In vivo animation of auditory-language-induced gamma-oscillations in children with intractable focal epilepsy

We determined if high-frequency gamma-oscillations (50- to 150-Hz) were induced by simple auditory communication over the language network areas in children with focal epilepsy. Four children (aged 7, 9, 10 and 16 years) with intractable left-hemispheric focal epilepsy underwent extraoperative electrocorticography (ECoG) as well as language mapping using neurostimulation and auditory-language-induced gamma-oscillations on ECoG. The audible communication was recorded concurrently and integrated with ECoG recording to allow for accurate time lock on ECoG analysis. In three children, who successfully completed the auditory-language task, high-frequency gamma-augmentation sequentially involved: i) the posterior superior temporal gyrus when listening to the question, ii) the posterior lateral temporal region and the posterior frontal region in the time interval between question completion and the patient's vocalization, and iii) the pre- and post-central gyri immediately preceding and during the patient's vocalization. The youngest child, with attention deficits, failed to cooperate during the auditory-language task, and high-frequency gamma-augmentation was noted only in the posterior superior temporal gyrus when audible questions were given. The size of language areas suggested by statistically significant high-frequency gamma-augmentation was larger than that defined by neurostimulation. The present method can provide in vivo imaging of electrophysiological activities over the language network areas during language processes. Further studies are warranted to determine whether recording of language-induced gamma-oscillations can supplement language mapping using neurostimulation in presurgical evaluation of children with focal epilepsy.     

Spatiotemporal dynamics of electrocorticographic high gamma activity during overt and covert word repetition

Language is one of the defining abilities of humans. Many studies have characterized the neural correlates of different aspects of language processing. However, the imaging techniques typically used in these studies were limited in either their temporal or spatial resolution. Electrocorticographic (ECoG) recordings from the surface of the brain combine high spatial with high temporal resolution and thus could be a valuable tool for the study of neural correlates of language function. In this study, we defined the spatiotemporal dynamics of ECoG activity during a word repetition task in nine human subjects. ECoG was recorded while each subject overtly or covertly repeated words that were presented either visually or auditorily. ECoG amplitudes in the high gamma (HG) band confidently tracked neural changes associated with stimulus presentation and with the subject's verbal response. Overt word production was primarily associated with HG changes in the superior and middle parts of temporal lobe, Wernicke's area, the supramarginal gyrus, Broca's area, premotor cortex (PMC), primary motor cortex. Covert word production was primarily associated with HG changes in superior temporal lobe and the supramarginal gyrus. Acoustic processing from both auditory stimuli as well as the subject's own voice resulted in HG power changes in superior temporal lobe and Wernicke's area. In summary, this study represents a comprehensive characterization of overt and covert speech using electrophysiological imaging with high spatial and temporal resolution. It thereby complements the findings of previous neuroimaging studies of language and thus further adds to current understanding of word processing in humans.     

Motor speech perception modulates the cortical language areas

Traditionally, the left frontal and parietal lobes have been associated with language production while regions in the temporal lobe are seen as crucial for language comprehension. However, recent evidence suggests that the classical language areas constitute an integrated network where each area plays a crucial role both in speech production and perception. We used functional MRI to examine whether observing speech motor movements (without auditory speech) relative to non-speech motor movements preferentially activates the cortical speech areas. Furthermore, we tested whether the activation in these regions was modulated by task difficulty. This dissociates between areas that are actively involved with speech perception from regions that show an obligatory activation in response to speech movements (e.g. areas that automatically activate in preparation for a motoric response). Specifically, we hypothesized that regions involved with decoding oral speech would show increasing activation with increasing difficulty. We found that speech movements preferentially activate the frontal and temporal language areas. In contrast, non-speech movements preferentially activate the parietal region. Degraded speech stimuli increased both frontal and parietal lobe activity but did not differentially excite the temporal region. These findings suggest that the frontal language area plays a role in visual speech perception and highlight the differential roles of the classical speech and language areas in processing others' motor speech movements.     

Productive and perceptive language reorganization in temporal lobe epilepsy

The aim of this work was to determine whether productive and perceptive language functions are differentially affected in homogeneous groups of epilepsy patients with right and left temporal lobe epilepsy (TLE). Eighteen patients with left TLE, 18 with right TLE, and 17 healthy volunteers were studied using fMRI during performance of three tasks assessing the productive and perceptive aspects of language (covert semantic verbal fluency, covert sentence repetition, and story listening). Hemispheric dominance for language was calculated in the frontal and temporal regions using laterality indices (LI). Atypical lateralization was defined as a right-sided LI (LI<-0.20) in the frontal lobes during the verbal fluency task or in the temporal lobes during the story listening task. Control subjects and right TLE patients demonstrated a strong left lateralization for language in the frontal lobes during the fluency task, whereas activation was less lateralized to the left hemisphere in left TLE patients, although the difference did not reach significance. In the story listening and the repetition tasks, activation was significantly more right sided in the temporal lobes of patients with left TLE. Atypical language representation was found in 19% of TLE patients (five left and two right TLE). The shift toward the right hemisphere was significantly larger in the temporal than the frontal lobes in patients with atypical language lateralization compared to TLE patients with a typical language lateralization. Neuropsychological performances of patients with atypical language patterns were better than those of patients with typical patterns, suggesting that this reorganization may represent a compensatory mechanism.     

Strengthened functional connectivity in the brain during muscle fatigue

By combining language functional magnetic resonance imaging and voxel-based morphometry in patients with left-sided mesial temporal lobe epilepsy and hippocampal sclerosis, we studied whether atypical language dominance is associated with temporal and/or extratemporal cortical changes. Using verbal fluency functional magnetic resonance imaging for language lateralisation, we identified 20 patients with left-sided mesial temporal lobe epilepsy with hippocampal sclerosis and atypical language lateralisation. These patients were compared with a group of 20 matched left-sided mesial temporal lobe epilepsy patients who had typical language lateralisation. Using T1-weighted 3D images of all patients and voxel-based morphometry, we compared grey matter volumes between the groups of patients. We also correlated grey matter volumes with the degree of atypical language activation. Patients with atypical language lateralisation had increases of grey matter volumes, mainly within right-sided temporo-lateral cortex (x = 59, y = − 16, z = − 1, T = 6.36, p < .001 corrected), and less significantly within frontal brain regions compared to patients with typical language lateralisation. The degree of atypical fronto-temporal language activation (measured by lateralisation indices and relative functional magnetic resonance imaging activity) was correlated with right-sided temporal and frontal grey matter volumes. Patients with atypical language lateralisation did not differ in terms of language performance from patients with typical language dominance. Atypical language lateralisation in patients with left-sided mesial temporal lobe epilepsy was associated with increased grey matter volume within the non-epileptic right temporal and frontal lobe. Grey matter increases associated with atypical language might represent morphological changes underlying functional reorganisation of the language network. This hard-wired reorganised atypical language network seems to be suitable to support language functions.     

Generators of the intracranial P50 response in auditory sensory gating

Clarification of the cortical mechanisms underlying auditory sensory gating may advance our understanding of brain dysfunctions associated with schizophrenia. To this end, data from nine epilepsy patients who participated in an auditory paired-click paradigm during pre-surgical evaluation and had grids of electrodes covering temporal and frontal lobe were analyzed. A distributed source localization approach was applied to the intracranial P50 response and the Gating Difference Wave obtained by subtracting the response to the second stimuli from the response to the first stimuli. Source reconstruction of the P50 showed that the main generators of the response were localized in the temporal lobes. The analysis also suggested that the maximum neuronal activity contributing to the amplitude reduction in the P50 time range (phenomenon of auditory sensory gating) is localized at the frontal lobe. Present findings suggest that while the temporal lobe is the main generator of the P50 component, the frontal lobe seems to be a substantial contributor to the process of sensory gating as observed from scalp recordings.     

Abnormal processing of speech during oddball target detection in schizophrenia

Healthy subjects show increased activation in left temporal lobe regions in response to speech sounds compared to complex nonspeech sounds. Abnormal lateralization of speech-processing regions in the temporal lobes has been posited to be a cardinal feature of schizophrenia. Event-related fMRI was used to test the hypothesis that schizophrenic patients would show an abnormal pattern of hemispheric lateralization when detecting speech compared with complex nonspeech sounds in an auditory oddball target-detection task. We predicted that differential activation for speech in the vicinity of the superior temporal sulcus would be greater in schizophrenic patients than in healthy subjects in the right hemisphere, but less in patients than in healthy subjects in the left hemisphere. Fourteen patients with schizophrenia (selected from an outpatient population, 2 females, 12 males, mean age 35.1 years) and 29 healthy subjects (8 females, 21 males, mean age 29.3 years) were scanned while they performed an auditory oddball task in which the oddball stimuli were either speech sounds or complex nonspeech sounds. Compared to controls, individuals with schizophrenia showed greater differential activation between speech and nonspeech in right temporal cortex, left superior frontal cortex, and the left temporal-parietal junction. The magnitude of the difference in the left temporal parietal junction was significantly correlated with severity of disorganized thinking. This study supports the hypothesis that aberrant functional lateralization of speech processing is an underlying feature of schizophrenia and suggests the magnitude of the disturbance in speech-processing circuits may be associated with severity of disorganized thinking.     

Attentional and linguistic interactions in speech perception

The role of attention in speech comprehension is not well understood. We used fMRI to study the neural correlates of auditory word, pseudoword, and nonspeech (spectrally rotated speech) perception during a bimodal (auditory, visual) selective attention task. In three conditions, Attend Auditory (ignore visual), Ignore Auditory (attend visual), and Visual (no auditory stimulation), 28 subjects performed a one-back matching task in the assigned attended modality. The visual task, attending to rapidly presented Japanese characters, was designed to be highly demanding in order to prevent attention to the simultaneously presented auditory stimuli. Regardless of stimulus type, attention to the auditory channel enhanced activation by the auditory stimuli (Attend Auditory>Ignore Auditory) in bilateral posterior superior temporal regions and left inferior frontal cortex. Across attentional conditions, there were main effects of speech processing (word+pseudoword>rotated speech) in left orbitofrontal cortex and several posterior right hemisphere regions, though these areas also showed strong interactions with attention (larger speech effects in the Attend Auditory than in the Ignore Auditory condition) and no significant speech effects in the Ignore Auditory condition. Several other regions, including the postcentral gyri, left supramarginal gyrus, and temporal lobes bilaterally, showed similar interactions due to the presence of speech effects only in the Attend Auditory condition. Main effects of lexicality (word>pseudoword) were isolated to a small region of the left lateral prefrontal cortex. Examination of this region showed significant word>pseudoword activation only in the Attend Auditory condition. Several other brain regions, including left ventromedial frontal lobe, left dorsal prefrontal cortex, and left middle temporal gyrus, showed Attention x Lexicality interactions due to the presence of lexical activation only in the Attend Auditory condition. These results support a model in which neutral speech presented in an unattended sensory channel undergoes relatively little processing beyond the early perceptual level. Specifically, processing of phonetic and lexical-semantic information appears to be very limited in such circumstances, consistent with prior behavioral studies.     

Language lateralization in patients with temporal lobe epilepsy: a comparison of functional transcranial Doppler sonography and the Wada test

This study prospectively investigates whether noninvasive functional transcranial Doppler sonography (fTCD) is a useful tool to determine hemispheric language lateralization in the presurgical evaluation of patients with medically intractable temporal lobe epilepsy (TLE). fTCD results were compared with the Wada test as the gold standard. Wada test and fTCD were performed in 13 patients suffering from TLE. fTCD continuously measured blood flow velocities in both middle cerebral arteries, while the patient was performing a cued word generation task. During the Wada test, spontaneous speech, comprehension, reading, naming, and repetition were investigated. A laterality index (LI) was obtained by both procedures. Due to a lack of an acoustic temporal bone window, fTCD could not be performed in two patients (15%). In 9 of the remaining 11 patients hemispheric language dominance was found on the left side, in 1 patient on the right side, and 1 patient showed bihemispheric language representation. In all patients fTCD and the Wada test were in good agreement regarding hemispheric language lateralization, and the LI of both techniques were highly correlated (r = 0.776, P = 0.005). fTCD gives predictions of hemispheric language dominance consistent with the Wada test results even in children, patients with low IQ, and nonnative speakers. It is an alternative to the Wada test in determining language lateralization in patients with temporal lobe epilepsy.     

督脉取穴针刺联合Schuell语言康复训练对脑卒中后失语症患者言语功能、MoCA评分及语言中枢活动功能的影响

目的探讨督脉取穴针刺联合Schuell语言康复训练对脑卒中后失语症患者言语功能、MoCA评分及语言中枢活动功能的影响。方法前瞻性选取2018年3月至2019年3月贵州中医药大学第二附属医院收治的96例脑卒中后失语症患者,按随机数字表法分为对照组和治疗组,每组各48例。对照组单纯进行Schuell语言康复训练,治疗组在对照组基础上采取督脉取穴针刺治疗。比较2组患者临床疗效、言语功能、认知功能及语言中枢活动功能。结果治疗后,治疗组总有效率(91.67%)高于对照组(75.00%),差异有统计学意义(P<0.05)。2组患者言语功能及蒙特利尔认知评估量表(MoCA)评分均较治疗前升高,差异有统计学意义(P<0.05),且治疗组言语功能及MoCA评分[(138.15±6.85)、(22.93±4.71)分]均高于对照组[(85.21±6.07)、(18.19±5.06)分],差异均有统计学意义(P<0.05)。治疗组右侧梭状回、右侧额下回、右侧内侧颞叶、左侧楔前叶、左侧额上回、左侧小脑的局部一致性值与对照组相比均较高(P<0.05),左侧颞下回、右侧舌回、右侧中央前回的局部一致性值与对照组相比较低(P<0.05)。结论对脑卒中后失语患者进行督脉取穴针刺联合Schuell语言康复训练治疗,疗效显著,对患者言语功能及认知功能改善作用明显。其原因和有效调节右侧梭状回、右侧额下回、左侧楔前叶、左侧额上回、左侧颞下回、右侧舌回、右侧中央前回等脑区有关。     

视频脑电图与皮层脑电图在顽固性癫痫手术中的比较分析

目的探讨顽固性癫痫外科术前与术中癫痫病灶定位的异同及手术方式的选择。方法 2002年7月2009年10月收治复杂、部分发作的顽固性癫痫78例。术前癫痫病灶定位主要采用头MRI及24h视频脑电图检查,癫痫病灶局限于颞叶31例,颞叶、额叶47例。术中行24导皮层脑电图监测进一步定位癫痫病灶,并在其指导下联合多种癫痫术式完成手术。结果术前视频脑电图检查定位癫痫病灶与术中皮层脑电图监测定位具有高度一致性,但后者定位范围较前者有扩大。结论术中皮层脑电图监测证实并进一步精确定位癫痫病灶范围,以及在指导手术切除癫痫病灶范围,癫痫术式选择方面具有重要意义。     

Neural mechanisms underlying auditory feedback control of speech

The neural substrates underlying auditory feedback control of speech were investigated using a combination of functional magnetic resonance imaging (fMRI) and computational modeling. Neural responses were measured while subjects spoke monosyllabic words under two conditions: (i) normal auditory feedback of their speech and (ii) auditory feedback in which the first formant frequency of their speech was unexpectedly shifted in real time. Acoustic measurements showed compensation to the shift within approximately 136 ms of onset. Neuroimaging revealed increased activity in bilateral superior temporal cortex during shifted feedback, indicative of neurons coding mismatches between expected and actual auditory signals, as well as right prefrontal and Rolandic cortical activity. Structural equation modeling revealed increased influence of bilateral auditory cortical areas on right frontal areas during shifted speech, indicating that projections from auditory error cells in posterior superior temporal cortex to motor correction cells in right frontal cortex mediate auditory feedback control of speech.     

母语为汉语中国人语言区的皮质电刺激研究

目的 研究母语为汉语中国人语言区的构筑特点.方法 回顾性分析手术治疗20例优势半球语言区低级别胶质瘤.在唤醒麻醉下应用术中皮质电刺激确定语言区.结果 16例患者至少发现1个以上语言阳性部位,3例患者仅额叶有语言阳性部位,1例患者仅颞叶有语言阳性部位.语言阳性部位主要分布在侧裂周围,额下回语言阳性部位基本符合经典的Broca区;颞上回语言阳性部位明显多于颞中回.结论 个体之间语言阳性部位的分布存在较大变异,经典的语言-解剖模式需要改进.由于患者例数太少,目前的数据尚不能完全反映母语为汉语中国人语言区的构筑特点.     

Functional segregation of the temporal lobes into highly differentiated subsystems for auditory perception: an auditory rapid event-related fMRI-task

With this study, we explored the blood oxygen level-dependent responses within the temporal lobe to short auditory stimuli of different classes. To address this issue, we performed an attentive listening event-related fMRI study, where subjects were required to concentrate during the presentation of different types of stimuli. Because the order of stimuli was randomized and not predictable for the subject, the observed differences between the stimuli types were interpreted as an automatic effect and were not affected by attention. We used three types of stimuli: tones, sounds of animals and instruments, and words. We found in all cases bilateral activations of the primary and secondary auditory cortex. The strength and lateralization depended on the type of stimulus. The tone trials led to the weakest and smallest activations. The perception of sounds increased the activated network bilaterally into the superior temporal sulcus mainly on the right and the perception of words led to the highest activation within the left superior temporal sulcus as well as in left inferior frontal gyrus. Within the left temporal sulcus, we were able to distinguish between different subsystems, showing an extending activation from posterior to anterior for speech and speechlike information. Whereas posterior parts were involved in analyzing the complex auditory structure of sounds and speech, the middle and anterior parts responded strongest only in the perception of speech. In summary, a functional segregation of the temporal lobes into several subsystems responsible for auditory processing was visible. A lateralization for verbal stimuli to the left and sounds to the right was already detectable when short stimuli were used.     

间期痫样发放对内侧颞叶癫痫脑网络的影响

目的探讨间期痫样发放对内侧颞叶癫痫患者脑静息态网络的影响,揭示间期癫痫活动发放对全脑功能的损害机制。材料与方法从45例行同步脑电f MRI数据采集单侧颞叶癫痫患者中,挑选35例(左侧颞叶癫痫患者18例、右侧颞叶癫痫患者17例),以同步脑电图监测,每一患者均采集间期痫样发放及无痫样发放状态静息态f MRI数据。采用独立成分分析方法,分别提取患者两种状态的核心网络、背侧注意网络、执行控制网络、默认网络及感觉运动网络等7套内在连接网络。采用配对t检验比较痫样发放及无痫样发放状态m TLE患者脑内在连接网络的差异。结果相比未发放状态,发放状态下颞叶癫痫患者核心网络的前扣带回功能连接增强,听觉网络的脑岛及颞上回功能连接减低。此外,背侧注意网络的顶上小叶在左侧颞叶癫痫患者表现为功能连接增强,而在右侧表现为连接减弱。前默认网络的额中回在右侧表现为功能连接减弱,而后默认网络颞中回及后扣带回在右侧表现为功能连接增强。执行控制网络的中扣带回和视觉网络枕叶皮层在左侧表现为功能连接增强。相关分析结果显示,左侧组视觉网络及右侧组听觉网络内连接强度的变化与发放状态下IEDs发放次数呈正相关。结论内侧颞叶癫痫发作间期痫样发放对脑高级认知网络及感知觉网络均产生了广泛影响,尤其是对参与脑高级认知功能网络的损害,这有助于进一步了解海马硬化这一特异性内侧颞叶癫痫在发作间期脑功能受损机制。     

Resting functional MRI with temporal clustering analysis for localization of epileptic activity without EEG

We report on the methods and initial findings of a novel noninvasive technique, resting functional magnetic resonance imaging (fMRI) with temporal clustering analysis (TCA), for localizing interictal epileptic activity. Nine subjects were studied including six temporal lobe epilepsy (TLE) patients with confirmed localization indicated by successful seizure control after resection. The remaining three subjects had standard presurgical evaluations with inconsistent results or suspected extratemporal lobe foci. Peaks of activity, presumably epileptic, were detected in all nine subjects, using the resting functional MRI with temporal clustering analysis. In all six patients who underwent resective surgery, the fMRI with temporal clustering analysis accurately determined the epileptogenic hippocampal hemisphere (P = 0.005). In the three subjects without confirmed localization, the technique determined regions of activity consistent with those determined by the presurgical assessments. Though more studies are required to validate this technique, the results demonstrate the potential of the resting fMRI with temporal clustering technique to detect and localize epileptic activity without the need for simultaneous electroencephalography (EEG). The greatest potential benefit of this technique will be in the evaluation of patients with suspected extratemporal lobe epilepsy and patients whose standard assessments are discordant.     

无灶性癫痫静息态功能MRI的功能连接研究

目的应用静息态功能MRI(rs-f MRI)功能连接方法(FC)研究无灶性癫痫(NLE)的脑功能改变,探论FC对NLE的应用价值。加深对NLE病理生理机制的理解,为其诊断及治疗提供可靠的理论依据。材料与方法对43例NLE患者和46例性别、年龄、教育程度及利手相匹配的健康志愿者(对照组),采用3.0 T超导MR扫描仪进行静息态功能序列扫描,然后将病例组与对照组分别进行FC分析,再对ALFF分析结果进行两样本t检验分析,并分析FC统计脑图与病程的相关性。结果与正常对照组相比,病例组右侧海马FC增加的脑区位于右颞上回、左颞下回、双颞中回、双前额内侧回,右额中回;左侧海马FC增加的脑区位于双颞上回、左海马旁回、左额叶、右前额内侧回、左顶下小叶、右中央后回。右侧海马FC降低的脑区位于左内囊膝、左顶下小叶、右扣带回、左额上回、左额叶;左侧海马降低的脑区位于右小脑后叶、左小脑前叶、右颞上回、右丘脑。病例组右侧海马FC病程正相关的脑区位于:左额下回、左颞下回、左颞上回、右额叶、右楔前叶、右顶叶、右顶下小叶、右额中回;左侧海马FC与病程正相关的脑区位于左舌回、双额中回、左顶下小叶、右中央后回。病例组右侧海马FC与病程呈负相关的脑区位于左小脑前叶、左内囊膝;病例组左侧海马FC与病程负相关的脑区位于左小脑扁桃体、左额上回、右颞上回、左楔前叶。结论 ALFF和FC方法可作为一种无创的脑功能研究方法,能检测出NLE静息态脑功能变化,了解与临床变量(病程)的相关性,为癫痫的病理生理机制研究提供可靠的理论依据。     

Mapping anterior temporal lobe language areas with fMRI: a multicenter normative study

Removal of the anterior temporal lobe (ATL) is an effective surgical treatment for intractable temporal lobe epilepsy but carries a risk of language and verbal memory deficits. Preoperative localization of functional zones in the ATL might help reduce these risks, yet fMRI protocols in current widespread use produce very little activation in this region. Based on recent evidence suggesting a role for the ATL in semantic integration, we designed an fMRI protocol comparing comprehension of brief narratives (Story task) with a semantically shallow control task involving serial arithmetic (Math task). The Story > Math contrast elicited strong activation throughout the ATL, lateral temporal lobe, and medial temporal lobe bilaterally in an initial cohort of 18 healthy participants. The task protocol was then implemented at 6 other imaging centers using identical methods. Data from a second cohort of participants scanned at these centers closely replicated the results from the initial cohort. The Story-Math protocol provides a reliable method for activation of surgical regions of interest in the ATL. The bilateral activation supports previous claims that conceptual processing involves both temporal lobes. Used in combination with language lateralization measures, reliable ATL activation maps may be useful for predicting cognitive outcome in ATL surgery, though the validity of this approach needs to be established in a prospective surgical series.     

A cerebral network model of speech prosody comprehension

Comprehension of information conveyed by the tone of voice is highly important for successful social interactions (Grandjean et al., 2006). Based on lesion data, a superiority of the right hemisphere for cerebral processing of speech prosody has been assumed. According to an early neuroanatomical model, prosodic information is encoded within distinct right-sided perisylvian regions which are organized in complete analogy to the left-sided language areas (Ross, 1981). While the majority of lesion studies are in line with the assumption that the right temporal cortex is highly important for the comprehension of speech melody (Adolphs et al., 2001; Borod et al., 2002; Heilman et al., 1984), some studies indicate a widespread network of partially bilateral cerebral regions to contribute to prosody processing including the frontal cortex (Adolphs et al., 2002; Hornak et al., 2003; Rolls, 1999) and the basal ganglia (Cancellieve & Kertesz, 1990; Pell & Leonard, 2003). More recently, functional imaging experiments have helped to differentiate specific functions of distinct brain areas contributing to recognition of speech prosody (Ackermann et al., 2004; Schirmer & Kotz, 2006; Wildgruber et al., 2006). Observations in healthy subjects indicate a strong association of cerebral responses and acoustic voice properties in some regions (stimulus-driven effects), whereas other areas show modulation of activation linked to the focusing of attention to specific task components (task-dependent effects). Here we present a refined model of prosody processing and cross-modal integration of emotional signals from face and voice which differentiates successive steps of cerebral processing involving auditory analysis and multimodal integration of communicative signals within the temporal cortex and evaluative judgements within the frontal lobes.     

Voxel-by-voxel comparison of automatically segmented cerebral gray matter--A rater-independent comparison of structural MRI in patients with epilepsy.

Quantitative evaluation of MRI in patients with epilepsy can give more information than qualitative assessment. Previously developed volume-of-interest-based methods identified subtle widespread structural changes in the neocortex beyond the visualized lesions in patients with malformations of cortical development (MCD) and hippocampal sclerosis (HS) and also in MRI-negative patients with juvenile myoclonic epilepsy (JME). This study evaluates a voxel-based automated analysis of structural MRI in epilepsy. After fully automated segmentation of cerebral gray matter from structural T1-weighted, high-resolution MRI scans, we applied the automated and objective technique of statistical parametric mapping (SPM) to the analysis of gray matter of 35 control subjects, 10 patients with partial seizures and MCD, 10 patients with left temporal lobe epilepsy (TLE) and HS, 10 patients with left TLE and normal MR quantitation of the hippocampus, and 20 patients with JME. At a corrected threshold of P < 0.05, significant abnormalities were found in 3/35 controls; in all 10 patients with MCD, 6 of whom had additional lesions beyond the margins of the visualized abnormalities; in 2/10 TLE patients with HS; in 2/10 MRI-negative TLE; and in 4/20 JME patients. Group comparisons between control subjects and HS patients identified the affected left temporal lobe with an increase in gray matter in the posterior temporal lobe, but did not identify hippocampal atrophy. The group of MRI-negative TLE patients showed no abnormalities compared with control subjects. Group comparison between control subjects and JME patients identified a mesial frontal increase in gray matter. The SPM-based voxel-by-voxel comparison of gray matter distribution identified MCD and abnormalities beyond the visualized lesion in individual MCD patients. The method did not reliably identify HS in individual patients or identify abnormalities in individual MRI-negative patients with TLE or JME in a proportion larger than the chance findings in the control group. Using group comparisons, structural abnormalities in the neocortical gray matter of patients with TLE and HS were lateralized to the affected temporal lobe. In patients with JME as a group, an increase in gray matter was localized to the mesial frontal area, corroborating earlier quantitative MRI findings.