Benign partial epilepsies of adolescence: a report of 37 new cases

PURPOSE: To delineate the electroclinical features of patients with partial seizures in adolescence with a benign outcome. METHODS: Patients were recruited in five different Italian epilepsy centers. Patients were selected among those with partial seizures between ages 11 and 17 years. We excluded benign childhood epilepsies, those with neurologic or mental deficits, and those with neuroradiologically documented lesions. We also excluded patients with less than 3 years' follow-up or who were still receiving antiepileptic therapy. RESULTS: There were 37 (22 male, 15 female) patients. Seizures started at the mean age of 14.5 years (range, 11-16.11). Two main electroclinical patterns emerged: 16 of 37 patients had somatomotor seizures frequently associated with focal theta discharges involving the centroparietal regions. Ten of 37 patients showed versive seizures and interictal spiking involving the posterior regions. A third group had clinical characteristics resembling the cases described by Loiseau. All had a favorable outcome. CONCLUSIONS: This relevant multicenter study further confirms the existence of benign partial epilepsies with onset during adolescence.     

脑磁图对病灶性新皮质癫(疒间)术前评估的价值

目的 研究病灶性新皮质癫(疒间)发作间期MEG 和MRI 一致性与预后的关系.方法 23 例病灶性新皮质癫(疒间)接受了术前评估及手术治疗,所有患者术前均接受MEG 检测,数据分析处理采用等价电流偶极子(ECD)法和合成孔径法(SAMg2).7 例患者接受了颅内电极植入后长程视频皮层脑电图监测.术后随访一年以上并运用Engel 法评价预后.结果 MEG 与MRI 一致的病例手术有效率(Engel class I or II)及术后无发作率(Engel class IA)均优于不一致者.结论 病灶性新皮质癫(疒间),MEG 结果与MRI 结果一致时手术效果良好,对此类病例不需要再进行颅内电极植入行癫(疒间)灶定位,颅内电极植入仅适用于MEG 结果与MRI 结果不一致的病例或需要功能区定位者.     

Neocortical kindling is associated with opposing alterations in dendritic morphology in neocortical layer V and striatum from neocortical layer III

Previous research has shown that seizures kindled in the corpus callosum result in a persistent enhancement of the callosal-neocortical evoked response but only a transient reduction in layer III pyramidal cell morphology. To date, there are no reports on the direct effects of repeated seizures on dendritic morphology in layer V, the pyramidal layer thought to mediate the kindling-induced enhanced evoked response. This experiment examined the effect of repeated seizures elicited from the corpus callosum, at the level of the frontal neocortex, on the morphology of sensorimotor frontal (Fr1) and occipital (OC1) neocortical layer V, as well as striatal and neuronal dendrites, in male rats. After 25 days of electrically elicited seizures or handling control, rats were sacrificed either 2 days or 3 weeks following the last seizure and processed for Golgi-Cox staining. Analysis of the impregnated pyramidal cell dendrites indicated a significant increase in the amount of dendritic length and branching in rats 2 days, but a decrease 3 weeks, following the last seizure. There was no effect at the distant occipital site. The differential effect between layer V pyramidal neurons and layer III pyramidal neurons suggests that these areas play different roles in the expression of seizures and the adaptation of the brain to the persistent effect of kindling.     

脑梗塞后脑代谢及高糖对脑代谢影响的研究

目的 探测脑梗塞后梗塞区及对照区域的代谢变化并探讨高糖对梗塞区域代谢的影响，为脑梗塞的临床治疗提供理论依据。方法 雄性SD大鼠左侧颈内动脉插线法制作脑梗塞模型。用磁共振定域^1H—MRS技术，在同一活体上分别连续检测梗塞区及对照区域代谢变化。结果 脑梗塞后梗塞区NAA、Cho、Pcr／Cr强度均低于对照区，并出现明显的Lac信号。NAA在脑梗塞急性期明显降低。加用高糖1～2h内，所选区域NAA、Cho、Pcr／Cr均有小幅回升，随后又渐趋下降；原有乳酸信号成倍增加(2．4倍)。结论 (1)NAA的变化可反映神经元的功能状况，可望作为MRS早期诊断脑梗死的有效指标。(2)Lac峰的出现是脑梗死早期的敏感指标，其含量变化可直接反映局部病理代谢状况。(3)NAA和Cho的降低证明脑梗塞后即发生细胞膜结构、膜功能及膜间连接损伤；(4)高糖可加剧脑梗塞区的病理代谢导致Lac大量积聚；(5)采用MRS定域波谱技术可更精确、更客观地连续检测活体动物大脑各区域代谢变化。     

Spatial distribution of neuronal complexity loss in neocortical lesional epilepsies

PURPOSE: Nonlinear EEG analysis is valuable in characterizing the spatiotemporal dynamics of the epileptogenic process in mesial temporal lobe epilepsy. We examined the ability of the measure neuronal complexity loss (L*) to characterize the primary epileptogenic area of neocortical lesional epilepsies during the interictal state. METHODS: Spatial distribution of L* (L* map) was extracted from electrocorticograms (n = 52) recorded during presurgical assessment via subdural 64-contact grid electrodes covering lesions in either frontal, parietal, or temporal neocortex in 15 patients. The exact location of recording contacts on the brain surface was identified by matching a postimplant lateral x-ray of the skull with a postoperatively obtained sagittal MRI scan. Reprojecting L* maps onto the subject's brain surface allowed us to compare the spatial distribution of L* with the resection range of the extended lesionectomy. RESULTS: In each of the six patients who became seizure-free, maximum values of L* were restricted to recording sites coinciding with the area of resection. In contrast, L* maps of most patients who had no benefit from the resection indicated a more widespread extent or the existence of additional, probably autonomous, foci. The mean of L* values obtained from recording sites outside the area of resection correctly distinguished 13 patients (86.7 %) with respect to seizure outcome. CONCLUSIONS: Relevant information obtained from long-lasting interictal electrocorticographic recordings can be compressed to a single L* map that contributes to a spatial characterization of the primary epileptogenic area. In neocortical lesional epilepsies, L* allows for identification and characterization of epileptogenic activity and thus provides an additional diagnostic tool for presurgical assessment.     

Interictal cerebral blood flow abnormality in cryptogenic West syndrome

Purpose: To elucidate the abnormality of interictal regional cerebral blood flow (rCBF) of West syndrome at the onset . Methods: Quantitative measurement of rCBF with an autoradiography method using N‐isopropyl‐(¹²³I) p‐iodoamphetamine single photon emission computed tomography (SPECT) was performed on 14 infants with cryptogenic West syndrome. Regions of interest (ROIs) for rCBF were placed automatically using an automated ROI analysis software (three‐dimensional stereotactic ROI template), and were grouped into 12 segments: callosomarginal, precentral, central, parietal, angular, temporal, posterior cerebral, pericallosal, lenticular nucleus, thalamus, hippocampus, and cerebellum. We compared rCBF between the patients and seven age‐matched infants with cryptogenic focal epilepsy as a control group. The patients were divided into two groups according to the duration from onset to SPECT, to compare rCBF. Results: Quantitative analysis revealed cerebral hypoperfusion in cryptogenic West syndrome with normal SPECT images under visual inspection. In bilateral central, posterior cerebral, pericallosal, lenticular nucleus, and hippocampus, and in the left parietal, temporal, and cerebellum, and in the right angular and thalamus segments there were statistical differences (p < 0.05). Compared with the duration from onset to SPECT, there were no significant differences of rCBF in all segments. Discussion: Broad cerebral hypoperfusion with posterior predominance involving the hippocampus and lenticular nucleus implies that even cryptogenic West syndrome has a widespread cerebral dysfunction at least transiently, which would correspond to clinical manifestations of hypsarrhythmia and epileptic spasms. Hippocampal hypoperfusion suggests the dysfunction of hippocampal circuitry in the brain adrenal axis, and may contribute to subsequent cognitive impairment of cryptogenic West syndrome.     

Single photon emission computed tomography studies of partial epilepsies

Abstract At present, in the field of clinical epilepsy, it has been established that single photon emission computed tomography (SPECT) is useful for the regional determination of epileptic foci. In particular, it seems to be of great advantage to the field of clinical epilepsy that epileptic foci situated in the deep regions of the brain are detectable by the three-dimensional resolution power in SPECT, because such foci are not often represented on routine scalp electroencephalograph (EEG). In reference to our review published previously,¹ recent findings in SPECT studies of partial epilepsies are surveyed here.     

Interictal cerebral glucose metabolism in partial epilepsy and its relation to EEG changes

Interictal positron computed tomography (PCT) with 18F-fluorodeoxyglucose was performed on 50 patients with partial seizures disorders. Electroencephalographic (EEG) monitoring was carried out during the metabolic studies using scalp and sphenoidal electrodes in 33 patients and stereotaxically implanted depth electrodes in 17. Four patients in this series had focal abnormalities on x-ray computed tomographic scans, but these were at the site of the presumed epileptogenic lesion in only 2. One or more discrete zones of hypometabolism were identified in 35 patients, and only 1 patient appeared to show focal interictal hypermetabolism. No quantitative relationship could be demonstrated between the degree of focal hypometabolism and either the frequency of interictal EEG spikes of the presence of focal nonepileptiform EEG changes. It was concluded that metabolic and electrophysiological techniques measure different aspects of cerebral dysfunction in seizure disorders. Although interictal PCT in patients with partial epilepsy usually demonstrates zones of hypometabolism this finding, per se, does not reveal the epileptic nature of the abnormality.     

Speech preservation using a non-linear paradigm for determination of the extent of neocortical resection in patients with mesial temporal sclerosis submitted to cortico-amygdalo-hippocampectomy (CAH)

Rationale

The rationale for using a non-linear (proportional) paradigm for determining the extent of the neocortex to be removed in temporal lobe resection was based on anatomical and intra-operative cortical mapping findings. We present our results regarding speech preservation in patients submitted to CAH using the central artery as an anatomical landmark for determining the posterior border of neocortical resection.

Methods

Two hundred and fifty consecutive right-handed patients with left unilateral mesial sclerosis were studied. All patients were submitted to CAH under general anesthesia and without intraoperative electrocorticography. The posterior border of the lateral neocortical resection was defined by a line perpendicular to the temporal axis at the level of the central artery.

Results

Seven patients had transient (1–3 weeks; mean = 9 days) receptive speech disturbance. There was no permanent speech deficit. Imaging documented edema or contusion at the posterior temporal cortical border in all patients who had transient speech deficits. The mean extent of cortical resection was 3.9 cm in adults and 3.1 cm in kids.

Discussion

This is the first report in the literature discussing the use of a non-linear paradigm to determine the extent of lateral neocortical removal in this patient population. We found no permanent speech disturbances in this series. The non-linear approach used in this series proved to be safe and effective to avoid post-operative speech disorders. It was able to compensate for different brain and head sizes, and allowed smaller neocortical removal when compared to traditional linear approaches.     

Interictal patterns of cerebral glucose metabolism,perfusion, and magnetic field in mesial temporal lobe epilepsy

PURPOSE: To characterize the epileptogenic condition of patients with mesial temporal lobe epilepsy, the interictal patterns of glucose metabolism, perfusion, and magnetic field in the temporal lobe were evaluated by using [18F]fluorodeoxyglucose-positron emission tomography, [99mTc]-ethylcysteinate dimer-single photon emission computed tomography, and magnetoencephalography (MEG). METHODS: Twenty-one patients with mesial temporal lobe epilepsy related to hippocampal sclerosis were studied. The ictal-onset area was located by continuous video-EEG monitoring. Quantitative analysis of glucose metabolism and perfusion in the temporal lobe was performed, and the cerebral magnetic field was evaluated to measure the equivalent current dipole (MEG-ECD). RESULTS: Although hypometabolism and hypoperfusion in the temporal lobe were lateralized with the ictal-onset area in 16 (76.2%) and in 11 (52.4%) respectively, they were localized in diverse ways without any coupling. MEG-ECD was distributed in diverse ways unrelated to the ictal-onset area: ipsilateral medial temporal origin in five (23.8%), ipsilateral lateral temporal origin in two (9.5%), ipsilateral mixed (medial and lateral) temporal origin in six (28.6%), bilateral temporal origin in four (19.0%), and contralateral temporal origin in two (9.5%). CONCLUSIONS: MEG-ECD was distributed in varied ways with the disorder and uncoupling of glucose metabolism and perfusion in the temporal lobe. These results may help resolve the clinical controversy over the possibility that the cortical irritative area generating the interictal epileptic discharge is distinct from the ictal-onset area, and also may have some functional implications in identifying different brain compartments in the generation of metabolic signals.     

A hypothesis for how non-REM sleep might promote seizures in partial epilepsies: a transcranial magnetic stimulation study

PURPOSE: To investigate alterations of inhibitory and excitatory cortical circuits during non-rapid eye movement (NREM) sleep in drug-naive patients with partial epilepsies and sleep-bound seizures only. METHODS: A paired-pulse TMS paradigm was used to test intracortical inhibition (ICI) and facilitation (ICF) in the hemisphere of the epileptic focus in three untreated patients with nonlesional, nongenetic frontal lobe epilepsy in NREM2 (three patients), NREM3/4 (one patient), and wakefulness (three patients). RESULTS: All three patients exhibited a major decrease of ICI in NREM sleep as opposed to the physiological enhancement of ICI with the progression of NREM sleep. CONCLUSIONS: Decreased ICI might reflect a substrate for the association of epileptic processes with thalamocortical networks that propagate sleep. Thus our findings contribute to a hypothesis of how NREM sleep could promote seizures.     

Changes in cerebral glucose metabolism with normal aging

The pattern of changes in cerebral glucose metabolism occurring with normal aging has been unclear. Advances in imaging technology, such as improved resolution and anatomical referencing, allow for more precise regional measurement than previously possible. This study explored cerebral glucose metabolism in 17 normal controls ranging in age from 20 to 74 years. High resolution PET scanning, with MRI-based regions of interest correcting for partial volume and atrophy effects, revealed a linear association between advancing age and declining cerebral glucose metabolism. The decline averaged 8% per decade for the whole brain. Changes were most pronounced in limbic structures, and could be implicated in age-associated memory loss.     

Acute ethanol administration selectively alters localized cerebral glucose metabolism

The effects of acute ethanol administration on glucose utilization in the CNS of rat were studied using the 2-deoxyglucose technique. Cerebral glucose utilization was determined for 53 brain regions at peak and descending blood ethanol concentrations averaging 14, 26 and 66 mM. Decreased glucose utilization was the predominant finding and was observed in 20% of the regions evaluated, with median raphe, vestibular nucleus, cerebellar vermis, and various structures associated with the auditory system showing the greatest reductions. The only structures that showed increased glucose utilization were the dentate region of the hippocampus and the superior olive, and this was only apparent at a blood ethanol concentration of 14 mM.     

妥泰单药治疗部分性癫痫的疗效观察

目的 观察妥泰单药治疗部分性癫痫病人的疗效及安全性。方法 对30例部分性癫痫患者应用妥泰单药治疗20周,于治疗前观察并记录基础发作频率,剂量从25mg/d开始,每周增加25mg,共8周,达有效剂量或200mg/d后维持治疗12周,并观察癫痫发作频率变化及不良反应等。结果 发作完全控制16例（53．3％）,发作减少≥75％6例（20％）,发作减少≥50％2例（6．7％）,发作减少＜50％6例（20％）。病程短者治疗效果较好。首次接受抗癫痫药物治疗者发作完全控制比例明显高于经治过的病人。治疗过程中无严重不良反应。结论 妥泰单药治疗对控制单纯部分发作及复杂部分性发作均有良好的效果,且耐受性、安全性好。     

Carbamazepine, phenytoin and phenobarbital in drug-resistant partial epilepsies

96 monotherapies with carbamazepine, phenytoin, phenobarbital and primidone were assessed in 42 patients with partial epilepsy. Those whose seizure frequency was reduced by 75% or more were considered to have improved. In 54 comparisons of monotherapies significant improvement in seizure frequency was achieved in only 16.7% of cases. Nonresponding patients showed practically no change across all comparisons according to the Fischer test.

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Sommario In 42 pazienti con epilessia parziale, sono state analizzate un totale di 96 monoterapie con Carbamazepina, Fenitoina, Fenobarbital o Primidone. Sono stati considerati migliorati i pazienti che durante la seconda o terza monoterapie hanno presentato una riduzione delle crisi pari o maggiore al 75%. Tra i 54 confronti effettuati tra le varie monoterapie, solo una esigua percentuale, pari al 16.7% ha presentato un miglioramento significativo della frequenza delle crisi.Nei pazienti farmaco-resistenti, la frequenza delle crisi osservata confrontando le varie monoterapie con il test di Fischer è praticamente invariata.

     

Alteration of cerebral ganglioside metabolism in developing Snell dwarf mice

The ganglioside metabolism of the Snell dwarf cerebrum was examined on postnatal days 15 and 20, by monitoring the rate of incorporation of radioactivity into each ganglioside species from tritiated . It was found that the turnover rate of the G_M3 ganglioside was reduced throughout the entire period of development, resulting in retardation of A pathway metabolism which becomes abundant during late cerebral development. In addition, the turnover rate of the G_M4 species, which is considered related to myelin formation, was also found to be reduced throughout the entire period of cerebral development.     

Interictal hippocampal benzodiazepine receptors in temporal lobe epilepsy: comparison with coregistered hippocampal metabolism and volumetry

The significance of benzodiazepine receptor (BZR) concentration in comparison with hippocampal metabolism and volumetry was assessed in 14 patients diagnosed with temporal lobe epilepsy (TLE) without hippocampal signal change on T2-weighted magnetic resonance imaging (MRI) scans. Focus lateralization was achieved by clinical, electroencephalographic and neuropsychological examinations. Three-dimensional positron emission tomography (PET) and MRI scans were coregistered for determination of hippocampal 11C-flumazenil (FMZ) binding, normalized to average cortical values for glucose metabolism (rCMRglc) and volume. The hippocampi were individually outlined on T1-weighted MRI. Volumes of interest (VOI) were used for calculation of asymmetries between clinically affected and unaffected sides. Eleven out of 14 TLE patients presented a significant reduction in hippocampal volume. In nine of these 11 patients hippocampal FMZ binding and in seven cases hippocampal CMRglc was also reduced. In two patients without hippocampal volume asymmetry FMZ binding was markedly reduced in the mesial temporal lobe appropriately to the clinically diagnosed side. In our study volumetry is therefore the most sensitive tool for the detection of hippocampal abnormality in TLE. However, in cases without hippocampal atrophy the reduction of FMZ may indicate functional impairment of BZR before neuronal loss becomes evident. Our results emphasize the complementary nature of these tests in TLE patients.     

成人颞叶癫痫发作间期CT灌注成像的变化

目的探讨成人颞叶癫痫发作间期单侧和双侧痫性放电CT灌注成像的变化。方法将21例颞叶癫痫患者根据视频脑电图监测分为单侧痫性放电组11例、双侧痫性放电组10例,两组患者均在发作间期行CT灌注成像检查,计算每例患者双侧颞叶脑血流量(cerebral blood flow,CBF)、脑血容量(cerebral blood volume,CBV)、平均通过时间(mean transit ti me,MTT)的灌注参数,并比较每组患者颞叶CBF、CBV、MTT以及两组的CBF、CBV、MTT不对称指数(asymmetry index,AI)。结果21例患者头颅CT平扫均无异常,每组患者发作间期双侧颞叶CBF、CBV、MTT差异无统计学意义(P>0.05),两组患者CBF不对称指数差异有统计学意义(t=2.269,P=0.035),CBV和MTT不对称指数差异无统计学意义(P>0.05),在单侧痫性放电组中,痫性放电侧颞叶脑血流量较对侧有所减低,但比较差异无统计学意义(t=-2.093,P=0.063)。结论颞叶癫痫CT灌注成像显示颞叶区发作间期单侧痫性放电较双侧痫性放电脑血流量不对称。