The hidden face of hemispherectomy: Visuo-spatial and visuo-perceptive processing after left or right functional hemispherectomy in 40 children.

Functional hemispherectomy results in good outcomes in cases of refractory epilepsy and constitutes a unique situation in which to study cerebral plasticity and the reorganization of lateralized functions of the brain, especially in cases of infancy or childhood surgery. Previous studies have highlighted the remarkable ability of the brain to recover language after left hemispherectomy. This leads to a reorganization of language networks toward right hemisphere, causing limitation in the development of visuo-spatial abilities, known as a crowding effect in the right hemisphere. Deficits in nonverbal functions have also been described as a more direct consequence of right hemipherectomy, but the results from case studies have sometimes been contradictory. We conducted a group study which may effectively compare patients with left and right hemispherectomy and address the effects of the age of seizure onset and surgery. We analyzed the general visuo-spatial and visuo-perceptive abilities, including face and emotional facial expression processing, in a group of 40 patients aged 7-16 years with left (n = 24) or right (n = 16) functional hemispherectomy. Although the groups did not differ, on average, in general visuo-spatial and visuo-perceptive skills, patients with right hemispherectomy were more impaired in the processing of faces and emotional facial expressions compared with patients with left hemispherectomy. This may reflect a specific deficit in the perceptual processing of faces after right hemispherectomy. Results are discussed in terms of limited plasticity of the left hemisphere for facial and configural processing.

Usefulness of preschool and school versions of the Behavioral Rating Inventory of Executive Functions in the evaluation of the daily life executive function in myoclonic-atonic epilepsy.

PURPOSE: Executive functions (EF) are high-order cognitive skills that have a major influence on quality of life, social skills, and school achievement. We aimed to screen EF daily life abilities in young patients with myoclonic-atonic epilepsy (MAE) using an ecological questionnaire and to correlate EF to epilepsy characteristics. METHODS: Behavioral Rating Inventory of Executive Functions - Preschool (BRIEF-P) and BRIEF - for school-aged patients - parental questionnaires were proposed to patients with MAE and typically developing children (TDC) including Inhibit, Shift, Emotional control, Working memory (WM), Plan/Organize, Initiate, Organization of materials, and Monitor subscales. We included prospectively 12 patients with MAE and 44 TDC aged 3 to 5 years and seven patients with MAE and 21 TDC aged 6-7 years. We performed in addition for all patients an intellectual efficiency evaluation using WPPSI-IV (Wechsler intelligence scale for preschool children version IV) and collected demographics, age at onset of epilepsy, epilepsy duration, response to treatment, number and type of treatments including AEDs (antiepileptic drugs), and ketogenic diet. RESULTS: Four out of 12 patients for BRIEF-P and 6/7 patients for BRIEF had pathological scores for at least one domain. Behavioral Rating Inventory of Executive Functions' questionnaires showed higher pathological scores for WM, Plan/Organize, Initiate, Monitor, and Metacognition Index in patients with MAE compared to TDC suggesting higher problems reported by parents. Working memory scores were higher in the group with MAE than TDC for both BRIEF-P and BRIEF. Response to treatment is a predictor of multiple BRIEF-P domains. Epilepsy duration predicts Shift and WM domains while age at onset predicts WM domain on BRIEF in this syndrome. CONCLUSIONS: This study is the first to assess prospectively EF in young patients with MAE. We show everyday deficits in EF reported by parents. Metacognition and more specifically WM, appear to be a core deficit. Early evaluation of EF using both questionnaires and standardized tools is necessary for early detection of EF deficit and initiating tailored rehabilitation. Given the normal development before seizure onset and the absence of cerebral lesion in MAE, these results are in favor of the impact of epilepsy on EF.

Language plasticity after hemispherotomy of the dominant hemisphere in 3 patients: Implication of non-linguistic networks.

The neural networks involved in language recovery following hemispherotomy of the dominant hemisphere after language acquisition in children remain poorly known. Twelve hemispherotomized children (mean age at surgery: 11.3years) with comparable post-operative neuropsychological patterns underwent multi-task language functional MRI. Three of them had recovered from an initial postoperative aphasia i.e., hemispherotomy was performed on the language-dominant hemisphere. Our main results revealed (1) perisylvian activations in all patients after either left or right hemispherotomy; (2) no differences in activations between groups regarding the side of hemispherotomy; (3) additional activations in pre-frontal (3/3) and hippocampal/parahippocampal and occipito-parietal (2/3) areas, when comparing language activation in each of the three subjects with hemispherotomy of the language-dominant hemisphere to the group of 9 non-dominant hemispherotomized patients. These neural networks support the stronger engagement of learning and memory during language recovery in a hemisphere that was not initially actively subserving language.

The development of pragmatic skills in children after hemispherotomy: Contribution from left and right hemispheres.

PURPOSE: Hemispherotomy (H) is the standard treatment used to cure hemispheric epileptic syndromes in childhood. The postoperative linguistic profile involves hemispheric specialization processes and developmental cognitive plasticity. This research concerns pragmatic aspects of language as a tool for communication which involves both linguistic and extralinguistic communication in context. Our aim was to analyze whether any correlation exists with age at surgery and side of surgery on pragmatic skills following H. METHOD: Forty children who underwent H (23 females, 16 right H) were evaluated at a mean age of 12.8 years (±2.6) with two receptive tasks (oral comprehension and syntactic judgment), the Children's Communication Checklist (CCC) rating scale, and the Behavioral Rating Inventory of Executive Function (BRIEF) questionnaire in order to evaluate the role of executive functions on pragmatic skills. Children operated on before the age of 18 months were considered the "early" group (5 right H and 9 left H), while those operated on later were called the "late" group (11 right H and 15 left H). KEY FINDINGS: The whole group had significant deficits in all three measures. We demonstrated a statistically significant crossed interaction between the side of H and the age at H with pragmatic language impairments (F(1,36)=17.48; p=.0002) and disorders in executive function (F(1,36)=5.80; p=.021) in left early H and in right late H patients. These findings are consistent with the previous studies of pragmatic language impairments concerning adolescents and adults with right hemisphere damage and emphasize the contribution of structural language in the early stage of verbal communication. SIGNIFICANCE: These results emphasize for the first time that hemispherotomized children have pragmatic language impairments that are independent of receptive language. Our findings are congruent with the recent theory on pragmatic language development in childhood with evidence of a participation of the left hemisphere at the early age followed by right hemispheric specialization and involvement of executive functions, independently of receptive language.

Exceptional verbal intelligence after hemispherotomy in a child with Rasmussen encephalitis.

We report a longitudinal case study of a left-handed girl who underwent left hemispherotomy at 7 years for Rasmussen encephalitis (RE). Presurgical evaluation showed mild hemiparesis, no visual defect, and light neuropsychological impairment with short-term memory weakness. Language fMRI showed a right hemispheric dominance. Postoperatively, the patient exhibited right hemiplegia and hemianopsia but preserved intellectual capacities. She became seizure-free, and antiepileptic medication was discontinued. Long-term follow-up showed very high verbal intelligence at 11 years of age (VCI of 155) and improvement in working memory as well as language and reading abilities. Furthermore, a significant visuoverbal discrepancy became increasingly pronounced. Thus, early surgical treatment of epilepsy avoided the global cognitive deterioration usually associated with RE. Finally, such a high level of verbal functioning combined with low spatial reasoning with a single hemisphere provides additional information on the neurocognitive profile of children with RE after hemispherotomy.

Language recovery after left hemispherotomy for Rasmussen encephalitis.

PURPOSE: Hemispherotomy (H) is the gold standard treatment to cure epilepsy in Rasmussen encephalitis (RE). Linguistic prognosis after surgery remains the main issue when the dominant hemisphere is involved. The topic of the present research is to specify the long-term linguistic profile of the right hemisphere after left dominant H for RE. METHODS: We followed 6 children 8.4 to 14.6 years of age who underwent left H for RE. Preoperatively, four children experienced aphasia, but for two, worsening occurred after surgery. Age at H ranged from 4.1 to 8.4 years. The mean duration of epilepsy was 1.2 years and 5.6 years for follow-up. Neuropsychological evaluation included longitudinal follow-up of intellectual efficiency measurement and a long-term outcome of language using various components of receptive and expressive oral speech with computerized tasks. KEY FINDINGS: Preoperatively, verbal comprehension index (VCI) was dramatically decreased in 4/6 patients, and performance reasoning index (PRI) was low in 5/6 participants, demonstrating a global impact of RE itself. Postoperatively, all children recovered sufficiently to attend a regular VCI (above 70) in a mean of 5 years after H, and 5/6 recovered normal or adapted school. There was a dissociation in favor of VCI, while PRI decreased in 5/6 patients. We found a specific linguistic profile for these children recovering language in the right hemisphere: normal verbal comprehension, and weakness of grammatical judgment, word repetition, statement production, semantic verbal fluency and metaphonological abilities. Language recovery scores were statistically correlated with those of Working Memory Index. SIGNIFICANCE: This study emphasizes for the first time the ability of the right hemisphere to functionally reorganize language over a long period of time following left H for RE. Syntactic abilities and phonology remain low and support the hypothesis of an early left hemispheric specialization. Nevertheless, lexico-semantic processes recover in the right hemisphere that could reflect a pre-existing potential of both hemispheres. Our results support a decision to proceed to H in classical left RE disease until the late childhood even if there is no complete aphasia before surgery. These data should be taken in account in the overall postoperative follow-up and rehabilitation strategy.

Associative episodic memory and recollective processes in childhood temporal lobe epilepsy.

While the current literature on children suffering from temporal lobe epilepsy (CTLE) mostly focuses on material-related episodic memory deficits according to seizure-onset lateralization, the present study examined associative episodic memory according to the type of information to memorize (e.g., factual, spatial, and sequential) and further investigated subjective and objective recollection. Eleven children with left temporal lobe epilepsy (LTLE), 10 children with right temporal lobe epilepsy (RTLE), among whom 9 displayed hippocampal sclerosis (HS), and 42 healthy controls completed the WHAT-WHEN-WHERE protocol (Guillery-Girard et al., 2013). Group comparisons were first conducted according to the affected side and second according to the underlying pathology. Results showed associative memory impairments in patients irrespective of the affected side. Moreover, this study revealed that HS is particularly deleterious to associative and subjective recollection in CTLE. In addition, this study emphasizes the need for assessing episodic memory in childhood TLE beyond material specificity.

Reading impairment in an adolescent with temporo-occipital epilepsy. Pre- and post-surgical evaluation.

We present a 16 year-old right-handed case who underwent a left temporo-occipital resection to treat intractable epilepsy. Pre- and post-surgical evaluations showed an average intellectual quotient, preserved abilities in language and visuo-spatial functions and increased reading and spelling deficits (difficulties with irregular words, homophones and phonologically valid spelling errors of irregularly spelled words, associated with preserved performances in non-words). This pattern of characteristic lexical route deficits highlights the major role of the temporo-occipital areas in reading acquisition. We discussed the consequences of temporo-occipital dysfunction on reading.

Facial expression recognition and emotion understanding in children after neonatal open-heart surgery for transposition of the great arteries.

AIM: Theory of mind impairments are part of the cognitive morbidities associated with transposition of the great arteries (TGA). We sought to assess core components of social cognition in school-aged children with TGA. METHOD: Thirty-eight children with neonatal corrected TGA (27 males, 11 females; mean age 7y 3mo, SD 1y 2mo) and a comparison group (n=31; 24 males, 7 females; mean age 7y 4mo, SD 1y 1mo) participated in this study. All children completed measures of facial expression recognition, emotion comprehension, and second-order cognitive and affective false-belief tasks. The association of medical pre-, intra-, and postoperative variables with cognitive outcomes was explored. RESULTS: After controlling for potential covariates, children with TGA performed significantly less accurately in the mental category of the emotion comprehension battery (p=0.002) and on second-order affective false-belief tasks (p<0.05). Preoperative variables including an associated ventricular septal defect (p=0.02), a younger age at open-heart surgery (p=0.03), and a prenatal diagnosis of TGA (p=0.02) were significantly associated with better outcomes. INTERPRETATION: School-aged children with TGA display significant impairment on complex affective mental state understanding even though facial expression recognition was generally preserved. Preoperative factors may be important determinants for long-term outcomes after cyanotic congenital heart disease.

Use of early remedial services in children with transposition of the great arteries.

OBJECTIVES: To characterize the prevalence of use of early remedial services and its associated demographic, medical, and cognitive factors in children aged 4-6 years with corrected transposition of the great arteries (TGA). STUDY DESIGN: This was a prospective study of neurocognitive outcomes after TGA. Children underwent formal neuropsychological testing including general intelligence and a comprehensive battery of executive functions (EF) including motor and interference control, short-term memory, and working memory as well as cognitive flexibility. Parental reports on the children's behavior and EF were also evaluated. Demographic factors and preoperative, intraoperative, and postoperative factors as well as cognitive factors were examined according to the current use of remediation. RESULTS: Forty-five patients (67% male) and their parents participated in this study. Twenty-four (53%) patients were receiving remedial services. Male sex, a postnatal diagnosis of TGA, and a longer postoperative intensive care unit stay were significantly associated with use of remediation. Children receiving remediation had lower EF scores, had more severe EF deficits as observed by formal testing, and were rated as having more behavioral daily life difficulties. However, in the group without remediation, 13 children (43%) also displayed EF deficits rated as moderate to severe. CONCLUSIONS: Demographic and medical factors could help identify children at higher risk for neurocognitive delays. Evaluation of executive functioning from an early age may influence referral for remediation.

Impact of prenatal diagnosis on neurocognitive outcomes in children with transposition of the great arteries.

OBJECTIVES: To assess the effect of prenatal diagnosis of congenital heart disease on neurocognitive outcomes in children with d-transposition of the great arteries (TGA) after surgical correction. STUDY DESIGN: A prospective study of children born with a TGA between 2003 and 2005 and aged 4 to 6 years was conducted. General intelligence, language, executive functions, and social cognition scores and preoperative, intraoperative, and postoperative factors were evaluated according to time of TGA diagnosis. Neurocognitive data were also compared with a control group. RESULTS: Forty-five eligible patients (67% male) were examined; 29 had a prenatal diagnosis of TGA and 16 did not. All children were comparable in age, sex, and demographic variables. Diagnostic groups did not differ in preoperative, intraoperative, and postoperative variables. Preoperative acidosis was more frequent in the postnatal group (18% versus 3%). All patients had normal IQ scores, language, and verbal working memory. However, neurocognitive deficits were more prevalent and more severe in children with a postnatal-TGA. Prenatal diagnosis was associated with better outcomes in executive functions. CONCLUSIONS: Prenatal diagnosis of TGA is associated with better neurocognitive outcomes. Time of diagnosis may influence the development of early complex cognitive skills such as executive functions.

Cognitive outcome after left functional hemispherectomy on dominant hemisphere in patients with Rasmussen encephalitis: beyond the myth of aphasia. Patient series.

BACKGROUND: Rasmussen encephalitis is a rare chronic neurological pathology frequently treated with functional hemispherectomy (or hemispherotomy). This surgical procedure frees patients of their severe epilepsy associated with the disease but may induce cognitive disorders and notably language alterations after disconnection of the left hemisphere. OBSERVATIONS: The authors describe longitudinally 3 cases of female patients with Rasmussen encephalitis who underwent left hemispherotomy in childhood and benefited from a favorable cognitive outcome. In the first patient, the hemispherotomy occurred at a young age, and the recovery of language and cognitive abilities was rapid and efficient. The second patient benefited from the surgery later in childhood. In addition, she presented a reorganization of language and memory functions that seem to have been at the expense of nonverbal ones. The third patient was a teenager during surgery. She benefited from a more partial cognitive recovery with persistent disorders several years after the surgery. LESSONS: Recovery of cognitive functions, including language, occurs after left hemispherotomy, even when performed late in childhood. Therefore, the surgery should be considered as early as possible to promote intercognitive reorganization.

Cognitive outcome of parietooccipital resection in children with epilepsy.

PURPOSE: We followed the neuropsychological development of five children who underwent unilateral neurosurgery of the occipitoparietal lobes as a treatment for epilepsy caused by a developmental lesion (cortical dysplasia). METHODS: The follow-up period ranged from 3-7 years postsurgery. RESULTS: Two participants had a verbal intelligence quotient (IQ) >100 and three had a verbal IQ between 65 and 80. All five children had abnormal nonverbal IQ and exhibited deficits related to visual attention, object recognition, and praxis. Nevertheless, our results suggest that brain plasticity after parietooccipital epilepsy surgery in young children allows for a schooling level of cognitive skills such as reading and arithmetic. DISCUSSION: Although recovery for visual perceptual cognition was more limited than for verbal functions, long-term neuropsychological outcomes showed that early surgery for epilepsy offers the possibility of optimizing cognitive outcomes in children with posterior intractable epilepsies.

Memory dysfunctions.

Since the seminal work on the patient HM, who in his adulthood presented an acquired amnesic syndrome following the resection of the bilateral temporal lobe, other research has described several cases of isolated memory dysfunction in children. This chapter presents developmental and long-lasting memory disorders emerging from an organic or neurologic cause at birth or in infancy. More notably, we focus on developmental amnesic syndrome caused by neonatal bihippocampal damage and memory dysfunction caused by medial temporal developmental epilepsy. We describe these two pediatric populations and present the consequences of hippocampal/medial temporal lobe damage in the development of memory systems. We review episodic memory deficits in children with developmental amnesia and temporal lobe epilepsy and highlight their impact on new learning, personal memories, and independent life. Finally, we provide a brief overview of some of the insights and debates emerging from classic work and recent advances in the context of episodic memory dysfunction displayed by children with hippocampal/medial temporal lobe amnesia and propose new perspectives in child neuropsychology of memory, suggesting new avenues for more ecologic memory assessment and rehabilitation.

Verbal emotional memory in children and adolescents with temporal lobe epilepsy: a first study.

That emotional memory enhancement is compromised in adult patients with temporal lobe epilepsy (TLE), particularly in the case of early cerebral damage, has been suspected. We conducted a study in which we compared 20 children and adolescents aged 11-15 years with early TLE with 40 healthy control subjects. We studied the effect of emotional information on verbal memory performance using story recall and word list learning tasks. Our results highlighted the existence of emotional memory facilitation in healthy subjects, whereas there was no beneficial impact of emotional material on memory in young patients with TLE. Our study suggests that early TLE can impair the development of emotional memory processes.

Verbal and spatial learning after temporal lobe excisions in children: an adaptation of the Grober and Buschke procedure.

Using an adaptation of Grober and Buschke's procedure, we assessed verbal and visuospatial learning abilities in 16 children after left or right anteromesial temporal resection and 16 healthy controls to evaluate material-specific memory deficits. All children had relatively well-preserved verbal and spatial learning capacities after unilateral temporal resection. Children who had left temporal resection showed impaired verbal memory performance despite semantic control by cued recall. No memory deficits with visual material were detected in children who underwent right anteromesial temporal resection. Grober and Buschke's procedure appears relevant for the detection of verbal memory disorders in children with left-sided temporal resection.

Impaired facial expression recognition in children with temporal lobe epilepsy: impact of early seizure onset on fear recognition.

The amygdala has been implicated in the recognition of facial emotions, especially fearful expressions, in adults with early-onset right temporal lobe epilepsy (TLE). The present study investigates the recognition of facial emotions in children and adolescents, 8-16 years old, with epilepsy. Twenty-nine subjects had TLE (13 right, 16 left) and eight had fronto-central epilepsy (FCE). Each was matched on age and gender with a control subject. Subjects were asked to label the emotions expressed in pictures of children's faces miming five basic emotions (happiness, sadness, fear, disgust and anger) or neutrality (no emotion). All groups of children with epilepsy performed less well than controls. Patterns of impairment differed according to the topography of the epilepsy: the left-TLE (LTLE) group was impaired in recognizing fear and neutrality, the right-TLE (RTLE) group was impaired in recognizing disgust and, the FCE group was impaired in recognizing happiness. We clearly demonstrated that early seizure onset is associated with poor recognition of facial expression of emotion in TLE group, particularly for fear. Although right-TLE and left-TLE subjects were both impaired in the recognition of facial emotion, their psychosocial adjustment, as measured by the CBCL questionnaire [Achenbach, T. M. (1991). Manual for the Child Behavior Checklist and Youth Self-report. Burlington, VT: University of Vermont Department of Psychiatry], showed that poor recognition of fearful expressions was related to behavioral disorders only in children with right-TLE. Our study demonstrates for the first time that early-onset TLE can compromise the development of recognizing facial expressions of emotion in children and adolescents and suggests a link between impaired fear recognition and behavioral disorders.

Memory functions following surgery for temporal lobe epilepsy in children.

Surgical treatment appears to improve the cognitive prognosis in children undergoing surgery for temporal lobe epilepsy (TLE). The beneficial effects of surgery on memory functions, particularly on material-specific memory, are more difficult to assess because of potentially interacting factors such as age range, intellectual level, left-handedness, type of surgery and seizure outcome. This study investigated memory functions in 20 right-handed children who had left or right-temporal lobe surgery - including hippocampectomy - and became seizure-free. The neuropsychological evaluation included tests measuring verbally and visually mediated episodic memory, everyday memory as well as attention/working memory and language/semantic memory. We also assessed the relationships between age of seizure onset, general cognitive ability and memory functions. Children with TLE showed poor memory efficiency before surgery that tended to improve about 1 year after surgery. We found a material-specific memory effect, especially after surgery-9 (out of 12) children with left TLE had worse verbal memory results while 5 (out of 8) with right TLE had worse visual memory results. Post-operatively, most children had poor everyday memory performance on the Rivermead Behavioural Memory Test. No significant relationship was observed between episodic memory scores and age of epilepsy onset but children with early onset remained with lower Performance IQ values, Rey's figure copy scores and naming performances after surgery. Surgery significantly improved all the attention/working memory scores, some verbal episodic memory tasks and naming test performances. A different pattern of episodic and semantic memory limitations related to left or right TLE was observed.

How children suffering severe amnesic syndrome acquire new concepts?

Recent studies revealed that children with developmental amnesia acquired new semantic information. However, they failed to investigate the growth of such knowledge during childhood, and they did not bring evidence concerning the putative role of residual episodic memory in semantic acquisition. This prospective study sought to clarify this issue by assessing both semantic and episodic memory in two amnesic children (RH and KF) with different neuropsychological profiles. We thus applied errorless semantic learning and vanishing cues methods, together with assessments of episodic memory using original recognition tasks within the same protocol. Results demonstrated learning and long-lasting maintenance of multicomponent concepts (comprising labels, categories and features) in both amnesic children. Importantly, episodic memory assessments revealed differential residual abilities in these children, which may account for their respective profiles of semantic acquisition. Thus, RH, who demonstrated residual episodic abilities, acquired normally. However, the learning of KF, who had a massive impairment of episodic memory, remained slower than her controls. In conclusion, even though an episodic impairment may slacken new semantic learning, our research provides new evidence for the de novo acquisition of semantic concepts in childhood amnesic syndrome and strengthens the idea that semantic learning can occur without any recruitment of episodic memory.

Deficit of preparatory attention in children with frontal lobe epilepsy.

We compared the performance of a sustained attention task by children with epilepsy in either the frontal or temporal lobe. In a new simple task that specifically measures preparatory attention, developed recently by LaBerge, Auclair, and Siéroff [LaBerge, D., Auclair, L., & Siéroff, E. (2000). Preparatory attention: Experiment and theory. Consciousness and Cognition, 9, 396-434], patients responded to a target presented in the centre of the display and ignored a distracter presented at locations to the right or the left side of the target. The distracter was presented prior to the onset of the target and the relative frequency of the distracter to target was varied within a block of trials (from 0% to 67%). Children with frontal lobe epilepsy showed a higher mean slope of response time to the target as a function of distracter probability compared to children with temporal lobe epilepsy or compared to the response time slope of control subjects. The response time slope of children with temporal lobe epilepsy did not differ from that of control subjects. These results indicate that the presence of frontal lobe epilepsy selectively affects the capacity of these patients to resist the interference a distracter.