颞叶癫痫语言皮层的功能性MR定位研究

目的： 采用功能性ＭＲ对颞叶癫痫患者语言皮层定位, 为研究颞叶癫痫患者语言功能及手术治疗顽固性颞叶癫痫提供新的定位手段; 方法： 对８ 例顽固性颞叶癫痫患者进行颞叶语言皮层的功能性ＭＲ扫描, 作为选择术式的参考依据; 结果： ８ 例患者均发现颞叶皮层出现信号改变, 其中６ 例位于左侧颞叶; ２ 例发现有右侧颞叶活动, ３ 例患者接受阿米妥实验, 与功能ＭＲ结果一致; 术后患者未出现语言功能障碍。结论： 采用功能性ＭＲ可为颞叶癫痫患者语言皮层活动提供可靠的术前判断。     

Lateralizing value of postictal automatisms in temporal lobe epilepsy

PURPOSE: To describe clinical characteristics and lateralizing value of postictal automatisms in patients with temporal lobe epilepsy (TLE). METHODS: One hundred and ninety-three videotaped seizures of 55 consecutive patients with refractory TLE and postoperatively seizure-free outcome were analyzed. Ictal as well as postictal (manual, oral and speech) automatisms were monitored. RESULTS: Thirty-four (62%) of the 55 patients showed PA at least once during their seizures. Postictal automatism was observed in 70 (36%) attacks as manual (21%), oral (13%) or speech (9%) automatisms. Fifteen seizures contained a combination of two different postictal automatisms. The presence of postictal oral automatisms did not lateralize the seizure onset zone (p=0.834). Speech automatisms (repetitive verbal behavior) occurred more frequently after left-sided seizures (p=0.002). Postictal unilateral manual automatism showed no lateralizing value occurring by the ipsilateral hand in 10 and the contralateral upper limb in 6 seizures (p=0.454). CONCLUSION: : Postictal automatism is a relatively frequent phenomenon in TLE. Postictal speech automatism lateralizes the seizure onset zone to the left hemisphere. Our observation can help the presurgical evaluation of TLE because verbal perseveration frequently occurs spontaneously, even in seizures without appropriate postictal language testing.     

The localizing value of auditory event-related potentials (P300) in patients with medically intractable temporal lobe epilepsy

The localizing value of postictal versus interictal event-related potentials (ERPs) was studied in patients with medically intractable TLE admitted for long-term video EEG monitoring. Ten patients with partial seizures and secondary generalization underwent preictal (upon hospital admission), postictal (6 h after seizure), and interictal (7–48 h after seizure) ERP recordings of an auditory oddball paradigm. Preictal ERPs were compared to postictal and interictal recordings. Intraclass correlations, transformed into z scores, were utilized to analyze amplitude differences between electrodes placed on the hemisphere ipsilateral versus contralateral to the epileptogenic focus. The results showed that in 9 out of 10 patients the ERP amplitude was reduced in postictal compared to preictal recordings for electrodes placed ipsilateral to the epileptogenic focus (P<0.0001). However, there was no difference in amplitude between ipsilateral and contralateral electrodes in preictal and interictal recordings. These findings suggest that postictal ERPs are of localizing value in patients with TLE while interictal ERPs are not.     

Comparison of localizing values of various diagnostic tests in non-lesional medial temporal lobe epilepsy

Though the surgical treatment for medial temporal lobe epilepsy yields a high success rate, more studies are needed in order to determine the most efficacious pre-operative algorithm. The authors studied the relationship between surgical outcome and the localization results of various pre-operative diagnostic tests to assess the predictive value. Seventy-one consecutive patients who had undergone anterior temporal lobectomy with amygdalohippocampectomy with the diagnosis of non-lesional medial temporal lobe epilepsy, who had been followed up more than 24 months, were analyzed retrospectively. Electroencephalogy (EEG), magnetic resonance imaging (MRI), proton emission tomography (PET), single photon emission computed tomography (SPECT), the Wada test, and neuropsychological testing were analyzed. There was no diagnostic test that was found to have a statistically significant relationship between Engel Class I outcome and localization results (P & 0.05). SPECT, neuropsychological testing, and the Wada test all had less predictive values (P < 0.01). EEG and PET had comparable predictive values for Engel Class I with MRI (P & 0.05). No single diagnostic test alone is sufficient to make a diagnosis of non-lesional medial temporal lobe epilepsy. MRI, EEG and PET had comparable predictive values for Engel Class I. SPECT, neuropsychological testing, and the Wada test had less predictive values.     

颅内电极监测对顽固性颞叶癫痫致痫灶的定位价值

目的:探讨发作期及发作间期颅内电极监测对癫痫灶的定位作用。方法:20例难治性颞叶癫痫,经临床、影像学及头皮脑电图不能确定致痫灶部位,应用立体定向技术,在患者双侧颞叶植入硬膜下条状电极,进行长时间视频脑电图监测,记录发作期和发作间期的脑电图变化,并与头皮脑电图、MRI进行比较,分析癫痫灶部位,进行手术治疗,术后跟踪随访,评估致痫灶定位的准确性。结果:20例癫痫病人颅内电极埋藏时间1～5天,每个患者至少监测到2次临床发作,每一病例均记录发作间期和发作期的异常放电活动。15例发作间期与发作期定侧一致,2例发作间期为双侧棘波病灶,3例发作间期定位与发作期不一致。按Engel术后效果分级:手术效果满意(癫痫发作消失)13例(65%),显著改善3例(15%),良好3例(15%),无效1例(5%)。所有病例均未出现因颅内电极埋藏而致的并发症。结论:对于致痫灶不能定位的难治性癫痫,应用颅内电极记录方法,尤其是发作期起始时脑电图变化,可以确定致痫灶位置,为癫痫手术治疗提供可靠的依据。     

Lateralizing value of memory tests in drug-resistant temporal lobe epilepsy

Our aim was to test the lateralizing value of a neuropsychological battery including several memory tests on a large sample of consecutive patients with drug-resistant temporal lobe epilepsy (TLE) evaluated for epilepsy surgery. We studied 73 right-handed patients (56% males, mean age 35.3 +/- 11.2 years, 49% left TLE) aged 16 years or older with normal IQ who underwent a preoperative neuropsychological assessment including several memory tests and were seizure-free after at least 1 year of follow-up. Forty-seven had TLE due to hippocampal sclerosis, whilst 26 had TLE secondary to tumors or other lesions. Receiver Operating Characteristic (ROC) analysis and discriminant function analysis were used to evaluate the lateralization value of selected tests and of the battery as a whole, respectively. In patients with TLE secondary to tumors or other lesions, no test showed significant lateralizing value. In patients with TLE due to hippocampal sclerosis, the immediate (P < 0.01) and delayed (P < 0.001) Rey Auditory Verbal Learning Test (RAVLT) displayed substantial discriminatory ability. The battery as a whole correctly classified 82% of patients with respect to side of epileptogenesis. Our findings suggest that a non-invasive, relatively short and unexpensive neuropsychological battery based on memory tests may profitably complement other well-established diagnostic procedures such as video-EEG or magnetic resonance imaging (MRI), at least in patients with drug-resistant TLE due to hippocampal sclerosis.     

CT, MR and SPECT imaging in temporal lobe epilepsy.

Cranial computed tomography (CT) with modified temporal lobe technique, 0.15T magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT) were carried out on 30 patients with intractable temporal lobe epilepsy. Lateralising abnormalities were detected in 21/30 patients overall. Specific lesions were detected by CT in one patient and by MRI in seven patients (in one case bilateral). In addition CT detected asymmetry of the sylvian fissures or temporal horns in 10 patients, and MRI in eight patients. SPECT detected lateralising abnormalities in 19 patients (in five cases bilateral). It is concluded that low field MRI is superior to modified CT in demonstrating subtle structural lesions of the temporal lobe. Functional scanning with SPECT supports the evidence of origin of an epileptic focus in a substantial proportion of cases and may improve the selection of patients for surgery.     

Extratemporal lobe circuits in temporal lobe epilepsy

There is increasing interest in the functional anatomy of epilepsy with the goal to identify the critical nodes in the seizure circuits so that therapy can be directed at them. This goal is especially important because direct delivery of therapy, either through electrical stimulation, drug infusion, or molecular therapies such as optogenetics, has become increasingly possible. In this article, we will review the basic functional anatomy of mesial temporal lobe epilepsy and its primary subcortical connection, the medial dorsal nucleus of the thalamus. Based on its anatomical connections and known physiological interactions, we propose a key role for this thalamic nucleus that is essential for the development of seizures, and this role suggests that this region is a potential therapeutic target.This article is part of a Special Issue entitled “NEWroscience 2013”.     

Frontal lobe function in temporal lobe epilepsy

Temporal lobe epilepsy (TLE) is typically associated with long-term memory dysfunction. The frontal lobes support high-level cognition comprising executive skills and working memory that is vital for daily life functioning. Deficits in these functions have been increasingly reported in TLE. Evidence from both the neuropsychological and neuroimaging literature suggests both executive function and working memory are compromised in the presence of TLE. In relation to executive impairment, particular focus has been paid to set shifting as measured by the Wisconsin Card Sorting Task. Other discrete executive functions such as decision-making and theory of mind also appear vulnerable but have received little attention. With regard to working memory, the medial temporal lobe structures appear have a more critical role, but with emerging evidence of hippocampal dependent and independent processes. The relative role of underlying pathology and seizure spread is likely to have considerable bearing upon the cognitive phenotype and trajectory in TLE. The identification of the nature of frontal lobe dysfunction in TLE thus has important clinical implications for prognosis and surgical management. Longitudinal neuropsychological and neuroimaging studies assessing frontal lobe function in TLE patients pre- and postoperatively will improve our understanding further.     

Localizing value of rapid eye movement sleep in temporal lobe epilepsy

Sleep state is a physiological modulator of epilepsy. Non rapid-eye-movement (NREM) sleep generally increases interictal epileptiform discharges (IEDs) and expands their field of distribution. In contrast, rapid eye movement (REM) sleep tends to suppress IEDs and may limit their spread outside of the region of primary seizure origin. The ability of REM sleep to restrict IEDs may have localizing value in temporal lobe epilepsy patients undergoing evaluations for epilepsy surgery. We present the case of a woman with medically-refractory seizures secondary to a mesial temporal glioma. Although scalp and intracranial electroencephalographic (EEG) seizure recordings supported bilateral epileptic foci, the IEDs recorded during REM sleep were restricted to the region of the glioma, and the patient had a successful surgical outcome. Our findings support the usefulness of combining sleep recordings with EEG monitoring in the evaluation of candidates for epilepsy surgery.     

Lateralizing value of behavioral arrest in patients with temporal lobe epilepsy

Analysis of ictal semiology is essential to presurgical evaluation of patients with epilepsy. To assess the localizing value of behavioral arrest in temporal lobe epilepsy (TLE), we analyzed 107 video/EEG monitoring-documented seizures of 107 adult patients with TLE for a set of defined seizure phenomena with respect to frequency and sequence of occurrence in relation to epileptogenic (mesial vs extramesial, left vs right) origin. Behavioral arrest was observed more frequently in left-sided temporal seizures: 25.7% of left-sided mesial seizures and 25.0% of left-sided extramesial seizures exhibited behavioral arrest, whereas only 3.4% of right-sided mesial seizures and 10.5% of right-sided extramesial seizures were associated with behavioral arrest. In addition, occurence of behavioral arrest within the sequence of seizure phenomena was remarkably consistent, being observed mainly as the first apparent feature of seizure onset. Thus, behavioral arrest is a valuable early indicator of a left-sided temporal epileptogenic focus in adult patients with TLE.     

Localizing and lateralizing value of epileptic symptoms in temporal lobe epilepsy

The symptoms and signs associated with all stages of a temporal lobe seizure may be helpful in determining both the localization and lateralization of seizure onset. Auras, when present, may be very suggestive of temporal lobe onset and may further localize to a mesiobasal or lateral temporal lobe site of onset. During the ictus, automatisms and motor phenomena may be highly indicative of temporal lobe seizure activity and may even help lateralize the discharge. In the post-ictal period, motor paresis and aphasia are helpful in lateralization. Video E.E.G. data has provided extensive information on the utility of ictal symptomatology in seizure localization. Thus, the seizure semiology provides important adjunctive information in evaluating patients for epilepsy surgery and should be concordant with information obtained from ictal EEG, neuroimaging and neuropsychology.     

Hypersalivation in temporal lobe epilepsy

PURPOSE: We sought to determine whether hypersalivation helps lateralize seizure onset during complex partial seizures of temporal lobe origin. Several clinical signs, which help lateralize seizure onset, have been reported in temporal lobe epilepsy (TLE). Increased salivation only occasionally has been reported as a manifestation of partial epilepsy. METHODS: Of 590 consecutive patients admitted for video-EEG monitoring, either as a part of a presurgical evaluation of medically intractable epilepsy or for diagnosis and clarification of their paroxysmal symptoms, we identified 10 patients with ictal hypersalivation as a prominent manifestation of complex partial seizures. We reviewed the clinical features, scalp-sphenoidal video-EEG monitoring, intracarotid amytal (Wada) testing, hippocampal volumetric magnetic resonance imaging (MRI), and fluorodeoxyglucose-positron emission tomography (FDG-PET) scans of these patients. RESULTS: Of the 10 patients with ictal hypersalivation, seven patients had nondominant/right TLE, and three patients had dominant/left TLE. All patients had hippocampal atrophy on volumetric MRI. Eight of the 10 patients underwent standard temporal lobectomy with amygdalohippocampectomy (six right, two left). All of the operated-on patients had a seizure-free (Engel class I) outcome, and their increased salivation resolved. Two patients, who did not undergo surgical treatment, continue to have complex partial seizures with increased salivation. CONCLUSIONS: We conclude that increased salivation as a prominent ictal finding in complex partial seizures of temporal lobe origin is more likely to be of nondominant temporal lobe origin. Further studies with larger numbers of patients are needed to replicate this finding.