Thalamofrontal neurodevelopment in new-onset pediatric idiopathic generalized epilepsy

Predictors of therapeutic response following thalamic neuromodulation for drug-resistant pediatric epilepsy: A systematic review and individual patient data meta-analysis

We sought to perform a systematic review and individual participant data meta-analysis to identify predictors of treatment response following thalamic neuromodulation in pediatric patients with medically refractory epilepsy. Electronic databases (MEDLINE, Ovid, Embase, and Cochrane) were searched, with no language or data restriction, to identify studies reporting seizure outcomes in pediatric populations following deep brain stimulation (DBS) or responsive neurostimulation (RNS) implantation in thalamic nuclei. Studies featuring individual participant data of patients with primary or secondary generalized drug-resistant epilepsy were included. Response to therapy was defined as >50% reduction in seizure frequency from baseline. Of 417 citations, 21 articles reporting on 88 participants were eligible. Mean age at implantation was 13.07 ± 3.49 years. Fifty (57%) patients underwent DBS, and 38 (43%) RNS. Sixty (68%) patients were implanted in centromedian nucleus and 23 (26%) in anterior thalamic nucleus, and five (6%) had both targets implanted. Seventy-four (84%) patients were implanted bilaterally. The median time to last follow-up was 12 months (interquartile range = 6.75-26.25). Sixty-nine percent of patients achieved response to treatment. Age, target, modality, and laterality had no significant association with response in univariate logistic regression. Until thalamic neuromodulation gains widespread approval for use in pediatric patients, data on efficacy will continue to be limited to small retrospective cohorts and case series. The inherent bias of these studies can be overcome by using individual participant data. Thalamic neuromodulation appears to be a safe and effective treatment for epilepsy. Larger, prolonged prospective, multicenter studies are warranted to further evaluate the efficacy of DBS over RNS in this patient population where resection for curative intent is not a safe option.

To explore the potential mechanisms of cognitive impairment in children with MRI-negative pharmacoresistant epilepsy due to focal cortical dysplasia: A pilot study from gray matter structure view

Objectives

To investigate the characteristics of brain structure in children with focal cortical dysplasia (FCD)-induced pharmacoresistant epilepsy, and explore the potential mechanisms of cognitive impairment from the view of gray matter alteration.

Methods

25 pharmacoresistant pediatric patients with pathologically confirmed focal cortical dysplasia (FCD), and 25 gender-matched healthy controls were included in this study. 3.0T MRI data and intelligence tests using the Wechsler Intelligence Scale for Children-Forth Edition (WISC-IV) were generated for all subjects. Voxel-based morphometry (VBM)-diffeomorphic anatomical registration through exponentiated lie algebra (DARTEL) and surface-based morphometry (SBM) analyses were performed to analyze gray matter volume and cortical structure. Two-sample t-tests were used to compare the differences in gray matter volume (P＜0.05, FWE) and cortical thickness (P＜0.001, FWE) between the two groups. Also, the Spearman rank correlation analyses were employed to determine the relationship between structural alterations and neuropsychological results.

Results

The WISC-IV scores of the FCD group were significantly lower than those of the HC group in terms of full-scale intelligence quotient (FSIQ), verbal comprehension index (VCI), perceptual reasoning index (PRI), working memory index (WMI), and processing speed index (PSI) (all P＜0.01). Compared with the HC group, in the FCD group, the gray matter volume (GMV) reduced significantly in the left cerebellum_8, cerebellum_Crus2, and bilateral thalamus (P＜0.05, FWE); the GMV increased in the bilateral medial frontal gyrus, right precuneus, and left inferior temporal gyrus (P＜0.05, FWE), and the cortical thickness increased in the bilateral frontal, parietal, and temporal areas (P＜0.001, FWE). Correlation analyses showed that the age of seizure onset had positive correlations with the WISC-IV scores significantly. Meanwhile, the cortex thicknesses of the left pars opercularis gyrus, left middle temporal gyrus, and right inferior temporal gyrus had negative correlations with the WISC-IV scores significantly.

Conclusion

FCD patients showed subtle structural abnormalities in multiple brain regions, with significant involvement of the primary visual cortex and language function cortex. And we also demonstrated a crucial correlation between gray matter structural alteration and cognitive impairment.

Febrile seizures reduce hippocampal subfield volumes but not cortical thickness in children with focal onset seizures

OBJECTIVES

Whether febrile seizures (FS) produce long-term injury to the hippocampus or other brain structures is a critical question concerning focal onset seizures in children. Our aims are to evaluate the effect of FS on subfields of the hippocampus, thalamic nuclei, amygdala, cortical thickness, and surface area quantitatively in children with FS who later developed focal seizures and to identify biomarkers based on MRI structures.

METHODS

Children who had focal onset seizures with or without previous FS and normal 3-T MRI findings were included retrospectively. The MRI was performed within 2 years after the onset of focal seizures. Age-matched controls were also recruited. Hippocampal subfields and thalamic nuclei, amygdala volumes, cortical thickness, and cortical surface area in individual cortical regions were segmented by FreeSurfer version 7.1.1. Volumetric and morphometric data among children who had focal seizures with or without previous FS, as well as controls, were compared and correlated with clinical parameters.

RESULTS

Children with a history of FS who had focal seizures exhibited smaller right cornu ammonis (CA) 1 and right molecular cell layer of the hippocampus, compared to those without FS. A larger left hippocampal fissure was also found in FS with focal seizures compared to age-matched controls. There were no statistically significant differences in each nucleus of the thalamus, amygdala, cortical thickness, and surface area of each cortical region among the three groups. A smaller whole hippocampal volume was found for the right hippocampus in children with FS and focal seizures compared to those without FS. A trend of negative correlation was found between the frequency of FS and the left and right CA1 subfield volume ratios of the hippocampus.

CONCLUSIONS

We concluded that multiple episodes of FS may be associated with a trivial difference in volume reduction in the CA1 and molecular layer of the right hippocampus and an enlarged hippocampal fissure of the left hippocampus, but not with individual cortical thicknesses, surface area, thalamic nuclei, or amygdala in children with focal onset seizures.The hippocampal subfield CA1 and molecular layer of the right hippocampus may be more vulnerable than the cortices in children with focal seizures who experienced multiple FS episodes. This study highlights the minimal differences in brain volumes among children with recent onset focal seizures with or without FS history and controls, suggesting that the brain injurious aspects of the FS and recent onset focal seizures may have been previously overstated. This suggests that physicians can be reassuring about brain injury associated with these seizure types when discussing outcomes with parents and patients.

Structural brain abnormalities in epilepsy with myoclonic atonic seizures

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Prevalence and psychopathologic significance of hallucinations in individuals with a history of seizures

OBJECTIVE

A relationship between seizure activity and hallucinations is well established. The psychopathologic significance of hallucinations in individuals with seizures, however, is unclear. In this study, we assessed the prevalence of auditory and visual hallucinations in individuals who reported a seizure history and investigated their relationship with a number of mental disorders, suicidal ideation, and suicide attempts.

METHODS

Data were from the "Adult Psychiatric Morbidity Survey," a population-based cross-sectional survey. Auditory and visual hallucinations were assessed using the Psychosis Screening Questionnaire. Mental health disorders were assessed using the Clinical Interview Schedule. Logistic regressions assessed relationships between hallucinatory experiences and mental disorders, suicidal ideation, and suicide attempts.

RESULTS

A total of 14 812 adults (58% female; mean [standard error of the mean; SEM] age 51.8 [0.15]) completed the study; 1.39% reported having ever had seizures (54% female), and 8% of individuals with a seizure history reported hallucinatory experiences (odds ratio [OR] 2.05, 95% confidence interval [CI] 1.24-3.38). Individuals with seizures had an increased odds of having any mental disorder (OR 2.34, 95% CI 1.73-3.16), suicidal ideation (OR 2.38, 95% CI 1.77-3.20), and suicide attempt (OR 4.15, 95% CI 2.91-5.92). Compared to individuals with seizures who did not report hallucinatory experiences, individuals with seizures who reported hallucinatory experiences had an increased odds of any mental disorder (OR 3.47, 95% CI 1.14-10.56), suicidal ideation (OR 2.58, 95% CI 0.87-7.63), and suicide attempt (OR 4.61, 95% CI 1.56-13.65). Overall, more than half of individuals with a seizure history who reported hallucinatory experiences had at least one suicide attempt. Adjusting for psychopathology severity did not account for the relationship between hallucinatory experiences and suicide attempts.

SIGNIFICANCE

Hallucinatory experiences in individuals with seizures are markers of high risk for mental health disorders and suicidal behavior. There is a particularly strong relationship between hallucinations and suicide attempts in individuals with seizures. Clinicians working with individuals with seizures should routinely ask about hallucinatory experiences.

Cognitive Function in Genetic Generalized Epilepsies: Insights From Neuropsychology and Neuroimaging

Genetic generalized epilepsies (GGE), previously called idiopathic generalized epilepsies, constitute about 20% of all epilepsies, and include childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy, and epilepsy with generalized tonic-clonic seizures alone (CAE, JAE, JME, and GGE-GTCS, respectively). GGE are characterized by high heritability, likely underlain by polygenetic mechanisms, which may relate to atypical neurodevelopmental trajectories. Age of onset ranges from pre-school years, for CAE, to early adulthood for GGE-GTCS. Traditionally, GGE have been considered benign, a belief contrary to evidence from neuropsychology studies conducted over the last two decades. In JME, deficits in executive and social functioning are common findings and relate to impaired frontal lobe function. Studies using neuropsychological measures and cognitive imaging paradigms provide evidence for hyperconnectivity between prefrontal and motor cortices, aberrant fronto-thalamo-cortical connectivity, and reduced fronto-cortical and subcortical gray matter volumes, which are associated with altered cognitive performance. Recent research has also identified associations between abnormal hippocampal morphometry and fronto-temporal activation during episodic memory. Longitudinal studies on individuals with newly diagnosed JME have observed cortical dysmaturation, which is paralleled by delayed cognitive development compared to the patients' peers. Comorbidities and cognitive deficits observed in other GGE subtypes, such as visuo-spatial and language deficits in both CAE and JAE, have also been correlated with atypical neurodevelopment. Although it remains unclear whether cognitive impairment profiles differ amongst GGE subtypes, effects may become more pronounced with disease duration, particularly in absence epilepsies. Finally, there is substantial evidence that patients with JME and their unaffected siblings share patterns of cognitive deficits, which is indicative of an underlying genetic etiology (endophenotype), independent of seizures and anti-epileptic medication.

Subcortical gray matter changes in pediatric patients with new-onset juvenile myoclonic epilepsy

OBJECTIVE

The objective of the study was to identify the relationship between subcortical gray matter (GM) volumes and juvenile myoclonic epilepsy (JME).

METHODS

We analyzed the brain magnetic resonance imaging (MRI) scans that were performed during the time of the diagnosis of epilepsy by using voxel-based morphometry (VBM) method. The volumetric three-dimensional sequence was used for structural investigation. The volumes of the thalamus, caudate nucleus, pallidum, and putamen were measured in both hemispheres of patients with JME, patients with generalized tonic-clonic seizures alone (GTCS) (as a disease control group) and healthy controls (HCs). All patients were drug-naïve, and treatment had been started after evaluating MRI results.

RESULTS

Fifteen patients with JME (9 females, mean age = 16.1 ± 3.2), 18 patients with GTCS (10 females, mean age = 15.5 ± 2.9), and 43 HCs (24 females, mean age = 15.9 ± 2.8) were included in the analysis. No significant difference was found for relative globus pallidus, caudate, and putamen volumes among the groups with JME, GTCS, and the HC group. The relative left and right thalamic volumes were significantly different between groups (Kruskal-Wallis rank test, p = 0.007, p = 0.001). In pairwise comparisons, both right and left relative thalamic volumes were lower in patients with JME than in HCs (right thalamus: means: 0.521 ± 0.066 vs. 0.597 ± 0.058, p < 0.001; left thalamus: means: 0.526 ± 0.088 vs. 0.605 ± 0.057, p < 0.001, Bonferroni post hoc corrections) and in patients with JME than in patients with GTCS (right thalamus: means: 0.521 ± 0.066 vs. 0.578 ± 0.066, p = 0.03; left thalamus: means: 0.526 ± 0.088 vs. 0.592 ± 0.068, p = 0.01, Bonferroni post hoc corrections), whereas there was no significant difference between the HCs and patients with GTCS (right thalamus: means: 0.597 ± 0.058 vs. 0.578 ± 0.066, p = 0.8; left thalamus: means: 0.605 ± 0.057 vs. 0.592 ± 0.068, p = 0.999, Bonferroni post hoc corrections).

CONCLUSION

This study allowed us to know that microstructural abnormalities exist from the disease onset, and the thalamus might play a critical role in the pathogenesis of JME.

Altered Structural Network in Newly Onset Childhood Absence Epilepsy

BACKGROUND AND PURPOSE

Recent quantitative neuroimaging studies of childhood absence epilepsy (CAE) have identified various structural abnormalities that might be involved in the onset of absence seizure and associated cognitive and behavioral functions. However, the neuroanatomical alterations specific to CAE remain unclear, and so this study investigated the regional alterations of brain structures associated with newly diagnosed CAE.

METHODS

Surface and volumetric magnetic resonance imaging data of patients with newly diagnosed CAE (n=18) and age-matched healthy controls (n=18) were analyzed using Free-Surfer software. A group comparison using analysis of covariance was performed with significance criteria of p<0.05 and p<0.01 in global and regional analyses, respectively.

RESULTS

Compared with control subjects, the patients with CAE had smaller total and regional volumes of cortical gray-matter (GM) in the right rostral middle frontal, right lateral orbitofrontal, and left rostral middle frontal regions, as well as in the right precentral, right superior, middle, left middle, and inferior temporal gyri. The cortex in the right posterior cingulate gyrus and left medial occipital region was significantly thicker in patients with CAE than in controls.

CONCLUSIONS

Patients with CAE showed a reduced bilateral frontotemporal cortical GM volume and an increased posterior medial cortical thickness, which are associated with the default mode network. These structural changes can be suggested as the neural basis of the absence seizures and neuropsychiatric comorbidities in CAE.

Language function in childhood idiopathic epilepsy syndromes

PURPOSE

To examine the impact of diverse syndromes of focal and generalized epilepsy on language function in children with new and recent onset epilepsy. Of special interest was the degree of shared language abnormality across epilepsy syndromes and the unique effects associated with specific epilepsy syndromes.

METHODS

Participants were 136 youth with new or recent-onset (diagnosis within past 12 months) epilepsy and 107 healthy first-degree cousin controls. The participants with epilepsy included 20 with Temporal Lobe Epilepsy (TLE; M age = 12.99  years, SD = 3.11), 41 with Benign Epilepsy with Centrotemporal Spikes (BECTS; M age = 10.32, SD = 1.67), 42 with Juvenile Myoclonic Epilepsy (JME; M age = 14.85, SD = 2.75) and 33 with absence epilepsy (M age = 10.55, SD = 2.76). All children were administered a comprehensive test battery which included multiple measures of language and language-dependent abilities (i.e., verbal intelligence, vocabulary, verbal reasoning, object naming, reception word recognition, word reading, spelling, lexical and semantic fluency, verbal list learning and delayed verbal memory). Test scores were adjusted for age and gender and analyzed via MANCOVA.

RESULTS

Language abnormalities were found in all epilepsy patient groups. The most broadly affected children were those with TLE and absence epilepsy, whose performance differed significantly from controls on 8 of 11 and 9 of 11 tests respectively. Although children with JME and BECTS were less affected, significant differences from controls were found on 4 of 11 tests each. While each group had a unique profile of language deficits, commonalities were apparent across both idiopathic generalized and localization-related diagnostic categories.

DISCUSSION

The localization related and generalized idiopathic childhood epilepsies examined here were associated with impact on diverse language abilities early in the course of the disorder.

Cortical morphologic changes in recent-onset, drug-naïve idiopathic generalized epilepsy

PURPOSE

Only a few studies have investigated the brain morphology abnormalities in structural MRI in patients with drug-naïve idiopathic generalized epilepsy (IGE) and mainly focused on brain volume changes. In the present study, we aimed to investigate the changes in three morphologic measurement differences including cortical thickness, cortical volume, and surface area using FreeSurfer in a pediatric cohort of recent-onset, drug-naïve IGE.

METHODS

Forty-five recent-onset, drug-naïve patients diagnosed with IGE and 32 demographically matched healthy controls were recruited. All participants underwent structural MRI scans with a 3.0 T MR system. FreeSurfer, an automated cortical surface reconstruction toolbox, was applied to compare the cortical morphology between patients and controls. The brain regions with significant group differences after multiple comparison correction were extracted in common space for each patient, and then correlated with their clinical characteristics (including onset age, duration of epilepsy, and mini-mental state examination (MMSE)) using partial correlation analysis with age, sex and intracranial volume as covariates.

RESULTS

Compared with controls, IGE patients showed decreased cortical thickness in the left rostral middle frontal gyrus, decreased cortical volume in the right cuneus and left superior frontal gyrus that extended to the precentral gyrus, and decreased surface area in the right cuneus and right inferior parietal gyrus. None of these regions showed significant relationships with clinical measurements in the patient group.

CONCLUSION

Our findings suggest that cortical thickness, cortical volume, and surface area changes occurred in the early stage of IGE. These findings provide structural neuroimaging evidence underlying the pathology of IGE.

Thalamic volume reduction in drug-naive patients with new-onset genetic generalized epilepsy

Objective

Patients with genetic generalized epilepsy (GGE) have subtle morphologic abnormalities of the brain revealed with magnetic resonance imaging (MRI), particularly in the thalamus. However, it is unclear whether morphologic abnormalities of the brain in GGE are a consequence of repeated seizures over the duration of the disease, or are a consequence of treatment with antiepileptic drugs (AEDs), or are independent of these factors. Therefore, we measured brain morphometry in a cohort of AED‐naive patients with GGE at disease onset. We hypothesize that drug‐naive patients at disease onset have gray matter changes compared to age‐matched healthy controls.

Methods

We performed quantitative measures of gray matter volume in the thalamus, putamen, caudate, pallidum, hippocampus, precuneus, prefrontal cortex, precentral cortex, and cingulate in 29 AED‐naive patients with new‐onset GGE and compared them to 32 age‐matched healthy controls. We subsequently compared the shape of any brain structures found to differ in gray matter volume between the groups.

Results

The thalamus was the only structure to show reduced gray matter volume in AED‐naive patients with new‐onset GGE compared to healthy controls. Shape analysis revealed that the thalamus showed deflation, which was not uniformly distributed, but particularly affected a circumferential strip involving anterior, superior, posterior, and inferior regions with sparing of medial and lateral regions.

Significance

Structural abnormalities in the thalamus are present at the initial onset of GGE in AED‐naive patients, suggesting that thalamic structural abnormality is an intrinsic feature of GGE and not a consequence of AEDs or disease duration.

Subcortical grey matter changes in juvenile myoclonic epilepsy

Recent neuroimaging studies have provided converging evidence of structural and functional abnormalities of the thalamus in patients with juvenile myoclonic epilepsy (JME). There has also been limited evidence indicating involvement of the subcortical grey matter structures other than thalamus in JME, but with inconsistent findings across the studies. In the present study, we combined volumetric MRI and diffusion tensor imaging analyses to investigate macrostructural and microstructural alterations of the subcortical grey matter in 64 JME patients compared to 58 matched control subjects. Raw volume, fractional anisotropy (FA), and mean diffusivity (MD) of 6 subcortical grey matter structures (amygdala, hippocampus, caudate, pallidum, putamen, thalamus) were measured in both hemispheres. Between-group (controls versus patients) comparisons of normalized volume, FA, and MD, as well as within-group (patients) correlation analyses between structural changes and clinical variables were carried out. Compared to controls, JME patients exhibited significant volume reductions in left pallidum and bilateral putamen and thalamus. Duration of epilepsy negatively correlated with bilateral putamen volumes. Patients and controls did not differ in FA values of all structures. Compared to controls, JME patients showed significant MD increases in left pallidum and bilateral hippocampus, putamen, and thalamus. Significant positive correlations were found between duration of epilepsy and MD values of bilateral hippocampus and thalamus. We have provided evidence that macrostructural and microstructural abnormalities may not only be confined to the thalamus but also affect basal ganglia and hippocampus in JME. Our findings could further support the pathophysiological hypothesis of striato-thalamo-frontal network abnormality underlying JME, and may implicate disease progression.

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Reduced volumes of left pallidum and bilateral putamen and thalamus in JME patients

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Negative correlation between disease duration and putamen volumes

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Increased MD of left pallidum and bilateral hippocampus, putamen, and thalamus in JME patients

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Positive correlation between disease duration and MD of bilateral hippocampus and thalamus

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Structural changes may not only be confined to the thalamus but also affect basal ganglia and hippocampus in JME.

White Matter Abnormalities in Patients with Treatment-Resistant Genetic Generalized Epilepsies

Background

Genetic generalized epilepsies (GGEs) are associated with microstructural brain abnormalities that can be evaluated with diffusion tensor imaging (DTI). Available studies on GGEs have conflicting results. Our primary goal was to compare the white matter structure in a cohort of patients with video/EEG-confirmed GGEs to healthy controls (HCs). Our secondary goal was to assess the potential effect of age at GGE onset on the white matter structure.

Material/Methods

A convenience sample of 23 patients with well-characterized treatment-resistant GGEs (13 female) was compared to 23 HCs. All participants received MRI at 3T. DTI indices, including fractional anisotropy (FA) and mean diffusivity (MD), were compared between groups using Tract-Based Spatial Statistics (TBSS).

Results

After controlling for differences between groups, abnormalities in DTI parameters were observed in patients with GGEs, including decreases in functional anisotropy (FA) in the hemispheric (left>right) and brain stem white matter. The examination of the effect of age at GGE onset on the white matter integrity revealed a significant negative correlation in the left parietal white matter region FA (R=−0.504; p=0.017); similar trends were observed in the white matter underlying left motor cortex (R=−0.357; p=0.103) and left posterior limb of the internal capsule (R=−0.319; p=0.148).

Conclusions

Our study confirms the presence of widespread white matter abnormalities in patients with GGEs and provides evidence that the age at GGE onset may have an important effect on white matter integrity.

Cognitive impairment in childhood onset epilepsy: up-to-date information about its causes

Cognitive impairment associated with childhood-onset epilepsy is an important consequence in the developing brain owing to its negative effects on neurodevelopmental and social outcomes. While the cause of cognitive impairment in epilepsy appears to be multifactorial, epilepsy-related factors such as type of epilepsy and underlying etiology, age at onset, frequency of seizures, duration of epilepsy, and its treatment are considered important. In recent studies, antecedent cognitive impairment before the first recognized seizure and microstructural and functional alteration of the brain at onset of epilepsy suggest the presence of a common neurobiological mechanism between epilepsy and cognitive comorbidity. However, the overall impact of cognitive comorbidity in children with epilepsy and the independent contribution of each of these factors to cognitive impairment have not been clearly delineated. This review article focuses on the significant contributors to cognitive impairment in children with epilepsy.

Reading, listening and memory-related brain activity in children with early-stage temporal lobe epilepsy of unknown cause-an fMRI study

BACKGROUND AND AIMS

The changes in functional brain organization associated with paediatric epilepsy are largely unknown. Since children with epilepsy are at risk of developing learning difficulties even before or shortly after the onset of epilepsy, we assessed the functional organization of memory and language in paediatric patients with temporal lobe epilepsy (TLE) at an early stage in epilepsy.

METHODS

Functional magnetic resonance imaging was used to measure the blood oxygenation level-dependent (BOLD) response to four cognitive tasks measuring reading, story listening, memory encoding and retrieval in a population-based group of children with TLE of unknown cause (n = 21) and of normal intelligence and a healthy age and gender-matched control group (n = 21).

RESULTS

Significant BOLD response differences were found only in one of the four tasks. In the story listening task, significant differences were found in the right hemispheric temporal structures, thalamus and basal ganglia. Both activation and deactivation differed significantly between the groups, activation being increased and deactivation decreased in the TLE group. Furthermore, the patients with abnormal electroencephalograms (EEGs) showed significantly increased activation bilaterally in the temporal structures, basal ganglia and thalamus relative to those with normal EEGs. The patients with normal interictal EEGs had a significantly stronger deactivation than those with abnormal EEGs or the controls, the differences being located outside the temporal structures.

CONCLUSIONS

Our results suggest that TLE entails a widespread disruption of brain networks. This needs to be taken into consideration when evaluating learning abilities in patients with TLE. The thalamus seems to play an active role in TLE. The changes in deactivation may reflect neuronal inhibition.

Seizure and Psychosocial Outcomes of Childhood and Juvenile Onset Generalized Epilepsies: Wolf in Sheep's Clothing, or Well-Dressed Wolf?

Studies of generalized electroclinical syndromes can provide guidance regarding long-term seizure, cognitive, and psychosocial outcomes. Childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy, and idiopathic generalized epilepsy with generalized tonic-clonic seizures alone are electroclinical syndromes typically associated with normal intellect and good response to antiseizure medications. However, studies have demonstrated significantly poorer psychosocial outcomes than expected for these syndromes, regardless of seizure control. Potential causes for this include underlying abnormalities in social skills, social stigma, and underlying abnormalities in brain development and maturation.

Behavioral Abnormalities in Lagotto Romagnolo Dogs with a History of Benign Familial Juvenile Epilepsy: A Long-Term Follow-Up Study

Background

Lagotto Romagnolo (LR) dogs with benign juvenile epilepsy syndrome often experience spontaneous remission of seizures. The long‐term outcome in these dogs currently is unknown. In humans, behavioral and psychiatric comorbidities have been reported in pediatric and adult‐onset epilepsies.

Hypothesis/Objectives

The objectives of this study were to investigate possible neurobehavioral comorbidities in LR with a history of benign familial juvenile epilepsy (BFJE) and to assess the occurrence of seizures after the remission of seizures in puppyhood.

Animals

A total of 25 LR with a history of BFJE and 91 control dogs of the same breed.

Methods

Owners of the LR dogs in the BFJE and control groups completed an online questionnaire about each dog's activity, impulsivity, and inattention. Principal component analysis (PCA) served to extract behavioral factors from the data. We then compared the scores of these factors between the 2 groups in a retrospective case–control study. We also interviewed all dog owners in the BFJE group by telephone to inquire specifically about possible seizures or other neurological problems after remission of seizures as a puppy.

Results

Lagotto Romagnolo dogs with BFJE showed significantly higher scores on the factors Inattention and Excitability/Impulsivity than did the control group (P = .003; P = .021, respectively). Only 1 of the 25 BFJE LR exhibited seizures after remission of epilepsy in puppyhood.

Conclusions and Clinical Importance

Although the long‐term seizure outcome in BFJE LR seems to be good, the dogs exhibit behavioral abnormalities resembling attention deficit hyperactivity disorder (ADHD) in humans, thus suggesting neurobehavioral comorbidities with epilepsy.

Diffusional kurtosis imaging reveals a distinctive pattern of microstructural alternations in idiopathic generalized epilepsy

OBJECTIVES

Idiopathic generalized epilepsy (IGE) arises from paroxysmal dysfunctions of the thalamo-cortical network. One of the hallmarks of IGE is the absence of visible abnormalities on routine magnetic resonance imaging (MRI). However, recent quantitative MRI studies showed cortical-subcortical structural abnormalities in IGE, but the extent of abnormalities has been inconsistent in the literature. The inconsistencies may be associated with complex microstructural abnormalities in IGE that are not completely detectable using conventional diffusion tensor imaging methods. The goal of this study was to investigate white-matter (WM) microstructural abnormalities in patients with IGE using diffusional kurtosis imaging (DKI).

MATERIALS AND METHODS

We obtained DKI and volumetric T1-weighted images from 14 patients with IGE and 25 matched healthy controls. Using tract-based spatial statistics, we performed voxel-wise group comparisons in the parametric maps generated from DKI: mean diffusivity (MD), fractional anisotropy (FA), and mean kurtosis (MK), and in probabilistic maps of WM volume generated by voxel-based morphometry.

RESULTS

We observed that conventional microstructural measures (MD and FA) revealed WM abnormalities in thalamo-cortical projections, whereas MK disclosed a broader pattern of WM abnormalities involving thalamo-cortical and cortical-cortical projections.

CONCLUSIONS

Even though IGE is traditionally considered a 'non-lesional' form of epilepsy, our results demonstrated pervasive thalamo-cortical WM microstructural abnormalities. Particularly, WM abnormalities shown by MK further extended into cortical-cortical projections. This suggests that the extent of microstructural abnormalities in thalamo-cortical projections in IGE may be better assessed through the diffusion metrics provided by DKI.

Impaired development of intrinsic connectivity networks in children with medically intractable localization-related epilepsy

Typical childhood development is characterized by the emergence of intrinsic connectivity networks (ICNs) by way of internetwork segregation and intranetwork integration. The impact of childhood epilepsy on the maturation of ICNs is, however, poorly understood. The developmental trajectory of ICNs in 26 children (8-17 years) with localization-related epilepsy and 28 propensity-score matched controls was evaluated using graph theoretical analysis of whole brain connectomes from resting-state functional magnetic resonance imaging (fMRI) data. Children with epilepsy demonstrated impaired development of regional hubs in nodes of the salience and default mode networks (DMN). Seed-based connectivity and hierarchical clustering analysis revealed significantly decreased intranetwork connections, and greater internetwork connectivity in children with epilepsy compared to controls. Significant interactions were identified between epilepsy duration and the expected developmental trajectory of ICNs, indicating that prolonged epilepsy may cause progressive alternations in large-scale networks throughout childhood. DMN integration was also associated with better working memory, whereas internetwork segregation was associated with higher full-scale intelligence quotient scores. Furthermore, subgroup analyses revealed the thalamus, hippocampus, and caudate were weaker hubs in children with secondarily generalized seizures, relative to other patient subgroups. Our findings underscore that epilepsy interferes with the developmental trajectory of brain networks underlying cognition, providing evidence supporting the early treatment of affected children.

Epilepsy and its main psychiatric comorbidities in adults and children

Psychiatric disorders seem to be more frequent in patients with epilepsy (PWE) than the general population. Although researchers have documented a strong association between epilepsy and psychiatric comorbidities, the nature of this relationship is poorly understood. According to this, psychiatric diseases are often underdiagnosed and undertreated in PWE with further decrease of the quality of life of patients. The aim of the review was to examine the most frequent psychiatric comorbidities in adults with epilepsy (AWE) and the main psychiatric comorbidities in children with epilepsy (CWE) in order to better understand the relationship between epilepsy and the development of psychiatric disorders.

Frequency-dependent amplitude alterations of resting-state spontaneous fluctuations in idiopathic generalized epilepsy

PURPOSE

Amplitude of low-frequency fluctuation (ALFF) of blood-oxygenation level-dependent (BOLD) has proven a promising way to detect disease-related local brain activity. However, routine approach employs an arbitrary frequency band of 0.01-0.08 Hz, which lacks frequency specificity and blinds to the information contained in other frequency bands. This study investigated the amplitude of fluctuations in full BOLD frequency bands, and addressed how amplitudes of fluctuations change in each specific frequency range in idiopathic generalized epilepsy (IGE).

METHODS

Thirty-four IGE patients with generalized tonic-clonic seizure and the same number of age- and sex-matched healthy controls were included. Functional MRI data were acquired using a 2s repetition time. Routine amplitude of low-frequency fluctuation analysis was first performed. The regions showing group difference were set as Region-of-interest for analysis of amplitudes of full-frequency. The amplitudes of BOLD fluctuations were consecutively performed at each frequency bin of 0.002 Hz, and specific frequency amplitude analyses were performed in five different frequency ranges (0-0.01 Hz, 0.01-0.027 Hz, 0.027-0.073 Hz, 0.073-0.198 Hz, and 0.198-0.25 Hz).

KEY FINDINGS

The thalamus and prefrontal cortex showed significant group differences in routine amplitude analysis. For amplitude of full-frequency analysis, a reverse pattern was found in the dynamic changes between the thalamus and prefrontal cortex in IGE. Moreover, the prefrontal cortex showed amplitude difference in the 0.01-0.027 Hz band, while the thalamus showed amplitude difference in the 0.027-0.073 Hz band. Both these two regions showed amplitude differences in 0.198-0.25 Hz band.

SIGNIFICANCE

We demonstrated the characteristic alterations of amplitude of BOLD fluctuations in IGE in frequency domain. The amplitude analysis of full frequency may potentially help to select specific frequency range for detecting epilepsy-related brain activity, and provide insights into the pathophysiological mechanism of IGE.

Regional brain volumes and cognition in childhood epilepsy: does size really matter?

PURPOSE

Recent studies have correlated neurocognitive function and regional brain volumes in children with epilepsy. We tested whether brain volume differences between children with and without epilepsy explained differences in neurocognitive function.

METHODS

The study sample included 108 individuals with uncomplicated non-syndromic epilepsy (NSE) and 36 healthy age- and gender-matched controls. Participants received a standardized cognitive battery. Whole brain T1-weighted MRI was obtained and volumes analyzed with FreeSurfer (TM).

KEY FINDINGS

Total brain volume (TBV) was significantly smaller in cases. After adjustment for TBV, cases had significantly larger regional grey matter volumes for total, frontal, parietal, and precentral cortex. Cases had poorer performance on neurocognitive indices of intelligence and variability of sustained attention. In cases, TBV showed small associations with intellectual indices of verbal and perceptual ability, working memory, and overall IQ. In controls, TBV showed medium associations with working memory and variability of sustained attention. In both groups, small associations were seen between some TBV-adjusted regional brain volumes and neurocognitive indices, but not in a consistent pattern. Brain volume differences did not account for cognitive differences between the groups.

SIGNIFICANCE

Patients with uncomplicated NSE have smaller brains than controls but areas of relative grey matter enlargement. That this relative regional enlargement occurs in the context of poorer overall neurocognitive functioning suggests that it is not adaptive. However, the lack of consistent associations between case-control differences in brain volumes and cognitive functioning suggests that brain volumes have limited explanatory value for cognitive functioning in childhood epilepsy.

Neurodevelopmental alterations of large-scale structural networks in children with new-onset epilepsy

Recent neuroimaging and behavioral studies have revealed that children with new onset epilepsy already exhibit brain structural abnormalities and cognitive impairment. How the organization of large-scale brain structural networks is altered near the time of seizure onset and whether network changes are related to cognitive performances remain unclear. Recent studies also suggest that regional brain volume covariance reflects synchronized brain developmental changes. Here, we test the hypothesis that epilepsy during early-life is associated with abnormalities in brain network organization and cognition. We used graph theory to study structural brain networks based on regional volume covariance in 39 children with new-onset seizures and 28 healthy controls. Children with new-onset epilepsy showed a suboptimal topological structural organization with enhanced network segregation and reduced global integration compared with controls. At the regional level, structural reorganization was evident with redistributed nodes from the posterior to more anterior head regions. The epileptic brain network was more vulnerable to targeted but not random attacks. Finally, a subgroup of children with epilepsy, namely those with lower IQ and poorer executive function, had a reduced balance between network segregation and integration. Taken together, the findings suggest that the neurodevelopmental impact of new onset childhood epilepsies alters large-scale brain networks, resulting in greater vulnerability to network failure and cognitive impairment.

Neurobehavioral comorbidities of pediatric epilepsies are linked to thalamic structural abnormalities

PURPOSE

Neurobehavioral comorbidities are common in pediatric epilepsy with enduring adverse effects on functioning, but their neuroanatomic underpinning is unclear. Striatal and thalamic abnormalities have been associated with childhood-onset epilepsies, suggesting that epilepsy-related changes in the subcortical circuit might be associated with the comorbidities of children with epilepsy. We aimed to compare subcortical volumes and their relationship with age in children with complex partial seizures (CPS), childhood absence epilepsy (CAE), and healthy controls (HC). We examined the shared versus unique structural-functional relationships of these volumes with behavior problems, intelligence, language, peer interaction, and epilepsy variables in these two epilepsy syndromes.

METHODS

We investigated volumetric differences of caudate, putamen, pallidum, and thalamus in children with CPS (N = 21), CAE (N = 20), and HC (N = 27). Study subjects underwent structural magnetic resonance imaging (MRI), intelligence, and language testing. Parent-completed Child Behavior Checklists provided behavior problem and peer interaction scores. We examined the association of age, intelligence quotient (IQ), language, behavioral problems, and epilepsy variables with subcortical volumes that were significantly different between the children with epilepsy and HC.

KEY FINDINGS

Both children with CPS and CAE exhibited significantly smaller left thalamic volume compared to HC. In terms of developmental trajectory, greater thalamic volume was significantly correlated with increasing age in children with CPS and CAE but not in HC. With regard to the comorbidities, reduced left thalamic volumes were related to more social problems in children with CPS and CAE. Smaller left thalamic volumes in children with CPS were also associated with poor attention, lower IQ and language scores, and impaired peer interaction.

SIGNIFICANCE

Our study is the first to directly compare and detect shared thalamic structural abnormalities in children with CPS and CAE. These findings highlight the vulnerability of the thalamus and provide important new insights on its possible role in the neurobehavioral comorbidities of childhood-onset epilepsy.

Volumetric and shape analysis of thalamus in idiopathic generalized epilepsy

Previous studies using voxel-based morphometry (VBM) provided emerging evidence of structural changes of the thalamus in idiopathic generalized epilepsy (IGE). However, the location of atrophy within the thalamus in IGE has been somewhat inconsistent across the studies. We, therefore, examined the location of thalamic atrophy and its relationship with clinical factors in IGE, using multiple analytic methods. Fifty IGE patients and 50 controls were scanned on a 3T MRI. Structural evaluation consisted of automated thalamic volumetry, VBM, and thalamic shape analysis. Group comparison between patients and controls was made to assess thalamic atrophy. Within-group correlations between thalamic atrophy and clinical variables were further performed in patients. Both thalamic volumes were reduced in IGE patients, and were negatively correlated with disease duration. The VBM showed a significant regional grey matter volume reduction in bilateral anterior-medial thalami in patients compared to controls. Voxel values extracted from the anterior-medial thalamic cluster were negatively correlated with disease duration. Vertex-based shape analysis revealed regional atrophy on the anterior-medial and posterior-dorsal aspects of thalamus bilaterally in patients compared to controls. Correlation analysis showed that anterior-medial and posterior-dorsal aspects of bilateral thalami were negatively correlated with disease duration. Combining multiple analyses, we demonstrated regional atrophy of anterior-medial and posterior-dorsal thalamus in patients with IGE. Given the anatomical connection of these thalamic regions with the frontal lobe, our finding of greater thalamic atrophy in relation to increasing disease duration further supports the pathophysiological concept of thalamo-frontal network abnormality underlying IGE, and may implicate frontal cognitive dysfunctions and disease progression.

Abnormal thalamocortical structural and functional connectivity in juvenile myoclonic epilepsy

Juvenile myoclonic epilepsy is the most common idiopathic generalized epilepsy, characterized by frequent myoclonic jerks, generalized tonic-clonic seizures and, less commonly, absences. Neuropsychological and, less consistently, anatomical studies have indicated frontal lobe dysfunction in the disease. Given its presumed thalamo–cortical basis, we investigated thalamo–cortical structural connectivity, as measured by diffusion tensor imaging, in a cohort of 28 participants with juvenile myoclonic epilepsy and detected changes in an anterior thalamo–cortical bundle compared with healthy control subjects. We then investigated task-modulated functional connectivity from the anterior thalamic region identified using functional magnetic resonance imaging in a task consistently shown to be impaired in this group, phonemic verbal fluency. We demonstrate an alteration in task-modulated connectivity in a region of frontal cortex directly connected to the thalamus via the same anatomical bundle, and overlapping with the supplementary motor area. Further, we show that the degree of abnormal connectivity is related to disease severity in those with active seizures. By integrating methods examining structural and effective interregional connectivity, these results provide convincing evidence for abnormalities in a specific thalamo–cortical circuit, with reduced structural and task-induced functional connectivity, which may underlie the functional abnormalities in this idiopathic epilepsy.

Uncovering the neurobehavioural comorbidities of epilepsy over the lifespan

Epilepsy is a common neurological disorder that is complicated by psychiatric, cognitive, and social comorbidities that have become a major target of concern and investigation in view of their adverse effect on the course and quality of life. In this report we define the specific psychiatric, cognitive, and social comorbidities of paediatric and adult epilepsy, their epidemiology, and real life effects; examine the relation between epilepsy syndromes and the risk of neurobehavioural comorbidities; address the lifespan effect of epilepsy on brain neurodevelopment and brain ageing and the risk of neurobehavioural comorbidities; consider the overarching effect of broader brain disorders on both epilepsy and neurobehavioural comorbidities; examine directions of causality and the contribution of selected epilepsy-related characteristics; and outline clinic-friendly screening approaches for these problems and recommended pharmacological, behavioural, and educational interventions.

Starting at the beginning: the neuropsychological status of children with new-onset epilepsies

This review examines the neurodevelopmental contribution to the cognitive and behavioural complications of epilepsy. Following a brief review of the lifespan complications of childhood epilepsies, attention turns to cognitive, psychiatric and social correlates of childhood epilepsies reported in population-based and tertiary care studies. The focus then becomes the neurobehavioural status of children with new-onset epilepsy; a point in time not confounded by the effects of years of recurrent seizures, medications, and social reactions to epilepsy. Recent research shows that abnormalities in cognition, brain structure and behaviour are present at or near the time of diagnosis. Further, careful history taking indicates that neurobehavioural problems may be present in advance of the first seizure suggesting the potential influence of epileptogenesis, antecedent neurodevelopmental abnormalities, genetic and environmental susceptibilities, and other risk factors. This becomes the substrate upon which to characterise the effects of epilepsy and its treatment on subsequent neurodevelopment. The review concludes with suggestions for future clinical care and research.

Impairments of thalamic nuclei in idiopathic generalized epilepsy revealed by a study combining morphological and functional connectivity MRI

OBJECTIVE

Neuroimaging evidence suggested that the thalamic nuclei may play different roles in the progress of idiopathic generalized epilepsy (IGE). This study aimed to demonstrate the alterations in morphometry and functional connectivity in the thalamic nuclei in IGE.

METHODS

Fifty-two patients with IGE characterized by generalized tonic-clonic seizures and 67 healthy controls were involved in the study. The three-dimensional high-resolution T1-weighted MRI data were acquired for voxel-based morphometry (VBM) analysis, and resting-state blood-oxygenation level functional MRI data were acquired for functional connectivity analysis. The thalamic nuclei of bilateral medial dorsal nucleus (MDN) and pulvinar, as detected with decreased gray matter volumes in patients with IGE through VBM analysis, were selected as seed regions for functional connectivity analysis.

RESULTS

Different alteration patterns were found in functional connectivity of the thalamic nuclei with decreased gray matter volumes in IGE. Seeding at the MDN, decreased connectivity in the bilateral orbital frontal cortex, caudate nucleus, putamen and amygdala were found in the patients (P<0.05 with correction). However, seeding at the pulvinar, no significant alteration of functional connectivity was found in the patients (P<0.05 with correction).

CONCLUSIONS

Some specific impairment of thalamic nuclei in IGE was identified using morphological and functional connectivity MRI approaches. These findings may strongly support the different involvement of the thalamocortical networks in IGE.

Neuroconnectivity and valproic acid: the myelin hypothesis

Neuropsychiatric medications that directly alter the epigenome, such as valproic acid, can under certain conditions reactivate critical developmental periods and thus impact adult neuroconnectivity. In animal models valproic acid was shown to inhibit the process of postnatal myelination and to replicate age-dependent decline in remyelination efficiency. The human central nervous system's myelination process, unlike that of non-human primates commonly used in the experimental models, is an intricate heterochronous process that continues well into adult life and which probably underlies later life neurocognitive changes and plasticity. Chronic exposure to valproic acid, especially in patients with epilepsy and neuropsychiatric disorders, may profoundly affect this process and its developmental trajectory. Further studies using novel MRI methods that allow in vivo mapping of myelination trajectories across the lifespan are urgently required to address the potential effects of valproic acid on brain development.

Reduced cortical thickness in children with new-onset seizures

BACKGROUND AND PURPOSE

Children with new-onset seizures may have antecedent neurobiologic alterations that predispose them to developing seizures. Our aim was to evaluate hippocampal and thalamic volumes and lobar cortical thickness of children with new-onset seizures.

MATERIALS AND METHODS

Twenty-nine children with new-onset seizures and normal MR imaging findings were recruited. Ten patients had generalized seizures, 19 had partial seizures, and 15 were on antiepileptic medications. Twenty-three age-matched healthy controls were also recruited. Hippocampal and thalamic volumes and lobar cortical thickness, including frontal, medial temporal, lateral temporal, parietal, cingulate, and occipital cortical thickness, were assessed by using volumetric T1-weighted imaging and were compared between patients and controls.

RESULTS

There were no significant differences in hippocampal and thalamic volumes of patients with new-onset seizures, including the subgroups with generalized and partial seizures and those on and off antiepileptic medications, compared with controls (P > .01). There was significant reduction in cortical thickness in right cingulate (P = .004), right medial temporal (P = .006), and left frontal (P = .007) cortices in patients with new-onset seizures. Patients with generalized seizures did not demonstrate a significant reduction in cortical thickness (P > .01). Patients with partial seizures demonstrated a significant reduction in cortical thickness in the right frontal (P = .008), right parietal (P = .003), and left frontal (P = .007) cortices. There were no significant differences in cortical thickness among patients on or off antiepileptic medications (P > .01).

CONCLUSIONS

We found reduced cortical thickness in children with new-onset seizures. Further studies are necessary to elucidate the neurobiologic relevance of these structural changes.

Robust subdivision of the thalamus in children based on probability distribution functions calculated from probabilistic tractography

Virtually all information that enters the cortex must first pass through the thalamus. This prominent role has made the human thalamus a target for detailed imaging studies. It has previously been shown that probabilistic tractography together with cortical parcellation allowed subdivision of the thalamus into its constituent substructures. A new method is presented that allows the subdivision of the thalamus according to its cortical projection targets based on the assumption that any cortical region receives input from the thalamus and calculates the probability of connectivity distribution functions based on probabilistic tractography. The feasibility of the method was tested in a data set of 43 healthy children aged between 8 and 13 years. A thalamic parcellation pattern similar to that previously found in adults and children below the age of 2 years was obtained. However, no evidence for an age related change in cortical parcellation volumes were found in line with previously reported studies of thalamic volumes during development. Lower standard deviations were found for the two smallest projections, the sensory and occipital projection using the new method. Furthermore it was found, through comparison with a published thalamic atlas, that the method allowed the localization of the center of the different thalamic projection areas within an accuracy of 2 mm.

Deformation-based morphometry of prospective neurodevelopmental changes in new onset paediatric epilepsy

Epilepsy is a prevalent childhood neurological disorder, but there are few prospective quantitative magnetic resonance imaging studies examining patterns of brain development compared to healthy controls. Controlled prospective investigations initiated at or near epilepsy onset would best characterize the nature, timing and course of neuroimaging abnormalities in paediatric epilepsy. In this study, we report the results of a deformation-based morphometry technique to examine baseline and 2-year prospective neurodevelopmental brain changes in children with new and recent onset localization-related epilepsies (n = 24) and idiopathic generalized epilepsies (n = 20) compared to healthy controls (n = 36). Children with epilepsy demonstrated differences from controls in baseline grey and white matter volumes suggesting antecedent anomalies in brain development, as well as abnormal patterns of prospective brain development that involved not only slowed white matter expansion, but also abnormalities of cortical grey matter development involving both greater and lesser volume changes compared to controls. Furthermore, abnormal neurodevelopmental changes extended outside the cortex affecting several subcortical structures including thalamus, cerebellum, brainstem and pons. Finally, there were significant differences between the epilepsy syndromes (localization-related epilepsies and idiopathic generalized epilepsies) with the idiopathic generalized epilepsies group showing a more disrupted pattern of brain structure both at baseline and over the 2-year interval.