SUMMARYPurpose: Epilepsy surgery in young children with focal lesions offers a unique opportunity to study the impact of severe seizures on cognitive development during a period of maximal brain plasticity, if immediate control can be obtained. We studied 11 children with early refractory epilepsy (median onset, 7.5 months) due to focal lesion who were rendered seizure-free after surgery performed before the age of 6 years. Methods: The children were followed prospectively for a median of 5 years with serial neuropsychological assessments correlated with electroencephalography (EEG) and surgery-related variables. Results: Short-term follow-up revealed rapid cognitive gains corresponding to cessation of intense and propagated epileptic activity [two with early catastrophic epilepsy; two with regression and continuous spike-waves during sleep (CSWS) or frontal seizures]; unchanged or slowed velocity of progress in six children (five with complex partial seizures and frontal or temporal cortical malformations). Longer-term follow-up showed stabilization of cognitive levels in the impaired range in most children and slow progress up to borderline level in two with initial gains. Discussion: Cessation of epileptic activity after early surgery can be followed by substantial cognitive gains, but not in all children. In the short term, lack of catch-up may be explained by loss of retained function in the removed epileptogenic area; in the longer term, by decreased intellectual potential of genetic origin, irreversible epileptic damage to neural networks supporting cognitive functions, or reorganization plasticity after early focal lesions. Cognitive recovery has to be considered as a ''bonus,'' which can be predicted in some specific circumstances. KEY WORDS: Epilepsy, Epilepsy surgery, Development, Neuropsychology, Child.Epilepsy surgery in young children with focal lesions offers a unique opportunity to study the impact of severe seizures on development if immediate seizure control can be obtained and pre-and postoperative development can be compared in subjects with maximal neural plasticity (Deonna & Roulet-Perez, 2005). The literature on outcome after surgical treatment in young children has focused primarily on seizure control related to different variables, such as type of procedures and pathologies. Until recently, studies did not provide comparative pre-and postoperative cognitive levels based on tests (Asarnow et al., 1997). Loddenkemper et al. (2007) were the first to use objective assessments in infants operated before 3 years of age to study their developmental outcomes. Their patients presented with catastrophic epilepsy, including infantile spasms due to hemispheric or more focalized lesions; a first developmental level was obtained before and a second 6 months after surgery. A modest improvement was found in the majority of patients, with the best results in the younger children who also happened to be those who had infantile spasms and the lowest initial developmental levels. However, individual results...

Ullman (2004) suggested that Specific Language Impairment (SLI) results from a general procedural learning deficit. In order to test this hypothesis, we investigated children with SLI via procedural learning tasks exploring the verbal, motor, and cognitive domains. Results showed that compared with a Control Group, the children with SLI (a) were unable to learn a phonotactic learning task, (b) were able but less efficiently to learn a motor learning task and (c) succeeded in a cognitive learning task. Regarding the motor learning task (Serial Reaction Time Task), reaction times were longer and learning slower than in controls. The learning effect was not significant in children with an associated Developmental Coordination Disorder (DCD), and future studies should consider comorbid motor impairment in order to clarify whether impairments are related to the motor rather than the language disorder. Our results indicate that a phonotactic learning but not a cognitive procedural deficit underlies SLI, thus challenging Ullmans' general procedural deficit hypothesis, like a few other recent studies.

AIM We report four cases of acquired severe encephalopathy with massive hyperkinesia, marked neurological and cognitive regression, sleep disturbance, prolonged mutism, and a remarkably delayed recovery (time to full recovery between 5 and 18mo) with an overall good outcome, and its association with anti-N-methyl-D-aspartate (anti-NMDA) receptor antibodies.METHOD We reviewed the four cases retrospectively and we also reviewed the literature. RESULTS Anti-NMDA receptor antibodies (without ovarian teratoma detected so far) were found in the two children tested in this study. INTERPRETATIONThe clinical features are similar to those first reported in 1992 by Sebire et al., 1 and rarely recognized since. Sleep disturbance was not emphasized as part of the disorder, but appears to be an important feature, whereas coma is less certain and difficult to evaluate in this setting. The combination of symptoms, evolution (mainly seizures at onset), severity, paucity of abnormal laboratory findings, very slow recovery, and difficult management justify its recognition as a specific entity. The neuropathological substrate may be anatomically close to that involved in encephalitis lethargica, in which the same target functions (sleep and movement) are affected but in reverse, with hypersomnolence and bradykinesia. This syndrome closely resembles anti-NMDA receptor encephalitis, which has been reported in adults and is often paraneoplastic.In 1992, Sebire et al.1 reported a series of six children presenting with a novel combination of intense dyskinesia and severe regression with prolonged cognitive impairment but who made an unexpected excellent recovery.1 Since then, similar cases have been described. The disorder is sometimes called Sebire syndrome and is considered inflammatory or infectious in aetiology.2-5 Hartley et al., 6 in a paper entitled 'Immune-mediated chorea encephalopathy syndrome in childhood', specifically commented on the marked similarity between their cases and those of Sebire et al. Sleep disturbances (hypersomnolence) and dyskinesia (parkinsonism) are hallmarks of encephalitis lethargica, a condition increasingly recognized in children and presumed to be of autoimmune aetiology. In some cases, phases of insomnia and hyperkinesia, as in Sebire syndrome, may occur, suggesting that the localization of the acquired brain dysfunction may be in closely related areas and that common pathogenetic mechanisms are involved. This clinical picture is similar to the recently recognized entity, anti-N-methyl-D-aspartate (anti-NMDA) receptor encephalitis, 7 which may be the underlying cause of the disorder reported by Sebire et al.We describe four new cases of Sebire syndrome, in which sleeplessness was a highly significant clinical feature 'masked' by severe dyskinesia and agitation, persisting long after dyskinesia had resolved. Anti-NMDA receptor antibodies were found in the two individuals who were tested. Their serum was analysed at the Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, UK (P...

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A boy with a right congenital hemiparesis due to a left pre-natal middle cerebral artery infarct developed focal epilepsy at 33 months and then an insidious and subsequently more rapid, massive cognitive and behavioural regression with a frontal syndrome between the ages of 4 and 5 years with continuous spike-waves during sleep (CSWS) on the EEG. Both the epilepsy and the CSWS were immediately suppressed by hemispherotomy at the age of 5 years and 4 months. A behavioural-cognitive follow-up prior to hemispherotomy, an per-operative EEG and corticography and serial post-operative neuropsychological assessments were performed until the age of 11 years. The spread of the epileptic activity to the "healthy" frontal region was the cause of the reversible frontal syndrome. A later gradual long-term but incomplete cognitive recovery, with moderate mental disability was documented. This outcome is probably explained by another facet of the epilepsy, namely the structural effects of prolonged epileptic discharges in rapidly developing cerebral networks which are, at the same time undergoing the reorganization imposed by a unilateral early hemispheric lesion. Group studies on the outcome of children before and after hemispherectomy using only single IQ measures, pre- and post-operatively, may miss particular epileptic cognitive dysfunctions as they are likely to be different from case to case. Such detailed and rarely available complementary clinical and EEG data obtained in a single case at different time periods in relation to the epilepsy, including per-operative electrophysiological findings, may help to understand the different cognitive deficits and recovery profiles and the limits of full cognitive recovery

Summary This article reviews the history of sign language (SL) and the rationale for its use in children with profound auditory agnosia due to Landau‐Kleffner syndrome (LKS), illustrated by studies of children and adults followed for many years and rare cases from the literature. The reasons that SL was successful and brought some children out of isolation while it could not be implemented in others are discussed. The nowadays earlier recognition and treatment of LKS and better awareness of the crucial need to maintain communication have certainly improved the outcome of affected children. Alternatives to oral language, even for less severe cases, are increasingly accepted. SL can be learned at different ages with a clear benefit, but the ambivalence of the patients and their families with the world and culture of the deaf may sometimes explain its refusal or limited acceptance. There are no data to support the fear that SL learning may delay or prevent oral language recovery in children with LKS. On the contrary, SL may even facilitate this recovery by stimulating functionally connected core language networks and by helping speech therapy and auditory training.

In this study, we investigated motor and cognitive procedural learning in typically developing children aged 8-12 years with a serial reaction time (SRT) task and a probabilistic classification learning (PCL) task. The aims were to replicate and extend the results of previous SRT studies, to investigate PCL in school-aged children, to explore the contribution of declarative knowledge to SRT and PCL performance, to explore the strategies used by children in the PCL task via a mathematical model, and to see whether performances obtained in motor and cognitive tasks correlated. The results showed similar learning effects in the three age groups in the SRT and in the first half of the PCL tasks. Participants did not develop explicit knowledge in the SRT task whereas declarative knowledge of the cue-outcome associations correlated with the performances in the second half of the PCL task, suggesting a participation of explicit knowledge after some time of exposure in PCL. An increasing proportion of the optimal strategy use with increasing age was observed in the PCL task. Finally, no correlation appeared between cognitive and motor performance. In conclusion, we extended the hypothesis of age invariance from motor to cognitive procedural learning, which had not been done previously. The ability to adopt more efficient learning strategies with age may rely on the maturation of the fronto-striatal loops. The lack of correlation between performance in the SRT task and the first part of the PCL task suggests dissociable developmental trajectories within the procedural memory system. Procedural learning belongs to the non-declarative or implicit learning system and refers to the ability to learn complex information without awareness. It consists in a progressive improvement of skills, without explicit knowledge or voluntary recall. Unlike declarativeWe are grateful to J. Mayor, M. Dubois and A. Posada for their help in the adaptation of the paradigms. We also thank F. Ludwig, Head of the School of St-Prex, and all the children and their parents who agreed to participate to these experiments.

Anti-N-methyl-D-aspartate (anti-NMDA) receptor encephalitis likely has a wider clinical spectrum than previously recognized. This article reports a previously healthy 16-year-old girl who was diagnosed with anti-NMDA receptor encephalitis 3 months after onset of severe depression with psychotic features. She had no neurological manifestations, and cerebral magnetic resonance imaging (MRI) was normal. Slow background on electroencephalogram and an oligoclonal band in the cerebrospinal fluid prompted the search for anti-NMDA receptor antibodies. She markedly improved over time but remained with mild neuropsychological sequelae after a trial of late immunotherapy. Only a high index of suspicion enables recognition of the milder forms of the disease masquerading as primary psychiatric disorders.