The authors have reviewed the clinical records of 110 patients with intracranial cavernous malformations diagnosed by histological examination and/or magnetic resonance imaging over a mean follow-up period of 4.71 years. These cases were divided, based on their presentation, into a hemorrhage group, a seizure group, and an incidentally diagnosed group. The rate of subsequent symptomatic bleeding was investigated in relation to age at onset, sex, and location of the initial lesion. A high rate of subsequent symptomatic bleeding episodes was found in the hemorrhage group, especially among younger females. The nonhemorrhagic-onset cases had a very low incidence of bleeding. The outcome was generally good, except in patients with lesions in the basal ganglia and brainstem. These findings will be helpful in planning a rational therapeutic strategy for intracranial cavernous malformations.

We found low-prevalence somatic mutations in MTOR in FCD type IIb, indicating that activating somatic mutations in MTOR cause FCD type IIb.

Summary:Purpose: To test the sensitivity of extracranial magnetoencephalography (MEG) for epileptic spikes in different cerebral sites.Methods: We simultaneously recorded MEG and electrocorticography (ECoG) by using subdural electrodes with 1-cm interelectrode distances for one patient with lateral frontal epilepsy and one patient with basal temporal epilepsy. We analyzed MEG spikes associated with ECoG spikes and compared the maximal amplitude and number of electrodes involved. We estimated and evaluated the locations and moments of the equivalent current dipoles (ECDs) of MEG spikes.Results: In patient 1, MEG detected 100 (53%) of 188 ECoG lateral frontal spikes, including 31 (46%) of 67 spikes that activated three subdural electrodes. MEG spike amplitudes correlated with ECoG spike amplitudes and the number of electrodes activated (p < 0.01). ECDs were perpendicular to the superior frontal sulcus. In patient 2, MEG detected 31 (26%) of 121 ECoG basal temporal spikes, but none that activated only three subdural electrodes. ECDs were localized in the entorhinal and parahippocampal gyri, oriented perpendicular to those basal temporal cortical surfaces. The ECD strength was 136.6 ± 71.5 nAm in the frontal region, but 274.5 ± 150.6 nAm in the temporal region (p < 0.01).Conclusions: When lateral frontal ECoG spikes extend >3 cm 2 across the fissure, MEG can detect >50%, correlating with spatial activation and voltage. In the basal temporal region, MEG requires higher-amplitude discharges over a more extensive area. MEG shows a significantly higher sensitivity to lateral convexity epileptic discharges than to discharges in isolated deep basal temporal regions. Key Words: Magnetoencephalography-Electrocorticography-Epilepsy-Extent of epileptic spikes-Sensitivity.Magnetoencephalography (MEG) measures the extracranial magnetic fields generated by intraneuronal electric currents with superconducting quantum interference devices (1). Extracranial magnetic fields result from intracranial tangential currents, such as neuronal activity, in the fissural cortex, which makes up two thirds of the surface of the human brain (2). During MEG analysis, magnetic field recordings are fitted to an equivalent current dipole (ECD) model to localize sources of intracranial activity, such as epileptic spikes; the spike source locations are then overlaid onto magnetic resonance (MR) images of corresponding areas of the brain. Because magnetic fields are relatively unaffected by the different electrical conductivities of the brain, cerebral spinal fluid, skull, and skin, MEG can accurately localize the source of intraneuronal electric currents that contribute to extracranial magnetic fields (3).Electroencephalography (EEG) dipole recordings delineate both radial and tangential currents (4). However, the electrical fields, as measured by EEG, are affected by the conductivities of different tissues.MEG has clinical application for patients with partial epilepsy. Neurosurgeons use advanced multisensor helmet-shaped, whole-head neuromagnetomete...

H ypotHalamic hamartoma (HH) is a rare congenital abnormality, which presents with a hallmark feature of intractable gelastic seizures (GS). There is now strong evidence that HH involves intrinsic epileptogenesis, [7][8][9][10][11][12]14,17 and surgical treatment of HH itself is considered important for seizure control. Although various surgical treatments are available for epileptic patients with HH, the selection of treatment modalities depends on the type and size of the HH, as well as the surgeons' preference.3 Mittal et al. reported that no single neurosurgical approach is likely to treat all forms of HH, and that a multimodal or staged procedure must be used to treat the lesion. 16 Similarly, the Barrow group commonly use staged and multiple surgical approaches for HH treatment, including microsurgical resection, endoscopic disconnection, and stereotactic radiosurgery. 6,19,24 We previously developed a surgical procedure involving MRI-guided stereotactic radiofrequency thermocoagulation (SRT) of HH and reported an early series of cases in which this technique was used.9,12 In the present study, which was undertaken to determine the invasiveness abbreviatioNs DQ = developmental quotient; EEG = electroencephalography; EFP = emotional facial paresis; FIQ = full-scale IQ; GS = gelastic seizures; HH = hypothalamic hamartoma; SISCOM = subtraction ictal SPECT co-registered to MRI; SMA = supplementary motor area; SPECT = single-photon emission computed tomography; SRT = stereotactic radiofrequency thermocoagulation; WAIS = Wechsler Adult Intelligence Scale; WAIS-R = WAIS-Revised; WAIS-III = WAIS-Third Edition; WISC = Wechsler Intelligence Scale for Children; WISC-R = WISC-Revised; WISC-III = WISC-Third Edition. The median duration of follow-up was 3 years (range 1-17 years). Seventy cases involved pediatric patients. Ninety percent of patients also had other types of seizures (non-GS). The maximum diameter of the HHs ranged from 5 to 80 mm (median 15 mm), and 15 of the tumors were giant HHs with a diameter of 30 mm or more. Comorbidities included precocious puberty (33.0%), behavioral disorder (49.0%), and mental retardation (50.0%). results A total of 140 SRT procedures were performed. There was no adaptive restriction for the giant or the subtype of HH, regardless of any prior history of surgical treatment or comorbidities. Patients in this case series exhibited delayed precocious puberty (9.0%), pituitary dysfunction (2.0%), and weight gain (7.0%), besides the transient hypothalamic symptoms after SRT. Freedom from GS was achieved in 86.0% of patients, freedom from other types of seizures in 78.9%, and freedom from all seizures in 71.0%. Repeat surgeries were not effective for non-GS. Seizure freedom led to disappearance of behavioral disorders and to intellectual improvement. coNclusioNs The present SRT procedure is a minimally invasive and highly effective surgical procedure without adaptive limitations. SRT involves only a single surgical procedure appropriate for all forms of epileptogenic HH and should be...

The present SRT procedure has favorable efficacy and invasiveness and has no adaptive limitations. SRT should therefore be considered before adulthood. The new HH classification is useful to understand clinical symptoms and to determine surgical strategies.

Summary:Purpose: To characterize the epileptogenic zone in neocortical epilepsy (NE) by using magnetoencephalography (MEG).Methods: We defined and compared locations of single and multiple clusters of equivalent current dipoles (ECDs) for interictal spikes with MRI findings, ictal-onset zones (IOZs) from subdural electroencephalography (SDEEG), resected areas, and postsurgical outcomes of 20 patients who underwent cortical resection for medically intractable NE.Results: Fourteen patients had single clusters; six had multiple clusters. Overlap of clusters and IOZs defined group A (nine patients), in which a single cluster coincided with the IOZ; group B1 (four patients), in which a single cluster was within or partially overlapped the IOZ; group B2 (five patients), in which multiplecluster sections overlapped IOZs; group C (two patients; one single; one multiple), in which no overlap was seen. More single clusters (nine of 14) than multiple clusters (none of six) coincided with the IOZ (p = 0.014). More patients with single clusters (10 of 14) than patients with multiple clusters (one of six) had seizure-free outcomes (p = 0.049). Eight of nine patients in group A, versus three of 11 in groups B1, B2, and C, achieved seizure-free outcomes (p = 0.0098). Correlations between MRI findings and postsurgical outcomes were not statistically significant; eight of 13 patients with single lesions, one of four with no lesions, and two of three with multifocal lesions had seizure-free outcomes.Conclusions: In neocortical epilepsy, MEG ECD clusters correlated with SDEEG IOZs. Single clusters indicated discrete epileptogenic zones that required complete resection for seizurefree outcome. Multiple clusters necessitated that the multiple or extensive epileptogenic zones be completely identified and delineated by SDEEG.

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Aims. Vagus nerve stimulation (VNS) is an established option of adjunctive treatment for patients with drug-resistant epilepsy, however, evidence for long-term efficacy is still limited. Studies on clinical outcomes of VNS in Asia are also limited. We report the overall outcome of a national, prospective registry that included all patients implanted in Japan. Methods. The registry included patients of all ages with all seizure types who underwent VNS implantation for drug-resistant epilepsy in the first three years after approval of VNS in 2010. The registry excluded patients who were expected to benefit from resective surgery. Efficacy analysis was assessed based on the change in frequency of all seizure types and the rate of responders. Changes in cognitive, behavioural and social status, quality of life (QOL), antiepileptic drug (AED) use, and overall AED burden were analysed as other efficacy indices.Results. A total of 385 patients were initially registered. Efficacy analyses included data from 362 patients. Age range at the time of VNS implantation was 12 months to 72 years; 21.5% of patients were under 12 years of age and 49.7% had prior epilepsy surgery. Follow-up rate was >90%, even at 36 months. Seizure control improved over time with median seizure reduction of 25.0%, 40.9%, 53.3%, 60.0%, and 66.2%, and responder rates of 38.9%, 46.8%, 55.8%, 57.7%, and 58.8% at three, six, 12, 24, and 36 months of VNS therapy, respectively. There were no substantial changes in other indices throughout the three years of the study, except for self/family-accessed QOL which improved over time. No new safety issues were identified. Conclusions. Although this was not a controlled comparative study, this prospective national registry of Japanese patients with drug-resistant epilepsy, with >90% follow-up rate, indicates long-term efficacy of VNS therapy which increased over time, over a period of up to three years. The limits of such trials, in terms of AED modifications and during follow-up and difficulties in seizure counting are also discussed.