Anne de Saint-Martin

Université de Strasbourg, Strasbourg, Alsace, France

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Publications (22)51.17 Total impact

  • Article: Epileptic encephalopathies of the Landau-Kleffner and continuous spike and waves during slow-wave sleep types: Genomic dissection makes the link with autism.
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    ABSTRACT: Purpose:  The continuous spike and waves during slow-wave sleep syndrome (CSWSS) and the Landau-Kleffner (LKS) syndrome are two rare epileptic encephalopathies sharing common clinical features including seizures and regression. Both CSWSS and LKS can be associated with the electroencephalography pattern of electrical status epilepticus during slow-wave sleep and are part of a clinical continuum that at its benign end also includes rolandic epilepsy (RE) with centrotemporal spikes. The CSWSS and LKS patients can also have behavioral manifestations that overlap the spectrum of autism disorders (ASD). An impairment of brain development and/or maturation with complex interplay between genetic predisposition and nongenetic factors has been suspected. A role for autoimmunity has been proposed but the pathophysiology of CSWSS and of LKS remains uncharacterized. Methods:  In recent years, the participation of rare genomic alterations in the susceptibility to epileptic and autistic disorders has been demonstrated. The involvement of copy number variations (CNVs) in 61 CSWSS and LKS patients was questioned using comparative genomic hybridization assays coupled with validation by quantitative polymerase chain reaction (PCR). Key Findings:  Whereas the patients showed highly heterogeneous in genomic architecture, several potentially pathogenic alterations were detected. A large number of these corresponded to genomic regions or genes (ATP13A4, CDH9, CDH13, CNTNAP2, CTNNA3, DIAPH3, GRIN2A, MDGA2, SHANK3) that have been either associated with ASD for most of them, or involved in speech or language impairment, or in RE. Particularly, CNVs encoding cell adhesion proteins (cadherins, protocadherins, contactins, catenins) were detected with high frequency (≈20% of the patients) and significant enrichment (cell adhesion: p = 0.027; cell adhesion molecule binding: p = 9.27 × 10(-7) ). Significance:  Overall our data bring the first insights into the possible molecular pathophysiology of CSWSS and LKS. The overrepresentation of cell adhesion genes and the strong overlap with the genetic, genomic and molecular ASD networks, provide an exciting and unifying view on the clinical links among CSWSS, LKS, and ASD.
    Epilepsia 06/2012; 53(9):1526-1538. · 3.96 Impact Factor
  • Article: Long-term outcome after cognitive and behavioral regression in nonlesional epilepsy with continuous spike-waves during slow-wave sleep.
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    ABSTRACT: To present the long-term follow-up of 10 adolescents and young adults with documented cognitive and behavioral regression as children due to nonlesional focal, mainly frontal, epilepsy with continuous spike-waves during slow wave sleep (CSWS). Past medical and electroencephalography (EEG) data were reviewed and neuropsychological tests exploring main cognitive functions were administered. After a mean duration of follow-up of 15.6 years (range, 8-23 years), none of the 10 patients had recovered fully, but four regained borderline to normal intelligence and were almost independent. Patients with prolonged global intellectual regression had the worst outcome, whereas those with more specific and short-lived deficits recovered best. The marked behavioral disorders resolved in all but one patient. Executive functions were neither severely nor homogenously affected. Three patients with a frontal syndrome during the active phase (AP) disclosed only mild residual executive and social cognition deficits. The main cognitive gains occurred shortly after the AP, but qualitative improvements continued to occur. Long-term outcome correlated best with duration of CSWS. Our findings emphasize that cognitive recovery after cessation of CSWS depends on the severity and duration of the initial regression. None of our patients had major executive and social cognition deficits with preserved intelligence, as reported in adults with early destructive lesions of the frontal lobes. Early recognition of epilepsy with CSWS and rapid introduction of effective therapy are crucial for a best possible outcome.
    Epilepsia 04/2012; 53(6):1067-76. · 3.96 Impact Factor
  • Article: ARX polyalanine expansions are highly implicated in familial cases of mental retardation with infantile epilepsy and/or hand dystonia.
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    ABSTRACT: Mutations in the ARX gene cause both nonsyndromic and several forms of syndromic mental retardation (MR). Two polyalanine (polyA) expansions of ARX are recurrent mutations. The most common one, the c.428_451dup, is associated with a wide spectrum of phenotypes, ranging from the most severe West syndrome to Partington syndrome (MR and hand dystonia), and even nonsyndromic X-linked mental retardation (NS-XLMR). Studies of patients not selected for specific clinical signs showed that the c.428_451dup is relatively frequent in families harboring X-linked MR (7.5%), but less common in familial cases compatible with X-linked NR (1%), and very rare in sporadic cases (0.1%). The c.333_334ins(GCG)7 expansion is less frequent and mainly associated with West syndrome. We screened for both ARX polyA expansions in 98 unrelated patients selected for the presence of NR associated with different types of epilepsy and/or with hand dystonia. We also studied two families with an initial diagnosis of NS-XLMR, one of which was identified as showing linkage to the ARX locus. The c.428_451dup was identified in three patients and the c.333_334ins(GCG)7 in one; all of the patients were from families with two affected brothers. We also found the c.428_451dup in the family linked to ARX, and clinical re-evaluation showed subtle, previously undetected signs. Our study illustrates that ARX polyA expansions are primarily associated with syndromic MR and shows a higher yield (18% in our cohort) when these mutations are screened in familial cases of MR with epilepsy and/or dystonia.
    American Journal of Medical Genetics Part A 01/2011; 155A(1):98-105. · 2.39 Impact Factor
  • Article: The onset of acute oxcarbazepine toxicity related to prescription of clarithromycin in a child with refractory epilepsy.
    British Journal of Clinical Pharmacology 03/2010; 69(3):314-6. · 2.96 Impact Factor
  • Article: A pediatric case of Fisher-Bickerstaff spectrum.
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    ABSTRACT: Miller Fisher syndrome is classically described as an acute inflammatory polyneuropathy clinical variant, associating external ophthalmoplegia, ataxia and loss of tendon reflexes. Despite recent advances in the comprehension of this syndrome, with the description of anti-GQ1b anti-ganglioside antibodies associated with abnormal neuromuscular transmission in the serum of Miller Fisher syndrome patients, there is ongoing debate on the peripheral or central origin of the symptoms. Some authors argue that there is a brainstem and cerebellar involvement. Indeed, since description of the syndrome, numerous cases have been reported with electrophysiologic and imaging evidences of brainstem involvement in the syndrome. Described and discussed here is the case of a 4-year-old child with Miller Fisher syndrome and cerebral lesions evident on magnetic resonance imaging, suggesting a Fisher-Bickerstaff spectrum.
    Pediatric Neurology 02/2010; 42(2):147-50. · 1.52 Impact Factor
  • Article: Impairment of cerebello-thalamo-frontal pathway in Rab-GDI mutated patients with pure mental deficiency.
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    ABSTRACT: Rab-GDI mutations are responsible for "pure" mental deficiency, without any specific clinical features or brain malformation. Therefore, screening for mutations in mentally retarded patients is not available on a routine basis. Moreover, neuronal networks involved in mental deficiency still remain largely unknown. We performed a fine neuropsychological and imaging study in five patients from two unrelated families, affected with mental deficiency due to a mutation in the Rab-GDI gene. High resolution 3D brain MRI of the five mentally retarded adult males (mean age 33 years) were compared to MRI of 14 healthy males (mean age 35 years) using a Voxel-Based Morphometric analysis (VBM). All patients had isolated moderate mental retardation (WAIS-III IQ range, 41-50; mean 45) without specific morphological or behavioural features. No obvious brain abnormality was observed on visual inspection of individual scans. Using VBM analysis, Rab-GDI mutated patients' MRIs exhibited significant brain changes compared to normal subjects (p<0.05, corrected for multiple comparisons): increased grey matter density in left cerebellum and in left angular gyrus, decreased grey matter volume in thalami, decreased white matter density in prefrontal lobes, right fusiform occipito-temporal gyrus, and decreased white matter volume in cerebellar peduncles. These morphological changes observed in Rab-GDI mutated patients, mainly localized in the cerebello-thalamo-prefrontal pathway, are consistent with the hypothesis that the cerebellum is one of the critical components of a global learning network. Our results open new avenues in the diagnosis of non-specific mental deficiency using gene-specific "brain maps" as endophenotypes.
    European journal of medical genetics 09/2008; 52(1):6-13. · 1.57 Impact Factor
  • Article: Proximal 15q familial euchromatic variant and PWS/AS critical region duplication in the same patient: a cytogenetic pitfall.
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    ABSTRACT: Cytogenetically detectable elongation of the 15q proximal region can be associated with Prader-Willi/Angelman critical region interstitial duplications or with inherited juxtacentromeric euchromatic variants. The first category has been reported in association with developmental delay and autistic disorders. These pathogenic recurrent duplications are more frequently of maternal origin and originate from unequal meiotic crossovers between chromosome 15 low-copy repeats. 15q juxtacentromeric euchromatic variants reflect polymorphic copy number variations of segments containing pseudogenes and usually segregate without apparent phenotypic consequence. Pathogenic relevant 15q11-q13 duplications are not distinguishable from the innocuous euchromatic variants with conventional cytogenetic methods. We report cytogenetic and molecular studies of a patient with hypotonia, developmental delay and epilepsy, carrying, on the same chromosome 15, both a de novo 15q11-q13 interstitial duplication and an inherited 15q juxtacentromeric amplification from maternal origin. The duplication, initially suspected by fluorescent in situ hybridization (FISH), has been confirmed by molecular studies. The 15q juxtacentromeric region amplification, which segregates in the family for at least three generations, has been confirmed by FISH using BAC probes overlapping the NF1 and GABRA5 pseudogenes. This report emphasizes the importance to distinguish proximal 15q polymorphic variants from clinically significant duplications. In any patient with inherited 15q proximal variant but unexplained developmental delay suggesting 15q11-q13 pathology, a pathogenic rearrangement has to be searched with adapted strategies, in order to detect deletions as well as duplications of this region.
    European journal of medical genetics 08/2008; 51(6):547-57. · 1.57 Impact Factor
  • Article: Diagnostic approach to neonatal hypotonia: retrospective study on 144 neonates.
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    ABSTRACT: The objectives of our study were to determine the actual frequency of the different disorders causing neonatal hypotonia and to assess the reliability of the first physical examination as well as the contribution of the main standard diagnostic tests. One hundred and forty-four infants diagnosed with neonatal hypotonia between January 1st 1999 and June 30th 2005 in our tertiary care facility were retrospectively included in the study. Perinatal history, clinical type of hypotonia, results of standard diagnostic tests, final diagnosis and outcome were abstracted from the original charts. A final diagnosis was reached in 120 cases. Central (cerebral) causes represented 82% of the elucidated cases, mostly hypoxic and hemorrhagic lesions of the brain (34%), chromosomal aberrations and syndromic disorders (26%) and brain malformations (12%). Peripheral (neuromuscular) causes were mainly represented by spinal muscular atrophy (6%) and myotonic dystrophy (4%). Positive predictive value of the initial clinical examination was higher in central type hypotonia. Neuroimaging, karyotype analysis and DNA-based tests were the most helpful diagnostic tools. These recent clinical data can be used to improve our strategy in investigating neonatal hypotonia and a diagnostic algorithm is proposed based on our findings.
    European Journal of Pediatrics 06/2008; 167(5):517-23. · 1.88 Impact Factor
  • Article: Multiple intracranial tuberculomas associated with partial status epilepticus and refractory infantile spasms.
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    ABSTRACT: We report the case of a 10 month-old girl presenting with multiple intracranial tuberculomas associated with partial status epilepticus and cerebrovascular accident in the left sylvian territory. She later developed paradoxical enlargement of the tuberculomas during antituberculous treatment and severe neurological sequelae with refractory infantile spasms. The development of infantile spasms in this context is particularly remarkable, and this case is illustrative of the complex interrelationship between intracranial lesions, partial status epilepticus, and infantile spasms. It also highlights the difficult diagnosis of cerebral tuberculomas in infants and further supports the need for continued vigilance in industrialized countries.
    Journal of Child Neurology 05/2008; 23(4):459-62. · 1.75 Impact Factor
  • Article: Severe relapse of epilepsy after vigabatrin withdrawal: for how long should we treat symptomatic infantile spasms?
    Epilepsia 04/2007; 48(3):612-3. · 3.96 Impact Factor
  • Article: Early-onset ophthalmoplegia in Leigh-like syndrome due to NDUFV1 mutations.
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    ABSTRACT: Mitochondrial disorders can be linked to mutations in both mitochondrial and nuclear deoxyribonucleic acid, corresponding to various clinical phenotypes. Mutations in nuclear genes, including NDUFV1, have been associated with severe encephalomyopathies in infants, but genotype-phenotype correlations have remained elusive. This report details the complete clinical, biochemical, and molecular data of a 7-year-old male who presented at the age of 7 months with progressive ophthalmoplegia and later developed cerebellar ataxia, spasticity, and dystonia. Complex I deficiency was demonstrated in muscle, and two pathogenic missense mutations were present in the NDUFV1 gene. Ketogenic diet has seemingly improved the oculomotor palsy but has been unable to correct other neurologic symptoms. Considering other cases from the literature, this report broadens our understanding of genotype-phenotype correlations for NDUFV1 mutations and illustrates a potential and partial efficacy of ketogenic diet in complex I deficient patients.
    Pediatric Neurology 02/2007; 36(1):54-7. · 1.52 Impact Factor
  • Article: Landau-Kleffner syndrome is not an eponymic badge of ignorance.
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    ABSTRACT: In a 1992 editorial article, Landau expressed the hope of collective agreement in the medical community about Landau-Kleffner syndrome (LKS) in terms of diagnosis criteria, etiology, pathophysiology and rational therapy. Since then, neurophysiological and neuroimaging studies have led to the view that LKS is an acquired aphasia, secondary to an epileptic disturbance affecting a cortical area involved in verbal processing. This fits with the hypothesis of a "functional ablation" caused by epileptic activity. Under these criteria, epileptic aphasia becomes a subgroup of the continuous spike-waves syndrome in which epileptic discharges originate from the temporal cortex. Genetic predisposition for KLS could be related to hyperexcitability and synchronization of interneurons within the perisylvian cortices, which generate the spike-waves. Activation of these waves during NREM sleep, following thalamo-cortical uncoupling, might then alter the blood brain barrier and provoke an autoimmune reaction. Interneuron hyperactivity might in turn have an antiepileptic protective effect, associated with the inhibition of a specific function, and spike-waves activity over the long term might eventuate in focal atrophy. This morphological defect might explain the poor verbal outcome in some cases of LKS. From this study we recommend a multicenter control study of good design and methodology be carried out to compare the efficacies of early versus delayed (3 months) corticosteroid treatment in patients with typical LKS that is being treated by clobazam (or diazepam) monotherapy.
    Epilepsy Research 09/2006; 70 Suppl 1:S239-47. · 2.29 Impact Factor
  • Article: SRPX2 mutations in disorders of language cortex and cognition.
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    ABSTRACT: The rolandic and sylvian fissures divide the human cerebral hemispheres and the adjacent areas participate in speech processing. The relationship of rolandic (sylvian) seizure disorders with speech and cognitive impairments is well known, albeit poorly understood. We have identified the Xq22 gene SRPX2 as being responsible for rolandic seizures (RSs) associated with oral and speech dyspraxia and mental retardation (MR). SRPX2 is a secreted sushi-repeat containing protein expressed in neurons of the human adult brain, including the rolandic area. The disease-causing mutation (N327S) resulted in gain-of-glycosylation of the secreted mutant protein. A second mutation (Y72S) was identified within the first sushi domain of SRPX2 in a male with RSs and bilateral perisylvian polymicrogyria and his female relatives with mild MR or unaffected carrier status. In cultured cells, both mutations were associated with altered patterns of intracellular processing, suggesting protein misfolding. In the murine brain, Srpx2 protein expression appeared in neurons at birth. The involvement of SRPX2 in these disorders suggests an important role for SRPX2 in the perisylvian region critical for language and cognitive development.
    Human Molecular Genetics 05/2006; 15(7):1195-207. · 7.64 Impact Factor
  • Article: Cognitive functions in children with benign childhood epilepsy with centrotemporal spikes (BECTS).
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    ABSTRACT: Benign childhood epilepsy with centrotemporal spikes (BECTS) is regarded as a benign form of epilepsy because of its usually favorable outcome, in terms of seizures. Eighteen children with BECTS were studied in terms of neuropsychological and learning abilities: intellectual quotient, oral language (phonological production, naming skills, verbal fluency and syntactic comprehension), drawing and visuo-spatial skills, visual and selective attention, verbal and visuo-spatial memory, reading, numeracy and spelling. The mean IQ of the population was within the normal range, but individual results were heterogeneous. Verbal functions and memory were normal. In contrast, drawing and visuo-spatial skills, attention and visuo-spatial memory were significantly weak compared to the normal range for age. Reading, numeracy and/or spelling ability were significantly delayed by one academic year or more in ten of the children. In conclusion, despite its benign outcome in terms of epilepsy, BECTS can be accompanied by specific cognitive disorders and low academic achievement.
    Epileptic disorders: international epilepsy journal with videotape 04/2006; 8(1):11-23. · 1.50 Impact Factor
  • Article: Congenital hyperekplexia: five sporadic cases.
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    ABSTRACT: We report fives sporadic cases of hyperekplexia or startle disease characterized by a highly exaggerated startle reflex and tonic attacks. Affected neonates suffer from prolonged periods of stiffness and are at risk for sudden death from apnea. An early diagnosis is needed. Sudden loud sounds, unexpected tactile stimuli or percussion at the base of the nose can also elicit excessive jerking or tonic attack. The diagnosis of hyperekplexia is a purely clinical one. A defect of the alpha1 subunit of inhibitory glycine receptor (GLRA1) has been observed in the dominant form with a mutation in the chromosome 5. Clonazepam is effective and decreases the severity of the symptoms. The disease tends to improve after infancy and the psychomotor development is normal. The major form of "hyperekplexia" should be considered whenever one is confronted with neonatal hypertonicity associated with paroxysmal tonic manifestations (without electroencephalography anomalies). Conclusion: the diagnosis of hyperekplexia should be evaluated in any neonate with tonic attacks without evident cause.
    European Journal of Pediatrics 03/2006; 165(2):104-7. · 1.88 Impact Factor
  • Article: Antiglial cell autoantibodies and childhood epilepsy: a case report.
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    ABSTRACT: We report the case of a patient with severe partial epilepsy associated with a focal rolandic, pathologically proven, cortical dysplasia. By measuring intracellular calcium concentrations, functional antiglial non-glutamate receptor 3 (GluR3) autoantibodies were identified in the serum of this patient. Antineuronal autoantibodies, which interfere with GluR3-receptor function, also were detected. This observation provides new clues about the involvement of immunologic mechanisms in epileptic disorders.
    Epilepsia 09/2005; 46(8):1308-12. · 3.96 Impact Factor
  • Article: Topiramate: efficacy and tolerability in children according to epilepsy syndromes.
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    ABSTRACT: To evaluate the efficacy and tolerability of topiramate (TPM) as add-on therapy in children less than 12 years of age with refractory epilepsy, according to epilepsy syndromes, we conducted an open, prospective, pragmatic and multicenter study in France. Efficacy was assessed, especially according to epilepsy syndromes, as well as tolerability. We included 207 children (41 of whom were less than 4 years of age). TPM was effective (responders with >50% decrease in seizure frequency) in 50% of 128 patients with partial epilepsy, and in 44% of 79 patients with generalized epilepsy. In case of generalized epilepsy, responders more frequently had generalized symptomatic epilepsy, severe myoclonic epilepsy and myoclono-astatic epilepsy, whereas response rate was mild in both infantile spasms and Lennox-Gastaut syndrome (LGS). Improvement was well maintained in all patients during the treatment period (median 5.6 months). Seizure frequency/severity increased (worsening) in 13% of patients with partial epilepsy and 17% with generalized epilepsy (particularly in those with infantile spasms), and resulted in withdrawal of TPM for 8%. The most frequently reported adverse events were moderate neurobehavioral and gastrointestinal disorders. Adverse events led to withdrawal of TPM from 13.5% of patients. Children less than 4 years of age had particularly good tolerability. Results confirm that TPM is effective and well tolerated in children under 12 years of age in a broad range of epilepsy syndromes, including refractory partial epilepsy, and symptomatic and myoclonic generalized epilepsy. Use of TPM should be considered in children under 4 years of age, and slow and progressive titration is important.
    Epilepsy Research 03/2003; 53(3):225-32. · 2.29 Impact Factor
  • Article: Antiepileptic effect of high-frequency stimulation of the subthalamic nucleus (corpus luysi) in a case of medically intractable epilepsy caused by focal dysplasia: a 30-month follow-up: technical case report.
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    ABSTRACT: Currently, some forms of epilepsy are resistant to both pharmacological and surgical interventions. As a result, there is a need for new therapeutic strategies. Because the nigral system modulates neuronal excitability in animal models of epilepsy, we considered therapeutic high-frequency stimulation of the subthalamic nucleus (STN). We were encouraged by the known relationship between the STN and the nigral system, as well as by our experience with high-frequency stimulation of the STN in Parkinsonian patients. A 5-year-old girl with pharmacologically resistant, inoperable epilepsy caused by focal centroparietal dysplasia underwent implantation with a permanent electrode in the left STN and was chronically stimulated. To date, we have followed up this patient for 30 months postoperatively. High-frequency stimulation of the STN induced a significant voltage-dependent reduction (by 80%) in the number and severity of seizures. In addition, consistent improvement in both motor and cognitive functions was noted as a result of reduced postictal states. The effect was more prominent for seizures occurring in clusters (89% reduction) and during the day (88% reduction) than for those that occurred during sleep (53% reduction). This is the first report of epilepsy control using chronic high-frequency stimulation of the STN. Preliminary observations in three other operated patients (at 2, 12, and 18 mo) confirm these data. We think that high-frequency stimulation of the STN may hold significant future potential as a treatment for epilepsy, similar to its established role in the treatment of Parkinson's disease. This finding opens completely new experimental and therapeutic avenues for the treatment of surgically and medically intractable epilepsy.
    Neurosurgery 07/2002; 50(6):1385-91; discussion 1391-2. · 2.79 Impact Factor
  • Article: Further clinical and sensorial delineation of Schinzel-Giedion syndrome: report of two cases.
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    ABSTRACT: Schinzel-Giedion syndrome is a rare multiple congenital malformation syndrome defined by an evocative midfacial retraction, kidney and urinary malformations and multiple skeletal abnormalities associated to a recently described neurodegenerative process. Two children with SGS are reported with identical clinical findings: megacalycosis, progressive neurodegeneration with infantile spasms and hypsarrhymtic activity. Ocular investigations revealed alacrimia and corneal hypoesthesia. Computed tomography of the temporal bone showed a tuning-fork malformation of the stapes for both children. These features may contribute to further delineation of SGS as additional clinical criteria.
    American Journal of Medical Genetics 06/2002; 109(3):211-7.
  • Chapter: Transitory Cognitive Disorders and Learning Impairment
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    ABSTRACT: The findings of the studies reviewed in this chapter show that an abnormal neural activity may be responsible for cognitive impairment even when overt clinical seizures are very rare. This abnormal neural activity, only evidenced on EEG, has not only immediate consequences on cognitive performances but also long-term effects. As they occur in childhood at a critical age for the development of most cognitive abilities and the acquisition of knowledge, they may be deleterious for further academic and psychosocial achievement. The demonstration that transitory cognitive impairments may be responsible for attention and learning problems in the so-called benign epilepsy suggests that the frequency of EEG abnormalities particularly spike-wave discharges should be taken into account as a criterion for therapeutic decision in the same way as the frequency of clinical seizures. In the same way, when an epileptic child has behavioral problems and learning difficulties that are not explained by frequent seizures or medication, the presence of TCI should be suspected. Finally, in a child with sub clinical discharges on EEG, even when the global IQ is normal, poor performances on specific subtests may be related to TCI.19
    12/2001: pages 159-169;