Pharmacological treatment for continuous spike-wave during slow wave sleep syndrome and Landau-Kleffner Syndrome.

BACKGROUND: Continuous spike-wave during slow wave sleep syndrome (CSWS) and Landau-Kleffner syndrome (LKS) are two epileptic encephalopathies that present with neurocognitive regression, aphasia, and clinical seizures, typically presenting in children around five years of age. The pathophysiology of these conditions is not completely understood. Some studies suggest a common origin for both. No systematic reviews have assessed the efficacy of pharmacological interventions for these conditions. OBJECTIVES: To assess the benefit and adverse effects of pharmacological interventions for the treatment of CSWS and LKS. SEARCH METHODS: On 8 September 2020, we searched the Cochrane Register of Studies (CRS Web) and MEDLINE Ovid (1946 to September 04, 2020). We applied no language restrictions. CRS Web includes randomised or quasi-randomised, controlled trials from CENTRAL, PubMed, Embase, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform. SELECTION CRITERIA: Randomised controlled trials, quasi-randomised controlled trials, and cluster-randomised trials comparing antiepileptic drugs alone, or with steroids or intravenous immunoglobulins, or both versus other antiepileptic drugs, or placebo, or no treatment, administered to children with CSWS and LKS. We planned to compare treatments for the two conditions separately. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed studies identified by the search strategy for inclusion. The primary outcomes considered in this review were neuropsychological-neurolinguistic functions. MAIN RESULTS: Our search strategy yielded 18 references. Two review authors independently assessed all references. We did not find any completed studies to include. We identified one ongoing trial, which was terminated because of lack of enrolment. AUTHORS' CONCLUSIONS: There was no evidence from trials to support or refute the use of pharmacological treatment for continuous spike-wave during slow wave sleep syndrome or Landau-Kleffner syndrome. Well-designed randomised controlled trials are needed to inform practice.

Acetazolamide for electrical status epilepticus in slow-wave sleep.

Electrical status epilepticus in slow-wave sleep (ESES) is characterized by nearly continuous spike-wave discharges during non-rapid eye movement (REM) sleep. ESES is present in Landau-Kleffner syndrome (LKS) and continuous spike and wave in slow-wave sleep (CSWS). Sulthiame has demonstrated reduction in spike-wave index (SWI) in ESES, but is not available in the United States. Acetazolamide (AZM) is readily available and has similar pharmacologic properties. Our aims were to assess the effect of AZM on SWI and clinical response in children with LKS and CSWS. Children with LKS or CSWS treated with AZM at our institution were identified retrospectively. Pre- and posttherapy electroencephalography (EEG) studies were evaluated for SWI. Parental and teacher report of clinical improvement was recorded. Six children met criteria for inclusion. Three children (50%) demonstrated complete resolution or SWI <5% after AZM. All children had improvement in clinical seizures and subjective improvement in communication skills and school performance. Five of six children had subjective improvement in hyperactivity and attention. AZM is a potentially effective therapy for children with LKS and CSWS. This study lends to the knowledge of potential therapies that can be used for these disorders, which can be challenging for families and providers.

Acquired auditory agnosia in childhood and normal sleep electroencephalography subsequently diagnosed as Landau-Kleffner syndrome: a report of three cases.

AIM: We report three cases of Landau-Kleffner syndrome (LKS) in children (two females, one male) in whom diagnosis was delayed because the sleep electroencephalography (EEG) was initially normal. METHOD: Case histories including EEG, positron emission tomography findings, and long-term outcome were reviewed. RESULTS: Auditory agnosia occurred between the age of 2 years and 3 years 6 months, after a period of normal language development. Initial awake and sleep EEG, recorded weeks to months after the onset of language regression, during a nap period in two cases and during a full night of sleep in the third case, was normal. Repeat EEG between 2 months and 2 years later showed epileptiform discharges during wakefulness and strongly activated by sleep, with a pattern of continuous spike-waves during slow-wave sleep in two patients. Patients were diagnosed with LKS and treated with various antiepileptic regimens, including corticosteroids. One patient in whom EEG became normal on hydrocortisone is making significant recovery. The other two patients did not exhibit a sustained response to treatment and remained severely impaired. INTERPRETATION: Sleep EEG may be normal in the early phase of acquired auditory agnosia. EEG should be repeated frequently in individuals in whom a firm clinical diagnosis is made to facilitate early treatment.

A review of the relationships between Landau-Kleffner syndrome, electrical status epilepticus during sleep, and continuous spike-waves during sleep.

The goal of this report is to review the relationships between Landau-Kleffner syndrome (LKS), electrical status epilepticus during sleep (ESES), and continuous spike-waves during sleep (CSWS). LKS is a clinical syndrome involving mainly acquired aphasia and sometimes seizures. Other clinical findings include cognitive impairments and global regression of behavior. The EEG may evolve from more benign conditions into ESES (or CSWS), seen in 50% of patients with LKS, or may also show focal findings. Seizures include atypical absence, generalized tonic-clonic, atonic, and partial motor attacks. Effective medications are discussed. The EEG patterns CSWS and ESES are likely equivalent terms. CSWS is used by some authors, and ESES by others. Patients with these patterns usually show mental retardation, seizures, and global regression. More benign EEG patterns, like focal discharges, may develop into these more severe generalized patterns, which are associated with atypical absences, negative myoclonus, and cognitive disturbances. Memory disorders are common, because the nearly continuous generalized discharges in sleep do not allow for the memory consolidation that also occurs during sleep. Medications and possible etiologies are discussed.

Long-term outcome of 32 children with encephalopathy with status epilepticus during sleep, or ESES syndrome.

PURPOSE: To prospectively evaluate the efficacy of drug treatment and long-term cognitive outcome in children with encephalopathy with status epilepticus during sleep (ESESS). METHODS: Thirty-two children were diagnosed and prospectively followed up for at least 3 years at our unit between 1991 and 2007. Twenty-seven children were included in the prospective treatment study with valproate (VPA) and 17 with VPA combined with ethosuximide (ESM). Treatment response of disappearance of electrical status epilepticus during sleep (SES) was documented with overnight EEG recordings. Neuropsychological follow up for at least 5 years was available in 18 patients. RESULTS: Six children had atypical rolandic (AR) epilepsy, nine Landau-Kleffner syndrome (LKS), and 17 symptomatic epilepsy. Before ESESS, 20 children were cognitively normal. Prospective treatment with VPA and ESM was effective in 3 of the 17 children (18%) treated. Abolition of SES with drug treatment was observed in 16 patients. In all, 10 children (31%), 4 with AR (67%), 3 with LKS (33%), and 3 with symptomatic etiology (19%), including 9 with treatment response regained the pre-ESESS cognitive level. Unfavorable cognitive outcome was predicted by younger age at ESESS diagnosis, lower IQ at the time of the diagnosis, and no response to drug treatment when compared with those with favorable cognitive outcome. Eight of the 16 nonresponders underwent epilepsy surgery. DISCUSSION: Treatment response with VPA combined with ESM was observed more often than with other drug combinations. Most children with ESESS experienced permanent cognitive impairment. Cognitive outcome depends on treatment response on electroencephalography (EEG) and seizures, and on underlying etiology.

Levetiracetam as add-on therapy in different subgroups of "benign" idiopathic focal epilepsies in childhood.

Several recent studies have shown that levetiracetam (LEV) can be beneficial in the treatment of children with typical rolandic epilepsy (RE). Reports about the effectiveness of LEV in the treatment of children with the less benign variants in the spectrum of "benign" idiopathic focal epilepsies are still rare. Little is known about the effect of LEV on interictal epileptiform discharges in these syndromes. We report on LEV therapy in 32 children (mean age: 10.6 years, range: 4-14) with RE or variants like atypical benign idiopathic partial epilepsy of childhood (ABIPEC), Landau-Kleffner syndrome (LKS), and continuous spikes and waves during sleep (CSWS) and in children with benign idiopathic focal epileptiform discharges of childhood (BIFEDC). Cognitive and behavioral problems, not seizures, may be related to the pathological EEG. Patients with a reduction in seizure frequency >50% and/or reduction in BIFEDC >90% 3 months after having started LEV therapy were defined as responders. The average dose of LEV was 39 mg/kg body wt per day; LEV was given in monotherapy to 31.3% of the patients. Overall, 20 of 32 patients (62.5%) did benefit: 12 of 24 patients had a >50% reduction in seizure frequency; 2 of 24 patients (8.3%) were completely seizure free; 18 of 32 patients (56.3%) had a >90% reduction in BIFEDC (including CSWS); 6 of 32 (18.8%) had an EEG completely free of epileptiform discharges; and 17 of 32 (53.1%) showed improvement in cognition and/or language functions and/or behavior. Surprisingly, LEV tended to be more helpful in atypical rolandic epilepsies and other variants.

Landau-Kleffner syndrome and CSWS syndrome: treatment with intravenous immunoglobulins.

This study reports results of therapy with immunoglobulin in children with Landau-Kleffner syndrome (LKS) or the syndrome of continuous spikes and waves during sleep (CSWS syndrome). In a prospective study, children diagnosed between 2002 and 2006 with either LKS or CSWS syndrome were treated soon after diagnosis with intravenous courses of immunoglobulin (IVIg). We compared the results with those reported in the literature and with data from a retrospective survey of our earlier patients. Six children (two girls), aged 4-9 years, were included. Three had LKS, and three had CSWS syndrome. One child-with typical LKS-had been treated with prednisone before (without response). No patient had seizures during IVIg treatment and follow-up. Their electroencephalography (EEG) findings did not improve. Neuropsychological improvement occurred in one child with CSWS syndrome. Three children did not show any beneficial effect; they were subsequently treated with steroids, one with a clearly positive result. We conclude that successful treatment of LKS and CSWS syndrome with IVIg occurs occasionally. However, the improvement cannot always be clearly attributed to this. It might also reflect the natural course of the disease. Although the temporal relation between IVIg treatment and clinical improvement cannot be denied in individual patients, its real value remains to be determined.

Rational treatment options with AEDs and ketogenic diet in Landau-Kleffner syndrome: still waiting after all these years.

Antiepileptic drugs (AEDs) remain a first treatment approach in Landau-Kleffner syndrome (LKS) and related syndromes. In the current literature, only class IV evidence is available. Inclusion criteria and outcome parameters are ill-defined. Most commonly, valproate, ethosuximide, and/or benzodiazepines are used. More recent case series show that sulthiame and especially levetiracetam can be considered as effective drugs. Smaller studies also point to the ketogenic diet as a valuable treatment option in LKS.

Corticosteroids as treatment of epileptic syndromes with continuous spike-waves during slow-wave sleep.

To assess the efficacy and tolerability of steroids in epileptic syndromes with continuous spike-waves during slow-wave sleep (CSWS), charts of 44 children (25 boys) who received corticosteroids for cognitive and/or behavioral deterioration associated with CSWS were retrospectively reviewed. Awake and sleep electroencephalography (EEG) records, clinical and neuropsychological assessments were available before, during, and after corticosteroid therapy. Evaluation focused on effects on EEG, behavior, and cognition. All but two patients received hydrocortisone (initial dose of 5 mg/kg/day). The treatment was slowly tapered with a total duration of 21 months. There were 18 symptomatic and 26 cryptogenic cases. Mean age was 7 years and mean intelligence quotient/developmental quotient (IQ/DQ) was 65. Mean CSWS duration before corticosteroid treatment was 1.7 years. Twenty patients had tried more than two antiepileptic drugs (AEDs) before steroids. Positive response to steroids was found during the first 3 months of treatment in 34 of 44 patients (77.2%), with normalization of the EEG in 21 patients. Relapse occurred in 14 of them. Hence, 20 patients (45.4%) were long-term responders after a single but prolonged trial of steroids, including all four cases of Landau-Kleffner syndrome. Positive response to steroids was highly significantly associated with higher IQ/DQ. Shorter CSWS duration, but not age, etiology, or previous AED trials, was associated with positive response to steroids. Early discontinuation of the treatment for side effects was encountered in seven patients. We conclude that corticosteroids are safe and efficient for treatment of epilepsy with CSWS. Poor responders are patients with very low IQ and long duration of CSWS.

Inhibition of epileptiform activity by neuropeptide Y in brain tissue from drug-resistant temporal lobe epilepsy patients.

In epilepsy patients, drug-resistant seizures often originate in one of the temporal lobes. In selected cases, when certain requirements are met, this area is surgically resected for therapeutic reasons. We kept the resected tissue slices alive in vitro for 48 h to create a platform for testing a novel treatment strategy based on neuropeptide Y (NPY) against drug-resistant epilepsy. We demonstrate that NPY exerts a significant inhibitory effect on epileptiform activity, recorded with whole-cell patch-clamp, in human hippocampal dentate gyrus. Application of NPY reduced overall number of paroxysmal depolarising shifts and action potentials. This effect was mediated by Y2 receptors, since application of selective Y2-receptor antagonist blocked the effect of NPY. This proof-of-concept finding is an important translational milestone for validating NPY-based gene therapy for targeting focal drug-resistant epilepsies, and increasing the prospects for positive outcome in potential clinical trials.

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.

[Adrenocorticotropic hormone therapy in acquired childhood epileptic aphasia]. / Szerzett gyermekkori epilepszias beszédzavar kezelése adrenokortikotrop hormonnal.

Although Landau-Kleffner syndrome, a childhood-acquired epileptic aphasia, is frequently studied either the underlying pathophysiology or the optimal therapy remained unknown. In our study we aimed to investigate the efficacy of ACTH therapy in Landau-Kleffner syndrome. We have analysed retrospectively the documentation of five children treated by ACTH, who suffered from Landau-Kleffner syndrome. We studied the longitudinal changes of the four most characteristic symptoms and signs of the syndrome: epileptiform EEG, speech and behaviour disorders, seizures together with the ACTH regimes. Besides, we analysed the relation between the starting date of the therapy and its efficacy. Before giving ACTH, epileptiform EEG and speech disorders were observed in all the five children, seizures in four of them, behaviour disorders in three of them. In two patients the speech disorder had been persisting for years before. Due to the starting ACTH stoss-therapy (20 E/day for one-two weeks) all the four examined signs disappeared or showed quick softening in all the five children in maximum two weeks. We adjusted long-term low dose maintenance therapy to avoid relapses in the long-term follow-up. Epileptiform EEGs have normalised in one case and have decreased in four cases. Speech disorders have disappeared in two and have softened in three children. Behaviour disorders have cured in 3/4 cases, softened in one case. Seizures have disappeared in all cases. One child is totally asymptomatic, four of them lives with softened symptoms. Analysing our data we found that the earlier the therapy starts, the more effective it is. On the basis of our data ACTH is an effective treatment for Landau-Kleffner syndrome. After giving it for only a short period, relapses often occur, to avoid relapses adjustment of long term low dose maintenance therapy is advisable.

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: an analysis of 10 cases in Venezuela]. / Síndrome de Landau-Kleffner: análisis de 10 casos en 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.

Current and Emerging Therapies of Severe Epileptic Encephalopathies.

In this article, we review the treatment options for the pediatric epileptic encephalopathies and provide an update on the new and emerging therapies targeted at the underlying pathophysiology of many of these syndromes. We illustrate how the identification of the specific genetic and autoimmune causes has made possible the evaluation and development of novel, better targeted therapies, as and at times, avoidance of potentially offending agents.

Management of Landau-Kleffner syndrome.

Landau-Kleffner syndrome (LKS) is an acquired epileptic aphasia disorder in which children, usually 3-8 years of age who have developed age-appropriate speech, experience language regression with verbal auditory agnosia, abnormal epileptiform activity, behavioral disturbances, and sometimes overt seizures. There are no controlled clinical trials investigating the therapeutic options for LKS. Only open-label data are available. Early diagnosis and initiation of prompt medical treatment appear to be important to achieving better long-term prognosis.Several antiepileptic drugs have been reported to be beneficial in treating this syndrome. These include valproic acid (valproate sodium), diazepam, ethosuximide, clobazam, and clonazepam. Reports on the efficacy of lamotrigine, sultiame, felbamate, nicardipine, vigabatrin, levetiracetam, vagal nerve stimulation, and a ketogenic diet are few and more experience is needed. Carbamazepine and possibly phenobarbital and phenytoin have been reported to occasionally exacerbate the syndrome. As initial therapy, valproic acid or diazepam is often empirically chosen. Subsequently, other antiepileptic drugs, corticosteroids, or intravenous immunoglobulin (IVIG) therapy are often used. Corticosteroid therapy should probably not be delayed more than 1-2 months after the initial diagnosis. Various corticosteroid regimens including oral prednisone and, recently, high doses of intravenous pulse corticosteroids, as well as corticotropin (adrenocorticotropic hormone) have been reported to be effective in LKS. Oral corticosteroids are used more often and usually need to be maintained for a long period of time to prevent relapses. The use of IVIG has been associated with an initial dramatic response in only a few patients. In our experience, a long-term worthwhile improvement has been noted in only 2 of 11 patients. These two patients had an immediate response to IVIG initially and after relapses before eventually achieving a long-term sustained remission. Surgical treatment by multiple subpial transection, which is reserved for patients who have not responded to multiple medical therapies, has been followed in selected cases by a marked improvement in language skills and behavior. However, a widely accepted consensus about suitable candidates for this surgery and about its efficacy is still lacking. Speech therapy, including sign language, and a number of classroom and behavioral interventions are helpful in managing LKS, and should be used in all patients.

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.