Neurocognitive and behavioral profiles of children with Landau-Kleffner syndrome.

This is a retrospective study of 14 cases of children with Landau-Kleffner syndrome (LKS), the most prominent feature of which is acquired aphasia. These children were followed at a tertiary care pediatric epilepsy center. From the research data base, all LKS cases with neuropsychological evaluation were extracted. Children ranged in age from 6 to 13 years (M = 9.12; SD = 2.19) at the time of assessment (1 to 10 years post-onset). The majority of the children were white males, and all but one continued to experience seizure activity. Global intellectual functioning ranged from 59 to 101 (M = 82.07; SD = 12.14). Across the 14 cases reviewed, the neuropsychological profiles are considered in the context of neurological and syndrome-related factors. For these cases, 86% demonstrated continued expressive, and 50% had receptive language problems with 57% exhibiting poor auditory processing. Furthermore, 50 to 57% had deficits in auditory working memory and verbal memory. Academically, the majority had poor reading fluency and comprehension; 50% exhibited difficulty with mathematics. Finally, 57% evidenced attentional or other behavioral problems. Better understanding of LKS can assist in targeted assessment and intervention planning.

Cortical interneuron dysfunction in epilepsy associated with autism spectrum disorders.

Autism and epilepsy are two associated disorders that are highly prevalent, share common developmental origins, and demonstrate substantial heritability. In this review, cross-disciplinary data in a rapidly evolving field that bridges neurology and psychiatry are synthesized to identify shared biologic mechanisms. The relationship between these debilitating, lifelong conditions is examined at the clinical, genetic, and neurophysiologic levels in humans and in animal models. Scopus and PubMed searches were used to identify relevant literature. Clinical observations have prompted speculation about the interdependence of autism and epilepsy, but causal relationships have proved difficult to determine. Despite their heritability, the genetic basis of autism spectrum disorder (ASD) and epilepsy has remained largely elusive until the advent of next-generation sequencing. This approach has revealed that mutations that are either causal or confer an increased disease risk are found in numerous different genes, any one of which accounts for only a small percentage of cases. Conversely, even cases with identical clinical phenotypes can be genetically heterogeneous. Candidate gene identification has facilitated the development of mouse genetic models, which in parallel with human studies have implicated shared brain regions and circuits that mediate disease expression. Diverse genetic causes of ASD and epilepsy converge on cortical interneuron circuits as one important mediator of both disorders. Cortical interneurons are among the most diverse cell types in the brain and their unique chemical and electrical coupling exert a powerful inhibitory influence on excitatory neurons via the release of the neurotransmitter, γ-aminobutyric acid (GABA). These multifaceted approaches have validated theories derived from the field of developmental neurobiology, which propose that the neurologic and neuropsychiatric manifestations are caused by an altered ratio of excitation to inhibition in the cortex.

Clinical genetic study of the epilepsy-aphasia spectrum.

PURPOSE: To characterize the frequency and nature of the family history of seizures in probands with epilepsy falling within the epilepsy-aphasia spectrum (EAS) in order to understand the genetic architecture of this group of disorders. METHODS: Patients with epileptic encephalopathy with continuous spike-and-wave during sleep (ECSWS), Landau-Kleffner syndrome (LKS), atypical benign partial epilepsy (ABPE), and intermediate epilepsy-aphasia disorders (IEAD) were recruited. All affected and available unaffected relatives up to three degrees of relatedness underwent phenotyping using a validated seizure questionnaire. Pedigrees were constructed for all families. The proportion of affected relatives according to each degree of relatedness was calculated. The epilepsy phenotypes in close relatives were analyzed. The data were compared to the families of probands with benign childhood epilepsy with centrotemporal spikes (BECTS) using the same methodology. KEY FINDINGS: Thirty-one probands, including five ECSWS, three LKS, one ABPE, and 22 IEAD were recruited. The mean age of seizure onset was 3.9 (range 0.5-7) years. A male predominance was seen (68%, 21/31) . Sixteen (51.6%) of 31 had a positive family history of seizures. Among 1,254 relatives, 30 (2.4%) had a history of seizures: 13 (10.2%) of 128 first-degree relatives, 5 (1.7%) of 291 second-degree relatives, and 12 (1.4%) of 835 third-degree relatives. Thirteen had febrile seizures, including two who had both febrile seizures and epilepsy. Of the 19 relatives with epilepsy, 4 had BECTS, 4 epilepsies with focal seizures of unknown cause, 3 IEAD, and 7 unclassified. One had genetic generalized epilepsy. In the families of the BECTS probands, 9.8% of first-degree, 3% of second-degree, and 1.5% of third-degree relatives had seizures, which was not significantly different from the EAS cohort families. SIGNIFICANCE: The frequencies of seizures in relatives of probands with EAS suggest that the underlying genetic influence of EAS is consistent with complex inheritance and similar to BECTS. The phenotypic pattern observed in the affected relatives comprised predominantly febrile seizures and focal seizures. These findings suggest that a shared genetic predisposition to focal epilepsies underpins the epilepsy-aphasia spectrum.

Landau-Kleffner syndrome in Norway: long-term prognosis and experiences with the health services and educational systems.

We have conducted a retrospective study based on the medical records of 19 children with Landau-Kleffner syndrome and semistructured interviews of their parents. There was considerable heterogeneity in the children's symptoms. Eleven children were followed for more than 10 years (mean=14.4 years); four have normal language, four have moderate language problems, and three have no functional verbal language today. Late-onset language decline, short duration of the initial aphasic period, and marked fluctuations in speech abilities appeared to be associated with a positive outcome with respect to future language skills. The parents reported having to argue strongly with the health authorities and educational system to obtain a correct diagnosis and receive adequate help. Their main concern was not being taken seriously when they expressed their worries, and they expressed a strong wish for someone who could ensure that appropriate support measures were implemented and who could coordinate assistance.

Efficacy and prognosis of a short course of prednisolone therapy for pediatric epilepsy.

PURPOSE: To evaluate the efficacy and safety of adjunctive prednisolone therapy in children with cryptogenic epileptic encephalopathy, other than infantile spasms, and to determine its prognosis. METHODS: Prednisolone, 2mg/kg per day for 6 weeks, tapered for a further 2 weeks, was given in combination with previously prescribed antiepileptic drugs. A retrospective assessment of 41 children thus treated included measurements of seizure frequency, electroencephalographic findings, global assessments of cognitive function, and adverse drug events. Long-term patient prognoses over a mean follow-up period of 3 years and 5 months (range, 14-90 months) were also examined. RESULTS: Of 41 patients, 32 had Lennox-Gastaut syndrome, 4 had Doose syndrome, 1 had Otahara syndrome, 2 had Landau-Kleffner syndrome, and 2 had other unspecified generalized epilepsies. After prednisolone therapy, 73% (30/41) of patients showed a reduction in seizure frequency of >50%, and 59% (24/41) became seizure free. However, only seven patients (four with Lennox-Gastaut syndrome, two with Doose syndrome, and one with unspecified generalized epilepsy) who became seizure free remained free of seizures at the time of the final follow-up. Electroencephalographic findings and global assessments of cognitive function correlated well with seizure outcomes. No significant demographic factors influenced the efficacy of prednisolone or patient prognoses after prednisolone tapering. Most adverse events were transient, or were tolerated well with conservative management, with maintenance of the medication. CONCLUSION: Prednisolone therapy may be a safe and effective adjunct in patients with cryptogenic epileptic encephalopathies, but the high relapse rate is of concern.

Autistic epileptiform regression.

Autistic regression is a well known condition that occurs in one third of children with pervasive developmental disorders, who, after normal development in the first year of life, undergo a global regression during the second year that encompasses language, social skills and play. In a portion of these subjects, epileptiform abnormalities are present with or without seizures, resembling, in some respects, other epileptiform regressions of language and behaviour such as Landau-Kleffner syndrome. In these cases, for a more accurate definition of the clinical entity, the term autistic epileptifom regression has been suggested. As in other epileptic syndromes with regression, the relationships between EEG abnormalities, language and behaviour, in autism, are still unclear. We describe two cases of autistic epileptiform regression selected from a larger group of children with autistic spectrum disorders, with the aim of discussing the clinical features of the condition, the therapeutic approach and the outcome.

The pathophysiological mechanisms of cognitive and behavioral disturbances in children with Landau-Kleffner syndrome or epilepsy with continuous spike-and-waves during slow-wave sleep.

Epilepsy with continuous spike- and -waves during slow-wave sleep and Landau-Kleffner syndrome are two rare childhood epilepsy syndromes. The underlying pathophysiology remains unknown. The current opinions about epidemiologic risk factors, genetic predisposition, EEG and MEG findings, influence of anti-epileptic drugs, neuroradiology, positron emission tomopgraphy, evoked potentials, auto-immunity and subpial transection are summarized.

Outcome at adulthood of the continuous spike-waves during slow sleep and Landau-Kleffner syndromes.

PURPOSE: The aim of this study was to determine the clinical, social, and/or professional and cognitive outcomes in adulthood of the continuous spike-waves during slow sleep (CSWS) and Landau-Kleffner syndromes, which are two rare epileptic syndromes occurring in children. METHODS: We enrolled seven young adults, five who had a CSWS syndrome, and two, a Landau-Kleffner syndrome in childhood. We evaluated their intellectual level as well as their oral and written language and executive functions. RESULTS: This study confirmed that the epilepsy associated with these syndromes has a good prognosis. Only one patient still had active epilepsy. However, the neuropsychological disorders particular to each syndrome persisted. Only two patients had followed a normal pathway in school. Three of the five patients with a CSWS syndrome during childhood remained globally and nonselectively mentally deficient. We found no evidence of the persistence of a dysexecutive syndrome in this study group. The intellectual functions of the two patients with Landau-Kleffner syndrome were normal; however, their everyday lives were disrupted by severe, disabling language disturbances. We discuss the role of some prognostic factors such as the location of the interictal electric focus and the age at onset of CSWS. CONCLUSIONS: These two epileptic syndromes of childhood are very similar in many respects, but their clinical outcomes in adulthood are different.

Landau-Kleffner syndrome responsive to levetiracetam.

A 5-year-old girl with Landau-Kleffner syndrome is discussed. The child began having seizures at age 4 associated with language deterioration despite anticonvulsant therapy. With levetiracetam monotherapy to a dose of 60 mg/kg/day and discontinuation of carbamazepine and valproic acid, her language has improved and seizures are controlled. Levetiracetam should be considered as therapy for Landau-Kleffner syndrome.

The Landau-Kleffner syndrome.

Landau-Kleffner Syndrome is a rare childhood disorder which involves seizures and acquired aphasia. Anticonvulsants, or the passage of time, may control the seizures, but speech recovery is variable, and the aphasia may persist.

Multiple subpial transection in Landau-Kleffner syndrome.

We have considered multiple subpial transection (MST) as a treatment option for Landau-Kleffner syndrome (LKS) for the past 6 years. The effect of this technique on language and cognitive ability, behaviour, seizures, and EEG abnormalities is analysed here. Five children (4 males, 1 female; aged 5.5 to 10 years) underwent MST with sufficiently detailed pre- and postoperative data for analysis. Behaviour and seizure frequency improved dramatically after surgery in all children. Improvement in language also occurred in all children, although none improved to an age-appropriate level. All five had electrical status epilepticus in sleep (ESES) before surgery, which was eliminated by the procedure. One child has had an extension of his MST due to the recurrence of ESES and accompanying clinical deterioration with good effect. An attempt is made to set the effect of MST against the natural history of the condition. MST is an important treatment modality in LKS, although the timing of this intervention and its effect on final language outcome remains to be defined.

Rolandic epilepsy: neuropsychology of the active epilepsy phase.

This paper reviews the main studies which have evaluated precisely cognitive functions in rolandic epilepsy. There are very few longitudinal data on the cognitive evolution of these children, particularly in relationship to the paroxysmal electroencephalographic activity. The difficulty to demonstrate direct effects of the epileptic EEG discharges on some cognitive functions and on learning, as occurs in some cases, is discussed.

Language outcome following multiple subpial transection for Landau-Kleffner syndrome.

Landau-Kleffner syndrome is an acquired epileptic aphasia occurring in normal children who lose previously acquired speech and language abilities. Although some children recover some of these abilities, many children with Landau-Kleffner syndrome have significant language impairments that persist. Multiple subpial transection is a surgical technique that has been proposed as an appropriate treatment for Landau-Kleffner syndrome in that it is designed to eliminate the capacity of cortical tissue to generate seizures or subclinical epileptiform activity, while preserving the cortical functions subserved by that tissue. We report on the speech and language outcome of 14 children who underwent multiple subpial transection for treatment of Landau-Kleffner syndrome. Eleven children demonstrated significant postoperative improvement on measures of receptive or expressive vocabulary. Results indicate that early diagnosis and treatment optimize outcome, and that gains in language function are most likely to be seen years, rather than months, after surgery. Since an appropriate control group was not available, and that the best predictor of postoperative improvements in language function was that of length of time since surgery, these data might best be used as a benchmark against other Landau-Kleffner syndrome outcome studies. We conclude that multiple subpial transection may be useful in allowing for a restoration of speech and language abilities in children diagnosed with Landau-Kleffner syndrome.

Acquired epileptiform aphasia.

The acquired epileptiform aphasias, with Landau-Kleffner's syndrome as the example, represent an important group of syndromes in our quest to understand the relationship between epilepsy, language, and behavior. The controversy that truly frames the literature on the acquired epileptiform aphasias is the role of epileptiform activity on language, behavior, and cognition. This review expands the model of Landau-Kleffner's syndrome to include two other encephalopathies with language and behavioral regression in association with an epileptiform electroencephalogram. Both of these encephalopathies, autistic epileptiform regression and disintegrative epileptiform regression, are associated with an acquired language disorder. The developmental period in which the acquired language disorder begins, the type of language disorder, and the location and type of the epileptiform activity are all important variables that may affect clinical manifestations and prognosis.