Influence of seizures on early development in tuberous sclerosis complex

OBJECTIVE

Epilepsy is commonly seen in Tuberous Sclerosis Complex (TSC). The relationship between seizures and developmental outcomes has been reported, but few studies have examined this relationship in a prospective, longitudinal manner. The objective of the study was to evaluate the relationship between seizures and early development in TSC.

METHODS

Analysis of 130 patients ages 0-36months with TSC participating in the TSC Autism Center of Excellence Network, a large multicenter, prospective observational study evaluating biomarkers predictive of autism spectrum disorder (ASD), was performed. Infants were evaluated longitudinally with standardized evaluations, including cognitive, adaptive, and autism-specific measures. Seizure history was collected continuously throughout, including seizure type and frequency.

RESULTS

Data were analyzed at 6, 12, 18, and 24months of age. Patients without a history of seizures performed better on all developmental assessments at all time points compared to patients with a history of seizures and exhibited normal development at 24months. Patients with a history of seizures not only performed worse, but developmental progress lagged behind the group without seizures. All patients with a history of infantile spasms performed worse on all developmental assessments at 12, 18, and 24months. Higher seizure frequency correlated with poorer outcomes on developmental testing at all time points, but particularly at 12months and beyond. Patients with higher seizure frequency during infancy continued to perform worse developmentally through 24months. A logistic model looking at the individual impact of infantile spasms, seizure frequency, and age of seizure onset as predictors of developmental delay revealed that age of seizure onset was the most important factor in determining developmental outcome.

CONCLUSIONS

Results of this study further define the relationship between seizures and developmental outcomes in young children with TSC. Early seizure onset in infants with TSC negatively impacts very early neurodevelopment, which persists through 24months of age.

Scalp EEG Ictal gamma and beta activity during infantile spasms: Evidence of focality

OBJECTIVE

We investigated temporal and spatial characteristics of ictal gamma and beta activity on scalp EEG during spasms in patients with West syndrome (WS) to evaluate potential focal cortical onset.

METHODS

A total of 1,033 spasms from 34 patients with WS of various etiologies were analyzed on video-electroencephalography (EEG) using time-frequency analysis. Ictal gamma (35-90 Hz) and beta (15-30 Hz) activities were correlated with visual symmetry of spasms, objective EMG (electromyography) analysis, and etiology of WS.

RESULTS

Prior to the ictal motor manifestation, focal ictal gamma activity emerged from one hemisphere (71%, 24/34) or from midline (26%, 9/34), and was rarely simultaneously bilateral (3%, 1/34). Focal ictal beta activity emerged from either one hemisphere (68%, 23/34) or from midline (32%, 11/34). Onsets of focal ictal gamma and beta activity were most commonly observed around the parietal areas. Focal ictal gamma activity propagated faster than ictal beta activity to adjacent electrodes (median: 65 vs. 170 msec, p < 0.01), and to contralateral hemisphere (median: 100 vs. 170 msec, p = 0.01). Asymmetric peak amplitude of ictal gamma activity in the centroparietal areas (C3-P3 vs. C4-P4) correlated with asymmetric semiology. On the other hand, most of the visually symmetric spasms showed asymmetry in peak amplitude and interhemispheric onset latency difference in both ictal gamma and beta activity.

SIGNIFICANCE

Spasms may be a seizure with focal electrographic onset regardless of visual symmetry. Asymmetric involvement of ictal gamma activity to the centroparietal areas may determine the motor manifestations in WS. Scalp EEG ictal gamma and beta activity may be useful to demonstrate localized seizure onset in infants with WS.

Dramatic response after functional hemispherectomy in a patient with epileptic encephalopathy carrying a de novo COL4A1 mutation

We describe the first case of a successful functional hemispherectomy in a patient with epileptic encephalopathy and a de novo collagen type IV alpha 1 (COL4A1) mutation. A 4-year-old girl was COL4A1 mutation-positive and suffered from drug-resistant epilepsy, hemiplegia, and developmental delay. Magnetic resonance imaging detected no porencephaly, and she had no cataract or renal abnormality. Following a presurgical evaluation for epilepsy, she underwent a functional hemispherectomy. She has been seizure free with no intracranial hemorrhage or other perioperative complications. Patients with a COL4A1 mutation have an increased risk for intracranial hemorrhage because of disrupted integrity in the vascular basement membrane due to the mutation. After weighing the risks and benefits to these patients, epilepsy surgery may not be absolutely contraindicated. Furthermore, pediatric neurologists should be aware of an undiagnosed COL4A1 mutation when a patient presents with an unexplained neurological phenotype, such as mild hemiparesis, even in the absence of porencephaly.

Complex observation of scalp fast (40-150 Hz) oscillations in West syndrome and related disorders with structural brain pathology

We investigated the relationship between the scalp distribution of fast (40-150 Hz) oscillations (FOs) and epileptogenic lesions in West syndrome (WS) and related disorders. Subjects were 9 pediatric patients with surgically confirmed structural epileptogenic pathology (age at initial electroencephalogram [EEG] recording: mean 7.1 months, range 1-22 months). The diagnosis was WS in 7 patients, Ohtahara syndrome in 1, and a transitional state from Ohtahara syndrome to WS in the other. In the scalp EEG data of these patients, we conservatively detected FOs, and then examined the distribution of FOs. In five patients, the scalp distribution of FOs was consistent and concordant with the lateralization of cerebral pathology. In another patient, FOs were consistently dominant over the healthy cerebral hemisphere, and the EEG was relatively low in amplitude over the pathological atrophic hemisphere. In the remaining 3 patients, the dominance of FOs was inconsistent and, in 2 of these patients, the epileptogenic hemisphere was reduced in volume, which may result from atrophy or hypoplasia. The correspondence between the scalp distribution of FOs and the epileptogenic lesion should be studied, taking the type of lesion into account. The factors affecting scalp FOs remain to be elucidated.

Neonatal nonepileptic myoclonus is a prominent clinical feature of KCNQ2 gain-of-function variants R201C and R201H

OBJECTIVE

To analyze whether KCNQ2 R201C and R201H variants, which show atypical gain-of-function electrophysiologic properties in vitro, have a distinct clinical presentation and outcome.

METHODS

Ten children with heterozygous, de novo KCNQ2 R201C or R201H variants were identified worldwide, using an institutional review board (IRB)-approved KCNQ2 patient registry and database. We reviewed medical records and, where possible, interviewed parents and treating physicians using a structured, detailed phenotype inventory focusing on the neonatal presentation and subsequent course.

RESULTS

Nine patients had encephalopathy from birth and presented with prominent startle-like myoclonus, which could be triggered by sound or touch. In seven patients, electroencephalography (EEG) was performed in the neonatal period and showed a burst-suppression pattern. However, myoclonus did not have an EEG correlate. In many patients the paroxysmal movements were misdiagnosed as seizures. Seven patients developed epileptic spasms in infancy. In all patients, EEG showed a slow background and multifocal epileptiform discharges later in life. Other prominent features included respiratory dysfunction (perinatal respiratory failure and/or chronic hypoventilation), hypomyelination, reduced brain volume, and profound developmental delay. One patient had a later onset, and sequencing indicated that a low abundance (~20%) R201C variant had arisen by postzygotic mosaicism.

SIGNIFICANCE

Heterozygous KCNQ2 R201C and R201H gain-of-function variants present with profound neonatal encephalopathy in the absence of neonatal seizures. Neonates present with nonepileptic myoclonus that is often misdiagnosed and treated as seizures. Prognosis is poor. This clinical presentation is distinct from the phenotype associated with loss-of-function variants, supporting the value of in vitro functional screening. These findings suggest that gain-of-function and loss-of-function variants need different targeted therapeutic approaches.

Infantile Spasms Treated with Intravenous Methypredinsolone Pulse

OBJECTIVE

Infantile spasms is diagnosed late even by expert pediatricians. Late diagnosis (later than 3 weeks) can have a negative effect on the long-term prognosis. We aimed to investigate infantile spasms treated with intravenous methylprednisolone pulse.

MATERIALS & METHODS

In this case series study, 20 infants with infantile spasms in 17-Shahrivar Hospital, Rasht, Iran were enrolled. Drugs were administered based on Mytinger protocol that included 3 days of methylprednisolone pulse and 56 days of oral prednisolone. The control of spasms and the omission of hypsarrhythmia in infants follow-up were the primary and secondary outcomes, respectively. Remission was indicated if the caregivers mentioned no spasms or >50% decrease regarding drug initiation for at least 5 consecutive days and the electroencephalography during sleep period noted the omission of hypsarrhythmia.

RESULTS

Eleven female (55%) and 9 male (45%) patients with the mean age of 4.95±1.39 months were enrolled. Mean rapid remission was noted as 4.41±1.50 days. Twelve patients (60%) noted early remission. seizure was controlled in 3(15%) patients completely after 24 months. Five (25%) occasional seizures were noted controlled by routine anticonvulsant drugs after 24 months and 12 (60%) no response was mentioned. Most of the patients (65%) had cryptogenic etiology for infantile spasms. Uncontrolled seizure was mentioned after initial remission.

CONCLUSION

Methyl prednisolone is an appropriate drug based on easy administering, low cost, and its accessibility.

Atonic elements combined or uncombined with epileptic spasms in infantile spasms

OBJECTIVE

To study the atonic elements combined or uncombined with epileptic spasms in infantile spasms.

METHODS

The demographic data, clinical characteristics, electroencephalogram (EEG), and polyelectromyography (PEMG) features were analyzed in 12 infantile spasm patients with atonic elements.

RESULTS

A total of 29 EEGs were recorded. Hypsarrhythmia or hypsarrhythmia variants were identified during interictal EEG. Insular or clustered epileptic spasms occurred in all. Three subtypes of atonic elements combined or uncombined with epileptic spasms (spasm-atonic, pure atonic, and atonic-spasm seizures) were observed electroclinically, which could present insularly or in cluster or altered with epileptic spasms in the same cluster. The ictal EEG showed generalized high-amplitude slow waves presenting alone or combined with other patterns. The corresponding PEMG showed an obvious electrical silence alone or preceding or following a crescendo-decrescendo pattern generated from myoelectric burst.

CONCLUSIONS

Atonic elements combined or uncombined with epileptic spasms was a newly noticed phenomenon in infantile spasms, which was artificially divided into three subtypes here. It might be a variant of epileptic spasms or a unique seizure type.

SIGNIFICANCE

Atonic elements combined or uncombined with epileptic spasms was a previously ignored phenomenon in infantile spasms, which should be seriously considered in clinical practice.

Cerebrotendinous Xanthomatosis Presenting with Infantile Spasms and Intellectual Disability

Cerebrotendinous xanthomatosis (CTX) is an inborn error of metabolism leading to progressive multisystem disease. Symptoms often begin in the first decade of life with chronic diarrhea, cataracts, developmental delay, intellectual disability, and cerebellar or pyramidal dysfunction. Later manifestations include tendon xanthomas, polyneuropathy, and abnormal neuroimaging. Pathogenic biallelic variants in CYP27A1 leading to compromised function of sterol 27-hydroxylase result in accumulation of detectable toxic intermediates of bile acid synthesis rendering both genetic and biochemical testing effective diagnostic tools. Effective treatment with chenodeoxycholic acid is available, making early diagnosis critical for patient care. Here we report a new patient with CTX and describe the early signs of disease in this patient. Initial symptoms included infantile spasms, which have not previously been reported in CTX. Developmental delay, mild intellectual disability with measured cognitive decline in childhood, was also observed. These clinical signs do not traditionally compel testing for CTX, and we highlight the need to consider this rare but treatable disorder among the differential diagnosis of children with similar clinical presentation. Increased awareness of early signs of CTX is important for improving time to diagnosis for this patient population.

APC conditional knock-out mouse is a model of infantile spasms with elevated neuronal β-catenin levels, neonatal spasms, and chronic seizures

Infantile spasms (IS) are a catastrophic childhood epilepsy syndrome characterized by flexion-extension spasms during infancy that progress to chronic seizures and cognitive deficits in later life. The molecular causes of IS are poorly defined. Genetic screens of individuals with IS have identified multiple risk genes, several of which are predicted to alter β-catenin pathways. However, evidence linking malfunction of β-catenin pathways and IS is lacking. Here, we show that conditional deletion in mice of the adenomatous polyposis coli gene (APC cKO), the major negative regulator of β-catenin, leads to excessive β-catenin levels and multiple salient features of human IS. Compared with wild-type littermates, neonatal APC cKO mice exhibit flexion-extension motor spasms and abnormal high-amplitude electroencephalographic discharges. Additionally, the frequency of excitatory postsynaptic currents is increased in layer V pyramidal cells, the major output neurons of the cerebral cortex. At adult ages, APC cKOs display spontaneous electroclinical seizures. These data provide the first evidence that malfunctions of APC/β-catenin pathways cause pathophysiological changes consistent with IS. Our findings demonstrate that the APC cKO is a new genetic model of IS, provide novel insights into molecular and functional alterations that can lead to IS, and suggest novel targets for therapeutic intervention.

Fast (40-150Hz) oscillations are associated with positive slow waves in the ictal EEGs of epileptic spasms in West syndrome

OBJECTIVE

To elucidate the generative mechanisms of epileptic spasms (ESs) in West syndrome, we investigated the temporal relationship between scalp fast (40-150Hz) oscillations (FOs) and slow waves in the ictal electroencephalograms (EEGs) of ESs.

METHODS

In 11 infants with WS, ictal FOs were detected in a bipolar montage based on spectral and waveform criteria. Their temporal distribution was analyzed in terms of the positive peaks (trough point, T_T) of identical EEG data in a referential montage. Among six EEG data sections defined according to T_T, the number of FOs, peak power values, and peak frequencies were compared.

RESULTS

We identified a total of 1014 FOs (946 gamma and 68 ripple oscillations), which clustered closely at T_T. The number of gamma oscillations in the 1s epoch including T_T was significantly higher than those in the prior and subsequent phases. Peak power values and frequencies tended to be higher in these positive phase sections.

CONCLUSIONS

The temporal association of FO clustering and positive slow waves in the ictal EEGs of ES indicated that active neuronal firing related to FOs underlies the generation of ESs and their ictal slow waves.

Antibodies against peptides of NMDA-type GluR in cerebrospinal fluid of patients with epileptic spasms

OBJECTIVE

We investigated the contribution of antibodies against N-methyl-d-aspartate (NMDA)-type glutamate receptor (GluR) in cerebrospinal fluid (CSF) to the clinical features of patients with epileptic spasms (ES).

METHODS

CSF samples were collected from 33 patients with ES with median (range) age 1.8 (0.2-8.5) years. Thirty patients without ES with 3.5 (0.5-7.0) years were also studied as disease controls. The CSF levels of antibodies against peptides of NMDA-type GluR subunits (GluN2B & GluN1) were measured by enzyme-linked immunosorbent assay.

RESULTS

The levels of antibodies against the n-terminal of GluN2B (GluN2B-NT2), c-terminal of GluN2B (GluN2B-CT) and n-terminal of GluN1 (GluN1-NT), were significantly higher in patients with ES than in disease controls (p < 0.01, p < 0.01 & p = 0.03). Levels of antibodies to GluN2B-NT2 & CT were not related with ACTH therapy nor conventional CSF factors (cell counts, protein level, etc). Levels of antibodies to GluN2B-NT2 & CT showed evidence of correlation within a linear regression model with intervals from the onset to the examination of CSF until 25 months (p = 0.01 & p = 0.01). The correlation was significant in patients with unknown cause (p = 0.01). Five of 33 patients (four unknown cause & one chromosomal anomaly) had higher level of antibodies to GluN2B-NT2 exceeding mean + 1 SD of all ES patients, and they had poor motor (score 0) and cognitive outcomes (score 0 or 1).

CONCLUSION

The CSF level of antibodies against GluN2B in ES patients with unknown cause was estimated to increase after onset. We hypothesize that some ES patients may have immune process after the onset of ES.

Response to second treatment after initial failed treatment in a multicenter prospective infantile spasms cohort

OBJECTIVE

Infantile spasms (IS) represent a severe epileptic encephalopathy presenting in the first 2 years of life. Recommended first-line therapies (hormonal therapy or vigabatrin) often fail. We evaluated response to second treatment for IS in children in whom the initial therapy failed to produce both clinical remission and electrographic resolution of hypsarhythmia and whether time to treatment was related to outcome.

METHODS

The National Infantile Spasms Consortium established a multicenter, prospective database enrolling infants with new diagnosis of IS. Children were considered nonresponders to first treatment if there was no clinical remission or persistence of hypsarhythmia. Treatment was evaluated as hormonal therapy (adrenocorticotropic hormone [ACTH] or oral corticosteroids), vigabatrin, or "other." Standard treatments (hormonal and vigabatrin) were compared to all other nonstandard treatments. We compared response rates using chi-square tests and multivariable logistic regression models.

RESULTS

One hundred eighteen infants were included from 19 centers. Overall response rate to a second treatment was 37% (n = 44). Children who received standard medications with differing mechanisms for first and second treatment had higher response rates than other sequences (27/49 [55%] vs. 17/69 [25%], p < 0.001). Children receiving first treatment within 4 weeks of IS onset had a higher response rate to second treatment than those initially treated later (36/82 [44%] vs. 8/34 [24%], p = 0.040).

SIGNIFICANCE

Greater than one third of children with IS will respond to a second medication. Choosing a standard medication (ACTH, oral corticosteroids, or vigabatrin) that has a different mechanism of action appears to be more effective. Rapid initial treatment increases the likelihood of response to the second treatment.

A case report on the efficacy of vigabatrin analogue (1S, 3S)-3-amino-4-difluoromethylenyl-1-cyclopentanoic acid (CPP-115) in a patient with infantile spasms

West Syndrome is characterized by infantile spasms, a hypsarrhythmic electroencephalogram (EEG) pattern, and a poor neurodevelopmental prognosis. First-line treatments include adrenocorticotrophic hormone (ACTH) and vigabatrin, but adverse effects often limit their use. CPP-115 is a high-affinity vigabatrin analogue developed to increase therapeutic potency and to limit retinal toxicity. Here, we present a child treated with CPP-115 through an investigational new drug protocol who experienced a marked reduction of seizures with no evidence of retinal dysfunction. Given the potential consequences of ongoing infantile spasms and the limitations of available treatments, further assessment of CPP-115 is warranted.

Acthar Gel(®)

Introduction

The purpose of this study was to describe healthcare resource utilization and costs resulting from early (within 30 days of diagnosis) versus late (>30 days after diagnosis) treatment with prescriptions for H.P. Acthar^® Gel (repository corticotropin injection; Acthar; Mallinckrodt) to manage infantile spasms (IS).

Methods

We included all patients in the Truven Health MarketScan^® Commercial Claims and Encounters Database and the Truven Health MarketScan Multi-State Medicaid Database who were diagnosed with IS from 2007 to 2012. We performed unadjusted and adjusted regressions examining the relationship between healthcare resource utilization variables and their associated costs to compare outcomes in the early and late Acthar users.

Results

A total of 252 patients with IS who received Acthar fit our study criteria; 191 (76%) were early Acthar users. In adjusted analyses, we found that early Acthar use was associated with, on average, 3.8 fewer outpatient services (99% CI 0.7–6.7 fewer services). We did not find significant associations between early prescriptions for Acthar and number of hospitalizations, emergency room visits, prescription medications filled, or total costs of health services.

Conclusion

Patients prescribed Acthar within 30 days of their IS diagnoses tended to have fewer outpatient services performed compared to patients prescribed Acthar later in the disease process. Although additional research is needed to confirm these exploratory findings, physicians may consider early treatment with Acthar to manage IS.

Funding

This study was funded by a grant to the University of Washington from Mallinckrodt Pharmaceuticals.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-016-0361-2) contains supplementary material, which is available to authorized users.

Long-term mortality of patients with West syndrome

Objective

To study long‐term survival and mortality among patients with West syndrome.

Methods

The study population included all children born in 1960–1976 and treated for West syndrome in three tertiary care hospitals in Helsinki, Finland. The participants were prospectively followed for five decades for survival. Death data were derived from the National Causes of Death Register of the Population Register Center of Statistics Finland.

Results

During follow‐up, 102 (49%) of 207 patients had died at the mean age of 19 years. The mean overall annual mortality rate was 15.3 per 1,000 patient‐years. The rates ranged from 18.2 per 1,000 after 10 years to 17.2 per 1,000 after 20 years and 15.4 per 1,000 patient‐years after 40 years of follow‐up. One fourth (25%) had died by 17.2 (95% CI 11.8–22.7) years and 50% by 48.6 (95% CI 38.5–NA) years of follow‐up. Etiology at onset was symptomatic in 87% patients and cryptogenic in 13%; 6 of the latter 26 patients later turned out to be symptomatic. The mean annual mortality rate was 3.7 per 1,000 for 4 patients with cryptogenic etiology and 17.6 per 1,000 for those with symptomatic etiology. The hazard of death was fivefold in patients with symptomatic etiology versus cryptogenic etiology. The overall autopsy rate was 73%. Pneumonia was the most frequent cause of death (46%). All patients who died of pneumonia had symptomatic etiology. SUDEP occurred in 10 patients and was the most common epilepsy‐related cause of death (10%).

Significance

Risk of excess death of participants with West syndrome is not limited to early age but continues into adulthood, particularly in those with symptomatic etiology, and leads to death in half the cases at around 50 years of age. Measures should be directed to prevent pneumonia, the most common overall cause, and SUDEP, the most frequent seizure‐related cause, of death.

Which children receive vigabatrin? Characteristics of pediatric patients enrolled in the mandatory FDA registry

Vigabatrin (Sabril®) is an antiepileptic drug (AED) currently indicated in the US as a monotherapy for patients 1month to 2years of age with infantile spasms (IS) and as adjunctive therapy for patients ≥10years of age with refractory complex partial seizures (rCPS) whose seizures have inadequately responded to several alternative treatments and for whom the potential benefits outweigh the risk of vision loss. The approval required an FDA mandated registry. This article describes 5years of demographic and treatment exposure data from US pediatric patients (<17years). Participation is mandatory for all US Sabril® prescribers and patients. A benefit-risk assessment must be documented for patient progression to maintenance therapy. This includes demographic diagnosis and reports of ophthalmologic assessments (where available). Patient data were grouped by age as proxies for indication (IS: <3years, rCPS: ≥3 to <17years). As of August 26, 2014, 5546/6823 enrolled patients were pediatric/total; 4472 (81%) were vigabatrin-naïve. Seventy-one percent of patients were <3years of age; 29% were ≥3 to <17years of age. Etiologies of IS were identified as cryptogenic (21%), symptomatic tuberous sclerosis (17%), and symptomatic other (42%). The majority of patients with IS (56%) attempted no prior treatments; 16% received adrenocorticotropic hormone prior to vigabatrin. A third of patients with IS were receiving 1 concomitant treatment with vigabatrin. For patients with rCPS, 39% attempted 1-3 prior treatments; 27% were receiving 2 concomitant treatments at enrollment. A total of 1852 (41%) patients did not undergo baseline ophthalmological assessment; 25% of patients with IS and 42% of patients with rCPS were exempted for neurologic disabilities. Kaplan-Meier estimates predict that 71% and 65% of vigabatrin-naïve patients with IS and rCPS, respectively, would remain in the registry at 6months. Most pediatric vigabatrin patients have IS as an underlying diagnosis, especially those <3years of age. A proportion of those with rCPS remain on long-term vigabatrin despite the risk of adverse events.

Infantile spasms with periventricular nodular heterotopia, unbalanced chromosomal translocation 3p26.2 -10p15.1 and 6q22.31 duplication

Patients presenting with infantile spasms, dysmorphic features, and periventricular nodular heterotopia may benefit from genetic copy number variation microarray, or whole-exome sequencing to identify candidate genes. This will allow personalized diagnosis and prognostication and the eventual understanding of single and combined gene functions in brain health and disease.

Effectiveness of once-daily high-dose ACTH for infantile spasms

There is insufficient evidence to recommend a specific protocol for treatment of infantile spasms (IS) and a lack of standardization among, and even within, institutions. Twice-daily dosing (for the first two weeks) of high-dose natural ACTH for IS is used by many centers and recommended by the National Infantile Spasms Consortium (NISC). Conversely, it is our practice to use once-daily dosing of high-dose natural ACTH for IS. In order to determine the effectiveness of our center's practice, we retrospectively reviewed 57 cases over the past four years at Boston Children's Hospital (BCH). We found that 70% of infants were spasm-free at 14days from ACTH initiation and 54% continued to be spasm-free at 3-month follow-up. Electroencephalogram showed resolution of hypsarrhythmia (when present on the pretreatment EEG) in all responders. Additionally, once-daily dosing of ACTH was well tolerated. We performed a meta-analysis to compare our results against the reports of published literature using twice-daily high-dose ACTH for treatment of IS. The meta-analysis revealed that our results were comparable to previously published outcomes using twice-daily ACTH administration for IS treatment. Our experience shows that once-daily dosing of ACTH is effective for treatment of IS. If larger prospective trials can confirm our findings, it would obviate the need for additional painful injections, simplify the schedule, and support a universal standardized protocol.

RARS2 mutations in a sibship with infantile spasms

Pontocerebellar hypoplasia is a group of heterogeneous neurodevelopmental disorders characterized by reduced volume of the brainstem and cerebellum. We report two male siblings who presented with early infantile clonic seizures, and then developed infantile spasms associated with prominent isolated cerebellar hypoplasia/atrophy on magnetic resonance imaging (MRI). Using whole exome sequencing techniques, both were found to be compound heterozygotes for one previously reported and one novel mutation in the gene encoding mitochondrial arginyl‐tRNA synthetase 2 (RARS2). Mutations in this gene have been classically described in pontocerebellar hypoplasia type six (PCH6), a phenotype characterized by early (often intractable) seizures, profound developmental delay, and progressive pontocerebellar atrophy. The electroclinical spectrum of PCH6 is broad and includes a number of seizure types: myoclonic, generalized tonic–clonic, and focal clonic seizures. Our report expands the characterization of the PCH6 disease spectrum and presents infantile spasms as an associated electroclinical phenotype.

Increased precipitation of spasms in an animal model of infantile spasms by prenatal stress exposure

Infantile spasms (IS) represent a serious epileptic syndrome, called West syndrome (WS) that occurs in the early infantile age. Although several hypotheses and animal models have been proposed to explain the pathogenesis of IS, the pathophysiology of IS has not been elucidated. Recently, we proposed a hypothesis for IS under prenatal stress exposure (also called Zou's hypothesis) by correlating diverse etiologies and prenatal stresses with IS development. This research aims to determine the mechanism through which prenatal stress affects the offspring and establish the potential underlying mechanisms. Pregnant rats were subjected to forced swimming in cold water. Rat pups exposed to prenatal stress were administered with N-methyl-D-aspartate (NMDA). Exposure to prenatal stress sensitized the rats against development of NMDA-induced spasms. However, this phenomenon was altered by administering adrenocorticotropin. Prenatal stress exposure also altered the hormonal levels and neurotransmitter receptor expression of the developing rats as well as influenced the tissue structure of the brain. These findings suggest that maternal stress could alter the level of endogenous glucocorticoid, which is the basis of IS, and cerebral dysplasia, hypoxic-ischemic encephalopathy (HIE), inherited metabolic diseases, and other factors activated this disease in developmental brain.

Sabril® registry 5-year results: Characteristics of adult patients treated with vigabatrin

Vigabatrin (Sabril®), approved in the US in 2009, is currently indicated as adjunctive therapy for refractory complex partial seizures (rCPS) in patients ≥ 10 years old who have responded inadequately to several alternative treatments and as monotherapy for infantile spasms (IS) in patients 1 month to 2 years of age. Because of reports of vision loss following vigabatrin exposure, FDA approval required a risk evaluation mitigation strategy (REMS) program. Vigabatrin is only available in the US through Support, Help, And Resources for Epilepsy (SHARE), which includes a mandated registry. This article describes 5 years of demographic and treatment exposure data from adult patients (≥ 17 years old) in the US treated with vigabatrin and monitored in the ongoing Sabril® registry. Registry participation is mandatory for all US Sabril® prescribers and patients. A benefit-risk assessment must be documented by the physician for a patient to progress to maintenance therapy, defined as 1 month of vigabatrin treatment for patients with IS and 3 months for patients with rCPS. Ophthalmologic assessments must be documented during and after completion of therapy. As of August 26, 2014, a total of 6823 patients were enrolled in the registry, of which 1200 were adults at enrollment. Of these patients, 1031 (86%) were naïve to vigabatrin. The majority of adult patients (n=783, 65%) had previously been prescribed ≥ 4 AEDs, and 719 (60%) were receiving ≥ 3 concomitant AEDs at vigabatrin initiation. Prescribers submitted an initial ophthalmological assessment form for 863 patients; an ophthalmologic exam was not completed for 300 (35%) patients and thus, were considered exempted from vision testing. Of these patients, 128 (43%) were exempted for neurologic disabilities. Clinicians discontinued treatment in 8 patients because of visual field deficits (VFD) (5 patients naïve to vigabatrin and 3 patients previously exposed). Based on Kaplan-Meier survival estimates, it is estimated that approximately 71%, 55%, and 40% of adult patients naïve to vigabatrin would remain in the registry at 3, 6, and 12 months, respectively. These demographic data suggest that a proportion of adult patients remain on vigabatrin long-term despite the risks of adverse events and significant underlying AED resistance and neurologic disease.

Limited efficacy of the ketogenic diet in the treatment of highly refractory epileptic spasms

PURPOSE

Numerous studies have suggested that the ketogenic diet is effective in the treatment of epileptic spasms, even in refractory cases. However, there has been very limited demonstration of prompt and complete (video-EEG confirmed) response. We set out to describe our center's experience with the ketogenic diet in the treatment of children with highly refractory epileptic spasms, with rigorous seizure outcome assessment.

METHOD

Children treated with the ketogenic diet for epileptic spasms between April, 2010 and June, 2014 were retrospectively identified. Seizure burden was tabulated at baseline and after 1, 3, 6, and 12-months of ketogenic diet exposure. Adverse events were similarly ascertained.

RESULTS

We identified a cohort of 22 consecutive patients who received ketogenic diet therapy, with median age of onset of epileptic spasms of 5.2 (IQR 2.0-9.0) months, with diet initiation beginning a median of 26.4 (12.5-38.7) months after onset, and following a median of 7 (IQR 5-7) treatment failures. Only 2 patients exhibited a complete response during ketogenic diet exposure, and response was more reasonably attributed to alternative therapies in both cases. A modest early reduction in seizure frequency was not sustained beyond 1 month of diet exposure. The diet was well tolerated, and continued in 6 patients with subjective and/or partial response.

CONCLUSION

In contrast to prior studies reporting substantial efficacy of the ketogenic diet, our findings suggest limited efficacy, albeit in a highly refractory cohort. Prospective studies in both refractory and new-onset populations, with both video-EEG confirmation of response and rigorous cognitive outcome assessment, would be of great value to more clearly define the utility of the ketogenic diet in the treatment of epileptic spasms.

Clinical profiles for seizure remission and developmental gains after total corpus callosotomy

PURPOSE

This study was aimed to determine what preoperative profiles were associated with seizure remission after corpus callosotomy and whether such seizure outcome was associated with the postoperative developmental outcome.

METHODS

This retrospective study included 26 consecutive patients with childhood onset epilepsy who underwent one-stage total corpus callosotomy at our institution and were followed up for a minimum of 1 year. The age at surgery ranged from 13 months to 32 years (median 6 years). The association between postoperative seizure freedom and preoperative profiles, post-operative developmental gains was examined.

RESULTS

Five patients achieved seizure freedom (Engel class I), and 10 patients achieved worthwhile reduction of seizures (class III), whereas the remaining patients had a class IV outcome. All five seizure-free patients had "lack of abnormal magnetic resonance imaging findings", "lack of proven etiology of seizures", and underwent "surgery at age 6 years or younger". These three factors were associated with seizure freedom (p<0.05, Fisher exact test). Post-operative gains in developmental quotient were significantly better in patients with seizure freedom than in those without (p<0.05, Mann Whitney U test).

CONCLUSION

Our study replicated the notion that seizure remission can be achieved after total corpus callosotomy in subsets of patients with medically-uncontrolled epilepsy, and suggested that a better developmental outcome can be expected in patients benefiting from seizure freedom.

Early Infantile Epileptic Encephalopathy with a de novo variant in ZEB2 identified by exome sequencing

Early Infantile Epileptic Encephalopathy (EIEE) presents shortly after birth with frequent, severe seizures, a burst-suppression EEG pattern, and progressive disturbance of cerebral function. We present a case of EIEE associated with a de novo missense variant in ZEB2. Heterozygous truncating mutations or deletions in ZEB2 are known to cause Mowat-Wilson syndrome (MWS), which is characterized by seizures with onset in the second year of life, distinctive dysmorphic facial features and malformations that were absent in this patient. This unique case expands the range of phenotypes associated with variants in ZEB2 and indicates that this gene should be included in the molecular investigation of EIEE cases.

Cerebal overinhibition could be the basis for the high prevalence of epilepsy in persons with Down syndrome

Down syndrome (DS) is the most common cause of genetic intellectual disability, and the trisomy 21 is associated with more than 80 clinical traits, including higher risk for epilepsy. Several hypotheses have been put forward to explain the mechanisms underlying increased seizure susceptibility in DS: inherent structural brain abnormalities, abnormal cortical lamination, disruption of normal dendritic morphology, and underdeveloped synaptic profiles. A deficiency or loss of GABA inhibition is hypothesized to be one of the main alterations related to the epileptogenic process. Paradoxically, enhanced GABA inhibition has also been reported to promote seizures. One major functional abnormality observed in the brains of individuals and mouse models with DS appears to be an imbalance between excitatory and inhibitory neurotransmission, with excessive inhibitory brain function. This review discusses the GABAergic system in the human DS brain and the possible implication of the GABAergic network circuit in the epileptogenic process in individuals where the pathogenetic basis for epilepsy is unknown.

Management of infantile spasms

West syndrome, or infantile spasms syndrome is a frequently catastrophic infantile epileptic encephalopathy with a variety of etiologies. Despite the heterogeneous nature of causes of infantile spasms, a careful diagnostic evaluation can lead to diagnosis in many patients and may guide treatment choices. Magnetic resonance imaging (MRI) brain remains the highest yield initial study in determining the etiology in infantile spasms. Treatment of infantile spasms has little class I data, but adrenocorticotropic hormone (ACTH), prednisolone and vigabatrin have the best evidence as first-line medications. Other therapies including the ketogenic diet and other anti-epileptics medications may also prove useful in the treatment of infantile spasms. In general, more studies are needed to determine the best treatment regimen for this condition. Prognosis is generally poor, with the majority of patients having some or profound neurocognitive delays. Patients without delays at diagnosis and without an identifiable etiology, if treated appropriately, have the greatest likelihood of a normal outcome.

Hemispherotomy for isolated infantile spasms following perinatal ischemic stroke

BACKGROUND

Infantile spasms (IS) are a severe epileptic encephalopathy. In patients with early focal ischemia and refractory IS, a preoperative evaluation is required even if IS are the only ictal manifestation.

METHODS

We report three such patients who presented with IS between 5 and 7 months of age without any other focal seizure types. Imaging exhibited a perinatal middle cerebral artery (MCA) stroke.

RESULTS

All patients had hemiparesis and experienced psychomotor regression after the onset of IS. Scalp video-electroencephalogram (EEG) monitoring for presurgical assessment showed interictal and ictal EEG characteristics between the pathological and the healthy hemisphere and surgery was proposed despite the lack of any focal seizures. The three patients underwent hemispherotomy at a mean age of 27 months and became seizure-free without medication (follow-up 49-144 months). The two patients who underwent early hemispherotomy acquired normal verbal intelligence, whereas the third, operated on at 38 months of age, remained with severe mental retardation.

CONCLUSION

Early hemispherotomy in drug-resistant epilepsy related to a perinatal MCA may cure the seizures even if the patient has IS as sole type and prevent mental retardation in some children.

β-Hydroxybutyrate attenuates NMDA-induced spasms in rats with evidence of neuronal stabilization on MR spectroscopy

BACKGROUND

Infantile spasms (IS) is a devastating epileptic encephalopathy. The ketogenic diet (KD) has been successfully used as a treatment for IS. This study was designed to test whether beta-hydroxybutyrate (BHB), a major metabolite of the KD, is effective in an animal model of IS.

METHODS

Pregnant rats received betamethasone on gestational day 15. The offspring received either single [30min prior to NMDA-triggered spasms on postnatal day (P) 15] or prolonged (three per day from P12 to P15) i.p. BHB. An additional experiment used repeated bouts of spasms on P12, P13, and P15 with randomized prolonged BHB treatment initiated after the first spasms. We determined the latency to onset of spasms and the number of spasms after the NMDA injection on P15. The rats that received randomized BHB treatment were also monitored with open field, sociability, and fear-conditioning tests and underwent in vivo (1)H MR imaging on a 9.4T MR system after NMDA-induced spasms. The acquired (1)H MR spectra were quantified using LC model.

RESULTS

Single-dose BHB pretreatment had no effect on spasms. In contrast, prolonged pretreatment with BHB significantly delayed the onset and decreased the frequency of spasms. In addition, randomized prolonged BHB treatment resulted in a significant reduction in number of spasms at P15. BHB treatment had no significant effect on motor activities, but significantly decreased the interactions with strangers and increased the contextual memory. On MR spectroscopic analysis of randomized prolonged BHB-treated rats at 24h after the cluster of spasms, the elevation of GABA, glutamine, glutamate, total creatine, macromolecule-plus lipids, and N-acetylaspartate levels after spasms were significantly attenuated by randomized BHB treatment (p<0.05).

SIGNIFICANCE

Prolonged administration of BHB directly suppresses development of spasms in a rat model of IS with acute stabilization of brain metabolites. Additionally, BHB appears to decrease the interests to other rats and improve memory responses.

Chromosomal microarray in unexplained severe early onset epilepsy - A single centre cohort

BACKGROUND

Severe early onset epilepsy may lead to impaired cognitive and motor development, and consists of a group of specific and overlapping electro-clinical phenotypes which may be the result of an inborn error of metabolism, congenital or acquired structural brain lesion, known chromosomal or mono-genetic disorder. A significant proportion of cases however remain unexplained, representing a major diagnostic and management challenge.

METHODS

In this study we describe a cohort of children with severe early onset epilepsy and examine the clinical utility of chromosomal microarray (array-comparative genomic hybridisation, CGH) in this group of epilepsies.

RESULTS

In 51 children with unexplained severe early onset epilepsy, all of whom had chromosomal array tested, copy number variants were detected in 17.6% and pathogenic variants in 5.9% of infants.

CONCLUSIONS

Chromosomal microarray is a useful investigation in early onset refractory epilepsy and epileptic encephalopathy. Detailed review of the precise array abnormality and phenotypes associated are important for determining significance.

Perceived efficacy of cannabidiol-enriched cannabis extracts for treatment of pediatric epilepsy: A potential role for infantile spasms and Lennox-Gastaut syndrome

There is a great need for safe and effective therapies for treatment of infantile spasms (IS) and Lennox-Gastaut syndrome (LGS). Based on anecdotal reports and limited experience in an open-label trial, cannabidiol (CBD) has received tremendous attention as a potential treatment for pediatric epilepsy, especially Dravet syndrome. However, there is scant evidence of specific utility for treatment of IS and LGS. We sought to document the experiences of children with IS and/or LGS who have been treated with CBD-enriched cannabis preparations. We conducted a brief online survey of parents who administered CBD-enriched cannabis preparations for the treatment of their children's epilepsy. We specifically recruited parents of children with IS and LGS and focused on perceived efficacy, dosage, and tolerability. Survey respondents included 117 parents of children with epilepsy (including 53 with IS or LGS) who had administered CBD products to their children. Perceived efficacy and tolerability were similar across etiologic subgroups. Eighty-five percent of all parents reported a reduction in seizure frequency, and 14% reported complete seizure freedom. Epilepsy was characterized as highly refractory with median latency from epilepsy onset to CBD initiation of five years, during which the patient's seizures failed to improve after a median of eight antiseizure medication trials. The median duration and the median dosage of CBD exposure were 6.8 months and 4.3mg/kg/day, respectively. Reported side effects were far less common during CBD exposure, with the exception of increased appetite (30%). A high proportion of respondents reported improvement in sleep (53%), alertness (71%), and mood (63%) during CBD therapy. Although this study suggests a potential role for CBD in the treatment of refractory childhood epilepsy including IS and LGS, it does not represent compelling evidence of efficacy or safety. From a methodological standpoint, this study is extraordinarily vulnerable to participation bias and limited by lack of blinded outcome ascertainment. Appropriately controlled clinical trials are essential to establish efficacy and safety.

Efficacy of long term weekly ACTH therapy for intractable epilepsy

BACKGROUND

Adrenocorticotropic hormone (ACTH) therapy is the first-line therapy for infantile spasms, and is effective for many other intractable epilepsies. While spasms may respond to ACTH for weeks, a substantial proportion of patients develop recurrent seizures over a yearly period. To maintain efficacy, we treated two children with intractable epilepsy with weekly ACTH therapy for 1 year and described the changes in clinical seizures, electroencephalograms, developmental assessments and side effects.

SUBJECTS AND METHODS

A girl with infantile spasms due to lissencephaly and a boy with atypical absence seizures were studied. In both cases, seizures were frequent and resistant to antiepileptic drugs; electroencephalograms showed continuous epileptiform activities, and the patients' development was delayed and stagnant prior to ACTH treatment. The initial ACTH therapy (daily 0.015 mg/kg for 2 weeks, 0.015 mg/kg every 2 days for 1 week, 0.0075 mg/kg every 2 days for 1 week), was transiently effective in both cases. The second-round ACTH therapy consisted of the initial ACTH therapy protocol followed by weekly ACTH injections (0.015 mg/kg or 0.0075 mg/kg) for 1 year. Both cases were followed for at least 1 year after therapy.

RESULTS

In both patients, clinical seizures were completely controlled during and 1 year after the second-round AHCH therapy. Continuous epileptiform discharges disappeared, while intermittent interictal epileptiform discharges remained. Both patients showed some developmental gains after achieving seizure control. No serious side effects were recorded.

CONCLUSION

Further studies are warranted to determine if a long-term weekly ACTH is a safe and effective treatment for intractable epilepsy.

How should children with West syndrome be efficiently and accurately investigated? Results from the National Infantile Spasms Consortium

OBJECTIVE

To prospectively evaluate the etiology of new-onset infantile spasms and evaluate the yield of genetic and metabolic investigations in those without obvious cause after initial clinical evaluation and magnetic resonance imaging (MRI).

METHODS

Twenty-one U.S. pediatric epilepsy centers prospectively enrolled infants with newly diagnosed West syndrome in a central database. Etiology and investigations performed within 3 months of diagnosis were documented.

RESULTS

From June 2012 to June 2014, a total of 251 infants were enrolled (53% male). A cause was identified in 161 (64.4%) of 250 cases (genetic,14.4%; genetic-structural, 10.0%; structural-congenital, 10.8%; structural-acquired, 22.4%; metabolic, 4.8%; and infectious, 2.0%). An obvious cause was found after initial clinical assessment (history and physical examination) and/or MRI in 138 of 161, whereas further genetic and metabolic studies were revealing in another 23 cases. Of 112 subjects without an obvious cause after initial evaluation and MRI, 81 (72.3%) had undergone genetic testing, which showed a causal abnormality in 23.5% and a variant of unknown significance in 14.8%. Although metabolic studies were done in the majority (serum, 79.5%; urine, 69.6%; and cerebrospinal fluid [CSF], 38.4%), these revealed an etiology in only five cases (4.5%). No correlation was found between type of health insurance (public vs. private) and either genetic or metabolic testing.

SIGNIFICANCE

Clinical evaluation and MRI provide a specific diagnosis in 55% of children presenting with West syndrome. We propose that a cost-effective workup for those without obvious cause after initial clinical evaluation and MRI includes an array comparative genomic hybridization (aCGH) followed by an epilepsy gene panel if the microarray is not definitive, serum lactate, serum amino acids, and urine organic acids.

Temporal lobe epilepsy in infants and children

Clinical expression of temporal lobe seizures is different with a more diverse and more extensive etiology in infants and children than it is in adults. It is dominated by cortical dysplasia, low-grade tumors and perinatal damage. Hippocampal sclerosis, although less frequent, exists in children usually as a dual pathology associated with ipsilateral neocortical lesions. The clinical semiology of temporal seizures is more varied, and sometimes misleading. Motor features including tonic, clonic or myoclonic behaviors, and infantile spasms predominate in infants. Classical complex partial seizures with behavioral arrest and automatisms, as well as lateralizing signs are rare and occur mostly with onset after the age of two years. Interestingly, aura, emotional, and autonomic signs seem to be independent on the brain maturation process. Moreover, the neuropsychological profile varies according to age of onset and duration, lateralization of the focus and etiology. Quality of care benefits from individual cognitive assessment for memory and emotional processes.

Impaired slow wave sleep downscaling in patients with infantile spasms

BACKGROUND

West syndrome is a severe epileptic encephalopathy of infancy, characterized by infantile spasms, global retardation, and a severely abnormal electroencephalogram (EEG) pattern known as hypsarrhythmia, which is most prominent during slow waves sleep. The restorative function of slow wave sleep has been linked to downscaling, a neuronal process ensuring a balance of global synaptic strength, which is important for normal cortical functioning and development. A key electrophysiological marker for this downscaling is the reduction of the slope of slow waves across the night.

METHODS

We retrospectively compared the slope of slow waves between 14 untreated patients with infantile spasms and healthy age and gender matched controls. Patients were examined in one all-night sleep EEG before treatment, and in two follow-up nap recordings, under and after treatment with corticosteroids.

RESULTS

In patients with infantile spasms the overnight reduction in the slope of slow waves was significantly diminished compared to controls (p = 0.009). Moreover, untreated patients revealed overall steeper slopes. During corticosteroid treatment the slope was reduced compared to controls (p = 0.001). After successful treatment the slope was similar between patients and controls.

CONCLUSION

Our results provide evidence for reduced downscaling in patients with infantile spasms. Moreover, the marked reduction of the slope during corticosteroid treatment may reflect a loss of synaptic connections due to the effect of glucocorticoids. This altered sleep dependent regulation of synaptic strength in infantile spasms may contribute the underlying pathomechanism of the developmental regression. Furthermore the normalization of synaptic strength due to corticosteroids might provide a potential mechanistic explanation for this treatment strategy.

Heart rate variability in infants with West syndrome

PURPOSE

West syndrome (WS) is a severe age-related acute epileptic encephalopathy of infancy characterized by infantile spasms, hypsarrhythmia and psychomotor delay. The aim of this study was to investigate if patients with WS had an altered autonomic output to the heart.

METHODS

In 23 patients with WS the heart rate variability (HRV) was investigated by examining time- and frequency-domain parameters of HRV at the time of the diagnosis of hypsarrhythmia and compared to 22 age-matched controls. For the WS patients the same dataset was obtained and compared again at the end of the study period, when hypsarrhythmia was no longer present.

RESULTS

Compared to controls, patients with WS during hypsarrhythmia had significantly lower SDNN (the standard deviation of the NN interval, i.e. the square root of variance) (19.2 ms; p = 0.007, Mann-Whitney's U-Test) and total power (242 ms(2); p = 0.044, Mann-Whitney's U-Test) in the awake state, indicating an abnormal autonomic output to the heart. Comparing the initial to the final examination demonstrated a significant increase in the HRV parameters SDNN (31.3 ms) and total power (757 ms(2); p = 0.001 and p = 0.013, Wilcoxon Signed Ranked Test). In addition, at the final examination the WS-patients no longer differed significantly from the controls.

CONCLUSION

Our data suggest that the initial reduction in HRV in patients at the time of onset of WS is transient and related to the presence of hypsarrhythmia.

Hypofibrinogenemia caused by adrenocorticotropic hormone for infantile spasms: a case report

We report the case of a 7-month-old boy who developed hypofibrinogenemia (66.6 mg/dL; reference value, 170-405 mg/dL) during adrenocorticotropic hormone (ACTH) therapy for infantile spasms. Although the patient showed no clinical signs of a bleeding diathesis, we recommend that plasma fibrinogen levels should be monitored during ACTH therapy, which should be discontinued when fibrinogen levels fall below hemostatic levels (60.0mg/dL) or when bleeding tendencies are recognized.

Detection of global DNA hypomethylation of peripheral blood lymphocytes in patients with infantile spasms

The pathogenesis of infantile spasms remains unclear. DNA methylation may play a pivotal role in the development of some types of neurological diseases, such as epilepsy. In this study, we aimed to investigate the relationship between global DNA methylation of peripheral blood leukocytes and cryptogenic infantile spasms. DNA from peripheral blood leukocytes was extracted from 20 patients with cryptogenic infantile spasms and 20 gender and age matched healthy controls. Global DNA methylation percentage of peripheral blood leukocytes was measured using a global DNA methylation quantification kit. Global DNA methylation levels of peripheral blood lymphocytes in patients with cryptogenic infantile spasms (23.4 ± 20.0%) were significantly lower than those in healthy controls (46.8 ± 8.4%). Furthermore, we did not find any association between the levels of DNA methylation and effectiveness of Adrenocorticotropic hormone treatment. Our study demonstrates that global DNA hypomethylation of peripheral blood lymphocytes is correlated with infantile spasms. This finding provides information for better understanding of the pathogenesis of infantile spasms.

Neurodevelopmental outcome of infantile spasms: A systematic review and meta-analysis

BACKGROUND

The aims of this systematic review and meta-analysis were to assess (i) estimates of good neurodevelopmental outcome in infantile spasms (IS), (ii) if neurodevelopmental outcome has changed since the publication of the first guideline on medical treatment of IS in 2004 and (iii) effect of lead time to treatment (LTTT).

METHODS

The Medline, Embase, Cochrane, PsycINFO, Web of Science and Scopus databases, and reference lists of retrieved articles were searched. Studies inclusion criteria were: (i) >5 patients with IS, (ii) mean/median follow-up of >6 months, (iii) neurodevelopmental outcome, and (iv) randomized and observational studies. The data extracted included proportion of good neurodevelopmental outcome, year of publication, cryptogenic or symptomatic IS and LTTT.

RESULTS

Of the 1436 citations screened, 55 articles were included in final analysis, with a total of 2967 patients. The pooled estimate for good neurodevelopmental outcome was 0.236 (95% CI: 0.193-0.286). There was no difference between the proportions of good neurodevelopmental outcome for the 21 studies published after 2004 [0.264 (95% CI: 0.197-0.344)] compared to the 34 studies published before 2004 [0.220 (95% CI: 0.168-0.283)] (Q value=0.862, p=0.353). The pooled estimate of good neurodevelopmental outcome for cryptogenic IS [0.543 (95% CI: 0.458-0.625)] was higher than symptomatic IS [0.125 (95% CI: 0.09-0.171)] (Q value=69.724, p<0.001). Risk ratio of LTTT <4weeks relative to >4weeks for good neurodevelopmental outcome of 8 studies was 1.519 (95% CI: 1.064-2.169).

CONCLUSION

Neurodevelopmental outcome was overall poor in patients with IS and has not changed since the publication of first guideline on IS. Although cryptogenic IS has better prognosis than symptomatic IS, the outcome for cryptogenic IS remained poor. There was heterogeneity in neurodevelopmental outcome ascertainment methods, highlighting the need for a more standardized and comprehensive assessment of cognitive, behavioural, emotional and functional outcomes.

"Subtotal" hemispherectomy in children with intractable focal epilepsy

OBJECTIVE

Cortical resections in epilepsy surgery tend to be larger in children, compared to adults, partly due to underlying pathology. Some children show unilateral multifocal seizure onsets involving much of the hemisphere. If there were a significant hemiparesis present, hemispherectomy would be the procedure of choice. Otherwise, it is preferable to spare the primary sensorimotor cortex. We report the results of "subtotal" hemispherectomy in 23 children.

METHODS

All children (ages 1 year and 4 months to 14 years and 2 months) were operated on between 2001 and 2013 at Children's Hospital of Michigan (Detroit). Patients were evaluated with scalp video-electroencephalography (EEG), magnetic resonance imaging (MRI), (18) F-fluorodeoxyglucose-positron emission tomography (FDG-PET) scans, and neuropsychological assessments when applicable. Subsequently, each case was discussed in a multidisciplinary epilepsy surgery conference, and a consensus was reached pertaining to candidacy for surgery and optimum surgical approach. The actual extent of resection was based on the results from subdural electrocorticography (ECoG) monitoring. The surgical outcome is based on International League Against Epilepsy (ILAE) classification (class 1-6).

RESULTS

Among the 23 patients, 11 had epileptic spasms as their major seizure type; these were associated with focal seizures in 3 children. MRI showed focal abnormalities in 12 children. FDG-PET was abnormal in all but one subject. All except two children underwent chronic subdural ECoG. Multiple subpial transections were performed over the sensorimotor cortex in three subjects. On histopathology, various malformations were seen in 9 subjects; the remainder showed gliosis alone (n = 12), porencephaly (n = 1), and gliosis with microglial activation (n = 1). Follow-up ranged from 13 to 157 months (mean = 65 months). Outcomes consisted of class 1 (n = 17, 74%), class 2 (n = 2), class 3 (n = 1), class 4 (n = 1), and class 5 (n = 2).

SIGNIFICANCE

Extensive unilateral resections sparing only sensorimotor cortex can be performed with excellent results in seizure control. Even with the presence of widespread unilateral epileptogenicity or anatomic/functional imaging abnormalities, complete hemispherectomy can often be avoided, particularly when there is little hemiparesis.

Infantile spasms syndrome, West syndrome and related phenotypes: what we know in 2013

The current spectrum of disorders associated to clinical spasms with onset in infancy is wider than previously thought; accordingly, its terminology has changed. Nowadays, the term Infantile spasms syndrome (ISs) defines an epileptic syndrome occurring in children younger than 1 year (rarely older than 2 years), with clinical (epileptic: i.e., associated to an epileptiform EEG) spasms usually occurring in clusters whose most characteristic EEG finding is hypsarrhythmia [the spasms are often associated with developmental arrest or regression]. The term West syndrome (WS) refers to a form (a subset) of ISs, characterised by the combination of clustered spasms and hypsarrhythmia on an EEG and delayed brain development or regression [currently, it is no longer required that delayed development occur before the onset of spasms]. Less usually, spasms may occur singly rather than in clusters [infantile spasms single-spasm variant (ISSV)], hypsarrhythmia can be (incidentally) recorded without any evidence of clinical spasms [hypsarrhythmia without infantile spasms (HWIS)] or typical clinical spasms may manifest in absence of hypsarrhythmia [infantile spasms without hypsarrhythmia (ISW)]. There is a growing evidence that ISs and related phenotypes may result, besides from acquired events, from disturbances in key genetic pathways of brain development: specifically, in the gene regulatory network of GABAergic forebrain dorsal-ventral development, and abnormalities in molecules expressed at the synapse. Children with these genetic associations also have phenotypes beyond epilepsy, including dysmorphic features, autism, movement disorders and systemic malformations. The prognosis depends on: (a) the cause, which gives origin to the attacks (the complex malformation forms being more severe); (b) the EEG pattern(s); (c) the appearance of seizures prior to the spasms; and (d) the rapid response to treatment. Currently, the first-line treatment includes the adrenocorticotropic hormone ACTH and vigabatrin. In the near future the gold standard could be the development of new therapies that target specific pathways of pathogenesis. In this article we review the past and growing number of clinical, genetic, molecular and therapeutic discoveries on this expanding topic.

The ketogenic diet and other dietary treatments for refractory epilepsy in children

The ketogenic diet is a high-fat, low-carbohydrate, and restricted protein diet that is useful in patients with refractory epilepsy. The efficacy of the ketogenic diet is better than most of the new antiepileptic drugs. Other modifications of the diet are also beneficial, such as the modified Atkins diet and the low glycemic index treatment. There is a lack of awareness of the ketogenic diet as a treatment modality for epilepsy amongst pediatricians and neurologists. In this review, the use of the ketogenic diet and other dietary treatments in refractory epilepsy is discussed. The Indian experience with the use of these dietary treatments is also briefly reviewed.

RBPJ is disrupted in a case of proximal 4p deletion syndrome with epilepsy

Proximal 4p deletion syndrome is characterized clinically by mental retardation, minor dysmorphic facial features, and is occasionally complicated with epilepsy. More than 20 cases of proximal 4p deletion syndrome have been reported, but the causative gene(s) remain elusive. We describe here a 2-year-old female patient with a common manifestation of proximal 4p deletion syndrome and infantile epileptic encephalopathy possessing a de novo balanced translocation t(4;13)(p15.2;q12.13). The patient was diagnosed as infantile spasms at 9 months of age. She presented with dysmorphic facial features and global developmental delay, compatible with proximal 4p deletion syndrome. Using fluorescence in situ hybridization, we determined the translocation breakpoint at 4p15.2 to be within RBPJ. RBPJ is a transcription factor in the Notch/RBPJ signaling pathway, playing a crucial role in the developing human brain, and particularly telencephalon development. Our findings, combined with those of previous studies, strongly suggest that RBPJ is causative for proximal 4p deletion syndrome and epilepsy in this case.

Epilepsy and outcome in FOXG1-related disorders

OBJECTIVE

FOXG1-related disorders are associated with severe intellectual disability, absent speech with autistic features, and epilepsy. Children with deletions or intragenic mutations of FOXG1 also have postnatal microcephaly, morphologic abnormalities of the corpus callosum, and choreiform movements. Duplications of 14q12 often present with infantile spasms, and have subsequent intellectual disability with autistic features. Long-term epilepsy outcome and response to treatment have not been studied systematically in a well-described cohort of subjects with FOXG1-related disorders. We report on the epilepsy features and developmental outcome of 23 new subjects with deletions or intragenic mutations of FOXG1, and 7 subjects with duplications.

METHODS

Subjects had either chromosomal microarray or FOXG1 gene sequencing performed as part of routine clinical care. Development and epilepsy follow-up data were collected from medical records from treating neurologists and through telephone parental interviews using standardized questionnaires.

RESULTS

Epilepsy was diagnosed in 87% of the subjects with FOXG1-related disorders. The mean age of epilepsy diagnosis in FOXG1 duplications was significantly younger than those with deletions/intragenic mutations (p = 0.0002). All of the duplication FOXG1 children with infantile spasms responded to hormonal therapy, and only one required long-term antiepileptic therapy. In contrast, more children with deletions/intragenic mutations required antiepileptic drugs on follow-up (p < 0.0005). All subjects with FOXG1-related disorders had neurodevelopmental disabilities after 3 years of age, regardless of the epilepsy type or intractability of seizures. All had impaired verbal language and social contact, and three duplication subjects were formally diagnosed with autism. Subjects with deletion/intragenic mutations, however, had significantly worse ambulation (p = 0.04) and functional hand use (p < 0.0005).

SIGNIFICANCE

Epilepsy and developmental outcome characteristics allow clinicians to distinguish among the FOXG1-related disorders. Further genotype-phenotype studies of FOXG1 may help to elucidate why children develop different forms of developmental epilepsy.

14q12 duplication including FOXG1: is there a common age-dependent epileptic phenotype?

INTRODUCTION

Duplications of 14q12 encompassing FOXG1 gene have been recently associated with developmental delay, severe speech impairment, epilepsy, aspecific neuroimaging findings and minor dysmorphisms.

AIM AND METHODS

In order to refine the epileptic phenotype associated with 14q12 duplications, we have performed a review of the electroclinical picture of the patients reported to date in the literature, adding a new personal case. A comprehensive set of clinical and instrumental data (with a particular focus on the electroclinical aspects including seizure type, age of onset, EEG at onset and after antiepileptic therapy, drug efficacy) has been taken into account.

RESULTS

9/14 patients carrying 14q12 duplications developed seizures, all in the first months of life. Most of them developed infantile spasms (8/9 epileptic patients) and presented hypsarrhythmia or modified hypsarrhythmia on EEG. After therapy 5/9 patients became seizure free and 3/9 present a good seizure control. At last available follow up, 2/3 of the epileptic patients displayed an almost normal EEG, or a quite organized background activity, with diffuse or focal (mostly temporal) slowing.

CONCLUSIONS

The review of the available data allowed to recognize a common epileptic core, characterized by early onset, age dependent epileptic encephalopathy with infantile spasms and typical, atypical or modified hypsarrhythmia. Antiepileptic therapy soon led to a good or complete control of seizures with a nearly normal background activity in most patients.

A proposed diagnostic approach for infantile spasms based on a spectrum of variable aetiology

AIM

To identify the aetiology of patients with infantile spasms and propose practical guidelines for diagnostic strategies.

METHOD

We performed a retrospective study of children with West syndrome. Prenatal and birth medical history, characteristics of epilepsy, psychomotor development, biological and genetic screening, and aetiology were reported. Brain MRI was performed at least once and was repeated after two years of age if no aetiology was identified.

RESULTS

Eighty children were included. Aetiology was identified in 40 children: 17 with acquired cause (seven with stroke and six with hypoxic-ischaemic encephalopathy) and 23 with developmental pathology (seven with tuberous sclerosis, eight with cerebral malformations, and eight with various genetic abnormalities). The yield of brain imaging was high, providing a diagnosis for 32 patients. Two subtle brain lesions were detected only after two years of age, based on subsequent MRI. Genetic testing provided a diagnosis for the remaining eight patients.

INTERPRETATION

Although this is a retrospective study, the results provide a basis to review the aetiology of infantile spasms and confirm the role of cerebral MRI in first-line diagnosis. Cases with a genetic aetiology have been diagnosed with increasing frequency due to better diagnostic capabilities. We propose guidelines for a practical diagnostic approach and discuss the relevant use of genetics in the future.

Intellectual development before and after the onset of infantile spasms: a controlled prospective longitudinal study in tuberous sclerosis

OBJECTIVE

Infantile spasms (IS) have long been suspected to be a risk factor for impairment in intellectual development, but there are no controlled, prospective longitudinal data in well-characterized conditions to confirm this suspicion. We tested the hypothesis in a longitudinal study of children with tuberous sclerosis (TS), who have a high risk of developing IS.

METHODS

Eleven infants with TS were recruited and studied longitudinally using the Mullen Scales of Early Learning. Seizure histories were assessed using a structured parent interview and by review of medical notes. Intellectual development was examined in relation to the onset and length of exposure to IS and other types of seizures.

RESULTS

Six children developed IS and five children developed other types of seizure disorders. Among those that developed IS, estimated mean IQ dropped significantly (nonparametric test for trend p = 0.002) from 92 (prior to onset of spasms) to 73 (after exposure to IS for a month or less) and 62 (after exposure to IS for more than a month). By contrast, there was no significant drop in estimated IQ among the five infants exposed to other types of seizure disorders (nonparametric test for trend p = 0.9). All six children exposed to infantile spasms developed clinically significant intellectual impairment.

SIGNIFICANCE

These data provide the first clear evidence of clinically significant, dose dependent, impairment in intellectual development following exposure to infantile spasms. The mechanisms underlying this developmental impairment and methods for preventing it require in depth study.

Infantile spasm: a review article

OBJECTIVE

Infantile spasm (IS) is a convulsive disease characterized by brief, symmetric axial muscle contraction (neck, trunk, and/or extremities). IS is a type of seizure that was first described by West in 1841, who witnessed the seizure in his own son. West's syndrome refers to the classic triad of spasms, characteristic EEG, and neurodevelopmental regression. Most cases involve flexors and extensors, but either of the types may be involved independently. IS, as its name implies, most often occurs during the first year of life with an incidence of approximately 1 per 2000-4000 live births. Most, but not all, patients with this disorder have severe EEG abnormalities; this pattern was originally referred to as hypsarrhythmia by Gibbs and Gibbs. Cases with known etiology or signs of brain damage are considered as symptomatic. The Overall prognosis of the disease is poor. Peak onset age of the epileptic syndrome is 3 to 7 months, which mainly occurs before 2 years of age in 93% of patients. Hypsarrhythmia is the EEG hallmark of IS, which comprised a chaotic, bilaterally asynchronous high-voltage polyspike, and slow wave discharges interspersed with multifocal spikes and slow waves. ETIOLOGICAL CLASSIFICATION IS AS FOLLOWS: 1) Symptomatic: with identifiable prenatal, perinatal, and postnatal causes with developmental delay at the presentation time; 2) Cryptogenic: unknown underlying cause, normal development at the onset of spasms, normal neurological exam and neuroimaging, and no abnormality in the metabolic evaluation; 3) Idiopathic: pure functional cerebral dysfunction with complete recovery, no residual dysfunction, normal neuroimaging and normal etiologic evaluation, and normal neurodevelopment.

Randomised clinical efficacy trial of topiramate and nitrazepam in treatment of infantile spasms

OBJECTIVE

Infantile spasms (IS) are among the most catastrophic epileptic syndromes of infancy. The purpose of this study was to compare efficacy and safety of topiramate (TPM) and nitrazepam (NZP) as first-line drugs in the treatment of IS.

MATERIALS & METHODS

In a parallel single-blinded randomized clinical trial, 50 patients with IS referred to Pediatric Neurology Clinic of Shahid Sadoughi University of Medical Sciences, Yazd, Iran, were evaluated from September 2008 to March 2010. Patients were randomly assigned to two groups to be treated with TPM or with NZP for 6 months. The primary endpoint was efficacy in cessation of all spasms or reduction of more than 50% in weekly seizure frequency, which was evaluated before and 6 months after the drug use. Secondary outcome was clinical sideeffects of the drugs.

RESULTS

Twenty boys (40%) and 30 girls (60%) with the mean age of 9.4±3.8 months were evaluated. Cessation of all spasms occurred in 12 (48%) infants in TPM group and 4(16%) in NZP group. Eight (32%) children in TPM group and 7 (28%) in NZP group had more than 50% reduction in spasms frequency. So, TPM was more effective. Side effects were seen in 32% of TPM and in 36% of NZP groups.

CONCLUSION

Topiramate is an effective and safe drug, which might be considered as the firstline drug for the treatment of ISs.

Neurodevelopmental and epilepsy outcome in children aged one to five years with infantile spasms--a North Indian cohort

PURPOSE

The present study was planned as there is paucity of outcome data of children with infantile spasms, from India where profile of patients is different from the western world. Moreover, most previous studies have either not used strict inclusion criteria or standardized psychometric tests for developmental outcome.

METHODS

Ninety-five children, aged one-to-five years under follow up for more than six months in Pediatric Neurology Clinic of a tertiary care hospital with the diagnosis of infantile spasm were enrolled in this cross-sectional study if they had completed one or more years after the onset of spasms. The study period was January-December 2011. Neurodevelopment of each child was assessed using Development Profile 3 and Gross Motor Function Classification System. History regarding epilepsy frequency and control in the last one year was taken.

RESULTS

Perinatal asphyxia was the commonest etiology in 43/95 children (45.2%). Favorable neurodevelopmental outcome was observed in 8/95 patients. Favorable epilepsy outcome in 58/95 (61.1%) patients was associated with treatment lag≤3 months between apparent onset of spasms and institution of therapy {OR 2 (1.1-3.8)} and response to first line antiepileptic drug {5 (2.6-10)}.

CONCLUSIONS

The commonest etiology was potentially preventable perinatal cause. Early appropriate treatment may have a favorable epilepsy outcome.

Electroclinical features and long-term outcome of cryptogenic epilepsy in children with Down syndrome

OBJECTIVE

To describe the electroclinical features and the long-term outcomes of epilepsy in a large cohort of males and females with Down syndrome who developed epilepsy in childhood.

STUDY DESIGN

Subjects with Down syndrome and cryptogenic epilepsy with onset in childhood were identified retrospectively from the databases of 16 Italian epilepsy centers over a 40-year period. For each subject, age at onset of seizures, seizure semiology and frequency, electroencephalography characteristics, treatment with antiepileptic drugs, and long-term clinical and electroencephalography outcomes were analyzed.

RESULTS

A total of 104 subjects (64 males [61.5%], 40 females [38.5%]) were identified. Seizure onset occurred within 1 year of birth in 54 subjects (51.9%), between 1 and 12 years in 42 subjects (40.4%), and after 12 years in 8 subjects (7.7%). Males had a younger age of seizure onset than females. Of the 104 subjects, 51 (49.0%) had infantile spasms (IS), 35 (33.7%) had partial seizures (PS), and 18 (17.3%) had generalized seizures (GS). Febrile seizures were recorded in 5 (4.8%) subjects. Intractable seizures were observed in 23 (22.1%) subjects, including 5 (9.8%) with IS, 8 (44.4%) with PS, and 10 (31.3%) with GS.

CONCLUSION

Cryptogenic epilepsy in Down syndrome may develop during the first year of life in the form of IS or, successively, as PS or GS. Electroclinical features of IS resemble those of idiopathic West syndrome, with a favorable response to treatment with adrenocorticotropic hormone seen. Patients experiencing PS and GS may be resistant to therapy with antiepileptic drugs.