The localizing value of ictal EEG in focal epilepsy.

OBJECTIVE: To investigate the lateralization and localization of ictal EEG in focal epilepsy. METHODS: A total of 486 ictal EEG of 72 patients with focal epilepsy arising from the mesial temporal, neocortical temporal, mesial frontal, dorsolateral frontal, parietal, and occipital regions were analyzed. RESULTS: Surface ictal EEG was adequately localized in 72% of cases, more often in temporal than extratemporal epilepsy. Localized ictal onsets were seen in 57% of seizures and were most common in mesial temporal lobe epilepsy (MTLE), lateral frontal lobe epilepsy (LFLE), and parietal lobe epilepsy, whereas lateralized onsets predominated in neocortical temporal lobe epilepsy and generalized onsets in mesial frontal lobe epilepsy (MFLE) and occipital lobe epilepsy. Approximately two-thirds of seizures were localized, 22% generalized, 4% lateralized, and 6% mislocalized/lateralized. False localization/lateralization occurred in 28% of occipital and 16% of parietal seizures. Rhythmic temporal theta at ictal onset was seen exclusively in temporal lobe seizures, whereas localized repetitive epileptiform activity was highly predictive of LFLE. Seizures arising from the lateral convexity and mesial regions were differentiated by a high incidence of repetitive epileptiform activity at ictal onset in the former and rhythmic theta activity in the latter. CONCLUSIONS: With the exception of mesial frontal lobe epilepsy, ictal recordings are very useful in the localization/lateralization of focal seizures. Some patterns are highly accurate in localizing the epileptogenic lobe. One limitation of ictal EEG is the potential for false localization/lateralization in occipital and parietal lobe epilepsies.     

The clinical usefulness of ictal surface EEG in neocortical epilepsy

PURPOSE: Localizable scalp EEGs, during ictal episodes, appear to be rare in neocortical epileptic syndromes. However, studies based on large numbers of patients are also rare. This study aims to identify the characteristic patterns of variable neocortical epilepsies and to evaluate their clinical usefulness in the localization of epileptogenic focuses. METHODS: We retrospectively assessed 394 noninvasive ictal recordings from 86 patients who subsequently underwent invasive study and resective surgery. Ictal EEGs were recorded using a video-EEG monitoring system with electrodes placed according to the International 10-20 system, with additional anterior temporal electrodes. The ictal recordings were analyzed according to localizing accuracy and frequency characteristics. The durations of discrete or regional ictal rhythms were also measured. RESULTS: The percentage of discrete or regional EEGs was 23% in frontal lobe epilepsy, 52% in lateral temporal lobe epilepsy, 70% in occipital lobe epilepsy, and 10% in parietal lobe epilepsy. In order of frequency, the localizable ictal rhythms were theta, beta, alpha, delta, and rhythmic spike-and-wave. The duration of discrete or regional ictal rhythms was significantly shorter in frontal lobe epilepsy and parietal lobe epilepsy than in other epilepsies. Ictal beta activity was the most common rhythm in discrete-patterned EEGs. Structural lesions found on MRI did not significantly affect the localization of epileptogenic focuses in the patients. The type of seizure was not related to the degree of localization, with the exception of simple partial seizure. CONCLUSIONS: Ictal surface EEG was clinically helpful in the localization of epileptogenic focuses in at least some neocortical epileptic syndromes.     

Focal functional deficits in temporal lobe epilepsy on PET scans and the intracarotid amobarbital procedure: comparison of patients with unitemporal epilepsy with those requiring intracranial recordings

PURPOSE: To analyze the relationship between the intracarotid amobarbital procedure (IAP) and positron emission tomography (PET) and study the lateralizing value of these tests in patients with unitemporal epilepsy and those requiring intracranial recordings. METHODS: We compared 51 patients with unitemporal epilepsy (group1) with 26 patients in whom surface recordings failed to reveal a distinct unitemporal focus, necessitating invasive recordings (group 2). RESULTS: The brain magnetic resonance imaging (MRI) scans for group 1 showed mesial temporal sclerosis in 70.5% of the patients. PET showed unilateral temporal hypometabolism in 88%. In addition, 74.5% of the patients in group 1 had impaired memory on the epileptogenic side on the IAP, and 89.4% of those patients also had ipsilateral temporal hypometabolism on PET scans. All the group 1 patients underwent temporal resections. The pathologic examination showed hippocampal sclerosis in 72% of the patients. Eighty percent of group 1 patients became seizure free, and 16% had rare seizures (follow-up, 2-7 years). MRIs for group 2 showed mesial temporal sclerosis in 31% of the patients; PET scans showed temporal hypometabolism in 39%. The IAP was lateralized in 47.8%. Sixty-nine percent had temporal lobe resections. The pathologic examination showed hippocampal sclerosis in 44% of the patients. Forty-four percent of group 2 patients became seizure free, and 27.7% had rare seizures (follow-up, 2-8 years). CONCLUSIONS: Ninety-six percent of the patients with unitemporal foci had focal functional deficits on the epileptogenic side on 18-fluorodeoxyglucose-(FDG) PET scans, the IAP, or both. The results of the FDG-PET were predictive of impaired memory on the IAP. Memory impairment contralateral to the temporal hypometabolism found on the PET scans was never seen. These patients had an excellent outcome. In contrast, <50% of the patients requiring intracranial recordings had focal functional deficits, suggesting that more a diffuse pathology may account for their less favorable outcome.     

Intracartotid Amobarbital Procedure Memory Performance and Age at First Risk for Seizures Distinguish Between Lateral Neocortical and Mesial Temporal Lobe Epilepsy

Summary: Purpose: To determine whether intracarotid amobarbital procedure (IAP) memory-performance asymmetries and early risk factors for epilepsy distinguish between lateral neocortical temporal lobe epilepsy (LNTLE) and mesiobasal temporal lobe epilepsy (MBTLE).
Methods: We studied 10 patients with LNTLE and 22 with MBTLE. All LNTLE patients showed (a) presence of temporal neocortical lesion or lateral seizure onset by intracranial recording, and (b) absence of mesial temporal sclerosis (MTS) by histopathologic analysis. All patients with MBTLE showed (a) video-scalp EEG seizures consistent with mesial TLE, and (b) presence of unilateral MTS by histopathologic analysis. All patients had good surgical outcomes (Engel I or II). Unilateral IAP memory performance was defined as percentage of memory items presented during hemispheric anesthesia that was recognized after recovery. IAP asymmetry scores were the differences in memory performance after right and left injections.
Results: Mean memory-asymmetry scores were significantly lower in the LNTLE than in the MBTLE group. An IAP memory asymmetry of <25% correctly classified seven of 10 patients with LNTLE, and an asymmetry of ≥25% correctly classified 18 of 22 patients with MBTLE. Age at first risk for epilepsy was significantly younger in those with MBTLE than in those with nonlesional LNTLE. Results suggest that both IAP memory performance and age at first risk can help distinguish between MBTLE and LNTLE.     

Interictal depression, anxiety, personality traits, and psychological dissociation in patients with temporal lobe epilepsy (TLE) and extra-TLE

PURPOSE: This study was performed to investigate the relation between symptoms of interictal depression, anxiety, personality traits, and psychological dissociation with the localization and lateralization of the epileptogenic zone in patients with partial epilepsy. METHODS: All patients were diagnosed according to the localization-related concept of the 1989 International League Against Epilepsy (ILAE) Classification of Epilepsies and Epileptic Syndromes, and the localization and lateralization of the epileptogenic zone was established by using the clinical criteria for noninvasive presurgical evaluation. This resulted in 67 patients with temporal lobe epilepsy (TLE) and 64 patients with extra-TLE. All patients were assessed on the various aspects of psychopathology by using a comprehensive battery of standardized diagnostic instruments. RESULTS: We did not find the hypothesized excess of psychiatric symptoms in patients with (mesial) TLE in comparison with patients with extra-TLE. We also found no differences between patients with the lateralization of epilepsy in the left versus the right hemisphere. CONCLUSIONS: TLE per se cannot be considered a risk factor in developing more or more severe symptoms of psychopathology in patients with partial epilepsy. Concomitant factors, such as the duration of epilepsy, seizure frequency, and frontal lobe dysfunction may play an additional role. Our findings support the hypothesis of a multifactorial explanation for the psychiatric symptoms in patients with epilepsy.     

Temporal lobe epilepsy with sensory aura: interictal glucose hypometabolism

Patients with mesial temporal lobe epilepsy (mTLE) exhibit marked depressions of the regional cerebral glucose metabolism (rCMRGlu) in the mesiotemporal region. We hypothesised that patients with temporal lobe epilepsy (TLE) who have a bilateral somatosensory or acoustic ( = temporolateral/SII-) aura can be differentiated from mTLE by rCMRGlu depressions primarily involving temporo-perisylvian locations. We therefore used this ictal semiology as a clinical criterion to define a subgroup of such patients and measured the rCMRGlu in 16 patients with TLE as evident from interictal and ictal EEG-video monitoring. Clinically, they presented with medically refractory complex partial seizures and were subjected to presurgical evaluation. The pattern of the interictal rCMRGlu in the TLE patients was different from that observed in patients with mTLE and showed significant depressions ipsilateral to the epileptic focus in mesial temporal and lateral temporal regions but spared the thalamus. The neocortical metabolic depressions were spatially more extended in right than in left TLE patients. Magnetic resonance images (MRI) were either normal (n = 5) or revealed unilateral or bilateral hippocampal atrophy/sclerosis (n = 7), or temporal or extratemporal focal cortical dysplasia (n = 4). The selected TLE patients presented here comprise a heterogeneous group showing most pronounced metabolic depressions in the lateral temporal cortex. Thus, our data suggest that non-invasive metabolic imaging can assist in identifying the neocortical symptomatogenic zone in putative temporo-perisylvian lobe epilepsy.     

Musicogenic seizures can arise from multiple temporal lobe foci: intracranial EEG analyses of three patients

PURPOSE: To determine the ictal-onset zone of musicogenic seizures by using intracranial EEG monitoring. METHODS: Musicogenic seizures in three patients with medically intractable musicogenic epilepsy were first localized by using noninvasive methods including, in one patient, ictal magnetoencephalography (MEG) and magnetic resonance spectroscopy (MRS). The ictal-onset zones in these patients were then further localized using by intracranial EEG monitoring, and the outcomes of the two patients who underwent epilepsy surgery were determined. RESULTS: Patient 1's musicogenic seizures localized to the right lateral temporal lobe, patient 2's originated in the right mesial temporal lobe, and patient 3's arose independently from both mesial temporal lobes. Patients 1 and 2 underwent resective epilepsy surgery and are seizure free (Engel class I). CONCLUSIONS: Musicogenic epilepsy is a heterogeneous syndrome with seizures that can arise from multiple temporal lobe foci. Patients with medically intractable musicogenic epilepsy and with unilateral ictal onset zones may be considered candidates for resective epilepsy surgery.     

MRI和CT阴性表现的脑致痫灶定位研究

目的回顾性分析难治性癫痫手术治疗的临床资料,探讨MRI和CT阴性表现病例的致痫灶定位方法.方法经MRI和CT检查呈阴性表现的癫痫患者42例,应用发作症状评估、长程头皮和颅内电极视频脑电图（video-EEG）监测等方法综合定位致痫灶.结果36例（85.7%）患者可以明确定位致痫灶,其中位于颞叶19例,额叶12例,额叶＋颞叶3例,顶枕叶2例;多灶性起源或定位不明确者6例,2例放弃手术.40例脑致痫灶组织均有不同程度的病理改变.结论一些局灶性皮质发育不良、微发育不良等细微脑组织改变通过现有的MRI和CT影像学检查尚难以发现,而它们常常是导致癫痫发作的病理基础.综合分析患者的临床发作特点,特别是长程EEG监测资料,可为大部分的此类病例明确定位脑致痫灶.     

Electrophysiological study of intractable epileptogenicity in human epilepsy: clinical usefulness of ictal DC shifts and cavernous sinus EEG]

In order to clarify the clinical and electrophysiological features in intractable epileptogenicity in human epilepsy, we applied the new techniques, ictal DC shifts and cavernous sinus EEG recording, for presurgical evaluation of patients with intractable partial epilepsy. (1) Ictal DC shifts were successfully recorded with subdural electrodes in 8 patients with intractable neocortical epilepsy, and an analysis of ictal DC shifts would add useful information to delineate an epileptogenic area. Scalp-recorded ictal DC shifts were also investigated in 3 patients with intractable neocortical epilepsy. It also delineated the epileptogenic area, but it was vulnerable for artifacts. (2) By using the techniques of intravascular EEG recording, we recorded EEG from the bilateral cavernous sinus (cavernous sinus EEG) in patients with intractable temporal lobe epilepsy. Cavernous sinus EEG well sensitively recorded interictal, also ictal in selected patients, epileptiform discharges which arose from the mesial temporal structure even though they were not recorded by scalp electrodes. It is concluded that the above two techniques are clinically useful for delineating an epileptogenic area in patients with neocortical epilepsy and temporal lobe epilepsy.     

Magnetoencephalography in partial epilepsy: Clinical yield and localization accuracy

The goals of this study were to determine (1) the yield of magnetoencephalography (MEG) according to epilepsy type, (2) if MEG spike sources colocalize with focal epileptogenic pathology, and (3) if MEG can identify the epileptogenic zone when scalp ictal electroencephalogram (EEG) or magnetic resonance imaging (MRI) fail to localize it. Twenty-two patients with mesial temporal (10 patients), neocortical temporal (3 patients), and extratemporal lobe epilepsy (9 patients) were studied. A 37-channel biomagnetometer was used for simultaneously recording MEG with EEG. During the typical 2–3–hour MEG recording session, interictal epileptiform activity was observed in 16 of 22 patients. MEG localization yield was greater in patients with neocortical epilepsy (92%) than in those with mesial temporal lobe epilepsy (50%). In 5 of 6 patients with focal epileptogenic pathology, MEG spike sources were colocalized with the lesions. In 11 of 12 patients with nonlocalizing (ambiguous abnormalities or normal) MRI, MEG spike sources were localized in the region of the epileptogenic zone as ultimately defined by all clinical and EEG information (including intracranial EEG). In conclusion, MEG can reliably localize sources of spike discharges in patients with temporal and extratemporal lobe epilepsy. MEG sometimes provides noninvasive localization data that are not otherwise available with MRI or conventional scalp ictal EEG.     

Spectroscopic metabolic abnormalities in mTLE with and without MRI evidence for mesial temporal sclerosis using hippocampal short-TE MRSI

PURPOSE: Long echo time (TE) spectroscopy reliably identifies the epileptogenic hippocampus in mesial temporal lobe epilepsy. Short-TE spectroscopy gives additional metabolic information but may have more artifacts. The aim of this study was to test (a) lateralization of the seizure focus by short-TE spectroscopy, and (b) value of myoinositol (MI) in the identification of the epileptogenic hippocampus. METHODS: Twenty-four patients with temporal lobe epilepsy: 16 with mesial temporal sclerosis (TLE-MTS), eight patients with normal magnetic resonance imaging (MRI; TLE-No), and 16 controls were studied with hippocampal 2D short-TE magnetic resonance spectroscopic imaging (MRSI). RESULTS: In TLE-MTS, the ipsilateral N-acetylaspartate (NAA) was decreased compared with contralateral (p = 0.03) or controls (p = 0.007). Additionally, the ipsilateral MI was decreased compared with controls (p = 0.012). TLE-No values showed no side differences and were not different from controls. Abnormalities in the anterior hippocampus correctly lateralized the epileptogenic hippocampus in 相似文献   

Lateralized memory deficits on the Wada test correlate with the side of lobectomy only for patients with unilateral medial temporal lobe epilepsy

The aim of this study was to determine whether the predictive value of the intracarotid amobarbital test (IAT) for the side to be resected is applicable only to medial temporal lobe epilepsy and to investigate whether there are different patterns of memory performances on the IAT between patients with unilateral mesial temporal sclerosis (UMT group) and those without (non-UMT group). We studied 30 patients in the UMT group and 10 in the non-UMT group, who underwent pre-surgical evaluation for intractable temporal lobe epilepsy. Memory performances on the IAT was defined as the percentage of memory items presented during unilateral hemispheric anesthesia that was recognized after recovery. More than a 20% decline of the memory performance on the IAT compared with the memory performance on the pre-test was regarded as a memory deficit. Age at onset of epilepsy was significantly younger in the UMT than in the non-UMT group. Surgical outcome was significantly better in the UMT than in the non-UMT group. The lateralizing value of unilateral memory deficits on the IAT was statistically confirmed. There was a significant association between falsely lateralizing memory performances and the non-UMT group. Excluding the exceptional cases with right-sided language dominance in spite of right-sided lesions, the high incidence of the unilateral right-sided memory deficits in the non-UMT group was statistically significant. This study suggested that the excellent lateralizing value of the memory performances on the IAT is limited to patients with mesial temporal lobe epilepsy. IAT memory performances in patients without such lesions can be misleading, even if lateralized, because their memory status presumably reflects a natural lateralization of the memory organization which is independent of the epileptogenic focus.     

Validation of the Wechsler Memory Scale-Revised in a Sample of People with Intractable Temporal Lobe Epilepsy

Summary: Purpose: The Wechsler Memory Scale-Revised (WMS-R) is used routinely for presurgical assessment of memory for patients considering elective resection of the temporal lobe and/or hippocampus for the relief of intractable temporal lobe epilepsy (TLE). We investigated the validity of the WMS-R in a population of people with TLE.
Methods: The sample consisted of 138 patients with a diagnosis of TLE in which the epileptogenic focus was clearly and exclusively lateralized to either the right or left hemisphere. They underwent a complete neuropsychological examination as a routine part of their investigation for epilepsy surgery. Psychometric scores included in this study were: Wechsler Adult Intelligence Scale-Revised (WAIS-R) I.Q. scores, National Adult Reading Test Revised (NART-R) predicted-I.Q. scores, and WMS-R Memory Index and subtest scores.
Results: Multiple univariate analyses were performed. The group with left temporal focus had significantly lower Verbal Memory Index, Logical memory (both immediate and delayed), and Digit Span scores. Visual/Verbal discrepancy scores incorrectly identified most patients with right temporal focus. Analyses of a total group of people with epilepsy (i.e., mixed temporal, frontal, occipital and unknown foci) as compared with the normative sample indicated that the patient group scored significantly lower across all memory index scores and most memory subtests.
Conclusions: Our results confirm that the WMS-R is capable of lateralizing to left hemispheric impairment but is more problematic in the assessment of right hemispheric impairment. The Visual/Verbal Memory Index discrepancy has questionable validity. People with epilepsy performed less well on the WMS-R than did the normative sample. The need for reliable and valid nonverbal tests of memory is therefore warranted.     

Clinical Usefulness of the Dipole Tracing Method for Localizing Interictal Spikes in Partial Epilepsy

Summary: Purpose: To clarify the clinical usefulness of the dipole tracing method in evaluation of interictal EEG spikes in patients with partial epilepsy.
Methods : Eight patients with partial epilepsy were studied. We compared the generator source of interictal spikes detected by the dipole tracing method with the results of magnetic resonance imaging (MRI), interictayictal measurement of cerebral blood flow (CBF) by single photon emission computed tomography (SPECT), interictal measurement of glucose metabolism by positron emission tomography (PET) and invasive electrocorticogram (ECoG).
Results : In 5 patients with mesial temporal lobe epilepsy (TLE), including 3 patients who underwent standard temporal lobectomy, the dipole tracing method showed results consistent with those of other examinations and better correlation with ECoG than with other noninvasive examinations. In a patient with mesial TLE who had defects in the skull due to previous surgery, the dipoles were located more laterally than expected. In a patient with frontal lobe epilepsy (FLE) who was finally proved to have an epileptogenic area in the lateral frontal area, the spike dipoles were identified in the medial side of the frontal lobe.
Conclusions : The dipole tracing method used in the present study is useful for localizing epileptogenic areas in patients with mesial TLE. However, in patients with partial skull defects and in those with FLE, the reliability of this method is still in accuracy of the lobe level.     

Semantic memory in partial epilepsy: verbal and non-verbal deficits and neuroanatomical relationships

Semantic memory was evaluated in 124 epilepsy patients, including 84 with left (n=44) or right temporal lobe epilepsy (TLE) (n=40) and 40 with left (n=25) or right frontal lobe epilepsy (FLE) (n=15), in order to determine their verbal and visual deficits, and the neuroanatomical relationships between them. The controls were 35 healthy subjects. Semantic memory was assessed by means of Picture Naming, Picture Pointing, the verbal Pyramid and Palm Trees Test (PPTT), the visual PPTT, Object Decision Hard, and Drawing From Memory. Episodic memory was assessed by means of the Short Story, Rey's Complex Figure, the Verbal and Visual Selective Reminding Procedure and Brown-Peterson Procedure. Factor analysis of the epilepsy patients distinguished their semantic memory scores from other neuropsychological domains. The semantic memory factor was significantly related to the side of the epileptic region, with lower scores in the left hemisphere and left TLE patients. In comparison with the controls, the left TLE patients were significantly impaired on Picture Naming, Picture Pointing, and Object Decision Hard. Subsequent analyses showed that, in comparison with the controls and the right TLE patients, the left TLE patients with lateral temporal lobe lesions were impaired in Picture Naming whereas, in comparison with the controls, the left TLE patients with mesial temporal lobe lesions were impaired in Object Decision Hard. On the contrary, the episodic memory factor was not related to the side of the epileptic region, and a few material-specific tests revealed opposite impairments in the left and right hemisphere patients. These results show that left TLE may cause semantic memory deficits involving verbal and visual information. Unlike the material-specific pattern of episodic memory, this pattern of impairment is in line with the view of an amodal semantic store in which all of the information about a thing overlaps. The semantic memory impairment may reflect damage in the lateral and mesial temporal lobe regions that impair neocortical functions in storing and retrieving information or hippocampal functions in processing meaningful stimuli.     

18F-FDG PET/CT在颞叶内侧癫痫外科定位诊断中的价值

目的探讨18F-脱氧葡萄糖(FDG)PET/CT检查在颞叶内侧癫痫(mesial temporal lobe epilepsy)术前评估和致痫灶定位中的应用价值。方法回顾性分析我科实施手术治疗的85例颞叶内侧癫痫患者的临床资料,经三大检查(症状学、MRI、V-EEG)和18F-FDG PET/CT检查证实致痫灶存在且位于颞叶内侧。经上述方法精准定位后,采用扩大额颞手术切口,皮层脑电描记引导下施行标准前颞叶切除术,部分加做海马杏仁核切除术或(和)皮层热灼术,对术前评估方法,18F-FDG PET/CT检查的意义和手术治疗预后进行分析。结果 85例患者术后随访6个月到5年,Engel效果分级:69例(81.2%)I级,9例(10.6%)Ⅱ级,7例(8.2%)Ⅲ级或Ⅳ级。4例出现硬膜外血肿,15例出现短期并发症,所有病人均无永久性并发症。患者术后服用抗癫痫药物较术前减少或停药。结论 18 F-FDGPET/CT检查是目前颞叶内侧癫痫致痫灶定位精确、直观而有效的手段之一,结合常规三大术前检查,是颞叶内侧癫痫致痫灶定位可靠的无创性检查方法。18F-FDG PET/CT检查对于颞叶内侧癫痫的术前定位诊断具有重要价值。     

Callosotomy and subsequent surgery for children with refractory epilepsy

Callosotomy has been considered as a palliative therapy for refractory epilepsy patients with non-focal onset seizures. Residual partial seizures and unilateral epileptiform discharges on electroencephalography (EEG) are sometimes observed after callosotomy. These findings suggest that some patients may be candidates for subsequent resective surgery. Of 149 children who received a callosotomy, resective/disconnective surgery was subsequently performed in 19 patients. Most patients had generalized seizures and epileptiform discharges on EEG before callosotomy. Two-third had normal neuroimaging studies at initial presurgical evaluation. After callosotomy, ictal symptoms evolved into asymmetric features suggesting partial onset seizures. Post-callosotomy EEG showed completely lateralized or localized epileptiform discharges responsible for residual partial seizures in 16 of 19 patients. Fifteen patients underwent resective surgery of the unilateral frontal lobe, and the remaining received hemispherotomy or posterior quadrantectomy. After subsequent surgery, favorable seizure outcomes were obtained in 11 patients (57.9%). Favorable seizure outcomes may be achieved with callosotomy and subsequent surgery in selected patients who are not candidates for a conventional resective surgery at initial presurgical evaluation.     

Comparison of the intracarotid amobarbital procedure and interictal cerebral 18-fluorodeoxyglucose positron emission tomography scans in refractory temporal lobe epilepsy.

The relationship between interictal focal hypometabolism determined by 18-fluorodeoxyglucose positron emission tomography (FDG-PET) scans and memory function with the intracarotid amobarbital procedure (IAP) was evaluated in 23 patients with temporal lobe epilepsy. All patients underwent prolonged EEG/video monitoring. The epileptogenic focus was defined by interictal epileptiform discharges and ictal onsets. All 23 patients had recorded seizures arising exclusively from one temporal lobe. PET showed temporal lobe hypometabolism ipsilateral to the epileptogenic focus in 86% (20 of 23) of patients; IAP showed impaired memory of the hemisphere of seizure onset in 65% (15 of 23). Sixty-five percent (13 of 20) of patients with focal hypometabolism had ipsilateral memory impairment. Memory impairment contralateral to the hypometabolic zone was not observed. Ninety-five percent (22 of 23) of patients demonstrated functional impairment by either PET or IAP (or both) on the epileptogenic side.     

颞叶内侧癫癎海马功能连接的功能磁共振成像研究

目的研究颞叶内侧癫癎患者右侧海马与全脑,尤其是默认网络功能连接的关系,探讨颞叶内侧癫癎患者默认网络异常的机制及其形成的颞叶癫癎网络。方法23例颞叶内侧癫癎患者,采用静息功能连接的功能磁共振成像,选择右侧海马作为兴趣区,获得正常对照组和颞叶内侧癫癎组受试者的脑功能连接激活图,观察其右侧海马与全脑的功能连接。结果正常对照组受试者默认网络包括海马、后扣带回和（或）楔前叶、前扣带回和（或）前额叶内侧、角回及前颞叶。颞叶内侧癫癎组患者右侧海马与默认网络的正向功能连接明显减弱,与右侧额下回、颞上回及第一运动感觉皮质下部的正向功能连接增强;与前额叶背侧、顶间沟及第一运动感觉皮质上部的负向功能连接减弱。结论在颞叶内侧癫癎患者功能连接网络中,默认网络及部分正向功能连接网络受损,提示患者存在广泛的、与海马相关的生理功能丧失;与右侧额下回、颞上回及第一感觉运动皮质下部的功能连接增强则可能与颞叶癫癎网络有关。     

Temporal lobectomy in congenital porencephaly associated with hippocampal sclerosis

BACKGROUND: Clinical and neuroimaging features of patients with epilepsy and coexisting extratemporal porencephaly and hippocampal sclerosis have been previously described. OBJECTIVE: To present the clinical characteristics and surgical outcome of 6 patients with intractable epilepsy and coexisting extratemporal porencephaly and hippocampal sclerosis.Patients and METHODS: Twenty-four patients with porencephaly and epilepsy were studied. Of these, 6 had an epileptogenic focus in the temporal region. All patients underwent video electroencephalogram monitoring, magnetic resonance imaging studies, and neuropsychological evaluation. Of the subset of patients with temporal lobe epilepsy, 1 patient underwent intracranial electroencephalogram monitoring. Temporal lobe resection was performed in 5 patients. Outcomes were evaluated using the Engel classification. RESULTS: Freedom from seizures was achieved in all patients. Pathologic analysis of the resected tissue confirmed the presurgical diagnosis of mesial temporal sclerosis. CONCLUSION: Patients with extratemporal porencephaly and intractable seizures should be evaluated early and be considered for temporal lobectomy if clinical, magnetic resonance imaging, and electroencephalogram findings support the diagnosis of temporal lobe onset seizures.