Clinical study of catastrophic infantile epilepsy with focal seizures

Clinical analysis of catastrophic epilepsy in infancy and early childhood: results of the Far-East Asia Catastrophic Epilepsy (FACE) study group

PURPOSE

We studied children younger than 6years old who developed catastrophic epilepsy and were registered in the FACE study group to clarify their clinical characteristics and prevalence of seizure as well as epilepsy types.

SUBJECTS

Subjects were prospectively recruited from children with epilepsy who satisfied the following criteria and underwent intensive examination between 2009 and 2012 in 14 collaborative centers: (1) younger than 6years old and (2) more than 10 seizures/month refractory to all available medical treatments including ACTH therapy, leading to significant psychosocial morbidity.

METHODS

We analyzed epilepsy onset age, predominant seizure type, etiology, neuropsychological findings, and syndromic classification according to the pre-determined registration format.

RESULTS

A total of 314 children were enrolled in this study. Epilepsy onset age in 239 cases (80%) was younger than 12months. The most frequent seizure type was epileptic spasms (ES), followed by generalized tonic seizures (GTS), which accounted for 42% and 20%, respectively. West syndrome (WS) was the most frequent epileptic syndrome and accounted for 37%, followed by unclassified epilepsy at 21%, neocortical epilepsy at 19%, Lennox-Gastaut syndrome at 12%, Dravet syndrome at 4%, Rasmussen syndrome at 2%, and others. The two most frequent causes of epilepsy were cortical dysplasia and chromosomal anomalies, as shown in 16% and 6%, respectively. However, the etiology of nearly one half of all patients remained unknown. Psychomotor development was already worse than a moderate degree in 62% of subjects at the first examination.

CONCLUSION

The highest proportion of catastrophic epilepsy was WS and its related syndromes featuring ES and GTS, followed by neocortical epilepsy, whose psychomotor development was significantly retarded at examinations.

Treatment of infantile spasms

BACKGROUND

Infantile spasms (West's Syndrome) is a syndrome that includes a peculiar type of epileptic seizure-the spasms-and an electroencephalographic (EEG) abnormality often called hypsarrhythmia. Psychomotor retardation is frequently found at follow-up. Approximately two-thirds of affected infants will have a detectable underlying neurological abnormality, but still little is known about the pathophysiological basis for infantile spasms, and treatment remains problematic.

OBJECTIVES

To compare the effects of single pharmaceutical therapies used to treat infantile spasms in terms of control of the spasms, resolution of the EEG, relapse rates, psychomotor development, subsequent epilepsy, side effects, and mortality.

SEARCH METHODS

To identify published data, we searched the Cochrane Epilepsy Group Specialised Register (October 2012), CENTRAL (The Cochrane Library 2012, Issue 9), MEDLINE (1946 to September Week 4, 2012), EMBASE (1980 to March 2003), and the reference lists of all retrieved articles.To identify unpublished data, we searched the ISRCTN Register (www.controlled-trials.com), corresponded with colleagues and drug companies, and made requests at international conferences.

SELECTION CRITERIA

All randomised controlled trials (RCTs) of the administration of drug therapy to patients with infantile spasms.

DATA COLLECTION AND ANALYSIS

Data collection from all relevant publications was independently undertaken by three review authors (before 2010) or by two review authors using a standard proforma. Analysis included assessment of study quality and a search for sources of heterogeneity.

MAIN RESULTS

We found 16 small RCTs (fewer than 100 patients enrolled) and 2 larger RCTs (more than 100 patients enrolled). These 18 studies looked at a total of 916 patients treated with a total of 12 different pharmaceutical agents. Overall methodology of the studies was poor, in part because of ethical dilemmas such as giving placebo injections to children. Two studies showed that placebo was not as good as active treatment in resolving the spasms. The strongest evidence suggested that hormonal treatment (prednisolone or tetracosactide depot) leads to resolution of spasms faster and in more infants than does vigabatrin. Responses without subsequent relapse may be no different. The same study suggests that hormonal treatments might improve the long-term developmental outcome compared with vigabatrin in infants not found to have an underlying cause for their infantile spasms.

AUTHORS' CONCLUSIONS

To date, few well-designed RCTs have considered the treatment of infantile spasms, and the numbers of patients enrolled have been small. In the majority, methodology has been poor, hence it is not clear which treatment is optimal in the treatment of this epilepsy syndrome. Hormonal treatment resolves spasms in more infants than vigabatrin, but this may or may not translate into better long-term outcomes. If prednisolone or vigabatrin is used, high dosage is recommended. Vigabatrin may be the treatment of choice in tuberous sclerosis. Resolution of the EEG features may be important, but this has not been proven. Further research using large studies with robust methodology is required.

Novel SCN1A mutation in a proband with malignant migrating partial seizures of infancy

OBJECTIVE

To characterize a novel SCN1A mutation in a proband with malignant migrating partial seizures of infancy.

DESIGN

Genomic DNA was isolated from blood and submitted for commercial testing. The identified missense mutation was confirmed in brain DNA obtained at autopsy. Genomic DNA from the brain of the proband was analyzed by comparative genome hybridization, and the coding exons of SCN9A were amplified. Quantitation studies of the mutant transcript were performed.

SETTING

Children's National Medical Center and Yale University School of Medicine. PROBAND: A full-term female infant who experienced seizure onset at age 10 weeks, with progression of hemiclonic, apneic, and multifocal migrating partial seizures leading to recurrent status epilepticus and death at age 9 months.

MAIN OUTCOME MEASURES

Electroencephalographic and magnetic resonance imaging results, quantitative RNA expression, and secondary mutation test results.

RESULTS

The heterozygous missense mutation c.C5006C>A was identified by sequencing genomic DNA from blood and was confirmed in brain DNA. The resulting amino acid substitution p.A1669E alters an evolutionarily conserved residue in an intracellular linker of domain 4 of the SCN1A sodium channel protein Na(v)1.1. The mutant transcript is found to be expressed at levels comparable to the wild-type allele in brain RNA. No variation in copy number was detected in the chromosome region 2q24 containing SCN1A or elsewhere in the genome. No mutations were detected in the linked sodium channel gene SCN9A, which has been reported to act as a modifier of SCN1A mutations.

CONCLUSION

This report expands the spectrum of SCN1A epileptic channelopathies to include malignant migrating partial seizures of infancy.

Treatment of infantile spasms

BACKGROUND

Infantile spasms (West's Syndrome) is a syndrome which includes a peculiar type of epileptic seizure, the spasms, and an electroencephalogram (EEG) abnormality often called hypsarrhythmia. Psychomotor retardation is frequently found at follow up. Approximately two thirds of affected infants will have a detectable underlying neurological abnormality, but still little is known about the pathophysiological basis for infantile spasms and treatment remains problematic.

OBJECTIVES

To compare the effects of single pharmaceutical therapies used to treat infantile spasms in terms of control of the spasms, resolution of the EEG, relapse rates, psychomotor development, subsequent epilepsy, side effects, and mortality.

SEARCH STRATEGY

Published data: Cochrane Epilepsy Group Specialised Register, CENTRAL (The Cochrane Library 2007, Issue 4), MEDLINE, EMBASE, and the reference lists of all retrieved articles.Unpublished data: ISRCTN Register (www.controlled-trials.com), correspondence with colleagues and drug companies, and requests at international conferences.

SELECTION CRITERIA

All randomised controlled trials of the administration of drug therapy to patients with infantile spasms.

DATA COLLECTION AND ANALYSIS

Data collection from all relevant publications was independently undertaken by three review authors using a standard proforma. Analysis included assessment of study quality and looking for sources of heterogeneity.

MAIN RESULTS

We found 12 small RCTs (less than 60 patients enrolled) and two larger RCT (more than 100 patients enrolled). These 14 studies looked at a total of 681 patients treated with a total of nine different pharmaceutical agents. Overall methodology of the studies was poor, partly because of ethical dilemmas such as giving placebo injections to children. Two studies showed that placebo was not as good as active treatment in resolving the spasms. The strongest evidence suggested that hormonal treatment leads to resolution of spasms faster and in more infants than does vigabatrin. Responses without subsequent relapse may be no different. The same study suggests that hormonal treatments (prednisolone or tetracosactide) might improve the long-term developmental outcome compared with vigabatrin in infants not found to have an underlying cause for their infantile spasms.

AUTHORS' CONCLUSIONS

To date, there have been few well-designed RCTs that considered the treatment of infantile spasms, and the numbers of patients enrolled have been small. Overall methodology has been poor, hence it is not clear which treatment is optimal in the treatment of this epilepsy syndrome. Hormonal treatment resolves spasms in more infants than vigabatrin but this may or may not translate into a better long-term outcome. If prednisone or vigabatrin are used then high dosage is recommended. Vigabatrin may be the treatment of choice in tuberous sclerosis. Resolution of the EEG features may be important but this has not been proven. Further research using large studies with robust methodology is still required.

Migrating focal seizures in infancy: analysis of the electroclinical patterns in 17 patients

We describe the electroclinical features, therapy, and long-term evolution of 17 patients with migrating focal seizures in infancy, and analyzed the charts of these patients seen between February 1985 and July 2005. Three different electroclinical patterns were recognized: (1) 8 cases with alternating simple focal motor seizures at onset. The ictal electroencephalography (EEG) pattern was characterized by recurrence of rhythmic focal spikes or rhythmic sharp activity in the Rolandic region; (2) 5 cases with complex focal seizures and progressive appearance of polymorphic delta- activity in 1 temporo-occipital region recurring independently; (3) 4 cases with focal complex seizures with motor manifestations. Ictal EEG showed flattening or fast activity in 1 frontotemporal region followed by unilateral fast poly-spikes in alternating clusters in both hemispheres. The focal seizures were refractory to antiepileptic drugs, and all patients except 3 had severe developmental delay. Migrating focal seizures in infancy is a newly defined and rare, but underrecognized, epileptic encephalopathy.

Brain inflammation in epilepsy: experimental and clinical evidence

Inflammatory reactions occur in the brain in various CNS diseases, including autoimmune, neurodegenerative, and epileptic disorders. Proinflammatory and antiinflammatory cytokines and related molecules have been described in CNS and plasma, in experimental models of seizures and in clinical cases of epilepsy. Inflammation involves both the innate and the adaptive immune systems and shares molecules and pathways also activated by systemic infection. Experimental studies in rodents show that inflammatory reactions in the brain can enhance neuronal excitability, impair cell survival, and increase the permeability of the blood-brain barrier to blood-borne molecules and cells. Moreover, some antiinflammatory treatments reduce seizures in experimental models and, in some instances, in clinical cases of epilepsy. However, inflammatory reactions in brain also can be beneficial, depending on the tissue microenvironment, the inflammatory mediators produced in injured tissue, the functional status of the target cells, and the length of time the tissue is exposed to inflammation. We provide an overview of the current knowledge in this field and attempt to bridge experimental and clinical evidence to discuss critically the possibility that inflammation may be a common factor contributing, or predisposing, to the occurrence of seizures and cell death, in various forms of epilepsy of different etiologies. The elucidation of this aspect may open new perspectives for the pharmacologic treatment of seizures.

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.