Neuropsychological Findings: Myoclonic Astatic Epilepsy (MAE) and Lennox-Gastaut Syndrome (LGS)

Structural brain abnormalities in epilepsy with myoclonic atonic seizures

OBJECTIVE

Epilepsy with myoclonic atonic seizure (EMAS) occurs in young children with previously normal to subnormal development. The outcome ranges from seizure freedom with preserved cognitive abilities to refractory epilepsy with intellectual disability (ID). Routine brain imaging typically shows no abnormalities. We aimed to compare the brain morphometry of EMAS patients with healthy subjects several years after epilepsy onset, and to correlate it to epilepsy severity and cognitive findings.

METHODS

Fourteen EMAS patients (4 females, 5-14 years) and 14 matched healthy controls were included. Patients were classified into three outcome groups (good, intermediate, poor) according to seizure control and cognitive and behavioral functioning. Individual anatomical data (T1-weighted sequence) were processed using the FreeSurfer pipeline. Cortical volume (CV), cortical thickness (CT), local gyrification index (LGI), and subcortical volumes were used for group-comparison and linear regression analyses.

RESULTS

Morphometric comparison between EMAS patients and healthy controls revealed that patients have 1) reduced CV in frontal, temporal and parietal lobes (p = <.001; 0.009 and 0.024 respectively); 2) reduced CT and LGI in frontal lobes (p = 0.036 and 0.032 respectively); and 3) a neat cerebellar volume reduction (p = 0.011). Neither the number of anti-seizure medication nor the duration of epilepsy was related to cerebellar volume (both p > 0.62). Poor outcome group was associated with lower LGI. Patients in good and intermediate outcome groups had a comparable LGI to their matched healthy controls (p > 0.27 for all lobes).

CONCLUSIONS

Structural brain differences were detectable in our sample of children with EMAS, mainly located in the frontal lobes and cerebellum. These findings are similar to those found in patients with genetic/idiopathic generalized epilepsies. Outcome groups correlated best with LGI. Whether these anatomical changes reflect genetically determined abnormal neuronal networks or a consequence of sustained epilepsy remains to be solved with prospective longitudinal studies.

Cognitive, adaptive, and behavioral effects of adjunctive rufinamide in Lennox-Gastaut syndrome: A prospective observational clinical study

INTRODUCTION

Lennox-Gastaut syndrome (LGS) is a severe pediatric epilepsy syndrome characterized by multiple drug-resistant seizure types. Children with LGS usually experience cognitive regression, and LGS is almost always associated with moderate to severe cognitive impairment. Rufinamide (RFM) was approved by the European Medicines Agency in 2007 for the adjunctive treatment of seizures associated with LGS in patients ≥4 years of age. The primary objective of our study was to assess cognitive, adaptive, and behavior functioning of patients with LGS after 12 months of RFM therapy.

METHODS

This was an observational, multicenter, prospective study involving 16 patients diagnosed with LGS aged between 7 and 58 years (mean = 22 ± 16.3). Fourteen of 16 patients were already on therapy with 3 antiseizure drugs and 2/16 with 4 antiseizure drugs; RFM has been added with 100 mg/week increments up to a dose of 300-2400 mg/day. The participants and their parents underwent a neuropsychological evaluation for the assessment of intellectual, adaptive, and emotional/behavioral functioning (Leiter International Performance Scale-Revised (LEITER-R), Vineland, and Child Behavior CheckList (CBCL), respectively) before the RFM introduction (baseline) and 12 months after the RFM therapy (T2). Physical and neurological examination, electroencephalography (EEG) recording, seizure type and frequency, and adverse reactions were also considered.

RESULTS

After 12 months, the total intelligence quotient (IQ) assessed by LEITER-R did not show statistical significant changes, such as there were no statistically significant changes in adaptive functions, assessed by Vineland. Furthermore, there were no statistically significant changes in internalizing and externalizing problems assessed by CBCL.

CONCLUSION

Adjunctive treatment with RFM did not negatively affect cognitive, adaptive function, and emotional profile in patients with LGS after 1 year of follow-up.

Usefulness of preschool and school versions of the Behavioral Rating Inventory of Executive Functions in the evaluation of the daily life executive function in myoclonic-atonic epilepsy

PURPOSE

Executive functions (EF) are high-order cognitive skills that have a major influence on quality of life, social skills, and school achievement. We aimed to screen EF daily life abilities in young patients with myoclonic-atonic epilepsy (MAE) using an ecological questionnaire and to correlate EF to epilepsy characteristics.

METHODS

Behavioral Rating Inventory of Executive Functions - Preschool (BRIEF-P) and BRIEF - for school-aged patients - parental questionnaires were proposed to patients with MAE and typically developing children (TDC) including Inhibit, Shift, Emotional control, Working memory (WM), Plan/Organize, Initiate, Organization of materials, and Monitor subscales. We included prospectively 12 patients with MAE and 44 TDC aged 3 to 5 years and seven patients with MAE and 21 TDC aged 6-7 years. We performed in addition for all patients an intellectual efficiency evaluation using WPPSI-IV (Wechsler intelligence scale for preschool children version IV) and collected demographics, age at onset of epilepsy, epilepsy duration, response to treatment, number and type of treatments including AEDs (antiepileptic drugs), and ketogenic diet.

RESULTS

Four out of 12 patients for BRIEF-P and 6/7 patients for BRIEF had pathological scores for at least one domain. Behavioral Rating Inventory of Executive Functions' questionnaires showed higher pathological scores for WM, Plan/Organize, Initiate, Monitor, and Metacognition Index in patients with MAE compared to TDC suggesting higher problems reported by parents. Working memory scores were higher in the group with MAE than TDC for both BRIEF-P and BRIEF. Response to treatment is a predictor of multiple BRIEF-P domains. Epilepsy duration predicts Shift and WM domains while age at onset predicts WM domain on BRIEF in this syndrome.

CONCLUSIONS

This study is the first to assess prospectively EF in young patients with MAE. We show everyday deficits in EF reported by parents. Metacognition and more specifically WM, appear to be a core deficit. Early evaluation of EF using both questionnaires and standardized tools is necessary for early detection of EF deficit and initiating tailored rehabilitation. Given the normal development before seizure onset and the absence of cerebral lesion in MAE, these results are in favor of the impact of epilepsy on EF.

Dravet Syndrome: An Overview

Dravet syndrome (DS), also known as severe myoclonic epilepsy of infancy (SMEI), is one of the rare early childhood intractable epileptic encephalopathies associated with pleomorphic seizure activity, cognitive decline, motor, and behavioral abnormalities. The convulsive seizure is the most common type seen in DS. After the first episode of seizure-like activity, behavioral disorders and cognitive decline are progressive and long-lasting. The most common etiology identified in patients with DS is a de-novo genetic mutation alpha-1 subunit of voltage-gated calcium channel gene (SCN1A). DS is diagnosed clinically and if unclear, genetic testing is recommended. DS treatment options include anti-epileptic drugs and cannabinoids; ketogenic diet therapy and surgical options such as the deep brain and vagal nerve stimulation. Due to drug-refractory epilepsy in DS, many more therapies are being investigated to increase the longevity of patients.

Diagnosis switching and outcomes in a cohort of patients with potential epilepsy with myoclonic-atonic seizures

INTRODUCTION

There is overlap in the electroclinical features of many childhood epilepsy syndromes, especially those presenting with multiple seizure types, such as epilepsy with myoclonic-atonic seizures (EMAS) and Lennox-Gastaut syndrome (LGS). This study aimed to determine the frequency of diagnosis switching and the factors influencing epilepsy syndrome diagnosis in a cohort of children with possible EMAS, as well as to explore the relationship between epilepsy syndrome diagnoses, key electroclinical features, and clinically relevant outcomes.

METHODS

This is a cross-sectional retrospective chart review of children treated at the Children's Hospital of Colorado with a potential diagnosis of EMAS.

RESULTS

There were 77 patients that met eligibility criteria, including 39% (n = 30) with an initial diagnosis of EMAS and 74% (n = 57) with a final diagnosis of EMAS. On average, for the 65% of patients who received more than one epilepsy diagnosis, the first, second, and third diagnoses were received within one year, three years, and ten years after epilepsy onset, respectively. Final diagnosis was significantly related to obtaining at least a six-month period of seizure freedom, p = 0.03. Classic LGS traits, including paroxysmal fast activity, slow spike-and-wave, and tonic seizures were present in 50% of the overall cohort, although a minority of these patients had a final diagnosis of LGS. However, the presence of more LGS traits was associated with a higher likelihood of ongoing seizures. Adjusted for age of epilepsy onset, seizure freedom was half as likely for every additional LGS trait observed (0.49[0.31, 0.77], p = 0.002).

CONCLUSION

Current epilepsy syndrome classification has reduced applicability due to overlapping features. This results in diagnosis switching and limited prognostic value for patients with an overlapping clinical phenotype. Future studies should attempt to stratify patients based not only on epilepsy syndrome diagnosis, but also on the presence of various electroclinical traits to more accurately predict outcome.

Epileptic Encephalopathies-Clinical Syndromes and Pathophysiological Concepts

Epileptic encephalopathies account for a large proportion of the intractable early-onset epilepsies and are characterized by frequent seizures and poor developmental outcome. The epileptic encephalopathies can be loosely divided into two related groups of named syndromes. The first comprises epilepsies where continuous EEG changes directly result in cognitive and developmental dysfunction. The second includes patients where cognitive impairment is present at seizure onset and is due to the underlying etiology but the epileptic activity may then worsen the cognitive abilities over time. Recent, large-scale exome studies have begun to establish the genetic architecture of the epileptic encephalopathies, resulting in a re-consideration of the boundaries of these named syndromes. The emergence of this genetic architecture has lead to three main pathophysiological concepts to provide a mechanistic framework for these disorders. In this article, we will review the classic syndromes, the most significant genetic findings, and relate both to the pathophysiological understanding of epileptic encephalopathies.

Comorbidity of childhood epilepsy

Epilepsy in children is occasionally associated with variable comorbidities although the frequency of such comorbidity is often difficult to determine. They can be divided into three categories: neurological, psychological, and physical comorbidities. The goal of the present review is to discuss the reported comorbidities of epilepsy in children. The possible mechanisms and associated risk factors-including the effect of seizure frequency and seizure control, types of epilepsy, age of seizure onset, duration of illness, and the possible detrimental effect of antiepileptic drugs-will be described.

Epilepsy with myoclonic atonic seizures: an electroclinical study of 69 patients

Epilepsy with myoclonic-atonic seizures is characterized by myoclonic-atonic, absence, tonic-clonic, and eventually tonic seizures, appearing in previously normal children at ages 18-60 months. We analyzed the electroclinical features, treatment, and outcome of 69 patients with myoclonic-atonic seizures; these patients were followed between 1990 and 2012 at the Juan P. Garrahan Pediatric Hospital, Buenos Aires, Argentina. No structural or metabolic etiology was identified. Based on the electroclinical features and evolution, two groups could be distinguished. The first group of 39 patients with myoclonic and myoclonic-atonic seizures with or without generalized tonic-clonic seizures and absences associated with generalized spike- and polyspike-and-wave paroxysms had excellent prognoses. The second group of 30 patients had myoclonic jerks and myoclonic-atonic seizures associated with other seizure types including tonic seizures; some had myoclonic status epilepticus and cognitive deterioration. The interictal EEG showed frequent generalized spike- and polyspike-and-wave paroxysms. In 16 patients, the seizures remitted within 3.6 years. The two groups were distinguished in retrospect, when enough time had elapsed to evaluate cognitive deterioration and different seizure types. In conclusion, epilepsy with myoclonic atonic seizures is an epileptic syndrome with a broad clinical spectrum and variable prognosis.

Problematic behavior in children with epilepsy: issues and management

This chapter is written on the premise the neurologist who will take on a new case of epilepsy or will have behavioral problems arise in an old case. "behavioral problems" is preferred to "psychiatric disorders" because the behavior is described by the parents and can be evident to the neurologist. All "behavior" is organized in the brain and can be dysfunctional if cerebral function is impaired by lesions, by genetic aberrations, or by medications. Epilepsy is also liable to give rise to prejudicial responses in all concerned. A detailed history of the family unit is essential from the start. The "illness" of epilepsy will arise from structural "disease" and will give rise to a painful "predicament"; anguish, distress. And all this is in a particular context. The best possible solution for the child will have to be "negotiated," rather than prescribed. Psychopathology also arises from "everyday life"; from the fact of chronic illness; and from alienation. These aspects are explored in detail. Mental handicap, specific learning difficulties, ADHD, and autism are frequently specifically associated with epilepsy.

Epileptic encephalopathies in adults and childhood

Epileptic encephalopathies are motor-mental retardations or cognitive disorders secondary to epileptic seizures or epileptiform activities. Encephalopaties due to brain damage, medications, or systemic diseases are generally not in the scope of this definition, but they may rarely accompany the condition. Appropriate differential diagnosis of epileptic seizures as well as subclinical electroencephalographic discharges are crucial for management of seizures and epileptiform discharges and relative regression of cognitive deterioration in long-term followup. Proper antiepileptic drug, hormonal treatment, or i.v. immunoglobulin choice play major role in prognosis. In this paper, we evaluated the current treatment approaches by reviewing clinical electrophysiological characteristics of epileptic encephalopathies.

"Epileptic encephalopathy" of infancy and childhood: electro-clinical pictures and recent understandings

There is growing interest in the diagnosis of cognitive impairment among children with epilepsy. It is well known that status of seizures control has to be carefully investigated because it can be sufficient "per se" to cause progressive mental deterioration conditions. Subclinical electroencephalographic discharges may have subtle effects on cognition, learning and sleep patterns, even in the absence of clinical or sub-clinical seizures. In this respect, electroencephalographic monitoring (long-term and nocturnal recording) and in particular an all night video-polysomnography (V-NPSG) record can be crucial to detect the presence of unrecognized seizures and/or an inter-ictal nocturnal EEG discharge increasing. Epileptic encephalopathies (EE) are a group of conditions in which the higher cognitive functions are deteriorate as a consequence of epileptic activity, which, in fact, consists of frequent seizures and/or florid and prolonged interictal paroxysmal discharges, focal or generalized. AEDs represent the first line in opposing the burden of both, the poor seizures control and the poor interictal discharges control, in the cognitive deterioration of EE affected children. Thus, to improve the long-term cognitive/behavioural prognosis in these refractory epileptic children, it should be taken into account both a good seizures control and a strict sleep control, choosing carefully antiepileptic drugs which are able to control not only seizures clinically recognizable but even the EEG discharges onset and its increasing and spreading during sleep. Here, we review the efficacy and safety of the newer AEDs that, to date, are used in the treatment of EE in infancy and childhood.

Lennox-Gastaut syndrome in adulthood: clinical and EEG features

PURPOSE

We performed a retrospective study to investigate seizure, EEG, social and cognitive outcome in adult LGS subjects.

METHODS

We retrospectively evaluated 27 LGS patients aged 40-59 years. We assessed in particular the evolution of different seizure types and EEG findings, as well as cognitive and social outcome.

RESULTS

During the early stages of the disease, all patients presented tonic seizures (TS) during wakefulness and sleep, 20/27 had atypical absences (AA), more rarely other seizure types. EEG showed slow background activity in 21/27 patients, diffuse slow spike-wave discharges (DSSW) during wakefulness in 22/27, and bursts of diffuse fast rhythms (DFR) in sleep in all patients. At last observation, 11 patients only had TS during wakefulness, but all still presented TS during sleep; AA persisted in 6 patients. EEG showed normal BA in 12/27 patients; only 7/27 still presented DSSW. On the contrary, sleep EEG showed the persistence of DFR in all. A moderate to severe cognitive impairment was observed in 26/27 patients.

CONCLUSIONS

In adult LGS patients TS during sleep remain the major seizure type; moreover, a standard waking EEG may be normal. Thus, polysomnography represents the most important mean of investigation also in adult LGS patients.

Neuropsychological deficits in childhood epilepsy syndromes

Seizure disorders are relatively common in childhood, and the International League Against Epilepsy (ILAE) provides a hierarchical classification system to define seizure types. At the final level of classification, specific epilepsy syndromes are defined that represent a complex of signs and symptoms unique to an epilepsy condition. The present review discusses the issues related to several of these epilepsy syndromes in childhood, including those classified as generalized idiopathic epilepsies (e.g., childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy), focal epilepsies (benign rolandic epilepsy, occipital epilepsy, temporal lobe epilepsy, frontal lobe epilepsy) and the "epileptic encephalopathies," including Dravet's Syndrome, West Syndrome, Lennox-Gastaut Syndrome, Myoclonic Astatic Epilepsy, and Landau-Kleffner Syndrome. For each syndrome, the epidemiology, clinical manifestations, treatments, and neuropsychological findings are discussed.

Neuropsychological deficits in childhood epilepsy syndromes

Seizure disorders are relatively common in childhood, and the International League Against Epilepsy (ILAE) provides a hierarchical classification system to define seizure types. At the final level of classification, specific epilepsy syndromes are defined that represent a complex of signs and symptoms unique to an epilepsy condition. The present review discusses the issues related to several of these epilepsy syndromes in childhood, including those classified as generalized idiopathic epilepsies (e.g., childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy), focal epilepsies (benign rolandic epilepsy, occipital epilepsy, temporal lobe epilepsy, frontal lobe epilepsy) and the "epileptic encephalopathies," including Dravet's Syndrome, West Syndrome, Lennox-Gastaut Syndrome, Myoclonic Astatic Epilepsy, and Landau-Kleffner Syndrome. For each syndrome, the epidemiology, clinical manifestations, treatments, and neuropsychological findings are discussed.