Pathophysiology of infantile spasms

A Pair of Compound Heterozygous IARS2 Variants Manifesting West Syndrome and Electrolyte Disorders in a Chinese Patient

Background  Aminoacyl-tRNA synthetases (ARSs) are evolutionarily conserved enzymes that ensure the accuracy of the translation process. Isoleucyl-tRNA synthetase 2 ( IARS2 ) gene is a type of ARS that encodes mitochondrial isoleucine-tRNA synthetase. Pathogenic variants in the IARS2 gene are associated with mitochondrial disease which involves several patients presenting broad clinical phenotypes. These clinical phenotypes include West syndrome, Leigh syndrome, and Cataract, growth hormone deficiency, sensory neuropathy, sensorineural hearing loss, and skeletal dysplasia syndrome. Only 29 cases have been reported worldwide. The patient manifested recurrent convulsions, and specific clinical manifestations included electrolyte disorders and recurrent infections. Methods  Whole-exome sequencing was performed on the child with West syndrome. Three-dimensional structure reconstruction and thermodynamic stability prediction were performed to further analyze the relationship between variation and phenotype. Conclusion  This study further expands the clinical spectrum of IARS2 pathogenic variants. The case summaries help raise clinical awareness of IARS2 -associated disease and reduce misdiagnosis. Result  In this report, a 13-month-old girl was diagnosed with West syndrome and Leigh syndrome for 7 months. Compound heterozygous variants in the IARS2 gene (NM_018060.4), c.2450G>A (Arg817His) and copy number variation (NC_000001. 11: g. (220267549_220284289) del), were detected by WES. This study further expands the clinical spectrum of IARS2 pathogenic variants. The case summaries help raise clinical awareness of IARS2-associated disease and reduce misdiagnosis.

Prediction model for long-term seizure and developmental outcomes among children with infantile epileptic spasms syndrome

Introduction

Children with infantile epileptic spasms syndrome (IESS) are likely to experience poor outcomes. Researchers have investigated the factors related to its long-term prognosis; however, none of them developed a predictive model.

Objective

This study aimed to clarify the factors that influence the long-term prognosis of seizures and their development and to create a prediction model for IESS.

Materials and methods

We conducted a retrospective cohort study enrolling participants diagnosed with IESS at the Tottori University Hospital. We examined the seizure and developmental status at 3 and 7 years after the IESS onset and divided the participants into favorable and poor outcome groups. Subsequently, we analyzed the factors associated with the poor outcome group and developed a prediction model at 3 years by setting cutoff values using the receiver operating characteristic curve.

Results

Data were obtained from 44 patients with IESS (19 female patients and 25 male patients). Three years after epileptic spasms (ES) onset, seizure and development were the poor outcomes in 15 (34.9%) and 27 (61.4%) patients, respectively. The persistence of ES or tonic seizures (TS) after 90 days of onset, moderate or severe magnetic resonance imaging abnormalities, and developmental delay before IESS onset were significantly associated with poor outcomes. Seven years after the onset of ES, seizures and development were the poor outcomes in 9 (45.0%) and 13 (72.2%) patients, respectively. We found that no factor was significantly associated with poor seizure outcomes, and only developmental delay before IESS onset was significantly associated with poor developmental outcomes. Our prediction model demonstrated 86.7% sensitivity and 64.3% specificity for predicting poor seizure outcomes and 88.9% sensitivity and 100% specificity for predicting poor developmental outcomes.

Conclusion

Our prediction model may be useful for predicting the long-term prognosis of seizures and their development after 3 years. Understanding the long-term prognosis during the initial treatment may facilitate the selection of appropriate treatment.

Quantitative pretreatment EEG predicts efficacy of ACTH therapy in infantile epileptic spasms syndrome

OBJECTIVE

This study aimed to determine the correlation between outcomes following adrenocorticotrophic hormone (ACTH) therapy and measurements of relative power spectrum (rPS), weighted phase lag index (wPLI), and graph theoretical analysis on pretreatment electroencephalography (EEG) in infants with non-lesional infantile epileptic spasms syndrome (IESS).

METHODS

Twenty-eight patients with non-lesional IESS were enrolled. Outcomes were classified based on seizure recurrence following ACTH therapy: seizure-free (F, n = 21) and seizure-recurrence (R, n = 7) groups. The rPS, wPLI, clustering coefficient, and betweenness centrality were calculated on pretreatment EEG and were statistically analyzed to determine the correlation with outcomes following ACTH therapy.

RESULTS

The rPS value was significantly higher in the delta frequency band in group R than in group F (p < 0.001). The wPLI values were significantly higher in the delta, theta, and alpha frequency bands in group R than in group F (p = 0.007, <0.001, and <0.001, respectively). The clustering coefficient in the delta frequency band was significantly lower in group R than in group F (p < 0.001).

CONCLUSIONS

Our findings demonstrate the significant differences in power and functional connectivity between outcome groups.

SIGNIFICANCE

This study may contribute to an early prediction of ACTH therapy outcomes and thus help in the development of appropriate treatment strategies.

Utility of Functional MRI and Magnetoencephalography in the Diagnosis of Infantile Spasms and Hypsarrhythmia

SUMMARY

Neuroimaging and neurophysiology techniques can add a significant contribution to the comprehension of infantile spasms (IS) and hypsarrhythmia. Functional MRI and magnetoencephalography (MEG) are two noninvasive tools that can be used in young children with IS. In the past two decades, interesting data about IS have emerged from functional MRI and MEG studies. Regarding their clinical utility, MEG has supported the concept that epileptic spasms can have a focal origin. Moreover, MEG might contribute to the localization of the epileptogenic zone in children with IS under investigation for epilepsy surgery. Functional MRI data have contributed to improve the knowledge about the physiopathology of IS and hypsarrhythmia. It has demonstrated abnormal brainstem involvement during the high-amplitude slow waves of hypsarrhythmia and cortical involvement during the epileptiform discharges. Since the feasibility of these techniques has been demonstrated in infants, it is possible that, in the future, larger functional MRI and MEG studies might contribute to the treatment and the definition of the long-term prognosis of children with IS.

Corpus Callosotomy for Controlling Epileptic Spasms: A Proposal for Surgical Selection

In 1940, van Wagenen and Herren first proposed the corpus callosotomy (CC) as a surgical procedure for epilepsy. CC has been mainly used to treat drop attacks, which are classified as generalized tonic or atonic seizures. Epileptic spasms (ESs) are a type of epileptic seizure characterized as brief muscle contractions with ictal polyphasic slow waves on an electroencephalogram and a main feature of West syndrome. Resection surgeries, including frontal/posterior disconnections and hemispherotomy, have been established for the treatment of medically intractable ES in patients with unilaterally localized epileptogenic regions. However, CC has also been adopted for ES treatment, with studies involving CC to treat ES having increased since 2010. In those studies, patients without lesions observed on magnetic resonance imaging or equally bilateral lesions predominated, in contrast to studies on resection surgeries. Here, we present a review of relevant literature concerning CC and relevant adaptations. We discuss history and adaptations of CC, and patient selection for epilepsy surgeries due to medically intractable ES, and compared resection surgeries with CC. We propose a surgical selection flow involving resection surgery or CC as first-line treatment for patients with ES who have been assessed as suitable candidates for surgery.

Case Report: Rituximab Improved Epileptic Spasms and EEG Abnormalities in an Infant With West Syndrome and Anti-NMDAR Encephalitis Associated With APECED

Background: Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy is a rare autosomal recessive disorder caused by a mutation in the autoimmune regulator gene. Patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy typically exhibit hypoparathyroidism, adrenocortical failure, and chronic mucocutaneous candidiasis. There are only a few case reports of autoimmune encephalitis during autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy, but not as an initial manifestation. Furthermore, there are no reports of patients with infantile spasms/West syndrome with autoimmune encephalitis, partly because the median age for paediatric patients with anti-N-methyl-D-aspartate receptor encephalitis, which is the most frequent and best characterised in paediatric autoimmune encephalitides, is 13–14 years. Herein, we present a case of a 3-month-old infant with autoimmune encephalitis as an initial manifestation of autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy who later developed infantile spasms/West syndrome.

Case Presentation: A 3-month-old girl was admitted to our hospital with a fever, involuntary movements in all four limbs, and right-side facial palsy. Acute central nervous system demyelination diseases were suspected from neuroimaging findings and the presence of the cerebrospinal fluid oligoclonal band. She did not respond to multiple methylprednisolone pulse therapies and later developed infantile spasms/West syndrome and diabetes mellitus. Rituximab, a chimeric mouse/human monoclonal antibody directed against human CD20 which depletes B cells, was initially administered as a treatment for autoimmune encephalitis. Unexpectedly, this treatment resulted in complete spasm cessation and resolution of hypsarrhythmia. The patient eventually showed severely delayed developmental milestones, and her electroencephalography findings showed periodic generalised slow spike-and-wave pattern.

Conclusions: Despite the limited ability to extrapolate findings from a single case, rituximab's effects may suggest that B cells play a crucial role in infantile spasms/West syndrome mechanisms; use of rituximab as an aetiology-specific treatment for infantile spasms/West syndrome patients with autoimmune encephalitis or its effectiveness for infantile spasms/West syndrome patients with other underlying mechanisms warrants further investigation.

Epileptogenic modulation index and synchronization in hypsarrhythmia of West syndrome secondary to perinatal arterial ischemic stroke

OBJECTIVE

Perinatal arterial ischemic stroke (PAIS) is associated with epileptic spasms of West syndrome (WS) and long term Focal epilepsy (FE). The mechanism of epileptogenic network generation causing hypsarrhythmia of WS is unknown. We hypothesized that Modulation index (MI) [strength of phase-amplitude coupling] and Synchronization likelihood (SL) [degree of connectivity] could interrogate the epileptogenic network in hypsarrhythmia of WS secondary to PAIS.

METHODS

We analyzed interictal scalp electroencephalography (EEG) in 10 WS and 11 FE patients with unilateral PAIS. MI between gamma (30-70 Hz) and slow waves (3-4 Hz) was calculated to measure phase-amplitude coupling. SL between electrode pairs was analyzed in 9-frequency bands (5-delta, theta, alpha, beta, gamma) to examine inter- and intra-hemispheric connectivity.

RESULTS

MI was higher in affected hemispheres in WS (p = 0.006); no differences observed in FE. Inter-hemispheric SL of 3-delta, theta, alpha, beta, gamma bands was significantly higher in WS (p < 0.001). In WS, modified Z-Score of intra-hemispheric SL values in 3-delta, theta, alpha, beta and gamma in the affected hemispheres were significantly higher than those in the unaffected hemispheres (p < 0.001) as well as 0.5-4 Hz (p = 0.004).

CONCLUSIONS

The significantly higher modulation in affected hemisphere and stronger inter- and intra-hemispheric connectivity generate hypsarrhythmia of WS secondary to PAIS.

SIGNIFICANCE

Epileptogenic cortical-subcortical transcallosal networks from affected hemisphere post-PAIS provokes infantile spasms.

Neocortical Slow Oscillations Implicated in the Generation of Epileptic Spasms

OBJECTIVE

Epileptic spasms are a hallmark of severe seizure disorders. The neurophysiological mechanisms and the neuronal circuit(s) that generate these seizures are unresolved and are the focus of studies reported here.

METHODS

In the tetrodotoxin model, we used 16-channel microarrays and microwires to record electrophysiological activity in neocortex and thalamus during spasms. Chemogenetic activation was used to examine the role of neocortical pyramidal cells in generating spasms. Comparisons were made to recordings from infantile spasm patients.

RESULTS

Current source density and simultaneous multiunit activity analyses indicate that the ictal events of spasms are initiated in infragranular cortical layers. A dramatic pause of neuronal activity was recorded immediately prior to the onset of spasms. This preictal pause is shown to share many features with the down states of slow wave sleep. In addition, the ensuing interictal up states of slow wave rhythms are more intense in epileptic than control animals and occasionally appear sufficient to initiate spasms. Chemogenetic activation of neocortical pyramidal cells supported these observations, as it increased slow oscillations and spasm numbers and clustering. Recordings also revealed a ramp-up in the number of neocortical slow oscillations preceding spasms, which was also observed in infantile spasm patients.

INTERPRETATION

Our findings provide evidence that epileptic spasms can arise from the neocortex and reveal a previously unappreciated interplay between brain state physiology and spasm generation. The identification of neocortical up states as a mechanism capable of initiating epileptic spasms will likely provide new targets for interventional therapies. ANN NEUROL 2021;89:226-241.

Infantile Spasms and West Syndrome - A Clinician's Perspective

Infantile spasms, though long recognised, are still a cause of significant morbidity in children. The knowledge of their etiology and pathogenesis is still evolving. Even the management strategies vary among different centres. Hormonal treatments and vigabatrin have been recognised as effective but controversies prevail on the exact protocols that best balance the risk benefit ratio. Collaborative studies have begun to provide some clarity on some of the management issues but further large scale studies that further standardise protocols are a felt need. This article attempts to provide a clinically relevant summary of the current knowledge.

Insufficient Efficacy of Corpus Callosotomy for Epileptic Spasms With Biphasic Muscular Contractions

Corpus callosotomy (CC) is the surgical strategy for drug-resistant epileptic seizures including epileptic spasms (ES). In this study we report a subtype of ES which is accompanied by two consecutive muscular contractions. This subtype has not been previously classified and may emerge via a complex epileptic network. We named these seizures “epileptic spasms with biphasic muscular contractions (ES-BMC)” and analyzed the association between them and CC outcomes. We enrolled 17 patients with ES who underwent CC before 20 years of age, and analyzed the records of long-term video-electroencephalogram (EEG) recordings. The outcomes of CC were ES-free (Engel's classification I) in 7 and residual ES (II to IV) in 10 patients. We statistically analyzed the associations between the presence of preoperative ES-BMC and the outcomes. Ages at CC ranged from 17 to 237 months. We analyzed 4–44 ictal EEGs for each patient. Five patients presented with ES-BMC with 6–40% of their whole ES on the presurgical video-EEG recordings, and all of them exhibited residual ES outcomes following CC. A Fisher's exact test revealed a significant positive correlation between the presence of preoperative ES-BMC and persistence of ES following CC (p = 0.044, odds ratio = 15.0, risk ratio = 2.0). The presence of ES-BMC may be useful in the presurgical prediction of CC outcomes in patients with ES.

Symmetry of ictal slow waves may predict the outcomes of corpus callosotomy for epileptic spasms

We aimed to analyse the ictal electrographic changes on scalp electroencephalography (EEG), focusing on high-voltage slow waves (HVSs) in children with epileptic spasms (ES) and tonic spasms (TS) and then identified factors associated with corpus callosotomy (CC) outcomes. We enrolled 17 patients with ES/TS who underwent CC before 20 years of age. Post-CC Engel’s classification was as follows: I in 7 patients, II in 2, III in 4, and IV in 4. Welch’s t-test was used to analyse the correlation between ictal HVSs and CC outcomes based on the following three symmetrical indices: (1) negative peak delay: interhemispheric delay between negative peaks; (2) amplitude ratio: interhemispheric ratio of amplitude values for the highest positive peaks; and (3) duration ratio: interhemispheric ratio of slow wave duration. Ages at CC ranged from 17–237 months. Four to 15 ictal EEGs were analysed for each patient. The negative peak delay, amplitude ratio and duration ratio ranged from 0–530 ms, 1.00–7.40 and 1.00–2.74, respectively. The negative peak delay, amplitude ratio and duration ratio were significantly higher in the seizure residual group (p = 0.017, <0.001, <0.001, respectively). Symmetry of ictal HVSs may predict favourable outcomes following CC for ES/TS.

EEG before and after total corpus callosotomy for pharmacoresistant infantile spasms: Fast oscillations and slow-wave connectivity in hypsarrhythmia

OBJECTIVE

We analyzed the features of fast oscillations (FOs) and connectivity in hypsarrhythmia to identify biomarkers for predicting seizure outcomes after total corpus callosotomy (TCC) in children with pharmacoresistant infantile spasms (IS). We hypothesize that the power of FOs and connectivity of slow waves in hypsarrhythmia would indicate the prognosis of IS.

METHOD

We retrospectively identified 42 children with pharmacoresistant IS who underwent TCC from 2009 to 2014 at Nagasaki Medical Center. We collected preoperative hypsarrhythmia for 200 seconds from each child. Children were categorized into three groups with interictal epileptic discharges on EEG at 6 months after TCC: group A, no epileptic discharge; group B, lateralized epileptic discharges; and group C; bilateral epileptic discharges. We analyzed spectral power and phase synchronization in preoperative hypsarrhythmia among the three groups.

RESULTS

We found 10 children in group A, 10 children in group B, and 22 children in group C. All group A and 1 in group B achieved seizure freedom after TCC. Six (67%) of 9 group B children who underwent further surgeries achieved seizure freedom. Ten (45%) of group C children had seizure reduction >50% after TCC, and 13 (87%) of 15 children who underwent further surgeries had residual seizures. The clinical profiles of the three groups did not differ significantly. The power of FOs (≥45 Hz) in hypsarrhythmia was significantly stronger in group C at the midline and temporal regions than in groups B and A (P = .014). The connectivity of theta (4-9 Hz) and FOs (29-70 Hz) tended to increase in group C, compared with the increased connectivity of 1-2 Hz in group A (P = .08).

SIGNIFICANCE

The increased power and connectivity of FOs in hypsarrhythmia may correlate with pharmacoresistant and surgically resistant seizures in IS. The existence and connectivity of FOs are associated with unilateral/bilateral cortical epileptogenicity in hypsarrhythmia. Prominent slow waves and connectivity without FOs might correlate with seizure freedom after TCC. Modulation of the callosal system with subcortical/cortical epileptic discharges might play a role in generating hypsarrhythmia and IS.

Successful corpus callosotomy for post-encephalopathic refractory epilepsy in a patient with MECP2 duplication syndrome

BACKGROUND

Patients with MECP2 duplication syndrome present with distinct facial anomalies and clinical features such as global developmental delay, recurrent respiratory infections, and epileptic seizures. Approximately half of all patients develop epileptic seizures which are refractory in most cases despite active medical management. Furthermore, no previous reports have discussed the efficacy of surgical treatment for seizures in patients with MECP2 duplication syndrome.

CASE REPORT

In the present report, we describe a case of MECP2 duplication syndrome in a 15-year-old boy who developed epileptic seizures following influenza-associated acute encephalitis. His frequent epileptic spasms, tonic, atonic, and partial seizures were refractory to multiple antiepileptic medications. Electroencephalography revealed continuous diffuse epileptic discharge, resulting in regression. A total corpus callosotomy (CC) was performed at the age of 14 years and 7 months. His seizures markedly decreased following CC, although he continued to experience brief partial seizures approximately once per month. Post-operative examination revealed that his epileptic discharges had disappeared, and that his developmental state had returned to pre-encephalopathy levels.

CONCLUSION

Our findings indicate that CC may represent a valuable surgical option for children with medically refractory generalized seizures following acute encephalopathy, irrespective of genetic disorders such as MECP2 duplication syndrome.

Concordance between the interictal focal EEG pattern and MRI lesions as a predictor of a favorable surgical outcome in patients with epileptic spasms: a Chinese study

OBJECTIVE

The aim of this study was to evaluate the electro-clinical features, etiology, treatment, and postsurgical seizure outcomes in patients with intractable epileptic spasms (ESs).

METHODS

The authors retrospectively studied the medical records of all patients who had presented with medically intractable ESs and had undergone surgery in the period between October 2009 and August 2015. The interictal electroencephalography (EEG) pattern, MRI studies, magnetoencephalography findings, and postsurgical seizure outcomes were compared.

RESULTS

Twenty-six patients, 12 boys and 14 girls (age range 3-22 years), were eligible for study inclusion. Of these 26 patients, 84.6% (22) presented with multiple seizure types including partial seizures (PSs) independent of the ESs (30.8%); ESs followed by tonic seizures (30.8%); myoclonic seizures (19.2%); tonic seizures (19.2%); ESs followed by PSs (19.2%); focal seizures with secondary generalization (15.4%); atypical absence (11.5%); PSs followed by ESs (7.7%); and myoclonic followed by tonic seizures (7.7%). Seventeen patients underwent multilobar resection and 9 underwent unilobar resection. At the last follow-up (mean 36.6 months), 42.3% of patients were seizure free (outcome classification [OC] 1), 23.1% had > 50% reduction in seizure frequency (OC2-OC4), and 34.6% had < 50% reduction in seizure frequency or no improvement (OC5 and OC6). Predictors of favorable outcomes included an interictal focal EEG pattern and concordance between interictal EEG and MRI-demonstrated lesions (p = 0.001 and 0.004, respectively).

CONCLUSIONS

A favorable surgical outcome is achievable in a highly select group of patients with ESs secondary to structural lesions. Interictal EEG can help in identifying patients with the potential for favorable resective outcomes.

Surgical and developmental outcomes of corpus callosotomy for West syndrome in patients without MRI lesions

OBJECTIVE

This retrospective study was designed to assess the impact of corpus callosotomy (CC) in patients with intractable West syndrome (WS) without lesions on magnetic resonance imaging (MRI).

METHODS

This study involved 56 patients with WS who underwent CC between January 2000 and December 2014. Seizure outcomes and changes in psychomotor development were analyzed.

RESULTS

Mean age at the onset of epilepsy and at the time of CC was 5.1 and 22.6 months, respectively. Mean duration of epilepsy before CC was 17.6 months. Video-electroencephalography (EEG) monitoring showed bilateral ictal and interictal abnormalities before CC. Mean follow-up duration was 36.6 months. At final follow-up, seizure outcomes after CC were seizure-free in 18 patients (32.1%), excellent (E: >80% reduction in seizure frequency) in 15 (26.8%), good (G: >50% reduction) in 10 (17.9%), and poor (P: <50% reduction) in 13 (23.2%). Epileptic spasms (ES) were eliminated in 24 patients (42.9%). However, tonic seizure (TS) outcomes were poor (P < 0.05). Of preoperative predictive factors related to seizure outcome, developmental delay before epilepsy onset correlated with poor outcome (P < 0.05). One year post-CC, 6 patients (10.7%) had no epileptic abnormality on EEG, 19 (33.9%) had lateralized epileptic abnormalities, and 31 (55.4%) had bilateral asynchronous epileptic abnormalities. All patients without epileptic discharge achieved seizure freedom. Fifteen of 19 (78.9%) patients in the lateralized group and 12 of 31 (38.7%) in the bilateral asynchronous group had worthwhile outcomes (F + E). The patterns of EEG changes after CC correlated with seizure outcome (P < 0.01). Progressive declines in developmental quotient were prevented in patients with worthwhile outcomes.

SIGNIFICANCE

CC represents an important therapeutic option for patients with WS without resectable MRI lesions. Transcallosal seizure bilateralization is critical for bilateral ES generation. Early identification of potential CC candidates and surgical intervention are important for better seizure control and cognitive capacity preservation before severe developmental delay development.

Compare Of the West Syndrome with Other Syndromes in the Epileptic Encephalopathy - Kosovo Experience

BACKGROUND:

West Syndrome (WS) represents as a specific epileptic encephalopathy characterised with a unique type of attacks, called infantile spasms, severe forms of abnormalities in electroencephalographic (EEG) records as a hypsarythmias and delays in the psychomotoric development. The characteristics of the disease, mostly affecting male gender, are infantile spasms and typical findings in EEG as a hypsarythmia. Infantile spasms are a consequence of many factors in the undeveloped brain.

AIM:

We aimed: (1) to see the incidence of the illness and the spreading out because of gender in rapport with other syndromes in the epileptic encephalopathies group; (2) to show principles of the treatment for the illness; and (3) to present the effects of the disease in the psycho-motoric development of affected children.

METHODS:

The study was designed as a cross-sectional study of the patients with epileptic encephalopathies, treated in Paediatric Clinic in Prishtina, from 1st of January 2013 until the 31st of December 2015.

RESULTS:

From the cohort group of 97 children diagnosed with epileptic encephalopathies, in 14 of them clinical and EEG signs of WS were noted. The earliest age of disease manifestation was 74 days (± 63.8 days). On the group of children with WS, 13 of them with Natrium Valpropat were treated, with the doses of 301.9 mg (± 64.1). From the cohort group, in 89 children (91.8%) psychomotoric retardation was documented, within the higher reoccurrence in the undifferentiated epileptic encephalopathies (96%) and the WS (78.6%).

CONCLUSION:

WS is a frequent disease of the encephalopathies with the epileptogenic framework. The resistance in anticonvulsive therapy is huge, and psychomotoric retardation follows a big percentage of children with this syndrome.

Pathophysiology of epileptic encephalopathies

The application of metabolic imaging and genetic analysis, and now the development of appropriate animal models, has generated critical insights into the pathogenesis of epileptic encephalopathies. In this article we present ideas intended to move from the lesions associated with epileptic encephalopathies toward understanding the effects of these lesions on the functioning of the brain, specifically of the cortex. We argue that the effects of focal lesions may be magnified through the interaction between cortical and subcortical structures, and that disruption of subcortical arousal centers that regulate cortex early in life may lead to alterations of intracortical synapses that affect a critical period of cognitive development. Impairment of interneuronal function globally through the action of a genetic lesion similarly causes widespread cortical dysfunction manifesting as increased delta slow waves on electroencephalography (EEG) and as developmental delay or arrest clinically. Finally, prolonged focal epileptic activity during sleep (as occurring in the syndrome of continuous spike-wave in slow sleep, or CSWSS) might interfere with local slow wave activity at the site of the epileptic focus, thereby impairing the neural processes and, possibly, the local plastic changes associated with learning and other cognitive functions. Seizures may certainly add to these pathologic processes, but they are likely not necessary for the development of the cognitive pathology. Nevertheless, although seizures may be either a consequence or symptom of the underlying lesion, their effective treatment can improve outcomes as both clinical and experimental studies may suggest. Understanding their substrates may lead to novel, effective treatments for all aspects of the epileptic encephalopathy phenotype.

Neuronal networks in west syndrome as revealed by source analysis and renormalized partial directed coherence

West syndrome is a severe epileptic encephalopathy of infancy with a poor developmental outcome. This syndrome is associated with the pathognomonic EEG feature of hypsarrhythmia. The aim of the study was to describe neuronal networks underlying hypsarrhythmia using the source analysis method (dynamic imaging of coherent sources or DICS) which represents an inverse solution algorithm in the frequency domain. In order to investigate the interaction within the detected network, a renormalized partial directed coherence (RPDC) method was also applied as a measure of the directionality of information flow between the source signals. Both DICS and RPDC were performed for EEG delta activity (1-4 Hz) in eight patients with West syndrome and in eight patients with partial epilepsies (control group). The brain area with the strongest power in the given frequency range was defined as the reference region. The coherence between this reference region and the entire brain was computed using DICS. After that, the RPDC was applied to the source signals estimated by DICS. The results of electrical source imaging were compared to results of a previous EEG-fMRI study which had been carried out using the same cohort of patients. As revealed by DICS, delta activity in hypsarrhythmia was associated with coherent sources in the occipital cortex (main source) as well as the parietal cortex, putamen, caudate nucleus and brainstem. In patients with partial epilepsies, delta activity could be attributed to sources in the occipital, parietal and sensory-motor cortex. In West syndrome, RPDC showed the strongest and most significant direction of ascending information flow from the brainstem towards the putamen and cerebral cortex. The neuronal network underlying hypsarrhythmia in this study resembles the network which was described in previous EEG-fMRI and PET studies with involvement of the brainstem, putamen and cortical regions in the generation of hypsarrhythmia. The RPDC suggests that brainstem could have a key role in the pathogenesis of West syndrome. This study supports the theory that hypsarrhythmia results from ascending brainstem pathways that project widely to basal ganglia and cerebral cortex.

Clinical profile of infants with hypsarrhythmia

OBJECTIVE

The present study was done in order to obtain a baseline profile of infantile spasms and associated neurological disorders.

PATIENT AND METHODS

The study included 50 patients with infantile spasm in Queen Rania Hospital for children in Jordan. The following data were obtained: sex, age at onset of spasms, details of seizure, family history of epilepsy, significant pre-/peri/ post-natal insults, Electroencephalography and detailed neuro imaging evaluation , detailed neurological, neuro developmental ,assessment were done by. Broad categories of possible etiologies were used the results were recorded for further study.

RESULTS

Age of onset of infantile spasms ranged from 1month to 1 year and 6 months , (mean 4.8 months). The mean time of presentation was 9.4 months . A male preponderance was noted (74 %). flexor spasms (52%) was the commonest . Other types of seizures also accompanied infantile spasm in 44% children . (84%) were born of normal delivery, History of birth asphyxia was obtained in 48%, 3 (6%) had positive family history Developmental delay was recognized prior to onset of spasms in 52%, microcephaly was the commonest associated problem, Imaging studies of the brain revealed abnormality in 18 patients. 78% patients were classified as symptomatic and 22 % as cryptogenic.

CONCLUSION

the pattern of infantile spasm in our country do not differ from that of developed countries, further researches is required to prevent both chronic epilepsy and psychomotor retardation and .preventive measurement to prevent birth asphyxia is recommended.

Localization of pediatric seizure semiology

OBJECTIVE

The aim of this study was to evaluate the relationship between semiology of seizures in children and adolescents to the corresponding EEG localization.

METHODS

Charts of 225 consecutive pediatric epilepsy patients undergoing Video-EEG monitoring (VEM) over 2 years were reviewed. Seizure semiology recorded during VEM was classified according to ILAE seizure semiology terminology and EEG localization, and analyzed based on onset as defined by the EEG data (generalized, frontal, temporal, parietal, occipital or multilobar).

RESULTS

A total of 1008 seizures were analyzed in 225 children (mean age 8.5 years, range 0-20), with 50% boys. Auras and seizures with automatisms arose predominantly from the temporal lobes (p<0.001). Tonic, clonic and tonic-clonic seizures had most commonly generalized onset (p<0.001). Hypomotor seizures were most frequently seen from the frontal lobes (p<0.001). Hypermotor seizures had most commonly temporal lobe or multiple lobe onset (p<0.001 and p<0.05 respectively). Atonic, myoclonic seizures and epileptic spasms had almost exclusively a generalized onset (p<0.001).

CONCLUSIONS

Different seizure semiologies relate to specific brain regions, with overlap between focal and generalized semiological seizure types, as identified electrographically.

SIGNIFICANCE

Semiology of seizures can provide important information for epilepsy localization, and should not be overlooked, especially in patients undergoing pre-surgical evaluation. Separation of clinical seizure description and EEG findings may be useful, in particular when only incomplete information is available. i.e. during the first office visit.

Epilepsy surgery of posterior quadrant dysplasia in the first year of life: experience of a single centre with long term follow-up

Posterior quadrant dysplasia (PQD) is a rare variant of cortical dysplasia involving the posterior regions of a single hemisphere. It is always associated with early onset, refractory epilepsy often characterized by a "catastrophic" evolution. The experience on its surgical management during the first year of life is limited to sporadic, isolated cases. Between 2002 and 2005, four children less than one-year-old and affected by drug-resistant epilepsy associated with PQD were admitted to our Institution and underwent surgical treatment. One patient remained seizure-free during all the follow-up (Engel I). The remaining three children showed a recurrence of the seizures, requiring subsequent surgical procedures in two cases. In one case (Engel II), the seizure control has been obtained thanks to pharmacological treatment. The other two patients respectively had only a partial (Engel III) and a less relevant reduction of the number of seizures (Engel IV). Both the epileptic and the neuropsychological outcome of our series were significantly influenced by persistent contralateral interictal anomalies rather than by the timing of the surgical procedure. Unpredictable results should be expected in this kind of patients if there is the detection of contralateral independent epileptiform activities on the EEG at diagnosis. Parents and relatives should be aware of the results' variability, even though a reduction of seizures may be expected, enabling an easier handling of the child's condition.

Infantile spasms: review of the literature and personal experience

This epileptic disorder has become a classic topic for neuropediatricians and the interest is documented by the large number of publications on this subject.The relative frequency among the epileptic syndromes is an another reason why not only neuropediatricians but also general pediatricians must be fully informed about diagnostic, clinical, imaging and genetic aspects.Early diagnosis is of paramount importance in order to obtain even complete results in patients with so called idiopathic situations. A number of problems are still to be solved. There is no agreement on the type and the schedule of treatment. A common denominator about this problem is not jet available even if some advances in this regard have been accomplished. Of paramount importance is an accurate clinical and laboratory examination as a prerequisite regarding prognosis and results of therapy in every single case.However, even if more than 170 years have elapsed since the first communication of dr. West on the peculiar syndrome that his child was suffering of, the interest of scientists on this subject has now been enriched and rewarded.

ICTAL EEG Fast Activity in West Syndrome: From Onset to Outcome

PURPOSE

To characterize the fast EEG activities associated with infantile spasms in West syndrome, and their value in predicting the recurrence and localization of late seizures.

METHODS

We selected 23 infants who were followed for at least 2 years. Selected EEG recordings underwent autospectra, coherence, and phase analyses in order to assess the changes during follow-up.

RESULTS

Short discharges of fast-rhythms (331 +/- 190 ms) with a lateralized onset were detected in 18 of the 23 infants (78.3%). There were no significant differences in the parameters characterizing ICTAL beta-activity (frequency, duration, inter-hemispheric coherence, or transfer time) between the infants with or without seizure recurrence. However, beta-discharges with a consistent location formed part of the ICTAL EEG in all 10 infants with seizure recurrence, but only in eight (61.5%) of those who remained seizure-free (SF) (p < 0.05). In all but one of the infants experiencing seizure recurrence, the ICTAL discharges associated with the late seizures apparently originated from the same hemisphere as that involved at the beginning of the spasm-associated beta-activity, although the precise location varied.

CONCLUSIONS

Spectral, coherence and phase analyses detected spasm-associated runs of lateralized beta-rhythms in many of our infants with West syndrome. This ICTAL pattern significantly correlated with seizure recurrence. The consistent lateralization of the ICTAL EEG events associated with both the early spasms and late seizures suggests that EEG beta-activities should be considered as indicating local cortical dysfunction in infants who fail to respond to early treatment and often progress toward severe epilepsy.

Pathogenesis of infantile spasms: a model based on developmental desynchronization

Infantile spasms is a severe epileptic encephalopathy of infancy. The fundamental cause is unknown, although a number of predisposing conditions are recognized. In this article, the authors critically review current knowledge concerning the pathophysiologic basis of infantile spasms and propose a new model based on developmental desynchronization. It is suggested that infantile spasms may result from a particular temporal desynchronization of two or more central nervous system developmental processes, resulting in a specific disturbance of brain function. The disturbance of function is postulated to be crucially dependent on an unbalanced maturational pattern, in which certain brain systems become dysfunctional owing to divergent developmental status. An important aspect of this model is the idea that disturbed function of a specific kind can result from multiple causative factors, and so can be associated with a variety of different anatomic and/or biochemical abnormalities. Thus, this concept is compatible with the observed diversity of pathologic findings and multiplicity of etiological associations observed in infantile spasms patients.

Profile of West syndrome in North Indian children

To study the profile of West syndrome (WS) in North Indian Children, 165 cases of WS were analyzed. Details of seizure semiology, prenatal and perinatal events, developmental milestones, treatment received, physical and neurological examination and investigations were recorded. The response of seizures to various therapeutic modalities and the final developmental status were taken as primary outcome variables. Analysis was done to find the factors influencing these outcome variables. The age of onset of infantile spasms ranged from 1 to 19 (mean 6.1 +/- 3.4) months. Age at presentation ranged from 1.5 months to 4.5 years (mean 14.7 +/- 11.4 months); 74% had flexor spasms. Other types of seizures were associated in 31 children. Antenatal problems and adverse perinatal events were reported in 26.7 and 59.4%, respectively. Developmental delay was recognized in 69.7% prior to and in 27.9% after onset of spasms. Microcephaly was seen in 72.7%. Interictal EEG showed hypsarrhythmia in 44; generalized spike and slow waves in 31% and burst suppression in 7%. Computed tomography scan done in 94 cases showed cerebral atrophy in 15%, infarcts in 8%, tubers in 7%, developmental malformations in 5%. Magnetic resonance imaging done in 77 cases showed periventricular T2WI white matter hyper intensities in 33.8% and cerebral atrophy in 21%. Prednisolone and ACTH were used in 57 and 35 cases, respectively. Complete control of seizures was seen in 49 and 46% cases. No significant difference in seizure control or developmental outcome was found in the two groups. Overall, 42.4, 30.9 and 16% children showed complete, partial and no control of seizures. After therapy, developmental improvement was seen in 55.8% and no change in 23.6% cases. The type of spasms had no correlation with the other parameters including etiology, seizure or developmental outcome. An early age of onset correlated with presence of antenatal problems (P < 0.05). Seizure control and developmental improvement correlated significantly (P < 0.005). Developmental outcome was better in cryptogenic as compared to symptomatic cases (P < 0.05). No other significant correlations were found. In India WS is often diagnosed late because of lack of awareness. Adverse perinatal events are important etiological factors. Non-affordability of ACTH and Vigabatrin prompts the use of prednisolone in most cases.

Infantile Epileptic Encephalopathy with Hypsarrhythmia (Infantile Spasms/West Syndrome)

Infantile spasms is a unique disorder peculiar to infancy and early childhood. In this article, the clinical manifestations and electroencephalographic features of the disorder are described. The possible pathophysiologic mechanisms underlying infantile spasms and the relation of this disorder to other childhood encephalopathies are discussed. Finally, the treatment of patients with infantile spasms and their long-term outcome are briefly reviewed.