Remote memory in epilepsy

PURPOSE: There is now a considerable amount of research relating to memory functioning in epilepsy. The majority of studies have focused on the retention of new information, and few reports have measured memory for past events. This study aims to redress this and measure the efficiency of remote memory in epilepsy. METHODS: A remote memory questionnaire was prepared and administered to three groups of patients with epilepsy and a control group without epilepsy. The questionnaire assessed knowledge of public events that occurred between 1980 and 1991, inclusive. The epilepsy groups comprised 33 patients with temporal lobe epilepsy (TLE), 33 with extratemporal epilepsy (ExTE), and 10 with primary generalized epilepsy (PGE). Thirty control subjects were tested. RESULTS: Patients with TLE performed significantly less well on the questionnaire than all other groups (p = 0.001), but no effect of laterality was recorded; patients with extratemporal or primary generalised epilepsy did not differ from controls. Performance on the questionnaire was not determined by verbal IQ, educational achievement, social class, or drug treatment, but was related to the number of generalised convulsions that had occurred since 1980. The strongest neuropsychological predictors of performance on this questionnaire were measures of verbal memory. CONCLUSIONS: The study demonstrated weak memory for past events in patients with TLE, thereby providing evidence of a broader memory disturbance in this group than has been previously highlighted. A test of remote memory, such as the one designed for this study, is easy to administer and provides clinically important information not available from conventional neuropsychological tests.     

Chemical shift imaging spectroscopy and memory function in temporal lobe epilepsy

PURPOSE: Hippocampal neuron loss and associated memory deficits are characteristic of intractable temporal lobe epilepsy (TLE). Proton chemical shift imaging (CSI) spectroscopy is a sensitive tool for detecting neuronal loss. The aim of this study was to investigate the correlation between memory functions and results provided by CSI spectroscopy of the hippocampal structures. METHODS: Ten patients with cryptogenic TLE participated. The study protocol involved both the acquisition of high-spatial-resolution CSI spectroscopy and neuropsychological evaluation, including memory testing and intracarotid sodium amytal test (IAT). The analysis of the CSI data was based on normative data obtained in 30 healthy volunteers. Memory functions were represented by verbal, visual, and general memory indices. RESULTS: A significant correlation was found between CSI spectroscopy of the hippocampal formation and the verbal memory indices for the dominant hemisphere. In addition, there was a significant correspondence of the qualitative judgment "hippocampal pathology indicated by CSI spectroscopy" and both "material specific memory deficit" and "memory deficit in the IAT." CONCLUSIONS: Our results demonstrate that CSI spectroscopy of the hippocampal structures is strongly related to lateralized memory deficits in patients with TLE. This suggests that CSI spectroscopy may be useful in the prediction of postoperative outcome in respect of seizure control and memory.     

Ictal spiking patterns recorded from temporal depth electrodes predict good outcome after anterior temporal lobectomy

PURPOSE: Investigators have shown that the presence of ictal spiking (IS) recorded from temporal depth electrodes is associated with mesial temporal sclerosis (MTS). We investigated the relation of IS to seizure control and pathology after anterior temporal lobectomy (ATL). METHODS: All patients undergoing intracranial ictal monitoring from a single institution since 1989 were identified. Those who did not undergo ATL or had postoperative follow-up of <1 year were excluded. All received at a minimum bilateral temporal depth electrodes. Ictal recordings were reviewed for the presence of IS, and the proportion of seizures with IS was determined for each patient. Outcome was determined by using Engel's classification. Surgical specimens were reviewed for pathology. Statistics used were chi2, Fisher exact test, and Wilcoxon rank sum. RESULTS: Forty patients with 571 seizures were reviewed. In 292 seizures from 32 patients, IS was seen. Outcomes were 24 class I (22 with IS), five class II (four with IS), three class III (one with IS), seven class IV (four with IS), and one lost to follow-up (with IS). Pathologic review revealed 25 with MTS, 22 of whom had IS. The presence of IS was associated with class I outcomes (p = 0.04), but not MTS (p = 0.06). Patients with class I outcomes had a significantly greater proportion of seizures with IS (mean, 0.58 +/- 0.3) compared with other outcomes (mean, 0.30 +/- 0.3, p = 0.02). CONCLUSIONS: The presence of IS and higher proportion of seizures with IS correlated with good seizure outcome after ATL. This information may be used in preoperative counseling.     

Severe neuroexcitatory symptoms after anaesthesia--with focus on propofol anaesthesia

Delayed neuroexcitatory symptoms after an uneventful anaesthesia are uncommon, although described in many reports. We want to report on two cases. The first patient developed muscle hypertonicity, jerky movements and unconsciousness after an uneventful anaesthesia with propofol, and later the same thing happened after anaesthesia with thiopentone. The second patient developed similar symptoms after an uneventful anaesthesia with propofol, but she never recovered completely after this and is now severely disabled. A search of the literature and the Swedish adverse drug reactions register revealed many similar cases. In both our patients the causal relationship between propofol and the neuroexcitatory symptoms remains uncertain, but we want to alert readers about this possible adverse reaction.     

Advances in computer-assisted single-photon emission computed tomography (SPECT) for epilepsy surgery in children

Epilepsy surgery has emerged as an important option in the treatment of children with epilepsy that is refractory to antiepileptic drug management. The cornerstone of successful surgery is accurate localization of the brain region of seizure onset. Traditional techniques of seizure onset localization, e.g. surface electroencephalography (EEG) recording and magnetic resonance imaging (MRI), allow accurate localization in a significant number of patients. When the focus of seizure onset is not apparent from these non-invasive techniques, other methods of localization, e.g. intracranial EEG recording, may be needed before resection of the focus. Single-photon emission computed tomography (SPECT) is a nuclear medicine blood-flow technique that has been used to identify a region of epileptogenic brain associated with low blood flow in the resting state (interictal SPECT) or increased blood flow at the time of seizure activity (ictal SPECT). This report describes the validation and utility of a computer-assisted method of subtracting the interictal from the ictal SPECT scans and co-registering the difference image on the MRI. This method, called subtraction ictal SPECT co-registered on MRI (SISCOM), is used in guiding the location and the extent of intracranial electrode implantation, or in obviating the need for the implantation in some cases.     

尼莫地平对戊四氮致癫痫大鼠的抗氧化作用

目的探讨尼莫地平对实验性癫痫鼠的抗氧化作用.方法 50只Wistar大鼠随机分为5组,各10只.正常对照组：腹腔注射生理盐水;癫痫组：腹腔注射戊四氮（PTZ）50 mg/kg, 诱发癫痫后30 min处死;尼莫地平0.1、0.3、0.5 mg/kg 组：腹腔注射PTZ 50 mg/kg前15 min分别注射尼莫地平注射液0.1、0.3、0.5 mg/kg, 每隔24 h重复1次,连续3 d后处死.观察各组大鼠癫痫样发作的潜伏期、持续时间、发作形式,并测定各组大鼠脑组织超氧化物歧化酶（SOD）、丙二醛（MDA）、谷光甘肽过氧化物酶（GSH-PX）活性.结果尼莫地平预处理各组大鼠癫痫发作类型以轻型发作为主,发作潜伏期明显延长,持续时间短; SOD活性较癫痫组明显增高,MDA、GSH-PX活性明显下降,差异均有显著性（F＝10.720～35.831,P〈0.01）.结论尼莫地平可通过抗氧化机制来发挥抗癫痫作用.     

Functional localization of epileptic foci in cats using manganeseenhanced MRI

Objective： To determine the encephalic region correlated with epilepsy by manganese-enhanced MRI （MEMRI） and determine the correlation of epilepsy with calcium overloading. Methods： The cats were divided into two groups. The first group underwent EEG examination and ethological observation. The second group underwent MEMRI measurement. Signal enhanced encephalic regions were sectioned. Results： The achievement ratio of convulsive cats intramusclelarly injected with PTZ was 80%. MEMRI showed diffuse signal enhancement in the cerebral cortex of the cats with generalized tonic-clonic convulsive seizures compared with control animals. The enhancement rate of frontal-parietal-occipital lobe was 34.6% and 22.9% in temporl lobe compared with the control groups. Signal enhancement on frontal-parietal lobe persisted for 24 h after epileptic seizures were induced. The neurons of enhanced encephalic regions showed obvious degeneration and necrosis. Conclusion： Seizures can be induced in cats by intramuscular injection of PTZ （55 mg/kg）. Frontal-parietal lobe is the correlated encephalic regions of epilepsy. MEMRI plays an important role in localizing and revealing pathogenesis of epileptic seizures.     

Lasting changes in NMDAR1 mRNA level in various regions of cerebral cortex in epileptogenesis of amygdaloid-kindled rat

The involvement of NMDA receptor subunit, NR1, with kindling phenomenon has been reported, but the role of NR1 in epileptogenesis is still unknown. We have examined the expression levels of NR1 mRNA in the cerebral cortices of amygdaloid-kindled rats. Northern blot analysis showed a significant increase in NR1 mRNA expression level in the ipsilateral frontal and temporal cortices at 4 weeks after the last generalized seizure. At the same time, NR1 mRNA decreased in the bilateral piriform cortices. These data suggest that NR1-mediated transmission may have an impact in the neurobiological basis of enduring epileptogenesis.     

经期性癫痫苯妥英血药浓度及药动学的周期性变化

目的:探讨经期性癫痫在月经周期苯妥英血药浓度及药动学的变化。方法:收集9例应用苯妥英的经期性癫痫,在连续3个月经周期中采用高效液相色谱法分别测定月经期和排卵期苯妥英血药浓度,并选择其中3例进行药动学研究。结果:月经期与排卵期的苯妥英平均血药浓度分别为(9·25±2·71)、(13·33±3·22)μg/ml(P<0·01);苯妥英月经期消除速率大于排卵期,月经期消除半衰期短于排卵期。结论:经期性癫痫月经期苯妥英血药浓度降低可能与其清除能力增强有关。     

联用托吡酯治疗难治性癫痫临床观察

目的:观察联用托吡酯(TPM)治疗难治性癫痫(IE)的疗效与安全性.方法:采用开放性试验的方法,对20例IE患者进行治疗,以加用TPM前3个月的月均发作频率为基数,并与加用TPM后3个月的稳定期月均发作频率进行比较,同时观察其不良反应.结果:联用TPM治疗IE,总有效率达到75.0%,显效率为55.0%,其中3例(15.0%)完全控制;不良反应发生率为30.0%,为一过性,主要涉及中枢神经系统,其中2例出现体重减轻.结论:联用TPM对IE有良好疗效,安全性好.