From lateral to mesial: the quest for a surgical cure for temporal lobe epilepsy

PURPOSE: A gap of more than a hundred years occurred between the first accounts of mesial temporal sclerosis and recognition of its role in the pathogenesis of psychomotor seizures. This paper reviews how the understanding and surgical treatment of temporal lobe epilepsy developed, particularly from the work of Penfield, Jasper, and their associates at the Montreal Neurological Institute (MNI). METHODS: Publications on EEG and surgery for temporal lobe seizures from 1935 to 1953 were reviewed and charts of selected patients operated on at the MNI in the same period were examined. Attention was focused on the evolution of surgical techniques for temporal lobe epilepsy. RESULTS: In the late 1930s, some EEG findings suggested deep-lying disturbances originating in the temporal lobe. However, it took another two decades before the correlation of clinical, neurophysiological, and anatomical findings provided evidence for the involvement of the mesial structures in psychomotor or temporal lobe seizures. From 1949 and onward, Penfield and his associates applied this evidence to extend the surgical resections to include the uncus and the hippocampus. CONCLUSION: The collaborative work of a team led by Penfield and Jasper at the MNI helped to define the role of neurophysiological studies in epilepsy surgery. As a result, the importance of removing the mesial structures in order to obtain better seizure control in patients with temporal lobe epilepsy became firmly established.     

立体定向热凝毁损海马杏仁核治疗海马病变所致难治性颞叶内侧癫

目的探讨立体定向手术热凝毁损海马杏仁核治疗海马病变所致难治性颞叶内侧癫癎的疗效。方法回顾分析19例由海马病变所致难治性颞叶内侧癫癎患者的临床表现、影像学（CT/MRI）脑电图（EEG/VEEG）资料和手术疗效。所有病例术前均行动态脑电图检查明确致癎灶完成定位诊断、术中行立体定向组织活检、快速冰冻病理确诊病变性质完成定性诊断。全部患者在计算机辅助下行致癎灶侧海马杏仁核立体定向热凝毁损术。手术效果按谭启富的评定标准进行评价。结果随访12～42个月，13例癫癎未再发作（满意），4例发作次数减少75%以上（明显改善），2例发作次数减少50%（改善）。未发现神经心理学改变及神经功能障碍等并发症。结论对于由海马病变所致难治性颞叶内侧癫癎，采用立体定向手术行海马杏仁核热凝毁损是控制癫癎发作的一种安全有效方法。     

伴海马硬化的颞叶内侧癫痫的外科治疗(附22例临床分析)

目的探讨伴海马硬化的颞叶内侧癫痫的手术疗效。方法对22例术前诊断伴海马硬化的颞叶癫痫患者,在术中脑电监测下行颞前叶及颞叶内侧结构切除术。结果术后病理诊断均为海马硬化。术后无重大并发症,随访均无癫痫发作。结论伴海马硬化的颞叶内侧癫痫的手术效果良好,确诊后应尽早手术治疗。     

以癫痫为首发症状的颞叶海绵状血管畸形的手术治疗方式

目的探讨以癫痫为首发症状的颞叶及颞叶内侧海绵状血管畸形的手术治疗方式。方法回顾性分析广东三九脑科医院2009~2013年手术治疗的49例以癫痫为首发症状的颞叶及颞叶内侧海绵状血管畸形患者,其中全面性强直-阵挛性发作26例,复杂部分性发作23例,20例行单纯病灶切除(A组),29例根据术中脑电监测结果,病灶及颞叶及/或内侧结构癫痫灶扩大切除术(B组)。结果采用Engel效果分级,A组中Ⅰ级为70%,Ⅱ级为20%,Ⅲ级10%;病理检查均为海绵状血管畸形。B组中Ⅰ级89.66%,Ⅱ级6.9%,Ⅲ级3.44%;病理检查为海绵状血管畸形,其中25例包括海马硬化,3例皮质发育不良。术中及术后均无明显并发症及死亡患者。结论对以癫痫为首发症状的颞叶海绵状血管畸形患者,通过积极的手术治疗可有效控制癫痫发作。结合术前及术中脑电结果,采用选择性扩大切除癫痫灶,对控制癫痫更为有效。颞叶及颞叶内侧海绵状血管畸形患者可能存在双重病理改变。     

Hypermotor seizures in patients with temporal pole lesions

Hypermotor seizures are considered to be characteristic of frontal lobe epilepsy, with only rare occurrence in temporal lobe epilepsy. After noting hypermotor seizures in several patients with lesions involving the pole of the temporal lobe, we investigated whether temporal pole lesions were associated with hypermotor seizures. We systematically reviewed medical records, MRI images and pathological findings in consecutive patients who underwent epilepsy surgery over the preceding 10 years in our institution and identified eight patients with temporal pole lesions and intractable complex partial seizures. We analyzed all recorded seizures for semiology, classifying seizures as hypermotor or typical "psychomotor." Four patients exhibited hypermotor seizure semiology and four patients manifested typical psychomotor seizure characteristics. In patients with hypermotor seizures, scalp EEG tended to demonstrate lateral anterior temporal ictal onset, with lesser involvement of the sphenoidal electrode, while the patients with psychomotor seizures had initial inferomesial temporal rhythmic theta activity. Two patients with hypermotor seizures had implanted frontal and temporal subdural grids demonstrating orbitofrontal spread before hypermotor behavior. Patients underwent either anterior temporal lobectomy or lesionectomy. All improved considerably, with six patients seizure-free since surgery. We conclude that hypermotor seizures occur frequently in patients with temporal pole lesions. A search for temporal pole pathology is recommended for patients with hypermotor seizures and temporal epileptiform discharges. Modification of the surgical approach to include this region should be considered in patients who exhibit hypermotor seizures.     

Adult absence semiology misinterpreted as mesial temporal lobe epilepsy

Correct diagnosis of seizure type and epilepsy syndrome is the foundation for appropriate antiepileptic drug selection. Inappropriate medication choices occur in the treatment of generalized epilepsy and may aggravate some seizure types, including absence seizures, potentially leading to pseudo‐drug resistance. Fortunately, a correct diagnosis of absence seizures is usually not difficult, though rarely demonstrates electroclinical overlap with focal seizures. EEG can be especially misleading when secondary bilateral synchronous discharges occur in patients with focal seizures. However, the semiology of focal seizures associated with mesial temporal lobe epilepsy has a characteristic and consistent semiology that is the mark of this common epilepsy syndrome in adulthood. We recently encountered a 53‐year‐old female with refractory seizures and a semiology strongly suggesting mesial temporal lobe epilepsy. Instead of focal seizures, prolonged absence seizures were validated by video‐EEG monitoring and she became seizure‐free after a change to broad‐spectrum antiepileptic drugs. This case further expands our understanding of the complexity of semiology in electroclinical classification and the spectrum that may occur in adult absence seizures. It serves to underscore the need for ictal EEG recordings and the importance of concordance with the clinical course during the pre‐surgical evaluation of patients with lesions and drug‐resistant epilepsy. [Published with video sequences]     

Complex partial seizures in childhood

A clinical and electroencephalographic study was undertaken on 215 children with complex partial seizures as selected on the basis of the International Classification of Epileptic Seizures (1981). Complex partial seizures were noted in 7.8% of the epileptic children. The ictal symptoms of complex partial seizures closely resembled those of psychomotor triad described by Lennox. Interictal EEG revealed seizure discharges from the temporal or frontal focus in 57.2%. There existed a group with automatism as a main symptom having both diffuse slow spike-waves and focal temporal spikes. This type should be interpreted to be one of secondary generalized epilepsies and be a variant of the Lennox syndrome.     

A case of temporal lobe epilepsy with improvement of clinical symptoms and single photon emission computed tomography findings after treatment with clonazepam

A 26-year-old female presented psychomotor seizures, deja vu and amnestic syndrome after meningitis at the age of 14 years. Repeated electroencephalograms (EEG) demonstrated occasional spikes localized in the right temporal region in addition to a considerable amount of theta waves mainly in the right fronto-temporal region. Single photon emission computed tomography (SPECT) showed a marked hypoperfusion corresponding to the region in which the EEG showed abnormal findings, although magnetic resonance imaging (MRI) demonstrated no abnormal findings associated with the clinical features. Treatment with clonazepam in addition to sodium valproate resulted in a remarkable improvement of clinical symptoms (i.e. psychomotor seizures and deja vu), as well as of the EEG and SPECT findings. The present study suggests that SPECT is a useful method not only to determine the localization of regions associated with temporal lobe epilepsy but also to evaluate the effect of treatment in temporal lobe epilepsy.     

Complex Partial Seizures in Childhood

Abstract. A clinical and electroencephalographic study was undertaken on 215 children with complex partial seizures as selected on the basis of the International Classification of Epileptic Seizures (1981).

• 1

  Complex partial seizures were noted in 7.8% of the epileptic children.
• 2

  The ictal symptoms of complex partial seizures closely resembled those of psychomotor triad described by Lennox.
• 3

  Interictal EEG revealed seizure discharges from the temporal or frontal focus in 57.2%.
• 4

  There existed a group with automatism as a main symptom having both diffuse slow spike-waves and focal temporal spikes. This type should be interpreted to be one of secondary generalized epilepsies and be a variant of the Lennox syndrome.

     

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.     

Re-examination of the value of localising aura sensations and lateralising interictal epileptiform discharges in view of structural lesions demonstrated by MRI

We examined the relationship between MRI lesions and electro-clinical findings with special attention to the localising value of aura sensations and the sides of interictal epileptiform discharges in 327 patients with symptomatic localisation-related epilepsy. As a result, while autonomic as well as psychic auras were correlated with temporal lesions, simple motor seizures were associated with extra-temporal ones. Within the group of patients with temporal lobe epilepsy, autonomic but not psychic auras concurred significantly more often with medial temporal structural lesions. Furthermore, there was a significant difference between concordance rates between sides of MRI lesions and EEG foci as a function of laterality: while the right-sided MRI lesions constantly showed ipsilateral EEG foci, EEG foci concurring with the left-sided MRI lesions proved to be often falsely lateralising. From these results, we assumed that lateral as well as medial temporal involvement is needed in the genesis of the psychic aura in contrast to the autonomic aura, which could be induced without lateral temporal involvement, and lesions in the left hemisphere are more apt to induce secondarily epileptogenic than those in the right hemisphere.     

Does the Co-occurrence of FGFR3 Gene Mutation in Hypochondroplasia,Medial Temporal Lobe Dysgenesis,and Focal Epilepsy Suggest a Syndrome?

BackgroundHypochondroplasia is a rare skeletal dysplasia characterized by disproportionately short stature, lumbar lordosis, and limited extension of the elbow caused by mutations in the fibroblast growth factor receptor 3 (FGFR3) gene that plays a role in controlling nervous system development. Hypochondroplasia with FGFR3 mutation associated with bilateral medial temporal lobe anomalies and focal epilepsy was previously reported in several patients.PatientWe report clinical, electroclinical, and neuroradiological findings of one patient affected by hypochondroplasia.ResultsClinical diagnosis was confirmed by molecular analysis of the FGFR3 gene, which showed a N540 K mutation. The patient had normal psychomotor development and showed early-onset focal seizures with left temporal localization on interictal and ictal electroencephalograph. The seizures were well controlled, and the patient has been seizure-free since infancy. Magnetic resonance imaging showed abnormal anteriorly posteriorly infolding in the hippocampus and abnormally oriented parahippocampus sulci, and additional cortical rim dysplasia with gray-white matter junction blurring in the hippocampus.ConclusionsThe present case of hypochondroplasia and FGFR3 mutation in Asn540Lys associated with characteristic abnormalities involving bilaterally medial temporal lobe structures, probable hippocampal cortex focal dysplasia, and early onset of focal epilepsy underscores the possibility of a rare syndrome.     

Hemifacial motor and crying seizures of temporal lobe onset: case report and review of electro-clinical localisation

OBJECTIVE: To report a case of temporal lobe epilepsy with clinical presentation of paroxysmal episodes of "tightness" over the right hemiface, and ictal crying, and review electroclinical localisation of this phenomenon. METHODS: Clinical semiology, neurophysiological localising tests, and epilepsy surgery outcome are reported in a subject presenting with paroxysmal right hemifacial movements and ictal crying. Pertinent past reports of somato-motor signs and ictal crying in temporal lobe epilepsy are reviewed and the findings correlated with proposed human facial cortical representation. RESULTS: Simple partial seizures caused by temporal lobe epilepsy presented with right sided tonic facial movements and ictal crying. Intracranial EEG monitoring documented a left medial temporal onset of seizures that remained asymptomatic until they propagated to the left cingulate region. Anterior temporal lobectomy with resection of the amygdala and anterior hippocampus resulted in cessation of seizures. CONCLUSIONS: This is a rare example of epileptic seizures of medial temporal onset presenting with isolated somato-motor manifestations and ictal crying. Anatomical-electrical-clinical correlations with cortical regions controlling facial movements were highly suggestive that this case represents secondary activation of "emotional" motor cortex M3 and M4 (rostral and caudal cingulate motor cortex), giving rise to focal hemifacial movements and ictal crying.     

Surgical Treatment of Epilepsy in the Comprehensive Care Program: Advantages and Considerations

Abstract: To properly establish the surgical treatment of epilepsy in the comprehensive care program, we planned a surgical strategy mainly for a temporal lobe epilepsy and have performed 60 temporal lobectomies. The surgical candidates were selected from 142 patients who met the initial criteria, and passed the initial evaluation for surgical intervention. Forty-five patients had long-term intracranial EEG recording, and circumscribed organic lesions were disclosed in 27 patients by neuroimaging techniques. The outcome of 23 patients who were followed for 2 years postoperatively was complete freedom from complex partial seizures in 17 patients (74%) and an increase in full employment from 2 to 10 patients. Despite the possible surgical complications, including detrimental effects on the higher cerebral functions, it is essential that the surgical treatment of epilepsy should be established as a part of the comprehensive care program. Our experiences and analyses of the state of the art in surgical intervention also suggest that surgical indications for more intractable patients whose social adjustment is less hopeful should be established and the surgical care system for these patients should also be planned. Furthermore, some patients may be free from recurrent seizures postoperatively, but still have difficulties in social rehabilitation. The problems for such patients remain unsolved.     

Parietal and Occipital Lobe Epilepsy: A Review

Summary: Parietal and occipital seizures have been investigated relatively little. Recent interest in seizures of frontal lobe origin has led to a definition of several well-identifiable clinical patterns of frontal lobe seizures. A similar delineation of the clinical and EEG pattern of parietal and occipital epilepsy, using modern investigations, appears appropriate, not least because the few reported series of surgical treatment in parietal and occipital epilepsy have indicated that operation may be relevant in selected cases, not only for removal of space-occupying lesions. Such a study is currently being undertaken at the National Hospital for Neurology and Neurosurgery and The Chalfont Centre for Epilepsy with the aim of developing and evaluating diagnostic criteria for these seizures. From the existing literature we can conclude that precise incidence and prevalence are largely unknown. A recent community-based study of 252 subjects with partial epileptic seizures in an epileptic population of 594, showed that parietal seizures and seizures of posterior origin each comprised 6.3% and central or sensory-motor seizures comprised 32.5% of focal seizures in the 160 cases in which seizures could be subclassified (Manford et al., 1992). This incidence seems low for occipital seizures as compared with the 1953 study by Gibbs and Gibbs, who observed occipital epileptiform activity in 8% of subjects with focal epilepsy. The most prominent clinical manifestations of parietal epilepsy are elementary sensory phenomena at the beginning of seizures and elementary visual hallucinations in occipital epilepsy. These symptoms are not associated solely with posterior hemisphere epilepsy, however, and more studies are obviously needed to define how close this relation is. Scalp EEG is frequently negative or maybe misleading; further-more, spread of epileptic discharges from the parietal and occipital lobes to frontal and temporal regions may obscure seizure origin. Because of these controversial symptoms, diagnostic criteria may be difficult to define. The wide difference in clinical and EEG manifestations between reported series of parietal and occipital epilepsy also reflects a considerable problem with patient sampling. Classification of epilepsy according to the anatomic division of the brain may be arbitrary, and it may be appropriate to define epileptic syndromes such as sensorimotor seizures or occipitotemporal seizures that cross such artificial divides.     

Correlation between inter-ictal regional cerebral blood flow and sphenoidal electrodes - recorded inter-ictal spikes in mesial temporal lobe epilepsy

Abstract

The objective of this study was to assess the reliability of the diagnosis of mesial temporal lobe epilepsy using EEG and sphenoidal electrodes. Inter-ictal 99 m Tc-HMPAO SPECT scans were registered in 21 patients with confirmed mesial temporal lobe epilepsy identified by scalp EEG and sphenoidal electrodes. Visual and quantitative SPECT analysis was performed blind to EEG data. An asymmetry index (Al) was measured from the ratio of two symmetrical regions of interest. A temporal lobe hypoperfusion was defined as an uptake reduced by 5% with respect to the contralateral region. Inter-ictal SPECT abnormalities were observed in 12 out of 21 patients (57%) from both visual and quantitative analysis (focal hypoperfusion in 11 cases, focal hyperperfusion in one case). In seven patients (33%) both visual and quantitative scintigraphy were normal. Abnormal Al was found in 11/15 patients with a high frequency of seizures and in 1/6 patients with a low frequency of seizures. The major data is that the probability to have an abnormal SPECT is statistically correlated to the frequency of the epileptic fits. The couple EEG recordings with sphenoidal electrodes and SPECT is sensitive and reliable in the diagnosis of mesial temporal lobe epilepsy. [Neurol Res 2000; 22: 674-678]     

Comparison of bitemporal and unitemporal epilepsy defined by depth electroencephalography

Of 166 consecutive patients studied with depth electroencephalography (EEG), 87 had seizures arising from one temporal lobe and 23 had seizures arising independently from each temporal lobe. We retrospectively reviewed and compared those patients with unitemporal and those with bitemporal seizures. There was no statistically significant differences between the two groups in terms of age at onset of seizures, duration of epilepsy, localization of scalp EEG abnormalities, surgical results, or pathological findings. The bitemporal group, however, had significantly fewer patients with a history of febrile seizures (p less than 0.025). Two patients with bitemporal seizures were later found to have extratemporal lesions, and one an extrahippocampal temporal lesion, on magnetic resonance scans; one patient's extratemporal lesion was resected and all habitual seizures stopped. These findings suggest that a single pathophysiological process accounts for unitemporal and some bitemporal epilepsy, but that independent onset of seizures from each temporal lobe detected by depth EEG may also indicate extratemporal foci.     

海马有病损的颞叶内侧癫(癎)手术15例临床分析

目的 探讨海马有病损的颞叶内侧癫(癎)的手术价值.方法 回顾性分析经手术治疗的15例伴有海马病损颞叶内侧癫(癎)患者.均经详细了解发作症状学、附加蝶骨电极的长程视频脑电图及颅脑磁共振等检查;经正规而详尽的术前评估,行前颞叶切除术,术后随访至少半年以上.结果 术后依据Engel分级,显效(Ⅰ级和Ⅱ级)占80.0％ (12/15)、好转(Ⅲ级)占20.0％(3/15)、无效(Ⅳ级)为0.0％.结论 颞叶内侧癫(癎)手术效果确切,是基层医院开展癫(癎)手术的理想选择.     

额叶癫癎发作的癫癎灶定位

目的 通过分析40例额叶癫痫发作患者术前定位的临床资料，探讨额叶癫痫发作的癫痫灶综合定位方法。方法 应用临床发作症状评估、MRI／CT扫描、单光子发射计算机体层摄影术(SPECT)检查、长程视频脑电图监测以及颅内电极记录等方法综合定位额叶癫痫患者的癫痫灶。结果 应用非侵袭性检查可以为45．0％的患者进行额叶癫痫灶定位；结合颅内脑电图长程记录，癫痫灶定位率可达90．0％；当影像学检查阴性时，78．9％的患者可以定位癫痫灶。结论 应用临床发作症状学评估、影像学检查、长程视频脑电图监测以及颅内脑电图长程记录相结合的综合定位方法，可以显著提高额叶癫痫发作的癫痫灶定位效果。     

Intracranial EEG in temporal lobe epilepsy.

Intracranial EEG monitoring before epilepsy surgery, while becoming less commonly performed in patients with unilateral mesial temporal lobe epilepsy, is still widely used when bilateral independent temporal lobe seizures are suspected or when extratemporal foci cannot be ruled out by noninvasive means. Additionally, many epilepsy centers are reporting excellent surgical outcome in patients with neocortical temporal lobe epilepsy, when resections are guided by intracranial EEG studies. This article reviews the indications, technical aspects, risks, and interpretation of intracranial EEG in patients with temporal lobe seizures. It also considers intracranial EEG features predictive of surgical outcome.