Epilepsy in peroxisomal diseases

Safety and tolerance of the ketogenic diet in patients with Zellweger Syndrome

Zellweger Syndrome is a peroxisomal disorder that can lead to elevation of long chain fatty acids and epilepsy, which can be drug resistant. The treatment of drug resistant epilepsy can include the ketogenic diet in appropriately chosen patients. Typically, the ketogenic diet is contraindicated in individuals with defects in fatty acid metabolism because of the diet's reliance on medium and long chain fatty acids. To our knowledge this is the first publication outlining the use of the ketogenic diet in patients with defects in beta oxidation of very long chain fatty acids. We present two patients with Zellweger Syndrome who were placed on a ketogenic diet for drug resistant epilepsy. Safety and tolerance of the ketogenic diet in patients with Zellweger Syndrome.

Forward Genetics-Based Approaches to Understanding the Systems Biology and Molecular Mechanisms of Epilepsy

Epilepsy is a highly prevalent, severely debilitating neurological disorder characterized by seizures and neuronal hyperactivity due to an imbalanced neurotransmission. As genetic factors play a key role in epilepsy and its treatment, various genetic and genomic technologies continue to dissect the genetic causes of this disorder. However, the exact pathogenesis of epilepsy is not fully understood, necessitating further translational studies of this condition. Here, we applied a computational in silico approach to generate a comprehensive network of molecular pathways involved in epilepsy, based on known human candidate epilepsy genes and their established molecular interactors. Clustering the resulting network identified potential key interactors that may contribute to the development of epilepsy, and revealed functional molecular pathways associated with this disorder, including those related to neuronal hyperactivity, cytoskeletal and mitochondrial function, and metabolism. While traditional antiepileptic drugs often target single mechanisms associated with epilepsy, recent studies suggest targeting downstream pathways as an alternative efficient strategy. However, many potential downstream pathways have not yet been considered as promising targets for antiepileptic treatment. Our study calls for further research into the complexity of molecular mechanisms underlying epilepsy, aiming to develop more effective treatments targeting novel putative downstream pathways of this disorder.

A Case of Rhizomelic Chondrodysplasia Punctata in a Neonate

Rhizomelic chondrodysplasia punctata (RCDP) is a rare, multisystem, autosomal recessive, peroxisomal disorder of a family of congenital disorders known as chondrodysplasia calcificans punctate (CCP). RCDP is characterized by disproportionately short extremities (rhizomelia), congenital cataracts, and joint contractures. Dysmorphic facial features include a broad nasal bridge, epicanthus, high-arched palate, dysplastic external ears, and micrognathia. Severe mental retardation with spasticity and seizures may also be present. X-ray of the limbs showed punctate calcifications in cartilage (chondrodysplasia punctata). Genetic testing reveals the severity of phenotype. Treatment is limited to supportive symptomatic relief and prevention of complications. To the best of our knowledge, after searching through PubMed, our case is the first reported case of RCDP in the Middle East.

Characterization of Severity in Zellweger Spectrum Disorder by Clinical Findings: A Scoping Review, Meta-Analysis and Medical Chart Review

Zellweger spectrum disorder (ZSD) is a rare, debilitating genetic disorder of peroxisome biogenesis that affects multiple organ systems and presents with broad clinical heterogeneity. Although severe, intermediate, and mild forms of ZSD have been described, these designations are often arbitrary, presenting difficulty in understanding individual prognosis and treatment effectiveness. The purpose of this study is to conduct a scoping review and meta-analysis of existing literature and a medical chart review to determine if characterization of clinical findings can predict severity in ZSD. Our PubMed search for articles describing severity, clinical findings, and survival in ZSD resulted in 107 studies (representing 307 patients) that were included in the review and meta-analysis. We also collected and analyzed these same parameters from medical records of 136 ZSD individuals from our natural history study. Common clinical findings that were significantly different across severity categories included seizures, hypotonia, reduced mobility, feeding difficulties, renal cysts, adrenal insufficiency, hearing and vision loss, and a shortened lifespan. Our primary data analysis also revealed significant differences across severity categories in failure to thrive, gastroesophageal reflux, bone fractures, global developmental delay, verbal communication difficulties, and cardiac abnormalities. Univariable multinomial logistic modeling analysis of clinical findings and very long chain fatty acid (VLCFA) hexacosanoic acid (C26:0) levels showed that the number of clinical findings present among seizures, abnormal EEG, renal cysts, and cardiac abnormalities, as well as plasma C26:0 fatty acid levels could differentiate severity categories. We report the largest characterization of clinical findings in relation to overall disease severity in ZSD. This information will be useful in determining appropriate outcomes for specific subjects in clinical trials for ZSD.

Zellweger spectrum disorder: A cross-sectional study of symptom prevalence using input from family caregivers

Zellweger spectrum disorders (ZSD) are rare, debilitating genetic diseases of peroxisome biogenesis that affect multiple organ systems and present with broad clinical heterogeneity. Although many case studies have characterized the multitude of signs and symptoms associated with ZSD, there are few reports on the prevalence of symptoms to help inform the development of meaningful endpoints for future clinical trials in ZSD. In the present study, we used an online survey tool completed by family caregivers to study the occurrence, frequency and severity of symptoms in individuals diagnosed with ZSD. Responses from caregivers representing 54 living and 25 deceased individuals with ZSD were collected over an 8-month period. Both perception of disease severity and prevalence of various symptoms were greater in responses from family caregivers of deceased individuals compared to those of living individuals with ZSD. Compared with previous reports for ZSD, the combined prevalence of seizures (53%) and adrenal insufficiency (45%) were nearly twice as high. Overall, this community-engaged approach to rare disease data collection is the largest study reporting on the prevalence of symptoms in ZSD, and our findings suggest that previous reports may be underreporting the true prevalence of several symptoms in ZSD. Studies such as this used in conjunction with clinician- led reports may be useful for informing the design of future clinical trials addressing ZSD.

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Zellweger spectrum disorders (ZSD) are rare, genetic multi-system disorders.

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There are few reports on symptom prevalence in ZSD.

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We present the largest caregiver-reported study to date on ZSD symptom prevalence.

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This study will help develop appropriate outcomes for clinical trials in ZSD.

Rhizomelic chondrodysplasia punctata: Role of EEG as a biomarker of impending epilepsy

Progressive deterioration of neuroimaging and electroencephalography (EEG) had been described in rhizomelic chondrodysplasia punctata (RCDP); however, serial EEG data showing sequential EEG changes(before and after seizure onset) is lacking. We report a child with a diagnosis of type 1 RCDP, who had a progressive decline in EEG and radiologic findings over a 5 year period. Her first EEG was normal at the age of 8 months. Follow-up EEG at the age of 2 years showed a mild background slowing as well as frequent 1–2 Hz central-parietal spike wave with midline involvement. Just before 3 years of age, she started to seizures, when the EEG showed further worsening with frequent multifocal spikes and bursts of generalized high amplitude spike and spike-wave discharges. The transition of EEG from normal background to the appearance of focal epileptiform abnormality before the seizure onset followed by further deterioration at the seizure onset had not been reported as per our knowledge. This study emphasizes that serial EEGs may provide valuable information about impending seizure activity. Further studies are needed to calculate the lag time between the detection of epileptiform activities and the onset of clinical seizure activities. In addition, research studies are warranted to determine if early (before or at the onset of epileptogenesis rather than after seizure onset) use of replacement therapy or antiepileptic therapy (antiepileptic drugs or diet) can modify epilepsy severity and neurologic prognosis in this devastating disease.

Inborn Errors of Metabolism and Epilepsy: Current Understanding, Diagnosis, and Treatment Approaches

Inborn errors of metabolism (IEM) are a rare cause of epilepsy, but seizures and epilepsy are frequently encountered in patients with IEM. Since these disorders are related to inherited enzyme deficiencies with resulting effects on metabolic/biochemical pathways, the term “metabolic epilepsy” can be used to include these conditions. These epilepsies can present across the life span, and share features of refractoriness to anti-epileptic drugs, and are often associated with co-morbid developmental delay/regression, intellectual, and behavioral impairments. Some of these disorders are amenable to specific treatment interventions; hence timely and appropriate diagnosis is critical to improve outcomes. In this review, we discuss those disorders in which epilepsy is a dominant feature and present an approach to the clinical recognition, diagnosis, and management of these disorders, with a greater focus on primarily treatable conditions. Finally, we propose a tiered approach that will permit a clinician to systematically investigate, identify, and treat these rare disorders.

Peroxisome biogenesis disorders in the Zellweger spectrum: An overview of current diagnosis, clinical manifestations, and treatment guidelines

Peroxisome biogenesis disorders in the Zellweger spectrum (PBD-ZSD) are a heterogeneous group of genetic disorders caused by mutations in PEX genes responsible for normal peroxisome assembly and functions. As a result of impaired peroxisomal activities, individuals with PBD-ZSD can manifest a complex spectrum of clinical phenotypes that typically result in shortened life spans. The extreme variability in disease manifestation ranging from onset of profound neurologic symptoms in newborns to progressive degenerative disease in adults presents practical challenges in disease diagnosis and medical management. Recent advances in biochemical methods for newborn screening and genetic testing have provided unprecedented opportunities for identifying patients at the earliest possible time and defining the molecular bases for their diseases. Here, we provide an overview of current clinical approaches for the diagnosis of PBD-ZSD and provide broad guidelines for the treatment of disease in its wide variety of forms. Although we anticipate future progress in the development of more effective targeted interventions, the current guidelines are meant to provide a starting point for the management of these complex conditions in the context of personalized health care.

The neurology of rhizomelic chondrodysplasia punctata

Background

To describe the neurologic profiles of Rhizomelic chondrodysplasia punctata (RCDP); a peroxisomal disorder clinically characterized by skeletal abnormalities, congenital cataracts, severe growth and developmental impairments and immobility of joints. Defective plasmalogen biosynthesis is the main biochemical feature.

Methods

Observational study including review of clinical and biochemical abnormalities, genotype, presence of seizures and neurophysiological studies of a cohort of 16 patients with RCDP.

Results

Patients with the severe phenotype nearly failed to achieve any motor or cognitive skills, whereas patients with the milder phenotype had profound intellectual disability but were able to walk and had verbal communication skills. Eighty-eight percent of patients developed epileptic seizures. The age of onset paralleled the severity of the clinical and biochemical phenotype. Myoclonic jerks, followed by atypical absences were most frequently observed. All patients with clinical seizures had interictal encephalographic evidence of epilepsy. Visual evoked (VEP) and brain auditory potential (BAEP) studies showed initial normal latency times in 93% of patients. Deterioration of VEP occurred in a minority in both the severe and the milder phenotype. BAEP and somatosensory evoked potentials (SSEP) were more likely to become abnormal in the severe phenotype. Plasmalogens were deficient in all patients. In the milder phenotype levels of plasmalogens were significantly higher in erythrocytes than in the severe phenotype. Phytanic acid levels ranged from normal to severely increased, but had no relation with the neurological phenotype.

Conclusion

Neurodevelopmental deficits and age-related occurrence of seizures are characteristic of RCDP and are related to the rest-activity in plasmalogen biosynthesis. Evoked potential studies are more likely to become abnormal in the severe phenotype, but are of no predictive value in single cases of RCDP.

Metabolic epilepsy: an update

Inborn errors of metabolism comprise a large class of genetic diseases involving disorders of metabolism. Presentation is usually in the neonatal period or infancy but can occur at any time, even in adulthood. Seizures are frequent symptom in inborn errors of metabolism, with no specific seizure types or EEG signatures. The diagnosis of a genetic defect or an inborn error of metabolism often results in requests for a vast array of biochemical and molecular tests leading to an expensive workup. However a specific diagnosis of metabolic disorders in epileptic patients may provide the possibility of specific treatments that can improve seizures. In a few metabolic diseases, epilepsy responds to specific treatments based on diet or supplementation of cofactors (vitamin-responsive epilepsies), but for most of them specific treatment is unfortunately not available, and conventional antiepileptic drugs must be used, often with no satisfactory success. In this review we present an overview of metabolic epilepsies based on various criteria such as treatability, age of onset, seizure type, and pathogenetic background.

Manifestations and treatment of epilepsy in children with neurometabolic disorders: a series from Jordan

PURPOSE

To examine the characteristics of epilepsy in children with neurometabolic disorders to reveal co morbidities and optimal treatment.

METHODS

We retrospectively reviewed the files of children diagnosed with a neurometabolic disorder and treated at Jordan University Hospital between 2001 and 2012. We examined the incidence, age at onset, clinical characteristics, and medical control of epilepsy.

RESULTS

Cases treated (40 boys, 30 girls) included the different categories of neurometabolic diseases. Twenty-nine patients (41.4%) were also diagnosed with epilepsy, with age at seizure onset ranging from 3 days to 7 years. All types of seizures were reported, but generalized tonic-clonic and mixed types were most common (16/29 patients, 55.2%). Patients were on either a single antiepileptic drug (16/29, 55.2%) or multiple drugs (13/29, 44.7%), and most drugs prescribed were older generation anticonvulsants. Complete seizure control was achieved in 19/29 patients (65.5%), partial control in 7/29 (24.1%), and poor or no control in 3/29 (10.3%). EEG recordings were missing from the medical files of 10/29 patients. The first EEG revealed epileptiform activity in 12/19 patients (63.2%) and was normal in 7/19 patients (36.8%).

CONCLUSIONS

Epilepsy was diagnosed in about half of pediatric neurometabolic disease patients, with the majority of seizure cases well controlled.

Inborn errors of metabolism causing epilepsy

Seizures may be the first and the major presenting feature of an inborn error of metabolism (IEM), for example in a neonate with pyridoxine-dependent epilepsy. In other IEMs, seizures may be preceded by other major symptoms: by a reduced level of consciousness in a child with an organic acidaemia or urea cycle defect; or by loss of skills, progressive weakness, ataxia, and upper motor signs in a child with a lysosomal storage disorder or peroxisomal leukodystrophy. This review concentrates on those IEMs for which specific treatment is available. The common metabolic causes of seizures vary according to the age at presentation. Features from the history, examination, imaging, and first line biochemical investigations can all provide clues to an inborn error. This review attempts to delineate these and to provide a guide to the specific tests that can be used to make the diagnosis of disorders with specific treatment.

Molecular and clinical findings and diagnostic flowchart of peroxisomal diseases

Peroxisomal diseases are categorized into three large groups - peroxisome biogenesis disorders (PBD), single enzyme deficiencies (SED) and contiguous gene syndrome. Thirteen complementation groups and PEX genes responsible for all subgroups of PBD, plus 10 diseases and their responsible genes in SED have been identified. We have established a diagnostic system for peroxisomal diseases in Japan, and identified 45 Japanese patients with PBD, 12 patients with beta-oxidation enzyme deficiencies and more than 100 patients with adrenoleukodystrophy (ALD). It is important for effective therapy of the cerebral form of ALD to diagnose earlier after onset, and pre-symptomatic diagnosis should also be valuable. The division of diagnostic system into several specified centers of peroxisomal diseases in the whole world should be functional for overcoming these rare inherited neurometabolic diseases.

Peroxisomal disorders with infantile seizures

Peroxisomes are organelles responsible for multiple metabolic pathways including the biosynthesis of plasmalogens and the oxidation of branched-chain as well as very-long-chain fatty acids (VLCFAs). Peroxisomal disorders (PDs) are heterogeneous groups of diseases and affect many organs with varying degrees of involvement. Even pathogenetically distinct PDs share some common symptoms. However, several PDs have uniquely characteristic clinical findings. The durations of survival in PDs are also variable. Infants with PDs are usually presented with developmental delay, visual and hearing impairment. Generalized hypotonia is present in severe cases. Epileptic seizures are also a common characteristic of patients with certain PDs. Nonetheless, the classification and evolution of epilepsy in PDs have not been elucidated in detail. Here, we review the relevant literatures and provide an overview of PDs with particular emphasis on the characteristics of seizures in infants.

Epilepsy in inherited metabolic disorders

INTRODUCTION

The study of neurometabolic diseases is still in a prolonged preliminary stage. The catalogue of these diseases continues to grow; some known clinical syndromes have been subdivided into a number of variants once the genes that cause them have been identified, and at the same time new metabolic disorders have been discovered that aggravate or contribute to forms of epilepsy not previously classified as cerebral metabolic disorders.

RESULTS

This review presents the basic principles underlying the recognition and treatment of epilepsy caused by neurometabolic diseases. These disorders are divided (purely for the sake of convenience) into epilepsy presenting in newborn infants, children, and adolescents and adults, recognizing that there is a significant degree of overlap between these chronological stages. Current analytical methods and therapeutic approaches are summarized both from a general point of view and within the context of each clinical syndrome, acknowledging that each patient presents specific peculiarities and that, in general, antiepileptic drugs provide few benefits compared with more specific types of therapy (eg, special diets or vitamins) when indicated. We also include therapeutic recommendations and a general approach to fulminant epilepsies of neurometabolic origin, emphasizing the importance of identifying all of the proband's relatives who may be potential carriers of a genetic disorder during the diagnostic and genetic counselling process. Particular emphasis is placed on disorders for which there is curative treatment and on the importance of follow-up by expert professionals.

CONCLUSION

It is expected that in a few years' time it will be possible to know the metabolomic profile of these diseases (possibly by non-invasive methods), thus facilitating accurate diagnosis and making it possible to establish the response to treatment and to identify all individuals who are carriers or remain minimally symptomatic in terms of their risk of manifesting or transmitting epilepsy.

D-bifunctional protein deficiency associated with drug resistant infantile spasms

Peroxisomal disorders appear with a frequency of about 1:5000 in newborns. Peroxisomal D-bifunctional protein (D-BP), encoded by the HSD17B4 gene (gene ID: 3294; locus tag: HGNC:5213, chromosome 5q2; official symbol: HSD17B4; name: hydroxysteroid (17-beta) dehydrogenase; gene type: protein coding) (OMIM *601860), comprises an 80 kDa multifunctional enzyme involved in peroxisomal beta-oxidation of certain fatty acids and the synthesis of bile acids. Its deficiency causes a very severe, Zellweger-like clinical phenotype and most patients die within the first year of life. In this paper, we report a case of D-BP deficiency in a patient with two heterozygous trinucleotide deletions (233_235 del AAG and 824_826 del AGA) in the HSD17B4 gene. The patient suffered from a peculiar epileptic phenotype (i.e. a West syndrome with a "modified hypsarrhythmic pattern"--Hrachovy et al. Epilepsia 1984;25:317-25), clinically appearing as drug-resistant asymmetric spasms. Vigabatrin seemed the most effective among the antiepileptic drugs. The patient died at the age of 23 months owing to respiratory complications. To date, only a few patients with D-BP deficiency have been described in the literature. This case adds to our knowledge of the clinical presentation of bifunctional protein deficiency.

Zonisamide - a review of experience and use in partial seizures

Zonisamide is a modern antiepileptic drug (AED) that is distinguished from other AEDs by its unique structure and broad mechanistic profile. Preclinical studies have reported a range of potential mechanisms of action for zonisamide, such as blocking voltage-gated sodium channels, reduction of T-type calcium channel currents, and enhancement of gamma-aminobutyric acid (GABA)-mediated inhibition, which are indicative of its broad antiseizure effects. Zonisamide has a favorable linear pharmacokinetic profile, a long half-life, and a low incidence of protein-binding interactions with other AEDs. Hepatically metabolized through the cytochrome P450 pathway, zonisamide does not induce its own metabolism or liver enzymes. For more than 2 decades, zonisamide has been extensively used as monotherapy and adjunctive therapy for the treatment of partial and generalized seizures in pediatric and adult patients in Japan. Zonisamide was approved in the USA in 2000 as adjunctive therapy for partial seizures in adults. With over 2 million patient-years of exposure internationally, zonisamide has demonstrated safety and efficacy against a multitude of epilepsy and seizure types, including both partial and generalized seizures. This review focuses on the experience and use of zonisamide in partial seizures, as well as possible new uses for zonisamide.

Épilepsies néonatales et erreurs innées du métabolisme

Metabolic disorders constitute an important cause of neurologic disease, including neonatal epilepsy. Epilepsy rarely dominates the clinical presentation, which is more frequently associated with other neurologic symptoms, such as hypotonia and/or vigilance disturbances. In most cases, epilepsy secondary to inherited metabolic disorders presents with polymorphic clinical and electrographic features that are difficult to classify into precise epileptic syndromes. However, specific types of seizures, such as myoclonic seizures or distinctive electroencephalographic patterns, such as suppression burst patterns, epileptic syndrome or early myoclonic encephalopathy, may suggest a specific metabolic disease. The aim of this article is to help clinicians in reviewing potential metabolic diagnoses and approaching metabolic evaluations.

Multimodal longitudinal imaging of focal status epilepticus

BACKGROUND

Little is understood about the evolution of structural and functional brain changes during the course of uncontrolled focal status epilepticus in humans.

METHODS

We serially evaluated and treated a nine-year-old girl with refractory focal status epilepticus. Long-term EEG monitoring, MRI, MRA, SPECT, intraoperative visualization of affected cortex, and neuropathological examination of a biopsy specimen were conducted over a three year time span. Imaging changes were correlated with simultaneous treatment and EEG findings.

RESULTS

The EEG monitoring showed almost continuous spike discharges emanating initially from the right frontocentral area. These EEG abnormalities were intermittently suppressed by treatment with anesthetics. Over time, additional brain areas developed epileptiform EEG abnormalities. Serial MRI studies demonstrated an evolution of changes from normal, through increased regional T2 signal to generalized atrophy. An MRA demonstrated dilatation of the middle cerebral artery stem on the right compared to the left with a broad distribution of flow-related enhancement. An 18FDG-PET scan showed a dramatically abnormal metabolic profile in the same right frontocentral areas, which modulated in response to treatment during the course of the illness. A right frontotemporal craniotomy revealed a markedly hyperemic cortical focus including vascular shunting. A sample of resected cortex showed severe gliosis and neuronal death.

CONCLUSIONS

The co-registration of structural and functional imaging and its correlation with operative and pathological findings in this case illustrates the relentless progression of regional and generalized abnormalities in intractable focal status epilepticus that were only transiently modified by exhaustive therapeutic interventions. Increased flow through large vessels appeared to be shunted and did not translate into increased microvascular perfusion.

Epilepsy in vacuolating megalencephalic leukoencephalopathy with subcortical cysts

Vacuolating megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a disorder characterised by acquired macrocephaly, developmental motor delay of varying degrees, slowly progressive cerebellar and pyramidal signs, and initially preserved intellectual function. More than 60% of the published cases had epileptic seizures. In this study, we analysed the seizures and EEG findings of nine patients with MLC. Six patients (66.6%) with moderate to severe neurological impairment had epilepsy, four with partial and two with generalised seizures. The EEG of five epileptic patients revealed epileptogenic foci over the temporal, frontal and parietal regions with variable predominance during waking and sleep. The facilitation of spike-and-wave paroxysms by eye closure, by intermittent photic stimulation and by hyperventilation were determined in four patients. Four patients also showed abnormalities in the background activity. In conclusion, we think that epilepsy is a significant component of MLC compared to the other leukodystrophies. The elucidation of the underlying molecular defect may explain the unusual pathogenetic relation between this leukoencephalopathy and the associated seizures.

Clinical study of catastrophic infantile epilepsy with focal seizures

This study investigated clinico-electrical and etiologic characteristics of catastrophic infantile epilepsy with focal seizures developed in early infancy. The patients included 15 children who fulfilled the following criteria: seizure onset before 12 months of age, presence of daily focal or secondarily generalized seizures resistant to antiepileptic drugs for at least 3 months, and exclusion of Ohtahara and West syndromes. Patients were classified into three subgroups. Three patients demonstrated progressively deteriorating neurologic symptoms associated with progressive cerebral atrophy and multifocal seizure onset. Three other children were characterized by hemiparesis and exclusively lateralized seizure onset because of focal cortical dysplasia in the contralateral hemisphere. The remaining nine children did not demonstrate any rapidly progressive neurologic deterioration or increasing cerebral atrophy and exhibited multifocal seizure onset. At the last examinations, all except one patient demonstrated moderate to severe psychomotor retardation. Catastrophic infantile epilepsy with focal seizures tended to demonstrate multifocal seizure onset and a deleterious clinical course with numerous focal seizures regardless of etiology. Because migratory focal seizures appear to be common in these infants, we have to search for the underlying etiopathogenesis of these patients, including not only metabolic errors but also localized or lateralized structural abnormality.

Neonatal seizures and neonatal epileptic syndromes

The neonatal period is defined as the first 28 days of life of a term infant; for premature infants the limit of this period is 44 completed weeks of the infant's conceptional age (CA)-defined as the chronological age plus gestational age (GA) at birth. The clinical and electroencephalographic (EEG) manifestations of seizures during this period are determined primarily by the development features of the immature brain at the time of seizure onset, but are also related to the type and diversity of etiologies and risk-factors for seizures neonates may face early in life. Neonatal seizures may be strikingly different from the clinical and electrical seizures of older children and adults. In addition, findings from basic science investigations suggest that immature animals are more likely to experience seizures in response to injury than more mature animals, although the developing brain is less susceptible to seizure-induced injury.

Epileptic seizures and electroencephalographic evolution in genetic leukodystrophies

The purpose of this study is to explore and compare epileptic seizures and EEG evolution in the various types of genetic leukodystrophy (GL). The authors reviewed the medical records and analyzed 69 serial EEGs in 27 patients with GLs: 13 with late infantile metachromatic leukodystrophy, one with juvenile metachromatic leukodystrophy, one with globoid cell leukodystrophy, six with X-linked childhood adrenoleukodystrophy, one with neonatal adrenoleukodystrophy, four with classic Pelizaeus-Merzbacher disease (PMD), and 1 with connatal Pelizaeus-Merzbacher disease. The diagnoses were made by biochemical and molecular studies. Two or more EEG studies with both awake and sleep traces were recorded during the varying clinical stages for each patient. At the beginning of the GLs, the EEGs were normal or showed mild slowing of background activity. Clinical seizures, mainly of focal origin, with progressive slowing and paroxysmal discharges on EEGs, usually appeared during the later stages of metachromatic leukodystrophy, X-linked childhood adrenoleukodystrophy, and classic Pelizaeus-Merzbacher disease. However, intractable seizures, mainly generalized in nature, and more severe slowing and abundant paroxysmal discharges on EEGs, with commensurate neurologic deterioration, were observed during the earlier course of globoid cell leukodystrophy, neonatal adrenoleukodystrophy, and connatal Pelizaeus-Merzbacher disease. These results indicate that GLs involve not only white matter, but gray matter as well. In all types of GL, there is good correlation between the severity of EEG changes, the severity of the diseases, and the clinical state of the patient.

A case of Zellweger syndrome with extensive MRI abnormalities and unusual EEG findings

Differential diagnosis in a newborn with dysmorphic features and profound neurologic dysfunction should include the cerebro-hepato-renal syndrome of Zellweger. Its distinct clinical features, markedly elevated plasma levels of very long chain fatty acids and characteristic radiological findings support the diagnosis, which can now be confirmed by genetic markers. Quite consistent abnormalities of the neurophysiological studies in this syndrome have also been reported. We report a case with typical clinical and biochemical findings in whom distinctive brain MRI abnormalities were found. The results of neurophysiological studies with an unusual EEG pattern of continuous negative vertex sharp waves and spikes are discussed. We believe that such a pattern could be considered as a pathognomonic EEG finding, especially in cases of Zellweger syndrome with extensive brain abnormalities and may even be closely associated with cortical dysplasias.

A 5-month-old with intractable epilepsy

The nosology of early infantile seizures and epilepsy syndromes is controversial. There are two age-related early infantile epileptic encephalopathy syndromes that are characterized by early onset of spasms, a burst-suppression EEG pattern, poor response to treatment, and poor prognosis. This paper examines the early myoclonic epilepsies.