Cerebral dominance in an unusual case of Landau-Kleffner syndrome

Landau-Kleffner syndrome (LKS) is described by the International Classification of Epileptic Syndromes since 1985 as a constellation of clinical and electrographic signs, including acquired aphasia, regression of language milestones and seizures, along with sleep-activated paroxysms on electroencephalogram which can progress to electrographic status epilepticus of sleep. In this case, a 7-year-old boy presented with an atypical history of new-onset aphasia and regression of language milestones with rare seizures. However, there was an electrographic mismatch in the form of right-sided epileptiform activity and continuous spike and wave of sleep pattern. Detailed speech analysis and perusal of the history revealed a possibly ambidextrous child with right hemispheric language dominance, and he was diagnosed with LKS and treated. This report illustrates the many pitfalls in the diagnosis and treatment of this rare epileptic syndrome.

Epileptic encephalopathies: new genes and new pathways

Epileptic encephalopathies represent a group of devastating epileptic disorders that occur early in life and are often characterized by pharmaco-resistant epilepsy, persistent severe electroencephalographic abnormalities, and cognitive dysfunction or decline. Next generation sequencing technologies have increased the speed of gene discovery tremendously. Whereas ion channel genes were long considered to be the only significant group of genes implicated in the genetic epilepsies, a growing number of non-ion-channel genes are now being identified. As a subgroup of the genetically mediated epilepsies, epileptic encephalopathies are complex and heterogeneous disorders, making diagnosis and treatment decisions difficult. Recent exome sequencing data suggest that mutations causing epileptic encephalopathies are often sporadic, typically resulting from de novo dominant mutations in a single autosomal gene, although inherited autosomal recessive and X-linked forms also exist. In this review we provide a summary of the key features of several early- and mid-childhood onset epileptic encephalopathies including Ohtahara syndrome, Dravet syndrome, Infantile spasms and Lennox Gastaut syndrome. We review the recent next generation sequencing findings that may impact treatment choices. We also describe the use of conventional and newer anti-epileptic and hormonal medications in the various syndromes based on their genetic profile. At a biological level, developments in cellular reprogramming and genome editing represent a new direction in modeling these pediatric epilepsies and could be used in the development of novel and repurposed therapies.

[Language disorders. Diagnosis and treatment]

AIMS

The study reviews language disorders in children. Taking their normal development as the starting point, the work puts forward a differential diagnosis based on the symptoms presented in the moment the patient visited the physician. It also suggests an approach for children with language disorders from the neuropaediatric point of view while also updating the management of some of its forms.

DEVELOPMENT

The acquisition of language is one of the key milestones in the development of children. A child's social and intellectual development is affected by delayed acquisition of language and this can give rise to a ongoing effect involving isolation and regression, which tends towards poor academic achievement and, eventually, leads to the development of learning and social problems. There are studies that evidence a close relationship in children between the development of spoken language and written language, as well as the importance of acquiring language as the basis for writing skills. These problems cause a great deal of anxiety in parents.

CONCLUSIONS

Knowledge of the problem allows the specialist to detect these children early on in the preschool stage and to ensure they receive the right attention. If treated in time, language learning can be modified to a significant degree, thereby avoiding the complications that affect its development. The specialist working with children must recognise these problems and channel them towards the most suitable therapy.

Sparse MEG source imaging in Landau-Kleffner syndrome

Epilepsy patients with Landau-Kleffner syndrome (LKS) usually have a normal brain structure, which makes it a challenge to identify the epileptogenic zone only based on magnetic resonance imaging (MRI) data. A sparse source imaging technique called variation based sparse cortical current density (VB-SCCD) imaging was adopted here to reconstruct cortical sources of magnetoencephalography (MEG) interictal spikes from an LKS patient. Realistic boundary element (BE) head and cortex models were built by segmenting structural MRI. 148-channel MEG was recorded for 10 minutes between seizures. Total 29 epileptiform spikes were selected for analysis. The primary cortical sources were observed locating at the left intra- and perisylvian cortex. Multiple extrasylvian sources were identified as the secondary sources. The spatio-temporal patterns of cortical sources provide more insights about the neuronal synchrony and propagation of epileptic discharges. Our observations were consistent with presurgical diagnosis for this patient and observation of aphasia in LKS. The present results suggest that the promising of VB-SCCD technique in assisting with presurgical planning and studying the neural network for LKS in determining the lateralization of epileptic origins. It can further be applied to non-invasively localize and/or lateralize eloquent cortex for language for epilepsy patients in general in the future.

[Landau-Kleffner syndrome: an analysis of 10 cases in Venezuela]

INTRODUCTION

Landau-Kleffner syndrome is characterised by acquired aphasia and encephalographic alterations that may or may not be accompanied by epileptic seizures. AIM. To analyse the clinical and encephalographic features and response to treatment of 10 patients with Landau-Kleffner syndrome.

PATIENTS AND METHODS

We reviewed the patient records, encephalograms and treatment administered to patients catalogued as having Landau-Kleffner syndrome.

RESULTS

The mean age of the patients was 44 months. Of these cases, 60% presented epilepsy when the diagnosis was established and 70% were found to have epileptic status during slow-wave sleep in the encephalographic study. Results showed that 40% corresponded to variants of Landau-Kleffner syndrome. No cause of the disease could be established in any of the patients. In the neuroimaging study, only one patient displayed abnormalities in the magnetic resonance imaging of the brain. All the patients received adrenocorticotropic hormone (ACTH)-based treatment, at a dose of 1 IU/kg/day for one month, administered together with antiepileptic drugs such as valproic acid and clobazam. Convulsive seizures and epileptic status during slow-wave sleep disappeared in all the patients. In the patients without epileptic status, epileptic activity became less frequent, although it did not completely disappear. Aphasia improved considerably, which meant that all the patients were able to enroll in normal schools.

CONCLUSIONS

We believe that early diagnosis, together with suitable and timely management of aphasic patients with encephalographic alterations that allow ACTH to be used at low doses, make it possible to offer an early education so as to provide maximum recovery from the disease.

The spectrum from BCECTS to LKS: The Rolandic EEG trait-impact on cognition

The laboratory hallmark of BCECTS is the rolandic discharge (RD) in the EEG of patients, occurring in a characteristic topographical, vigilance-related, event-related, and age-related pattern, disappearing during puberty. RDs are present in 2% of healthy children. About 8% of children with RDs have epilepsy. An increased prevalence rate of RDs is found in children with cognitive and behavioral disorders, with headaches and some genetic syndromes. In some patients, the cognitive disorders are transient but in others they are progressive, resulting in stable mental retardation after puberty. A recent study of 36 BCECTS patients addressed the following questions. (1) the possible relationship between the severity of RDs and the neuropsychological deficits; (2) the profile of neuropsychological deficits; (3) changes of cognition related to EEG changes; and (4) effects of therapy. No correlation was found between global IQ and the severity of the RDs. All the children had at least one specific learning disorder (sometimes long-lasting). When the children were treated, a correlation between cognitive and EEG improvement could not be demonstrated. Recently, 21 patients without epilepsy but with attention deficit and hyperactivity and/or learning disorders were studied: an open treatment trial with sulthiame resulted in improved sustained and selective attention. The neurobiology of RDs and their relationship to cognitive dysfunction and epilepsy requires further study.

Neuropsychological findings in Rolandic epilepsy and Landau-Kleffner syndrome

In an attempt to correlate neuropsychological deficits and various neurophysiological aspects of focal epileptic activity in benign childhood epilepsy, we have reviewed the findings of a longitudinal group study of benign childhood epilepsy with centrotemporal spikes (BCECTS) and several case studies of continuous spike-waves during slow sleep syndrome (CSWS). We first distinguish the temporary neuropsychological impairments often observed in the natural history of BCECTS from the more long-lasting and more specific neuropsychological deficits associated with CSWS, of which the Landau-Kleffner syndrome (LKS) is the most studied clinical form. A series of metabolic findings from (18)FDG-PET studies in BCECTS and CSWS children have shown that specific cognitive impairment is related to increased glucose uptake in cortical areas restricted to the associative cortex coincident with the focus of spike-wave discharges. From recent functional neuroimaging data of three patients recovered from LKS, we address the issue of the pathophysiology of cognitive impairment persisting after complete recovery of epilepsy. Finally, we discuss the reliability of the study of mismatch negativity to address the issue of the early effect of interictal discharges in typical and atypical BCECTS on the auditory cortex and the development of speech processing essential to verbal learning.

Treatment with flunitrazepam of continuous spikes and waves during slow wave sleep (CSWS) in children

We describe our treatment of two boys with continuous spikes and waves during slow wave sleep (CSWS). One of the boys was suffering from non-convulsive status epilepticus and the other from conscious disturbance with automatism. Their ictal EEG readings showed continuous diffuse spike and wave complexes, which were considered to show electrical status. The boys were diagnosed as having CSWS, and were later diagnosed with Landau-Kleffner syndrome (LKS). EEG readings returned to normal on intravenous injection of flunitazepam (FZP) at a dose of 0.02 mg/kg, suggesting that FZP is an effective treatment for CSWS.

Landau-Kleffner syndrome with mitochondrial respiratory chain-complex I deficiency

Landau-Kleffner syndrome is characterized by epileptic aphasia associated with electrical status epilepticus of slow wave sleep. A 5-year-old female, who had manifested normal developmental progress, was referred with principal complaints of fluctuating sensory aphasia and bizarre behavior during the preceding 4 months. Landau-Kleffner syndrome was confirmed by clinical and electroencephalographic features; in addition, the patient's mitochondrial respiratory chain-complex I deficiency was confirmed by fibroblast culture with the evidence of energy metabolism disorder. This patient's seizures were intractable to many antiepileptic drugs, adrenocorticotrophic hormone, and intravenous immunoglobulin, with catastrophic cognitive and behavioral decline, but the seizures were successfully controlled by ketogenic diet with supplementary mitochondrial cocktail including coenzyme Q10, riboflavin, L-carnitine, and high-dose multivitamins. The patient finally regained fully normal cognitive functioning. Landau-Kleffner syndrome with mitochondrial respiratory chain-complex I deficiency was controlled in this case by ketogenic diet and supplementary mitochondrial cocktail therapy.

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.

Corticosteroids for the treatment of Landau-kleffner syndrome and continuous spike-wave discharge during sleep

Landau-Kleffner syndrome and its variants such as continuous Spike-Wave Discharge during Sleep (CSWS) are progressive epileptic encephalopathies of childhood. The treatment of this unusual group of patients is controversial. We describe our experience in treating patients with Landau-Kleffner syndrome and CSWS with corticosteroids. The patients received Prednisone 1 mg/kg/day for 6 months, 1 year, then yearly. Follow-up was for 1-10 years (mean 4 years). Ten patients, 3 females, 7 males were studied. Age of onset ranged from 2 to 11 years (mean 7.5 years). Eight patients manifested Landau-Kleffner syndrome, and two had CSWS. Most patients had seizures (8/10); however, two patients did not have clinical seizures. MRI was normal in all patients. SPECT scan was abnormal in four patients, normal in three, and not available in three. All but one patient manifested significant improvement in language, cognition, and behaviour, which continued after the corticosteroid trial. Side effects were few (4/10) and transient and consisted of weight gain (2), behavioral change (1), and hypertension (1). Corticosteroids are a safe and effective treatment for patients with Landau-Kleffner syndrome and CSWS. Most patients had improvement in language, cognition, and behaviour after treatment. Side effects are few and reversible, and benefits appear long lasting. Corticosteroids should be considered as a treatment option in children with Landau-Kleffner syndrome and CSWS.

A Clinical and EEG Study on Idiopathic Partial Epilepsies with Evolution into ESES Spectrum Disorders

PURPOSE

Questioning the presence of any possible prognostic predictors, this study includes a long-term follow-up of clinical and EEG characteristics of 16 patients with idiopathic partial epilepsy (IPE) who subsequently developed epilepsy with electrical status epilepticus during slow sleep (ESES) spectrum disorders.

METHODS

Epilepsy, cognitive and behavioral parameters, and waking and non-rapid eye movement (NREM) EEG data were evaluated and scored for initial stage (i.e., IPE stage), preESES, ESES, and ESES remission periods, individually, on a chronologic basis. Data from 25 healthy subjects who had had IPE at the appropriate ages served for comparison with the patients' data during the IPE stage.

RESULTS

Results revealed a higher incidence in seizure frequency and variability in the ESES group and a resistance to a single antiepileptic drug (AED), as compared with controls, during the IPE stage. Mean age at onset of epilepsy was younger in the ESES group versus controls (5.5 and 7.3 years, respectively). At least one of the premonitory clinical features for development of ESES [an increase in the seizure frequency and/or addition of new types of seizures (93%), appearance of cognitive and/or behavioural changes (81.2%), or a progression in EEG abnormalities (66%)] was present in all patients. Epilepsy remitted in patients within the ESES spectrum at a similar age as in controls in 81.2%, as ESES findings in the EEG disappeared by age 13 years in 94%. Seizure prognosis proved to be the most favorable among the questioned parameters.

CONCLUSIONS

An increase in seizure frequency or development of new seizure types, a deviance in behavior or decrease in cognitive performance, or a spreading tendency of the previously focal abnormalities in control EEGs may be premonitory features of a developing ESES and necessitate close follow-ups with sleep EEGs in children with IPEs.

[Serial MEG change in a boy with Landau-Kleffner syndrome]

We report a 7-year-old boy with Landau-Kleffner syndrome (LKS), with emphasis on the effect of therapy and serial MEG. The equivalent current dipoles (ECDs) of spike discharges accumulated in the bilateral Heschl gyri, predominantly on the right. Although spike discharges on the scalp EEGs disappeared by treatment with clonazepam and sodium valproate, the auditory agnosia did not improve. Therapeutic trials with conventional antiepileptic drugs were unsuccessful. A high-dose corticosteroid was effective, with disappearance of ECDs, appearance of auditory evoked fields (AEF) in the bilateral Heschl gyri on MEG, and improvement of behavioral problems and amelioration of acquired aphasia. The clinical course of this patient suggests that MEG findings are useful not only in making precise diagnosis of LKS but also in assessing and predicting the effects of treatment.

Acquired aphasia without deafness in childhood--the Landau-Kleffner syndrome

A young boy presented with loss of speech and behaviour disturbance and was thought to be deaf. He was subsequently found to have the Landau-Kleffner syndrome (LKS), or acquired aphasia with epilepsy. Children with this disorder commonly present to an audiology or ENT clinic. Early recognition is important to initiate supportive, speech and educational care.

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.

[Bifocal atypical rolandic epilepsy with speech dyspraxia]

Clinical and neurophysiological analysis of a case of a 7 year old patient with typical benign partial seizures with rolandic spikes and speech disorder, differing from those in Landau-Kleffner syndrome and in typical benign partial epilepsy of childhood presenting as speech dyspraxia. Two independent foci (in the premotor cortex of the left front lobe (dominant hemisphere) and in the temporal lobe of the right hemisphere were found. Significant clinical improvement and electrographical positive effect in EEG were achiered after prednisolone and sodium valproate treatment.

[Landau-Kleffner syndrome (acquired epileptic aphasia)]

Landau-Kleffner syndrome is characterized by a complex group of symptoms including deterioration in language skills, seizures, and abnormal electroencephalography findings. A six-year-old male patient had aphasia for three years and generalized tonic-clonic epileptic seizures for two years. Pure-tone audiometry and auditory brain-stem response audiometry findings were normal. He had verbal auditory agnosia rather than true aphasia. Cranial computed tomography and magnetic resonance imaging studies did not show any abnormal findings. Single-photon emission computed tomography showed hypoperfusion in the right hemispheric temporal lobe. Despite treatment with corticosteroids and intravenous immunoglobulins, multiple exacerbations were interspersed in a four-year follow-up period.

[Electroclinical characteristics of Landau-Kleffner syndrome]

The study aimed at investigating epileptic attack's semiology and other electroclinical characteristics in Landau-Kleffner syndrome as well as therapeutic efficacy. Six patients with Landau--Kleffner syndrome, 5 boys, 1 girl, aged 6-10 years, mean age 7.5 years, have been analyzed. Epileptic attacks were observed only in 3 patients with debut at the age of 2.5-6 years (mean 4 years). In 50% of the cases, the attacks were not detected. The types of epileptic attacks were specified as follows: atypical absences--3 patients; pharyngo-oral--2; secondary generalized--2; atonic falls--1; hemiconvulsive--1. In routine EEG study, regional epileptiform activity was observed in all the patients, being localized in central temporal (3 cases), posterior temporal (1) and fronto-temporal (1) leads. In 3 cases (50%), diffusive epiactivity was also detected. During sleep, emergence of prolonged diffuse epiactivity was revealed for all the patients, with appearance of electrical status epilepticus during slow sleep in 50%. Valproates in dosage 30-60 mg/kg daily were highly effective for stopping epileptic seizures. Significant improvement of speech functions was observed only if antiepileptics sulthiame (ospolot) or clobasam (frizium) were used in addition to basic therapy. Clobasam in dosage 0.5-0.75 mg/kg daily was the most efficient in blockade of EEG diffuse epileptiform activity, reduction of aphasia symptoms and behavior improvement.

Landau Kleffner syndrome: electroclinical and etiopathogenic heterogeneity

Landau - Kleffner syndrome is a rare, functional, age-related epilepsy with aphasia and epileptiform discharges on EEG. The heterogenity of clinical presentations, course, long-term outcome and response to treatment suggests multiple underlying etiologies. Normal children abruptly develop deterioration of language functions along with spike and wave discharges on EEG. Clinical seizures may or may not be present. The aphasia responds poorly to most drugs. Valproic acid and benzodiazepines are most effective. Steroids and intravenous immunoglobulins have shown a variable response. Long-term outcome of aphasia is variable, many patients persist with residual impairment. Important questions regarding etiopathogenesis are unanswered.

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.

Landau-Kleffner syndrome beginning with stuttering: case report

Landau-Kleffner syndrome is marked by an acquired aphasia in children who have had normal language and motor development. A 3.5-year-old girl was referred to our clinic with stuttering. She was diagnosed as having benign myoclonic epilepsy of infancy at 3.5 months of age and treated with valproic acid. Her electroencephalogram (EEG) returned to normal at the end of the first year. The therapy was stopped after a 2-year seizure-free period. She started to stutter prominently 3 months after the discontinuation of antiepilepsy drugs. She had no verbal agnosia. Her EEG revealed multiple spike and wave discharges. She was diagnosed as having Landau-Kleffner syndrome. Her previous epilepsy history had contributed to her having obtained an EEG in the early period. We suggest that if a child with normal language function starts to stutter, Landau-Kleffner syndrome must be considered in the differential diagnosis.

Nonconvulsive status epilepticus presenting as a subacute progressive aphasia

We report a 62-year-old man with non-convulsive status epilepticus (NCSE) presenting as a progressive aphasia that developed insidiously over 5 weeks. On video-EEG monitoring, aggravation of the aphasia coincided with occurrence of seizure activities arising from the left fronto-temporal area. Brain MRI was noncontributory but a fluorodeoxyglucose-PET scan revealed a hypometabolism in the left anterior temporal area. Following anticonvulsant treatment, aphasia recovered gradually over several weeks despite prompt resolution of epileptic discharges on EEG. Our patient's findings, gradual onset of isolated aphasia with gradual resolution after initiation of treatment, may differ from previously reported cases with aphasic status epilepticus because their aphasia showed abrupt onset and rapid resolution with anticonvulsant medication.

Acquired epileptiform aphasia: a dimensional view of Landau-Kleffner syndrome and the relation to regressive autistic spectrum disorders

Acquired epileptiform aphasia (AEA) is characterized by deterioration in language in childhood associated with seizures or epileptiform electroencephalographic abnormalities. Despite an extensive literature, discrepancies and contradictions surround its definition and nosological boundaries. This paper reviews current conceptions of AEA and highlights variations in the aphasic disturbance, age of onset, epileptiform EEG abnormalities, temporal course, and long-term outcome. We suggest that AEA, rather than being a discrete entity, is comprised of multiple variants that have in common the features of language regression and epileptiform changes on EEG. Viewed this way, we argue that AEA can be conceptualized on a spectrum with other epileptiform neurocognitive disorders that may share pathophysiological features. The implications of this viewpoint are discussed, with emphasis on parallels between the AEA variants and regressive autistic spectrum disorders.

[Landau-Kleffner and autistic regression: the importance of differential diagnosis]

Some neurological disorders may present psychiatric signs and symptoms, therefore the search for an etiological diagnosis is crucial. The aim of this study is to report the case of a patient with a neurological disorder, diagnosed during a psychiatric admission. A boy with normal neuropsychomotor development until the age of 3 years, started presenting epileptic seizures, followed by behavioral disorder and language deterioration. During neurologic follow-up, the patient was referred to the Psychiatry Department with a diagnosis of autism, in this case an autistic regression (AR). During his admission, diagnosis of Landau-Kleffner syndrome (LKS) was established on clinical and EEG grounds. LKS is characterized by acquired aphasia, epilepsy, EEG abnormalities and behavioral changes, including autistic traits. Language regression is observed LKS and AR. We stress the main differences between these two entities because misdiagnosis may postpone early intervention and consequent benefits, as observed in our case.

Epileptic syndromes in childhood: clinical features, outcomes, and treatment

We reviewed the clinical features, outcome, and treatment of many of the epileptic syndromes that begin in the childhood from 2 to 12 years of age, using a review of the literature and personal experience, with most references to authoritative texts. The developmental tasks of childhood are centered on refinement of motor skills and development of complex intellectual and social skills. The childhood onset epilepsies can be divided into benign, intermediate, and catastrophic based on their impact on childhood development. The clearest benign epilepsy is benign rolandic epilepsy, which often does not require medication treatment. The definition of benign occipital epilepsy is still often vague. In the intermediate category, childhood absence epilepsy often has associated learning disorders and a poor social outcome. About 50% of children with cryptogenic partial seizures have a very benign course, even though their epilepsy syndrome is not well defined. Generalized epilepsy with febrile seizures plus (GEFS+) has a dominant inheritance with a defined defect in cerebral sodium channels, but varies considerably in severity within affected members of the same kindred. The catastrophic epilepsies in childhood all have an inconsistent response to AED treatment and include continuous spike-wave in slow sleep (with variable severity), Landau-Kleffner syndrome (with a confusing overlap with autistic regression), the Lennox Gastaut syndrome (with broad defining features), and myoclonic-astatic epilepsy (with important overlaps with Lennox-Gastaut). Many of the epilepsies that begin in childhood are benign. Others interfere seriously with cognitive and social development.

Landau-Kleffner syndrome: a case report

A healthy 5 year old boy developed aphasia, attention disorder and hyperkinesia preceded by transient formed visual hallucinations and emotional outburst, immediately after a stressful event of forced separation from his father. EEG showed generalized epileptiform activity. He was diagnosed as Landau-Kleffner syndrome (LKS). CT and MRI of the brain were normal. SPECT showed left mesial temporal hypoperfusion. He improved on antiepileptics and ACTH.

Landau-Kleffner syndrome: study of four cases

We describe four patients with clinical features of Landau-Kleffner syndrome and discuss electroencephalographic features, treatment and prognosis. Anticonvulsants and prednisone were used for treatment with good control of seizures in all cases and a less effect response in acquired aphasia. Further studies are necessary to elucidate the causes and management of this syndrome.

[Language and learning disorders in epilepsy with continuous spike-waves during slow sleep]

Efficacy of antiepileptic drugs in children with epilepsy is usually evaluated on the basis of reduction in seizure frequency. However, in a number of cases, the effect of a drug in reducing EEG paroxysmal activity should be considered. This applies particularly to Landau-Kleffner syndrome and to the syndrome of continuous spike-waves during slow sleep. In developmental language disorders, EEG paroxysmal activity is present in almost 30% of the cases. Paroxysmal abnormalities are usually less frequent than what is observed in epilepsy with continuous spike-waves during slow sleep. Pathogenesis remains unknown and the relationship between EEG evolution and language improvement is not as clear as in Landau-Kleffner syndrome.

Landau-Kleffner syndrome: a case of a dissociation between spoken and written language

A case of a girl affected by Landau-Kleffner syndrome (acquired aphasia with convulsive disorder) is reported. The girl showed epileptic seizures and EEG abnormalities. At the age of 7 years 10 months they were followed by onset of aphasic symptoms accompanied with behavioural disturbances. By the age of 9 years she developed a severe verbal auditory agnosia and loss of spoken language expression, but was able to use reading and writing to communicate. This unusual dissociation suggests that spoken or written language can be affected selectively. The girl was followed up to the age of 14 years 6 months and her language recovered well by this age. (Fig. 2, Ref. 42.)

Landau-Kleffner syndrome (acquired epileptic aphasia) in a Nigerian child

Epilepsy is one of the commonest disorders presenting the neurological clinics in developing countries. There are attendant complications especially in untreated or poorly treated cases. In this article, we report an uncommon complication known as Landau-Kleffner syndrome in a Nigerian girl. The syndrome, typically seen in children consists of an acquired aphasia frequently associated with clinical seizures and paroxysmal electroencephalographic (EEG) accompaniment. There had been no adequate neuropathlogical correlations to explain the symptomatology; thus, various forms of pathogenesis have been ascribed to the syndrome. The clinical seizure is easily controlled by an antiepileptic; but speech recovery is variable, and this is usually poor in cases presenting one or two years after onset.

[Landau kleffner syndrome]

INTRODUCTION

The Landau Kleffner syndrome (SLK) is associated with paroxystic alterations of the electroencephalogram which are intensified during sleep, with acquired aphasia and epilepsy, in 75 83% of the cases. The syndrome is associated with other features, such as personality disorders presenting as autistic behaviour, cognitive regression and in some cases, motor dysfunction. The epileptic activity appears to be responsible for the disorder. Treatment with anti epileptic drugs is ineffective in many cases, although there may be periods of spontaneous improvement, or there may be permanent sequelas of language. Design. A systematic revision of one case.

CASE REPORT

A five year old boy with no previous clinical history had, at the age of four years, presented with behaviour changes and aphasia, accompanied by paroxystic changes on the EEG and nocturnal polysomnogram. On cranial CT there was a mid line cyst. He had had no seizures. Treatment. Treatment with carbamazepine led to clinical improvement in behaviour, reduction in the paroxysms and appearance of sleep spindles, but little effect on the degree of aphasia.

CONCLUSIONS

The case described is a variant of SLK, with no epileptic seizures, some improvement on carbamazepine and a mid line cyst.

Sign language in childhood epileptic aphasia (Landau-Kleffner syndrome)

Acquired epileptic aphasia (AEA, or Landau-Kleffner syndrome) is a unique condition in which children can lose oral language (OL) comprehension and expression for a prolonged period. These children can benefit from visual forms of language, mainly sign language (SL), but the quality of SL has never been analyzed. The case is reported here of a boy with AEA who lost speech comprehension and expression from 3 years 6 months to 7 years and was educated in SL from the age of 6 years. His SL was evaluated at the age of 13 years and 6 months and compared with a control child with congenital sensorineural deafness. It was found that: (1) our patient achieved the same proficiency in SL as the control child with deafness; (2) SL learning did not compete with, but perhaps even hastened, the recovery of OL. Intact ability to learn a new linguistic code such as SL suggests that higher-order language areas were preserved and received input from a separate visual route, as shown by neuropsychological and functional imaging research in deaf and hearing signers.

Epileptic encephalopathy

Epileptic encephalopathies are conditions in which neurologic deterioration results mainly from epileptic activity. It can be due to very frequent or severe seizures, or to subcontinuous paroxysmal interictal activity. The former consists mainly of severe myoclonic epilepsy in infancy (SMEN), in which patients exhibit seizures from the middle of the first year of life with repeated episodes of status epilepticus, and migrating partial epilepsy in infancy, in which, from the first trimester of life, partial seizures affect various areas of the cortex randomly and in a subcontinuous fashion. Cases with subcontinuous paroxysmal interictal activity affect newborns with suppression bursts, thus consisting of either Ohtahara syndrome or neonatal myoclonic encephalopathy, and infants with infantile spasms (IS), although rare cases do not start until age 4 years. In childhood, it consists of various types of generalized seizures combined with either slow spike-waves of the Lennox-Gastaut syndrome (LGS) or with myoclonus and 3-Hz spike-waves of myoclonic-astatic epilepsy, and continuous spike-waves in slow sleep (CSWS) combined with various neuropsychological patterns including Landau-Kleffner syndrome, frontal lobe syndrome, orofacial dyspraxia, or negative myoclonus. Management differs for all these syndromes, with the combination of clobazam (CLB) and stiripentol (STP) being promising for SMEN, vigabatrin (VGB) for IS, lamotrigine (LTG) for LGS, and steroids for CSWS. It is important to avoid potential drug-induced worsening by phenobarbital (PB), phenytoin (PHT), carbamazepine (CBZ), tiagabine (TGB), and VGB; in children and especially in infants, treatment with valproate is preferred each time the proper diagnosis is not reached.

Landau Kleffner syndrome

An eight-year-old male child presenting with history of generalized convulsions, gradual loss of speech and generalized EEG (electroencephalography) abnormalities was diagnosed as Landau Kleffner Syndrome. He initially developed generalized convulsions which later changed to partial seizures during the course of illness. He was started on sodium valproate and continued with the drug (30 mg/kg/day) on which, he showed improvement in speech, behavior, hyperkinesis and frequency of convulsions during the follow-up.

Atypical benign partial epilepsy/pseudo-Lennox syndrome

The purpose of this report is to describe the full clinical and electroencephalograpic spectrum of atypical benign partial epilepsy (ABPE) or pseudo-Lennox syndrome (PLS). We retrospectively analyzed the clinical and EEG data of 43 children with ABPE/PLS seen in our department during the last 25 years. Criteria for diagnosis of ABPE/PLS were the occurrence of generalized minor seizures as previously described for ABPE/PLS and the detection of focal sharp waves indistinguishable from those of rolandic epilepsy (RE) with generalization during slow sleep. Mental development prior to onset of epilepsy was retarded in 26% of patients. In 74%, age at onset of seizures ranged from 2-5 years of age. Atonic-astatic seizures, atypical absences, and more rarely, myoclonic seizures were the predominating seizure types in 67% of patients. Status of minor seizures occurred in 40%. One or several episodes of partial and secondarily generalized seizures were observed. Rolandic seizures occurred in 28%. The EEG was characterized by a normal or slightly slowed background activity and predominantly multi-focal sharp waves (88%) which were activated to a bioelectrical status in 56% during sleep. No tonic seizures and no fast > 10 Hz spike discharges were observed in any of the 1.291 EEG of the patients. Despite an often temporarily therapy-resistant course which led to use of steroids in 51% of patients, seizures had ceased in 84% and epileptic discharges had disappeared in 72% of patients at last follow-up. All patients older than age 15 were seizure-free. However, the rate of mentally handicapped patients had more than doubled from 26 to 56%. EEG which could be performed in 41 out of 56 siblings demonstrated shw in 40% of siblings in whom EEG were done at the age of maximum penetrance of sharp waves (3-10 years). ABPE/PLS overlaps broadly with RE, but also with electrical status epilepticus during sleep and Landau-Kleffner syndrome. Therefore, ABPE/PLS can be ranked alongside RE and other idiopathic partial epilepsies. The high incidence of sharp waves in siblings suggests that ABPE/PLS and RE have a common underlying genetic etiology.

Landau-Kleffner syndrome: course and correlates with outcome

The presenting characteristics of 18 (11 female, seven male) children with Landau-Kleffner syndrome (LKS) were studied with respect to course and outcome of their condition at a mean length of 67 (SD 46) months' follow-up. All had regression of receptive language (mean age of onset 4 years 9 months) and electrical status epilepticus in sleep (ESES). Length of ESES correlated strongly with length of period between onset of illness and onset of recovery (p<0.006) and also with eventual receptive (p<0.001) and expressive (p<0.007) language. Behaviour during the acute phase was severely affected in nine children and associated with frontal lobe discharges in awake EEGs (p<0.004). Age at onset was not correlated with outcome. All children had impaired short-term memory at follow-up. Three children had language outcome within the normal range. No child with ESES lasting longer than 36 months had normal language outcome. These data lend support for intervention in ending ESES by 36 months using multiple subpial transection (MST) if steroids are ineffective or cause unacceptable side effects.

Interactions between sleep and epilepsy

Sleep is one of the best-documented factors influencing the expression of seizures and interictal discharges. Janz studied the relation between seizures and the sleep/wake cycle and divided the epilepsies into three categories: nocturnal, awakening, and diffuse. Since then, the effect of sleep on the ictal and interictal manifestations of epilepsy has been studied extensively. Many seizures are activated by sleep or arousal from sleep. Interictal discharges are also seen more commonly during sleep, with the greatest activation seen during nonrapid eye movement sleep. Sleep not only increases the frequency of epileptiform abnormalities, but also may alter their morphology and distribution. Sleep deprivation also facilitates both epileptiform abnormalities and seizures. Seizures, on the other hand, also impact sleep. Epileptic patients demonstrate multiple sleep abnormalities, including an increased sleep latency, fragmented sleep, increased awakenings and stage shifts, and an increase in stages 1 and 2 of nonrapid eye movement sleep. These disturbances may in turn be modulated by antiepileptic treatment. This review summarizes the interactions between sleep and epilepsy, including the timing of seizures during the sleep/wake cycle, the influence of sleep on various seizure disorders, the effects of sleep deprivation, and the changes in sleep patterns caused by seizures and their treatment.

Success of ambulatory EEG in children

SUMMARY

Continuous ambulatory EEG (AEEG) monitoring is a method used to (1) determine seizure type and location of seizure onset, and (2) to discriminate between epileptic and nonepileptic events. This study was performed to determine how successful AEEG would be in recording seizures when the events were reported to occur at least 3 days per week. AEEGs of children who were patients at Children's Hospital Oakland between December 1993 and June 1997 were reviewed to see why the recordings were performed and to determine whether typical seizures were recorded. Children who had seizurelike events needed to have typical spells 3 days or more per week to justify obtaining AEEG. Most AEEGs were performed to discriminate between epileptic and nonepileptic seizures. A total of 167 children underwent AEEG recording. Ten were recorded to determine whether they were having frequent subtle seizures or frequent interictal epileptiform discharges. The remaining 157 patients had discrete events. A total of 140 children (89%) had their typical spells recorded. A total of 107 of these children (76%) had nonepileptic events. Average duration of recording was 1.9 days. AEEG is very successful in recording children's seizurelike events when parents report events occur at least 3 days per week. The procedure is well tolerated and there are few technical problems that prolong recording time.

Language regression in childhood

Language regression is observed both in autistic regression and as part of acquired epileptic aphasia (Landau-Kleffner Syndrome). We prospectively identified 177 children with language regression at four major medical centers, and their clinical characteristics were recorded. Their mean age at regression was 22.8 months. The mean time-to-specialist referral was 38 months of age. Most children (88%) met criteria for autism or manifested autistic features. Males (P = 0.02) and children less than 3 years of age who regressed (P = 0.016) had a higher probability of developing autistic behaviors. Seizures were more common in children who regressed after they reached 3 years of age (P < 0.001), and children with seizures were less likely to have associated autistic regression (P < 0.001). Electroencephalogram abnormalities were reported in 37% of patients and were more common in children with seizures (P < 0.001). At last follow-up, language function was impaired in 88% of the children, although some improvement was noted in 57%. We conclude that the loss of previously acquired language at any age, even if that language only includes a few words or communicative gestures, is often associated with a more global regression in cognition and/or behavior and has serious implications for future function. Early identification and referral of these children is necessary to allow for diagnosis and intervention.

Atypical "benign" partial epilepsy or pseudo-Lennox syndrome. Part I: symptomatology and long-term prognosis

PURPOSE

Atypical benign partial epilepsy (ABPE) or pseudo-Lennox syndrome (PLS) is characterised by generalised minor seizures and focal sharp slow waves and spikes (SHW) as observed in Rolandic epilepsy (RE), but with exceptional pronounced activation during sleep. The aim of this study was to describe the full spectrum of ABPE in the hitherto largest group of patients.

METHODS

We retrospectively analysed the clinical and EEG data of 43 children who fulfilled the following criteria: occurrence of generalised minor seizures as described for ABPE (i.e., atonicastatic seizures, myoclonic seizures, atypical absences) and focal SHW identical to those observed in RE, but with generalisation during sleep.

RESULTS

Language development prior to onset of epilepsy was retarded in 26% of patients. In 74%, age at onset of epilepsy ranged from 2 to 6 years. Manifestation occurred earlier in boys than in girls. Generalised minor seizures constituted the predominating seizure type in 67% of patients. Twenty-eight percent of patients suffered from simple partial seizures of the oro-facial region or generalised tonic-clonic seizures originating from the oro-facial region. Additionally, generalised tonic-clonic (44%), unilateral (21%), partial motor (44%), versive (12%), focal atonic (9%), and complex-partial seizures (2%) were observed. A bioelectrical status was recorded in 56% of patients during sleep. No tonic seizures and no fast spike series (bursts of 10-20 Hz rhythms) were observed. At last follow-up, 84% of patients were in clinical remission. All subjects older than age 15 were seizure-free. However, 56% of patients attended a school for mentally handicapped children.

CONCLUSIONS

ABPE or PLS broadly overlaps with RE, electrical status epilepticus during sleep, and Landau-Kleffner syndrome. Regarding the epilepsy, the prognosis is excellent, mental deficit, however, seems to be frequent. The differentiation from Lennox-Gastaut syndrome and myoclonic astatic epilepsy is essential. Instead of ABPE, the term pseudo-Lennox syndrome is proposed.

Recent advances in candidate selection for pediatric epilepsy surgery

Many patients who were once considered inoperable are candidates for a wide variety of surgical procedures. This trend is particularly striking at pediatric centers that serve patients with diverse forms of epilepsy that compromise development. Newer diagnostic techniques, including structural and functional imaging, EEG monitoring, and surgical technology, can provide a complete representation of the etiology and expression of the epileptic focus, including accurate cortical localization. This review focuses on several forms of epilepsy that, until recently, were not regarded to be surgically amenable. The adverse seizure and neurobehavioral prognosis in patients with these disorders provides the justification to search for innovative treatments. With more sophisticated tools for preoperative evaluation and an expanding knowledge base, it is likely that the number of surgical candidates will continue to increase in the future.