizures involving this area. In the Hungarian neurological literature this topic--despite its neurophysiological and practical clinical importance--has been hardly touched. The authors, based on their own experience obtained from surgeries performed within the framework of the "Co-operative Epilepsy Surgery Program", describe the electrophysiological features of this area, its role in movement regulation and the symptoms of epileptic seizures stemmed from or spread onto this area. Using cases as illustrations, they demonstrate the reasoning and various algorithms of the multidisciplinary examination necessary to explore the seizure onset zone and the pathways of seizure spread. Details of the surgical solution are also described.

Preoperative mapping for patients with supplementary motor area epilepsy: multimodality brain mapping.

Surgical management and strategies for the supplementary motor area (SMA) epilepsy are described. The following is our preoperative evaluations. The steps include functional magnetic resonance imaging (fMRI), interictal dipole tracing (DT), subdural electrodes mapping, measurements of movement-related cortical potential (MRCP), and the use of the intraoperative open MRI under conscious craniotomy. Six patients with SMA epilepsy underwent surgery after the mapping procedures and are now seizure-free. Combinations of preoperative (fMRI, subdural electrodes mapping) and intraoperative mapping allow exact localization and identification of the critical functional areas. Early postoperative deficits in motor and speech function were profound but patients recovered rapidly. It is concluded that the step of mapping procedures plays an important role in the management of SMA epilepsy surgery.

MRI and EEG findings in surgically treated patients with partial seizures due to neuronal migration disorders, their relations to each other and to surgery outcome.

OBJECTIVES: To evaluate magnetic resonance imaging (MRI) and electro-encephalogram (EEG) findings of patients with therapy-resistant partial seizures due to neuronal migration disorders (NMD), and compare them with each other and with surgery outcome. MATERIAL AND METHODS: The MRI, interictal and ictal EEG findings, and their relations to each other in 41 patients with NMD were compared with class IA surgery outcome. RESULTS: The patients showed an MRI lesion in decreasing frequency from the frontal to the occipital areas. A predominantly extratemporal location of the interictal EEG foci (73.3%) and ictal patterns (82.4%) was therefore apparent, also showing a diminishing frequency from the anterior to the posterior areas. Comparing the EEG foci with the MRI lesions, the same location of the interictal foci was found in 68.4% and of the ictal foci in 52.7%, including several cases with a more widespread EEG focus or MRI lesion. The same location of interictal as well as ictal foci was evident in 85.7%. The most favourable surgery outcome (class IA) was, on average, apparent in patients with an MRI lesion (28.6% vs 25%), a main interictal EEG focus (50% vs 18%) and an ictal seizure pattern (37.5% vs 16.7%) located in the temporal area; likewise, if the interictal focus (30.8% vs 18.2%) and the ictal pattern (31.8% vs 12.5%) showed the same location as the MRI lesion, as well as when the interictal and ictal EEG changes had an equal location (30% vs 20%). CONCLUSION: MRI and EEG recordings show relatively close relations to each other and might be important methods to predict surgery outcome in NMD patients.

Electroencephalographic dipoles of spikes with and without myoclonic jerks caused by epilepsia partialis continua.

We used electroencephalographic (EEG) dipole analysis to investigate the generators of spikes with and without myoclonic jerks in a 12-year-old patient with epilepsia partialis continua secondary to left parietal cortical dysplasia. We recorded EEG and right wrist extensor electromyography (EMG) and collected 42 spikes with jerks (jerking spikes) and 42 spikes without jerks (nonjerking spikes). We applied a single moving dipole model to the individual and averaged spikes. Dipoles at the negative peak of individual jerking and nonjerking spikes were localized in the dysplastic area. At the onset of the averaged jerking spike that preceded the EMG discharges by 20 ms, the dipole was in the motor cortex, whereas for the averaged nonjerking spike, the dipole was in the sensory cortex. The dipole moment at averaged jerking spike onset was twice that of the averaged nonjerking spike. Electroencephalographic dipole analysis of averaged spikes differentiated the generator of jerking and nonjerking spikes in epilepsia partialis continua. Individual dipoles demonstrated the area of epileptogenic cortical dysplasia.

Epilepsy and perisylvian lipoma/cortical dysplasia complex.

Intracranial lipomas are congenital malformations composed of mature adipocytes. They are usually located in the midline, particularly in the pericallosal region, a hemispheric location accounting for only 3 to 7% of cases. Review of the literature found 21 previous cases of hemispheric lipoma. Although hemispheric cerebral lipomas are rare, association with epilepsy appears to be frequent. We have recently studied two patients in whom epilepsy was the first clinical manifestation of hemispheric cerebral lipoma in the sylvian region. The patients presented with simple motor partial seizures as the first manifestation of the lesion. Neurological examination was normal. MRI disclosed in both cases a lesion involving the sylvian fissure with characteristics of the lipid signal. MRI also demonstrated abnormalities involving the cerebral cortex in the vicinity of the lesion (pachygyria-like aspect). Partial excision of the lesion was achieved in one patient but was followed by a worsening of seizures and neurological condition (hemiparesis). According to the literature, the prognosis for epilepsy in patients with hemispheric lipoma appears good. Several other arguments support non-surgical management: the lesion is benign and can be identified with a high degree of certainty by imaging; surgery is technically difficult due to adherence to adjacent vascular and cerebral structures and hypervascularity; location near functional brain tissue increases the risk of postoperative sequelae. In addition, mechanisms of epilepsy probably involve vascular and cortical dysplasic abnormalities. In consideration of the complexity of the lesion, hemispheric lipomas are more appropriately classified with localized cortical malformations rather than as simple extracerebral malformations.