Sexual differences in functional hemispheric asymmetry: verbal tachistoscopic evaluation using microcomputers]

Study of sexual differences for the hemispheric prevalence on visual verbal stimuli using a microcomputer-based tachistoscope technic. Seventeen right-handed individuals, 10 males and 7 females (mean age 32 years old), without neurological or visual abnormalities were studied. The subjects performed a verbal trigram tachistoscope test, using a IBM PC microcomputer compatible. The trigram consists of 80 consonant-vowel-consonant pairs of stimuli presented randomly to right and left visual fields. The evaluation was made through two conditions: T1 and T2. In T1 Experiment stimuli exposition time was 260 ms, and in T2 Experiment the stimuli exposition time was 160 ms. In T1 Experiment 80% of females showed a Right Hemispherical Preference while 100% of males showed a Left Hemispherical Preference. In T2 Experiment, both sexes showed Left Hemispheric Preference. A close relationship between sexual difference and hemispheric preference was found. We point out the importance of stimuli exposition time in determination of sexual differences in lateral hemispherical asymmetry.     

Differences in hemispheric asymmetry between dyslexic and normal children on a lateralised lexical decision task

The present experiment was conducted in order to further investigate the relationship between deficits in left hemisphere processing and phonetic decoding in dyslexic children. We administered a lateralised lexical decision task that manipulated wordness, length, and word regularity of grapheme-phoneme conversion. Right-handed male dyslexic children and normal control children were presented with words and pronounceable nonwords. Although there were no overall differences in hemispheric asymmetry between the groups, they did differ in laterality effects in accuracy when responding to nonwords and to phonetically regular words, with the normal children showing the right visual field advantage/ sensitivity (left hemisphere dominance/sensitivity), while the dyslexics failed to show any visual field advantage or sensitivity for these stimuli. Further, group differences were observed in left but not right hemisphere functioning. The results suggest that deficits in left hemisphere processing are apparent only when the dyslexics are attempting to utilise the rules of phonics. Support for the use of this paradigm for use with dyslexic children is also discussed.     

Reading disorders in children with partial epilepsy

This study represents a neuropsychological evaluation of reading ability in children with partial epilepsy (PE), aged 7-14 years, of normal intelligence, without neurological deficits and physical handicaps, appropriate environment stimulation and learning opportunities. A control group consisted of 202 healthy school children. Reading disabilities were significantly more frequent in children with partial epilepsy, especially in patients with PE with complex symptomatology. The children from the control group had better results of the tests of both verbal and performance intelligence, but children with reading disabilities had greater performance IQ than verbal IQ. Significant intergroup difference was related to the children aged 7-10 years. Positive evidence of left dominant hemisphere superiority for reading has been shown. Dyslexia was significantly more frequent in patients with left hemisphere epileptic foci, than in those with right hemisphere focal EEG changes.     

Drug-resistant epilepsy in children with partial onset epilepsy treated with carbamazepine

Objective: To evaluate the outcome, including drug-resistant epilepsy (DRE) in children with newly diagnosed partial onset epilepsy treated with carbamazepine (CBZ). Methods: A retrospective medical records review and telephone questionnaire were undertaken on a total of 100 subjects. Results: Long-term follow-up was obtained on 79 children with a mean duration of 7.1 years from CBZ initiation. A total of 66 (83.5%) subjects achieved 2-year seizure remission, 48 (72.7%) subjects did so with CBZ monotherapy. Seven (10.6%) had seizure recurrence after 2-year seizure remission. DRE was diagnosed in seven (8.9%) subjects and five subjects had epilepsy surgery. The mean duration from seizure onset to epilepsy surgery was 5.3 (±2.1) years. Contributing factors for the prolonged duration from seizure onset to epilepsy surgery were identified including: relapsing–remitting course of seizure, family reluctance for epilepsy surgery and uncontrolled psychological problems. Conclusions: Over 80% of children with newly diagnosed partial onset epilepsy who were initially treated with CBZ achieved 2-year seizure remission, and more than 70% of this group did so with CBZ monotherapy. The majority of these patients maintained seizure remission overtime. However, 8.9% of this population met the criteria for DRE and most of them had epilepsy surgery. The duration from seizure onset to epilepsy surgery is an important potential area for improvement in DRE patient care.     

Correlation between interictal cerebral glucose hypometabolism and IQ in children with epilepsy

The aim of this study was to understand the relationship between IQ and glucose metabolism in brain cells in a wide variety of subjects with epilepsy. The study participants were 78 children with epilepsy and 15 healthy children for comparison. All participants were administered the Chinese Wechsler Intelligence Scale for Children (C-WISC). The verbal intelligence quotient (VIQ), performance intelligence quotient (PIQ), and full-scale intelligence quotient (FIQ) were compared between children with epilepsy and typically developing children. Seventy-eight patients underwent interictal positron emission computed tomography (PET) using 2-deoxy-2[¹⁸F]fluoro-d-glucose (FDG) as the tracer for evaluating brain glucose metabolism. Verbal intelligence quotient, PIQ, and FIQ based on the C-WISC were significantly lower in children with epilepsy than those in the healthy comparison group (P < 0.001, P = 0.001, and P < 0.001, respectively). The IQ of patients with normal metabolism, unifocal abnormal hypometabolism, and multifocal abnormal hypometabolism determined by PET differed significantly. The extent of the abnormal hypometabolism was negatively correlated with the FIQ (rs = − 0.549, P < 0.001). In patients with lateralized hypometabolism based on PET, the VIQ/PIQ discrepancy scores (|VIQ − PIQ| ≥ 15 points) differed significantly between the left hemisphere abnormal hypometabolism and right hemisphere abnormal hypometabolism subgroups, with negative values in the left and positive values in the right subgroups (P = 0.004). In conclusion, brain metabolic abnormalities are correlated with IQ, and performing interictal PET along with C-WISC can better assess the extent of severity of cognitive impairment and VIQ/PIQ discrepancy.     

The gaze and functional hemispheric activation in normal subjects

The aim of this work was to determine whether the study of lateral and vertical conjugated eye movement could serve as an indicator of the functional hemispheric activation. Questions of vocabulary, calculation, logic (V.C.L.) and visuo-spatial instructions, as well as music-listening (V.S.M.), were proposed to 60 control subjects (21 men, 39 women). They were divided in 4 groups of 15 according to their laterality (complete right handed, incomplete right handed, ambidextrous, left handed). Eye movements were recorded using a video system. Deviations of the eyes towards the right and left, upwards and downwards, as well as episodes of staring were noted. Concerning V.C.L. questions, there was a significant correlation between conjugated lateral eye movements and the contralateral hemisphere activation. The study of vertical eye movements revealed a correlation only in complete right-handed and left-handed subjects: deviation upwards during the left hemisphere activation, and downwards during the right hemisphere activation. This pattern of response was no longer found during V.S.M. questions which, in the 4 groups, evoked staring episodes in 56 to 72 per cent of the cases. The negative emotional stimuli (emotional words, non verbal stimuli, stressful situations) evoked preferentially, but independently of laterality, deviations towards the left and downwards in favor of the right hemisphere activation. This method of observation of eye movements seems therefore of significant interest in Neuropsychology, provided that methodologic rules are rigorously respected.     

Long-term outcomes of epilepsy surgery in school-aged children with partial epilepsy

The pediatric epileptic spectrum and seizure control in surgical patients have been defined in developed countries. However, corresponding data on school-aged children from developing countries are insufficient. We summarized epileptic surgical data from four centers in China, to compare surgical outcomes of school-aged children with intractable partial epilepsy from China and those from developed countries, and introduce surgical candidate criteria. Data from 206 children (aged 6-14 years) undergoing surgical resection for epilepsy between September 2001 and January 2007 were selected. Postoperative freedom from seizures was achieved in 173 cases (84.0%) at 1 year, 149 (72.3%) at 3 years, and 139 (67.5%) at 5?years. Patients with focal magnetic resonance imaging abnormalities and a short history of seizure were most likely to become seizure-free postoperatively. Those with preoperative low intelligence quotients who became seizure-free postoperatively achieved improvements in full memory quotients, intelligence quotients, and overall quality of life at 2 years. Significant differences were evident in mean changes of full intelligence quotient, full memory quotient, and overall quality of life between patients with preoperative low intelligence quotients who received corpus callosotomies and those with a normal preoperative intelligence quotient, and between seizure-free children and those with continual seizures.     

Speech and school performance in children with benign partial epilepsy with centro-temporal spikes (BCECTS)

PurposeTo assess prospectively language and speech ability in children with benign partial epilepsy with centro-temporal spikes (BCECTS). To evaluate academic performance and social competencies both during the active disease and after remission.MethodsRight-handed school children with typical BCECTS and a control group matched by age, sex, handedness and socioeconomic status were examined. The German version of WISC-R, the “Tübinger Luria Christensen Neuropsychological Test Set for children” (TÜKI), the “Verbal Learning Memory Test” (VLMT), the “Heidelberger Speech Development Test-second edition” (HSET), and the “Salzburger reading and writing test” (SLRT) were applied. The Child Behavior Checklist (CBCL) and a semi-structured interview were performed with the children's teachers to gain insight into school performance, behavioral and emotional problems.ResultsDuring the active phase, the patient group – despite normal global intellectual abilities – showed few, but significant impairments both in expressive speech and in receptive and expressive vocabulary. A significant deficit in the ability to recognize and express interpersonal relations was also found. Patients’ teachers stated deficits concerning academic performance and complained about disturbing behavior. Parents reported significantly more psycho-pathological features in the subscales “Aggressive Behavior”, “Attention Problems” and “Anxious/Depressed” of the CBCL. Results were independent of medication and spike localization.After complete recovery from BCECTS, these problems were not found any more.ConclusionsBoth deficits of speech-related abilities (in both expressive and receptive vocabulary) and behavioral disturbances can be detected in children with typical BCECTS, but are no longer apparent after remission of the seizure disorder.     

半球性癫痫手术治疗的疗效分析

目的探讨外科手术治疗半球性癫痫的疗效,评价手术对患者的社会心理及认知功能的影响。方法 93例半球性癫痫患者经过综合评估后行手术治疗,其中Adams's术式30例,Rasmussen's术式7例,大脑半球切开术3例,多脑叶切除术24例,多脑叶切除联合胼胝体切开术29例。术后随访2.5年~6年3个月。手术疗效以Engel分级标准判定。结果术后癫痫控制情况:EngelⅠ级43例,Ⅱ级24例,Ⅲ级19例,Ⅳ7例。手术后早期患者的偏瘫无明显加重,肌张力及痉挛状态得到不同程度缓解,辅助系统康复训练后,肢体功能明显改善;高级皮层功能,生活自理能力和社会适应能力得到不同程度的提高。结论手术治疗半球性癫痫不仅可有效控制癫痫发作,患者的言语、肢体运动功能无恶化,神经心理功能和生活质量还有不同程度提高。而上述功能改善程度与年龄呈正相关。     

Complex partial status epilepticus in children with epilepsy

Purpose: Complex partial status epilepticus (CPSE) is often under-diagnosed, especially in children. The aim of this study was to clarify the characteristics and pathophysiology of CPSE in children with epilepsy. Subjects and methods: We retrospectively reviewed the medical records and EEGs of 17 children with epilepsy who were diagnosed as having CPSE by ictal or postictal EEGs to investigate clinical and EEG features. Results: The ages at diagnosis of CPSE ranged from 3 months to 17 years. At the time of diagnosis of CPSE, 13 patients had symptomatic localization-related epilepsy, two had epilepsy with continuous spike-waves during slow wave sleep, and each patient had cryptogenic localization-related epilepsy and idiopathic localization-related epilepsy. Only subtle symptoms including autonomic ones associated with disturbance of consciousness were the main clinical features in 12 of 44 CPSE episodes. Another 22 episodes showed minor focal motor elements, and the other 10 had major convulsive phase during or immediately before CPSE. Ictal EEGs of CPSE were divided into three types according to the degree of high-voltage slow waves (HVS) and spike components. Ictal EEGs could show spike-dominant or spike and HVS mixed patterns even if patients showed only subtle symptoms. The epileptogenic areas estimated by the ictal or postictal EEGs showed variability with only two cases of temporal origin. Conclusion: The close observation of clinical symptoms such as various subtle symptoms and/or mild convulsive elements and ictal EEGs are absolutely needed for the diagnosis of CPSE in children.     

Sleep organization in children with partial refractory epilepsy

Although it is currently known that sleep can influence epilepsy and epilepsy can influence sleep organization, few data have been published on this mutual interaction concerning the pediatric population. The objective of this study was to verify the eventual presence of sleep alterations in children with partial refractory epilepsy. Seventeen patients with partial refractory epilepsy were submitted to whole-night polysomnography as part of their epilepsy investigation. Polysomnographic recordings were performed on a digital video-electroencephalography (EEG) system and consisted of the registration of EEG (24 channels), electro-oculogram, electromyogram, electrocardiogram, and nasal airflow and abdominal respiratory movements. Sleep stages were visually scored following standard criteria, and ictal events were classified according to the international classification of seizures. The patients were also subdivided into two subgroups based on the presence or absence of ictal episodes during the recording night. The results concerning sleep organization were compared with those obtained from a normal control group. The analysis of the sleep parameters showed a reduction of total time in bed and total sleep time in both subgroups of epileptic children; there was a higher number of stage shifts per hour in the control group than in both epileptic subgroups. The percentage of stage 2 shifts is significantly reduced in patients with epilepsy and seizures during the night and the percentage of stage 3 to 4 shifts is increased. Nonsignificant differences are evident for the number of awakenings per hour and the percentage of stage 1 shifts. The percentage of rapid eye movement (REM) sleep is reduced, and first REM latency is increased in both epileptic subgroups, compared with normal controls, without statistical significance. Nine of 17 patients had seizures during the polysomnographic recording; nocturnal ictal events occurred mostly during non-REM sleep stage 2. Our results show that patients with partial refractory epilepsies have only mild sleep structure abnormalities, and this can be considered as an effect of the epileptic syndrome per se or as a result of the chronic antiepilepsy drug treatment.     

Discontinuation of anticonvulsant therapy in children with partial epilepsy

To evaluate when it is possible to discontinue anticonvulsant treatment in children with cryptogenic partial epilepsy, the authors studied 89 epileptic children divided into two groups: Group A, 45 children whose therapy was discontinued after 1 year from the last seizure; and Group B, 44 children whose therapy was stopped after 2 years from the last seizure. After 5 years of follow-up, the recurrence rate was similar in the two groups of patients (Group A, 28.8%; Group B, 25%). It is safe to discontinue the anticonvulsant therapy in children with cryptogenic partial epilepsy who were seizure free for only 1 year.     

Academic performance in children with rolandic epilepsy

The aim of this study was to investigate the frequency of reading, writing, and calculation disabilities in children with typical rolandic epilepsy (RE) and healthy control children. We also aimed to define the possible electroclinical markers of specific cognitive dysfunctions in RE. School abilities were evaluated and compared in 20 children (eight males, 12 females; mean age 10y 3mo [SD 1y 7mo]; range 7y 9mo-12y 9mo) consecutively diagnosed with typical RE, and a group of 21 healthy controls (nine males, 12 females; mean age 10y 4mo [SD 1y 8mo]; range 7y 6mo-13y 3mo). All the children received standardized neuropsychological tests. For each patient an exhaustive seizure diary was kept and all the sleep electroencephalogram (EEG) recordings were reviewed. Specific difficulties with reading, writing, and calculation (diagnosed according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition) were found in nine out of 20 children with RE and two out of 21 healthy controls (chi2=0.01). The specific learning disabilities in the RE group were correlated with a marked increase in epileptiform discharges during sleep (chi2=0.02) and an early onset of epilepsy (chi2=0.02). Our findings suggest that seizure onset before age 8 years and epileptiform discharges (more than 50% of the sleep EEG recording) in several tracings over more than a year are relevant markers for identifying patients at risk of developing academic difficulties.     

Ictal emotional expressions of children with partial epilepsy

OBJECTIVE: To systematically analyze the lateralizing and localizing value of ictal emotional expressions (EEs) in children and compare these results with those of earlier adult studies. METHODS: Five hundred fourteen seizures of 100 consecutive children < or = 12 years with partial (61/100 temporal lobe) epilepsy and postoperative seizure free outcome were included in the study. Video recordings of seizures were reviewed by two independent investigators blinded to the patients' clinical data. RESULTS: Thirty-five patients produced EE at least once during their archived seizures, including fear (15), crying (12), smile (9), pain (5), happiness (3), and laughing (in one case). Emotional symptoms were divided into two groups: positive (smile, laughing, and happiness) and negative EEs (fear, crying, and pain). Emotional expressions appeared more frequently during extratemporal (49%) than temporal (26%) lobe seizures (p < 0.05). Positive EEs had an extratemporal dominance (p < 0.05), while frequency of negative EEs did not localize the seizure onset zone. Assessing their lateralizing value, positive EEs were more frequent during right-sided seizures (p < 0.05) while negative EEs did not lateralize the seizure onset zone. Frequency of EEs were independent of patients' ages, age at epilepsy onset or duration of epilepsy. CONCLUSION: This is the first comprehensive childhood study showing that ictal EEs are frequent in childhood and their localizing and lateralizing properties are different from those of adults.     

Topiramate: an experience in children with partial epilepsy

Topiramate (TPM) is a new drug currently used in Brazil. We verified the clinical responses to TPM in children under 15 years-old. We started with 12.5 mg/day (1-7 mg/kg/day) and the doses increased 12,5 mg each week. Eleven children were studied, 9 females and 2 males, from 3 to 14 years-old with partial epilepsy associated to different etiological factors. Only one patient had an intense abdominal pain. The patients had weekly or daily seizures and after began TPM 1 patient stayed free from seizures, 5 improved more than 75% in frequency, 1 patient improved more than 50% and 3 had no control. A good control of seizures was achieved with a low dose of TPM as monotherapy and add-on therapy with carbamazepine even in severe cases.     

Dual functional hemispheric asymmetry in visual perception: Effects of ocular dominance and postexposural processes

The authors investigated laterality differences in visual perception by assessing the effects of the directional post-exposure scanning movements associated with reading habits, the visual half-field (VHF) in which stimuli were presented, and eye dominance on an immediate recall task. Forty Chinese bilingual subjects (20 right-eye dominant and 20 left-eye dominant) were tested for their recall of forms, Chinese words and English words. The stimuli were projected tachistoscopically in the left and/or right VHFs under conditions of simulataneous and successive presentation. The results demonstrated a right field superiority for verbal stimuli under both conditions and a left field superiority for nonverbal stimuli when presented successively. Right-eyed subjects were better in processing verbal materials and left-eyed subjects were better in the perception and recall of nonverbal materials. The study supported the validity of the psychophysiological model of asymmetrical cerebral functioning and demonstrated the importance of reading habits and eye dominance. The findings were interpreted as preliminary support for Piaget's postulated relationship between perceptual and organic development.     

Atypical hemispheric asymmetries for the processing of phonological features in children with rolandic epilepsy

We assessed language lateralization in 177 healthy 4- to 11-year-old children and adults and atypical asymmetries associated with unilateral epileptic foci in 18 children with benign epilepsy with centrotemporal spikes (BECTS). Dichotic listening results revealed two indices of immature functional asymmetry when the focus was left-sided (BECTS-L). First, children with BECTS-L did not show left hemisphere dominance for the processing of place of articulation, which was recorded in children with BECTS-R and control children. On the contrary, healthy children exhibited a gradual increase in left hemisphere dominance for place processing during childhood, which is consistent with the shift from global to finer-grained acoustic analysis predicted by the Developmental Weighting Shift model. Second, children with BECTS-L showed atypical left hemisphere involvement in the processing of the voiced value (+V), associated with a long acoustic event in French stop consonants, whereas right hemisphere dominance increased with age for +V processing in healthy children. BECTS-L, therefore, interferes with the development of left hemisphere dominance for specific phonological mechanisms.