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.     

术前MRI检查与颞叶癫痫切除手术短期预后的关系

目的 评价术前MRI检查与难治性颞叶癫痫经过手术切除治疗后短期内预后关系. 方法 中国医科大学附属盛京医院神经外科自2009年1月至2010年12月共收治通过临床发作症状学以及视频脑电图诊断为颞叶癫痫的患者34例,按照MRI检查有无病灶分为2组,其中有病灶组18例,未发现病灶组16例.手术治疗后半年及1年,按照国际抗癫痫联盟(ILAE)术后疗效评估分类法判断2组患者不同预后情况. 结果 34例患者中术后半年达到ILAE-1级的有23例,占67.6％;术后1年达到ILAE-1级的有20例,占58.8％.其中有病灶组患者术后半年达到ILAE-1级的有16例,占88.9％;术后1年有14例,占77.8％;未发现病灶组患者术后半年达到ILAE-1级的有7例,占43.75％;术后1年有6例,占37.5％;差异均有统计学意义(P＜0.05). 结论 外科手术治疗对于颞叶难治性癫痫是一种有效的治疗方式;MRI检查阳性的颞叶癫痫患者宜积极行手术治疗.     

Beyond Pharmacotherapy: Surgical Management

Summary:  Purpose: To review the recent advances in the field of temporal lobe epilepsy (TLE) surgery.
Results: TLE surgery has recently demonstrated a highly significant superiority over optimal medical therapy in a randomized trial. Accordingly, a median rate of 70% of class I outcome (patients free of disabling seizures postoperatively) has emerged from the pooling of all data published since the early 1990s. In addition, successful TLE surgery appears likely to reduce the risk of seizure-related death. However, it remains largely underused and overly delayed, partly because of the legitimate fears of possible surgical complications, such as verbal memory deficits or failure to control seizures. Reasons for surgical failures are not completely understood, and include bitemporal, pseudotemporal, and temporal-plus epilepsies, as well as insufficient resection of the mesial temporal structures. Developing techniques such as intraoperative MRI, gamma-knife radiosurgery, and various types of cranial nerves or intracerebral chronic stimulation have the potential to alleviate part of the limitations of TLE surgery.
Conclusions: The overall benefit of surgical treatment in patients with drug-resistant TLE should encourage a more frequent and earlier referral of such patients to epilepsy surgery centers. Important progress toward higher rates of seizure-free outcome and lower morbidity remains to be made and may be obtained by taking advantage of the new available technologies.     

Temporal feature integration in the right parietal cortex

When searching for a target presented among distractors by means of Rapid Serial Visual Presentation (RSVP), participants often report the stimulus that is preceding or following the target as being the target. These so-called temporal binding errors are accompanied by high levels of confidence so that participants are bemused with the mismatch between their perceptual experience and the actual presented stimulus. By contrast with spatial binding the neural basis for temporal binding errors remains unexplored. Previous neuropsychology studies using non-spatial selective attention tasks have shown that right temporo-parietal cortex is involved in the temporal deployment of attention. Here we investigated the neural basis of temporal binding in five patients with visual extinction whose lesions involved different cortical areas in the right hemisphere, including the temporo-parietal cortex. Patients made significantly more binding errors for contralesional than ipsilesional stimuli and more binding errors than healthy controls. Incorrect binding from distractors near to the target was the most common for both patients and controls. Eye movements did not contribute to the pattern of results. These results show that right hemisphere cortical areas contribute to the accurate temporal coding of visual features.     

颞叶白质纤维束及相关结构的显微解剖学研究

目的 对颞叶白质纤维束及相关结构进行显微解剖学研究,分析其功能及临床意义.方法 选取100 g/L甲醛固定的国人成年尸体头颅标本10例(20侧大脑半球),在4～25倍手术显微镜辅助下,运用Klingler纤维剥离技术,解剖剥离大脑半球,观察颞叶白质纤维束及相关结构.结果 颞叶内存在大量复杂的白质纤维束,在侧脑室颞角周围尤为复杂.在颞角外侧由外向内依次有上纵束的垂直部、颞枕桥束、枕额下束、视辐射前中束.在颞角顶部上方由上向下依次有最外囊与外囊的颞盖部分、听辐射、钩状束、颞枕桥束出内囊的部分、部分枕额下束、前连合、视辐射前中束(包括Meyer's环)、脑脚袢、终纹.胼胝体放射组成侧脑室颞角外侧壁,其顶壁主要由尾状核尾及终纹构成,杏仁核组成颞角尖的前壁、上壁及内侧壁,海马构成侧脑室颞角的内侧壁.脑脚袢是侧脑室颞角内侧的一个重要结构.结论 颞叶内存在大量的白质纤维束,在侧脑室颞角尤为复杂,了解颞叶白质纤维束及相关结构的解剖特点,能够对颞叶部位的手术提供理论指导,减少手术并发症,降低手术致病率.     

MRI影像改变对颞叶癫痫术后疗效的影响

目的 研究颞叶癫痫(TLE)患者的MRI影像与病理结果 的相关性,分析不同MRI改变对术后疗效的影响.方法 回顾2005年1月至2008年12月在我科手术治疗且有效随访的121例TLE患者的临床资料,统计分析MRI影像改变与病理结果 的关系;根据MRI影像改变将患者分为内侧型TLE、有结构性改变的TLE和隐源性TLE,利用Engel分级将患者分为无发作组和发作组,比较不同类型TLE患者术后疗效的差异.结果 121例患者中MRI结果 阳性101例,病理结果 阳性107例,二者差异无统计学意义,具有良好的相关性.隐源性TLE患者的术后疗效较内侧型TLE和有结构性病变的TLE差,而后二者之间差异无统计学意义.结论 MRI检查对于TLE的确诊及预后判断具有重要意义.     

MRI影像改变对颞叶癫痫术后疗效的影响

目的 研究颞叶癫痫(TLE)患者的MRI影像与病理结果 的相关性,分析不同MRI改变对术后疗效的影响.方法 回顾2005年1月至2008年12月在我科手术治疗且有效随访的121例TLE患者的临床资料,统计分析MRI影像改变与病理结果 的关系;根据MRI影像改变将患者分为内侧型TLE、有结构性改变的TLE和隐源性TLE,利用Engel分级将患者分为无发作组和发作组,比较不同类型TLE患者术后疗效的差异.结果 121例患者中MRI结果 阳性101例,病理结果 阳性107例,二者差异无统计学意义,具有良好的相关性.隐源性TLE患者的术后疗效较内侧型TLE和有结构性病变的TLE差,而后二者之间差异无统计学意义.结论 MRI检查对于TLE的确诊及预后判断具有重要意义.     

Personality disorders as predictors of severe postsurgical psychiatric complications in epilepsy patients undergoing temporal lobe resections

Purpose. Psychiatric disorders emerging after temporal lobe resections are a serious problem threatening the surgical success of patients with epilepsy. The present study aims to find psychiatric predictors that would indicate patients’ risk to developing severe psychiatric complications after surgery.Methods. One hundred adult patients who had temporal lobe resections were followed prospectively over 2 years. Preoperative psychiatric diagnoses and postoperative development of the patients were documented. As a criterion of severe postoperative complication, admission to a psychiatric hospital was chosen.Results. Patients with personality disorders are at higher risk of suffering from postoperative psychiatric complications as compared with patients with other preoperative psychiatric conditions (such as depression) or with patients with no preoperative psychiatric diagnosis whatsoever.Conclusions. Personality disorders are caused by organic dispositions and negative environmental influence. They indicate a high mental vulnerability and compromise the brain’s ability to combat stress. As a consequence patients with personality disorders are prone to suffer from severe psychiatric complications after epilepsy surgery. To minimize the negative influence of personality disorders in the process of surgical interventions, psychotherapeutic efforts are needed to reduce perisurgical stress factors and to strengthen the self-efficacy and social skills of these patients.     

Selective temporal attention enhances the temporal resolution of visual perception: Evidence from a temporal order judgment task

We investigated whether attending to a particular point in time affects temporal resolution in a task in which participants judged which of two visual stimuli had been presented first. The results showed that temporal resolution can be improved by attending to the relevant moment as indicated by the temporal cue. This novel finding is discussed in terms of the differential effects of spatial and temporal attention on temporal resolution.     

Epileptic phenotype of FGFR3-related bilateral medial temporal lobe dysgenesis

Hypochondroplasia (HCH) is a skeletal dysplasia, characterized by short stature and macrocephaly. Clinical symptoms and radiological and histopathological features of HCH are similar, but milder than those seen in achondroplasia. Particularly, HCH patients with Asn540Lys mutation in the FGFR3 gene are reported to have medial temporal lobe dysgenesis and epilepsy.We report a 3-year-old girl who developed recurrent epileptic apnea, which started immediately after birth. The apneic seizures were refractory to antiepileptic medications; ictal electroencephalography showed rhythmic activity originating from the left or right temporal areas and rarely from the right frontal area. Macrocephaly was noted since birth. Neuroimaging revealed bilateral dysgenesis and hypometabolism of the medial temporal structures as well as perfusion changes in the left lateral temporofrontal areas during the ictal period. Clonazepam was initiated and acetazolamide dosage was increased at 6 months, resulting in complete seizure control after 8 months of age. Genetic analysis identified an Asn540Lys (c.1620 C > A) mutation in the FGFR3 gene. Characteristic bone findings on the lumbar spine, iliac bone, and femur were retrospectively confirmed on X-rays during infancy.This was the first report that delineated the epilepsy phenotype in FGFR3-related bilateral medial temporal lobe dysgenesis; such findings would lead to an early diagnosis and better epilepsy management.     

The importance of preoperative planning to perform safely temporal lobe surgery

Neurosurgeons should know the anatomy required for safe temporal lobe surgery approaches. The present study aimed to determine the angles and distances necessary to reach the temporal stem and temporal horn in surgical approaches for safe temporal lobe surgery by using a 3.0 T magnetic resonance imaging technique in post-mortem human brain hemispheres fixed by the Klingler method. In our study, 10 post-mortem human brain hemisphere specimens were fixed according to the Klingler method. Magnetic resonance images were obtained using a 3.0 T magnetic resonance imaging scanner after fixation. Surgical measurements were conducted for the temporal stem and temporal horn by magnetic resonance imaging, and dissection was then performed under a surgical microscope for the temporal stem. Each stage of dissection was achieved in high-quality three-dimensional images. The angles and distances to reach the temporal stem and temporal horn were measured in transcortical T1, trans-sulcal T1–2, transcortical T2, trans-sulcal T2–3, transcortical T3, and subtemporal trans–collateral sulcus approaches. The safe maximum posterior entry point for anterior temporal lobectomy was measured as 47.16 ± 5.00 mm. Major white-matter fibers in this region and their relations with each other are shown. The distances to the temporal stem and temporal horn, which are important in temporal lobe surgical interventions, were measured radiologically, and safe borders were determined. Surgical strategy and preoperative planning should consider the relationship of the lesion and white-matter pathways.     

颞下锁孔入路的实验研究

目的 探讨颞下锁孔入路的手术方法及该入路可暴露的解剖范围。方法 5具经福尔马林固定、颅内动脉灌注的新鲜尸体头颅标本,行右侧颞下入路,头位左旋70°,向后背伸15°,颅顶降低15°,于耳屏前做切口,显微镜下进行实验操作。结果 右侧颞下入路可暴露岩-斜部及岩-斜韧带、天幕裂孔和滑车神经。切开天幕游离缘可见后交通动脉、动眼神经、基底动脉顶部、大脑后动脉P1段及P1与P2的交界段和对侧的P1段。向后可暴露三叉神经,向前内方可见视神经后部的视神经-颈动脉间隙及颈动脉后间隙,颈内动脉床突上段、鞍上池、垂体柄和鞍背。向内侧可见中脑和上桥脑的前外侧部。结论 颞下锁孔入路与传统颞下入路同样可很好地暴露后循环及其周围解剖结构,适于进行手术操作。     

Temporal lobe epilepsy surgery and the quest for optimal extent of resection: a review

The efficacy of surgery to treat drug-resistant temporal lobe epilepsy (TLE) has been demonstrated in a prospective randomized trial. It remains controversial which resection method gives best results for seizure freedom and neuropsychological function. This review of 5 3 studies addressing extent of resection in surgery for TLE identified seven prospective studies of which four were randomized. There is considerable variability between the intended resection and the volumetrically assessed end result. Even leaving hippocampus or amygdalum behind can result in seizure freedom rates around 50%. Most authors found seizure outcome in selective amygdalohippocampectomy (SAH) to be similar to that of lobectomy and there is considerable evidence for better neuropsychological outcome in SAH. Studies varied in the relationship between extent of mesial resection and seizure freedom, most authors finding no positive correlation to larger mesial resection. Electrophysiological tailoring saw no benefit from larger resection in 6 of 10 studies. It must be concluded that class I evidence concerning seizure outcome related to type and extent of resection of mesial temporal lobe structures is rare. Many studies are only retrospective and do not use MRI volumetry. SAH appears to have similar seizure outcome and a better cognitive outcome than TLR. It remains unclear whether a larger mesial resection extent leads to better seizure outcome.     

Concurrent validity of Zimbardo Time Perspective Inventory profiles: A secondary analysis of data from the United Kingdom

This paper examined the association between membership in profiles based on a shortened form of the Zimbardo Time Perspective Inventory (ZTPI-S; McKay, Andretta, McGee, & Worrell, 2014) and other temporal and psychosocial variables. Participants consisted of 1620 adolescents attending high school in Northern Ireland. ZTPI-S scores had correlations with other temporal and psychosocial variables that were similar to those reported for ZTPI scores in previous studies. Four ZTPI-S profiles were identified—Balanced, Past Negative, Present Hedonistic, and Future—and results indicated that these profiles had theoretically meaningful relationships with self-esteem, self-efficacy, aggression, parental attachment, consideration of future consequences, and future temporal focus. Unlike studies of college students where the Balanced profile was related to more adaptive functioning, the Future profile was related to more adaptive functioning. Future studies are needed to establish the generalizability of these profiles and to determine if there are developmental differences in which profiles are more adaptive.     

Depression in temporal lobe epilepsy surgery patients: an FDG-PET study

PURPOSE: Depression is common in temporal lobe epilepsy (TLE) and after temporal lobectomy, and its etiology is obscure. In nonepileptic depression (including depression associated with other neurologic disorders), a consistent PET imaging finding is frontal lobe hypometabolism. Many TLE patients have hypometabolism involving frontal regions. Thus in data available from routine clinical assessments in an epilepsy surgery unit, we tested the hypothesis that the pattern of hypometabolism, particularly in the frontal lobe, may be associated with the depression seen in patients with TLE and TLE surgery. METHODS: We studied 23 medically refractory TLE patients who underwent anterior temporal lobectomy and who had preoperative FDG-PET scanning. All patients had pre- and postoperative psychiatric assessment. By using statistical parametric mapping (SPM-99), patterns of hypometabolism were compared between patients who had a preoperative history of depression (n=9) versus those who did not (n=14) and between those in whom postoperative depression developed (n=13) versus those in whom it did not (n=10). A significant region of hypometabolism was set at p<0.001 for a cluster of >or=20 contiguous voxels. RESULTS: Patients with a history of depression at any time preoperatively showed focal hypometabolism in ipsilateral orbitofrontal cortex compared with those who did not (t=4.64; p<0.001). Patients in whom depression developed postoperatively also showed hypometabolism in the ipsilateral orbitofrontal region (t=5.10; p<0.001). CONCLUSIONS: Although this study is methodologically limited, and other explanations merit consideration, orbitofrontal cortex dysfunction, already implicated in the pathophysiology of nonepileptic depression, may also be relevant to the depression of TLE and temporal lobectomy.     

Interhemispheric coupling between the posterior sylvian regions impacts successful auditory temporal order judgment

Accurate perception of the temporal order of sensory events is a prerequisite in numerous functions ranging from language comprehension to motor coordination. We investigated the spatio-temporal brain dynamics of auditory temporal order judgment (aTOJ) using electrical neuroimaging analyses of auditory evoked potentials (AEPs) recorded while participants completed a near-threshold task requiring spatial discrimination of left-right and right-left sound sequences. AEPs to sound pairs modulated topographically as a function of aTOJ accuracy over the 39-77 ms post-stimulus period, indicating the engagement of distinct configurations of brain networks during early auditory processing stages. Source estimations revealed that accurate and inaccurate performance were linked to bilateral posterior sylvian regions activity (PSR). However, activity within left, but not right, PSR predicted behavioral performance suggesting that left PSR activity during early encoding phases of pairs of auditory spatial stimuli appears critical for the perception of their order of occurrence. Correlation analyses of source estimations further revealed that activity between left and right PSR was significantly correlated in the inaccurate but not accurate condition, indicating that aTOJ accuracy depends on the functional decoupling between homotopic PSR areas. These results support a model of temporal order processing wherein behaviorally relevant temporal information - i.e. a temporal ‘stamp’ - is extracted within the early stages of cortical processes within left PSR but critically modulated by inputs from right PSR. We discuss our results with regard to current models of temporal of temporal order processing, namely gating and latency mechanisms.     

Seizure outcome after temporal lobectomy in temporal lobe cortical dysplasia

PURPOSE: To identify the temporal lobe cortical dysplasia (CD) histopathology classification subtype and determine the seizure outcome of patients who underwent temporal lobectomy with coincident CD. METHODS: We reviewed the data of 28 patients with temporal lobe epilepsy who underwent surgery with pathologically verified CD at our institution from 1990 to 2000. The seizure outcome was assessed at a minimum of 1 year after surgery according to Engel's classification. RESULTS: Of 28 patients who underwent surgery, nine (32.1%) had isolated CD, and 19 (67.9%) had CD and hippocampal sclerosis (CD&HS). Twenty-six (92.9%) patients had histopathology subtype Ia (architectural abnormalities). Twenty (71.4%) patients were seizure free (Engel class I). Favorable seizure outcome (Engel class I, II) was achieved in 26 (92.9%) patients. No difference in seizure outcome was noted between patients with CD and CD&HS. CONCLUSIONS: The most common histopathologic subtype in patients with temporal lobe CD is type Ia (architectural abnormalities). Temporal lobectomy in temporal lobe epilepsy patients with CD can achieve favorable seizure outcome.