Sleep quality and circadian rhythm profile of persons with juvenile myoclonic epilepsy in a tertiary epilepsy center: A case-control study.

PURPOSE: This study evaluated sleep quality, chronotype, and excessive diurnal somnolence in persons with Juvenile Myoclonic Epilepsy (JME) and their possible association with clinical variables. METHODS: This cross-sectional controlled study evaluated 49 consecutive patients (65% females, mean age 27.53 years) with an electroclinical diagnosis of JME and 49 healthy controls (55% females, mean age 28.55 years). The Pittsburgh Sleep Quality Inventory (PSQI) was used to assess sleep quality and the Epworth Sleepiness Scale (ESS) to evaluate excessive daytime sleepiness. The patients' chronotype was evaluated by the Morningness-Eveningness Questionnaire (MEQ). Epilepsy-related factors gathered from the medical chart and personal interview were epilepsy duration, age at onset, frequency of myoclonic (Mcl), generalized tonic-clonic (GTC) and absence (ABS) seizures, pharmacoresponse, and current antiseizure medication (ASM). RESULTS: Persons with JME did not differ from the control group regarding daytime sleepiness (p=0.840); however, the JME group had worse sleep quality (p=0.01) than the controls. Persons with JME presented a more evening chronotype than controls (p = 0.003). The age at onset, epilepsy duration, frequency of Mcl seizure, frequency of GTC seizure, frequency of ABS seizure, and drug response did not predict ESS and MEQ scales. Pharmacoresponsive patients had lower PSQI scores compared with pharmacoresistant patients (p=0.036). CONCLUSION: Persons with JME have worse sleep quality and a more evening chronotype. Notably, pharmacoresistant patients present a worse sleep quality that deserves attention and special care due to the relationship between sleep deprivation and seizure worsening.

More than one self-limited epilepsy of childhood in the same patient: A multicenter study.

OBJECTIVE: We describe the evolution of the electroclinical picture of patients with different types of self-limited epilepsy of childhood (SLEC) occurring at the same or at different times with or without atypical evolutions as well as patients with SLEC associated with childhood absence epilepsy (CAE). MATERIAL AND METHODS: A multicenter, retrospective, descriptive study was conducted evaluating patients with SLEC who had focal seizures of different types of SLEC including atypical evolutions as well as SLEC associated with absence epilepsy seen at eight Argentinian centers between April 2000 and April 2019. Of 7705 patients with SLEC, aged between 2 and 14 years (mean, 7.5 years), of whom 2013 were female and 5692 male (ratio, 1:2.8), 5068 patients had SLECTS, 2260 patients had self-limited childhood occipital epilepsy Panayiotopoulos type (SLE-P), 356 had self-limited childhood occipital epilepsy Gastaut type (SLE-G), and 21 had self-limited epilepsy with affective seizures (SLEAS). Electroclinical features typical of more than one SLEC syndrome were recognized in 998 (13 %) children. RESULTS: We recognized three well-defined groups of patients. The most frequent association was SLE-P and SLECTS, the paradigmatic type, but associations of SLE-P and SLE-G, SLECTS and SLE-G, and SLEAS and SLE-P or SLECTS were also recognized. The second-most-common association was SLEC and an atypical evolution. In this group, the most frequent combination was SLECTS with its atypical evolution, opercular status epilepticus, epileptic encephalopathy with continuous spike-and-waves during slow sleep, or Landau-Kleffner syndrome. SLE-P and SLE-G associated with an atypical evolution were also identified. The third, less-frequent group had SLECTS, SLE-P, or SLE-G associated with CAE. These cases support the concept that the different types of SLEC are part of a self-limited childhood seizure susceptibility syndrome. CONCLUSION: Our study demonstrated that 13 % of our patients with SLEC have with different types of SLEC occurring at the same or at different times with or without atypical evolutions - i.e. CSWSS - as well as patients with SLEC associated with CAE, supporting the concept of the self-limited childhood seizure susceptibility syndrome.

Absence epilepsy in male and female WAG/Rij rats: A longitudinal EEG analysis of seizure expression.

The WAG/Rij strain of rats is commonly used as a preclinical model of genetic absence epilepsy. While widely utilized, the developmental trajectory of absence seizure expression has been only partially described. Moreover, sex differences in this strain have been under-explored. Here, we longitudinally monitored male and female WAG/Rij rats to quantify cortical spike-and-wave discharges (SWDs) monthly, from 4 to 10 months of age. In both male and female WAG/Rij rats, absence seizure susceptibility increased with age. In contrast to previous reports, we found a robust and consistent increase in absence epilepsy susceptibility in male WAG/Rij rats in comparison to females across months. The increased absence seizure susceptibility was characterized by increased number and duration of SWDs, and consequently increased total SWDs duration. These findings highlight a previously un-recognized sex difference in a model of absence epilepsy and narrow the knowledge gap of age-dependent expression of SWDs in the WAG/Rij strain.

Hyperventilation maneuver during EEG in children with epilepsy after the COVID-19 pandemic. Is a routine procedure necessary?

OBJECTIVE: Hyperventilation (HV) is one of the main and basic activation methods during ambulatory electroencephalogram (EEG), unless medical reasons contraindicate it. During the COVID-19 pandemic, with the high risk of human-to-human infection, local guidelines and recommendations have been developed that suggest not to perform the HV maneuver routinely. Our objective was to characterize patients who present positive HV in an epilepsy center. METHODS: We analyzed retrospectively all the ambulatory EEGs performed during one year in our specialized ambulatory child and adolescent epilepsy center, and describe patients with positive maneuver. RESULTS: A total of 305 EEGs were performed. Patients under 3 years and 11 months were excluded as well as all patients that did not fill up the criteria for epilepsy diagnosis. From the 252 EEGs that were included in the study, 194 EEGs (77%) were classified as abnormal and 58 (23%) as normal. From these same 252 EEGs, 150 EEG finished correctly the HV maneuver. Physiological slowing response was found in 54 EEGs (36%), no changes (negative) in 83 (55%), and abnormal response (positive) in 13 EEGs (9%). The 13 HV-positive EEGs showed 4 patients with an increase of epileptiform activity, 3 patients experienced an increase of basal preregistered abnormal slowing, and 6 EEGs showed trigger of bilaterally synchronous and symmetric 2-4 Hz spike-and-slow wave discharges and absences. None of these last 6 patients needed more than 3 minutes to elicit the paroxysmal discharge. SIGNIFICANCE: Based on these findings and according with other studies, the low positivity and high specificity of the HV maneuver support the idea that HV could be excluded during the COVID-19 pandemic situation, and also reevaluate whether it could be changed to a complementary maneuver, restricted only for cases where absence epilepsy is suspected. Larger studies will be needed to reaffirm this proposal.

Evaluation of deep gray matter volume, cortical thickness and white matter integrity in patients with typical absence epilepsy: a study using voxelwise-based techniques.

INTRODUCTION: The objective of this study was to evaluate the cortical thickness and the volume of deep gray matter structures, measured from 3D T1-weighted gradient echo imaging, and white matter integrity, by diffusion tensor imaging (DTI) in patients with typical absence epilepsy (AE). METHODS: Patients (n = 19) with typical childhood AE and juvenile AE, currently taking antiepileptic medication, were compared with control subjects (n = 19), matched for gender and age. 3D T1 magnetization-prepared rapid gradient echo-weighted imaging and DTI along 30 noncolinear directions were performed using a 1.5-T MR scanner. FreeSurfer was used to perform cortical volumetric reconstruction and segmentation of deep gray matter structures. For tract-based spatial statistics analysis of DTI, a white matter skeleton was created, along with a permutation-based inference with 5000 permutations. A threshold of p < 0.05 was used to identify abnormalities in fractional anisotropy (FA). The mean, radial, and axial diffusivities were also projected onto the mean FA skeleton. RESULTS: Patients with AE presented decreased FA and increased mean diffusivity and radial diffusivity values in the genu and the body of the corpus callosum and right anterior corona radiata, as well as decreased axial diffusivity in the left posterior thalamic radiation, inferior cerebellar peduncle, right cerebral peduncle, and right corticospinal tract. However, there were no significant differences in cortical thickness or deep gray matter structure volumes between patients with AE and controls. CONCLUSION: Abnormalities found in white matter integrity may help to better understand the pathophysiology of AE and optimize diagnosis and treatment strategies.

Learning skills and academic performance in children and adolescents with absence epilepsy.

INTRODUCTION: Although cognitive and learning disorders have been described in patients with epilepsy, very few studies focus on specific disorders such as absence epilepsy. The aim of this study was to evaluate learning skills and academic performance in children and adolescents with absence epilepsy. METHODS: Observational case-control study. Cases were chosen from the Central League against Epilepsy's clinic in Bogotá, Colombia. Controls were selected from a private school and matched with cases by age, school year, and sex. Medical history, seizure frequency, antiepileptic treatment, and academic performance were assessed. Academic abilities were tested with Batería de Aptitudes Diferenciales y Generales (BADyG) (a Spanish-language test of differential and general aptitudes). Data were analysed using Student t-test. RESULTS: The sample consisted of 19 cases and 19 controls aged between 7 and 16. In 15 patients, seizures were controlled; all patients had received antiepileptic medication at some point and 78.9% were actively being treated. Although cases had higher rates of academic failure, a greater incidence of grade retention, and more therapeutic interventions than controls, these differences were not significant. Similarly, there were no significant differences on the BADyG test, except for the immediate memory subcategory on which cases scored higher than controls (P=.0006). CONCLUSION: Children treated pharmacologically for absence epilepsy, whose seizures are controlled, have normal academic abilities and skills for their age.

Treatment gaps of epilepsy and retention rates of sodium valproate in rural Guangxi, China.

This study aimed to investigate the prevalence and treatment gaps of epilepsy, as well as the clinical effects, drug safety, and retention rates of sodium valproate (VPA) for treating epilepsy. Physicians received supervised training to use the survey form recommended by the Chinese Association Against Epilepsy while screening for suspected or confirmed epilepsy cases. These cases were ultimately enrolled in the study by neurologists. Enrolled patients were given a year of free VPA treatment so that its efficacy and adverse effects during the follow-up period could be evaluated. In total, 302 patients were enrolled in this study, which included 189 males and 113 females. Among these cases, 179 (59.27%) were confirmed to have generalized seizures, 162 (53.6%) had tonic-clonic seizures, 10 (3.3%) had absence seizures, and 123 (40.72%) had partial seizures. Only 63 patients had received regular treatments 1 week before enrollment, with a treatment gap of 79.1%. The retention rates during the 6th, 12th, 18th, and 24th months were 100, 93.56, 89.05, and 77.06%, respectively. During the 1-year follow-up period, 30 cases encountered mild adverse effects, but no severe adverse reactions were reported. A large treatment gap for epilepsy still existed in the rural areas of southern China, with few adverse effects and high retention rates. VPA showed satisfactory effects in the treatment of epileptic patients.

The double generalization phenomenon in juvenile absence epilepsy.

The characterization of a seizure as generalized or focal onset depends on a basic knowledge of the underlying pathophysiology. Recently, an uncommon phenomenon in generalized epilepsy-evolution of seizures from generalized to focal followed by secondary generalization-was reported for the first time. We describe a 15-year-old boy, initially classified as having partial epilepsy, who had a typical absence seizure that became focal with second secondary generalization (double generalization). On the basis of these findings his epilepsy was classified as juvenile absence epilepsy and his treatment was changed, resulting in seizure freedom. This is the first report of this unusual electroclinical evolution in a patient with juvenile absence epilepsy. The recognition of this particular pattern allows correct classification and impacts both treatment and prognosis.

Absence seizures in the first 3 years of life: an electroclinical study of 46 cases.

PURPOSE: Early onset absence seizures have been considered a rare heterogeneous group with a poor prognosis. Only few patients may be categorized into well-known syndromes. We have evaluated electroclinical features, evolution, and the nosologic boundaries of early onset absence seizures. METHODS: Forty-six neurologically normal patients with absence seizures associated with bilateral, synchronic, or asynchronic, and symmetric or asymmetric spike-and-wave paroxysms with onset in the first 3 years of life were included. Patients with abnormal neurologic examination and brain imaging were excluded from the study. KEY FINDINGS: In our study, 39 patients met the clinical and electroencephalography (EEG) criteria of well-defined epileptic syndromes. Childhood absence epilepsy was found in 11 patients, benign myoclonic epilepsy in infancy in 18 patients, eyelid myoclonic epilepsy in 4, and epilepsy with myoclonic absences in 6. We did not find clinical and EEG criteria of well-recognized epileptic syndromes in seven children. Nine of 11 patients with simple absence seizures became seizure free. All these patients had normal neurologic and neuropsychological evaluations. Of the 35 patients who had absence seizures associated with myoclonic seizures, 20 became seizure free. Fifteen of 35 children continue having seizures. At the last visit, 20 of these 35 patients had normal neurologic and neuropsychological evaluations, 11 presented with mild mental retardation, and 4 with severe mental retardation. SIGNIFICANCE: Epilepsies with absence seizures of early onset are relatively uncommon. Most of the patients had well-defined epileptic syndromes with a variable evolution. The evolution depended on the epileptic syndromes.

Screening of GABRB3 in French-Canadian families with idiopathic generalized epilepsy.

Mutations in the GABRB3 have been recently associated with childhood absence epilepsy (CAE) in families from Honduras and Mexico. In this study, we aimed to determine the frequency of mutation in this gene in our cohort of families with CAE and other related idiopathic generalized epilepsy (IGE) syndromes. We screened the open reading frame of GABRB3 in 183 French-Canadian individuals with IGE, including 88 with CAE. A total of nine single nucleotide polymorphisms (SNPs) have been identified,five of which are novel. The previously described P11S missense mutation was found in three affected and one unaffected individuals from a French-Canadian family. However, the P11S variant was also found in one of our 190 control individuals of French-Canadian origin, suggesting that this variant is rather a rare polymorphism in this population. Further screening of other IGE cohorts from various ethnic origins would help to confirm the association between this rare functional variant and epilepsy.

[The myelin mutant taiep as a model for abscence crisis]. / El mutante de mielina taiep como un modelo de crisis de ausencia.

BACKGROUND: Taiep rat is a myelin mutant rat with hypomyelination followed by progressive demyelination. This mutant presents cortical discharges with a spindle form, with an ascending and descending phases similar to absence epilepsy. METHODS: Taiep rats were maintained under standard animal room conditions with free access to balanced rodent pellets and tap water. Rats were anesthetized with chloral hydrate under aseptic conditions; three stainless steel screws and a bipolar electrode were implanted in the hippocampus. The signals were amplified, filtered and recorded using a video-EEG Harmonie system (Canada). All data were analyzed using Sensa and Luna modules. RESULTS: Our results showed that taiep rats have spike-wave discharges (SWD) during wake, slow wake sleep (SWS) and rapid eye movement (REM), being statistically higher and longer during awake period than SWS or REM sleep. The systemic administration of pilocarpine, a cholinergic agonist, increased dramatically the cortical discharges with five characteristic seizures patterns and concomitantly decreased the frequency and duration of absence crisis. However, only 80% of the taiep rats tested showed this paroxysm. On the other hand, 100% of control Sprague-Dawley rats showed tonic clonic seizures, indicating some type of resistance to this muscarinic cholinergic drug in taiep rats. CONCLUSIONS: These results showed that the taiep rat, a myelin mutant, is a good model for the electrophysiological and pharmacological study of absence epilepsy, particularly considering its resistance to pilocarpine-induced seizures.

[Absence epilepsy models in rodents]. / Modelos de crisis de ausencia en roedores.

Animal models are a useful tool because it is possible to perform neuroanatomical, electrophysiological and pharmacological studies throughout their development. The most common models for experimental studies of absence seizures are the GAERS (Genetic Absence Epilepsy rat from Strasbourg) and the WAG/Rij (Wistar Absence Glaxo from Rijswik) rats. In WAG/RU rats it has been demonstrated that the perioral region in the somatosensorial cortex shows a zone with hyperexcitability which is the origin of spike wave discharges (SWD). In fact, this cortical area shows modifications in sodium channels which increase the excitability of cortical neurons; for this reason, local application of phenytoin or lidocaine, which block sodium channels, reduce SWD. Ethosuximide decreases and pentylenetetrazol increases SWD in GAERS and WAG/Rij rats. At the Institute of Physiology in the Benemérita Autonomous University of Puebla we have obtained a myelin mutant rat called "taiep", which is the acronym of tremor, ataxia, immobility episodes, epilepsy, and paralysis. This model shows a SWD with higher frequency during awaking periods; the SWD increases with systemic administration of pentylenetetrazol and decreases with ethosuximide. All these findings in animal models are susceptible to be tested in human beings through magneto- and electro-encephalographic recording techniques to discern the source of this type of epilepsy. Thus, in biomedical research, animal models are useful tools to discern the neural and network alterations responsible for the absence seizures, and allow to design of more specific therapeutic options with fewer side effects.

Clinical and electroencephalographic characteristics of a cohort of patients with epilepsy and absence seizures.

BACKGROUND: Epileptic syndromes with absence seizures (AS) possess unique clinical and electroencephalographic (EEG) characteristics. In typical or atypical AS, ictal phenomenology may include various characteristics. Vídeo-EEG monitoring enables findings to be correlated with ictal phenomenology. OBJECTIVE: To evaluate the different AS in a cohort of patients with drug-resistant epilepsy (DRE) based on the International League against Epilepsy (ILAE)'s 2006 classification, to correlate with ictal phenomenology recorded and to apply the Panayiotopoulos criteria. METHOD: This study included patients with criteria of AS followed up at the Epilepsy Clinic. A dual, cross-sectional cohort study was carried out between 2005 and 2008. Patients receiving care in the Epilepsy Program of the HUCFF-UFRJ, who had been investigated by video-EEG and who presented clinical and EEG criteria for absence seizures, typical or atypical, according to the criteria defined by the ILAE, were included in the study, independent of age onset, the review of clinical history, age onset, family history, epilepsy onset and evolution, seizures phenomenology, antiepileptic drugs response and neuroimaging studies were used to classify the patients among the different epileptic syndrome associated to absence seizures. RESULTS: Typical absences were more frequent (71.4%) than atypical absences. Cases of juvenile absence epilepsy were the most frequent (19%) in this series, followed by childhood absence epilepsy (14.4%) and juvenile myoclonic epilepsy (4.8%). In 14 patients (66.67%), diagnosis was modified from focal epilepsy to primary generalized epilepsy. Clinical and EEG diagnosis of absence epilepsy resulted in a dramatic improvement in the control of seizures following modification of diagnosis and indication of an appropriate antiepileptic drug. CONCLUSION: Our results show that typical AS are more frequent than atypical. AS was successfully defined in 10 patients following application of Panayiotopoulos' criteria. The consequent change in diagnosis and therapy resulted in resolution of refractoriness in 9 patients. We concluded that in DRE, AS associated to unusual ictal phenomenology improve dramatically when diagnosed by video-EEG, permitting seizures to be controlled. Clinical and EEG evaluation confirm that myoclonus, automatisms and autonomic disorders are involved and that the consciousness may be affected to different degrees.

Childhood absence epilepsy and electroencephalographic focal abnormalities with or without clinical manifestations.

PURPOSE: We studied the electroclinical features and evolution in patients with childhood absence epilepsy (CAE) associated with electroencephalographic findings similar to those of benign focal epilepsies (BFE) with or without clinical manifestations compatible with these focal idiopathic syndromes. METHODS: Between June 1994 and June 2002, we found 203 (3.6%) patients with typical electroclinical features of CAE among 8285 children with epilepsy. From this population of 203, we found 30 cases (14.7%) that also showed focal abnormalities of BFE on the EEG. Seven of these 30 cases also had clinical manifestations of BFE that preceded the onset of the absences. RESULTS: There were 20 (66.5%) boys and 10 (33.5%) girls. Age at onset of absences ranged from 2 to 10.5 years, with a mean age of 5.5 years. Of 30, 7 had focal clinical seizures as well. Three of seven had seizures characteristic of Panayiotopoulos syndrome (PS), and the other four had seizures compatible with childhood occipital epilepsy (COE) of Gastaut. The focal seizures started between 3 and 7 years of age. In all patients seizures were under control within 2-24 months (mean: 11 months) after onset. The focal discharges disappeared in 26 patients at a mean age of 8 years (range 4-13 years), 1 year after the typical absences had disappeared. In four patients the focal paroxysms are still present. CONCLUSION: The association of two different idiopathic focal and generalized epilepsies in the same patient may be merely coincidental, but a close genetic relationship between both epileptic syndromes might be another hypothesis. Another explanation could be that our series of patients represent a subgroup of CAE.

Myoclonic status in nonprogressive encephalopathies: study of 29 cases.

PURPOSE: Myoclonic status in nonprogressive encephalopaties (MSNE) is characterized by recurrence of long-lasting myoclonic status appearing in infants and young children with nonprogressive encephalopathy. Here, we describe the electroclinical features and evolution of MSNE. METHODS: Between February 1, 1990 and July 31, 2005, 29 patients who met diagnostic criteria of MSNE were enrolled in the study at our department and have been followed up to the present time. RESULTS: Three main subgroups could be identified. The first subgroup of 18 patients presented myoclonic absences and rhythmic myoclonias. These were followed by a brief silent period related to a subcontinuous delta-theta activity involving the central areas, and rhythmic delta waves with superimposed spikes mainly involving the parietooccipital regions and often activated by eye closure. It was found in all children with a genetic etiology. The second subgroup included five patients showing a pattern characterized by inhibitory phenomena associated with a dystonic component and sudden irregular rapid lightning-like jerks. The EEG showed subcontinuous multifocal slow spike-waves, predominating in frontocentral regions. These patients are affected by a cortical malformation or the etiology is unknown. The third subgroup included six children who initially suffered from myoclonic absences. The status was initially characterized by subcontinuous generalized spike-wave-type paroxysms related to rhythmic myoclonia of face and limbs. After 1-3 weeks, the EEG showed sharp theta waves with very slow pseudorhythmic continuous spikes in the central regions and vertex. The etiology was found to be perinatal anoxic injury. CONCLUSION: MSNE should be considered as a new epileptic syndrome in the group of epileptic encephalopathy.

Entropy changes in brain function.

The traditional way of analyzing brain electrical activity, on the basis of electroencephalography (EEG) records, relies mainly on visual inspection and years of training. Although it is quite useful, of course, one has to acknowledge its subjective nature that hardly allows for a systematic protocol. In the present work quantifiers based on information theory and wavelet transform are reviewed. The "relative wavelet energy" provides information about the relative energy associated with different frequency bands present in the EEG and their corresponding degree of importance. The "normalized total wavelet entropy" carries information about the degree of order-disorder associated with a multi-frequency signal response. Their application in the analysis and quantification of short duration EEG signals (event-related potentials) and epileptic EEG records are summarized.

Coexistence of childhood absence and rolandic epilepsy.

The coexistence of absence and rolandic epilepsy is extremely rare. This coexistence has been attributed to either the treatment or an atypical course of the disease. However, for some authors, this issue remains controversial. We report the case of a 9-year-old girl presenting with both absence seizures and focal seizures consistent with rolandic epilepsy.

Occipital intermittent rhythmic delta activity in absence epilepsy.

Occipital intermittent rhythmic delta activity (OIRDA) is considered good prognostic factor in typical absences (TA). We report electroclinical evolution in 14 patients with TA and OIRDA, which performed video-EEG. Seven patients were female; 9 had childhood absence epilepsy and the others did not present electroclinical characteristics for syndromic classification according to ILAE's classification (1989). Pyknolepsy was referred to in 13; TA was the only seizure type in 13; one had generalized tonic-clonic seizures (GTCS) and three had myoclonic jerks during TA. VPA monotherapy controlled seizures in 11, diVPA and ESM, in one each. After seizure control EEG normalized in 10 while in three, spike-wave complexes (SWC) persisted, accompanied by OIRDA in one. Finally in another, seizures were not controlled and SWC and OIRDA persisted. In conclusion, we observed in this series of TA and OIRDA with onset before 10 years, pyknolepsy as common finding and few GTCS. VPA controlled seizures in most cases and EEG normalized in 76.92%. We suggest that OIRDA could be considered good prognostic factor in TA associated with SWC and of epileptiform nature leading to appropriate investigation.

Voxel-based morphometry in patients with idiopathic generalized epilepsies.

Idiopathic generalized epilepsies (IGE) are a group of frequent age-related epilepsy syndromes. IGE are clinically characterized by generalized tonic-clonic, myoclonic and absence seizures. According to predominant seizure type and age of onset, IGE are divided in subsyndromes: childhood absence and juvenile absence epilepsy (AE), juvenile myoclonic epilepsy (JME) and generalized tonic-clonic seizures on awakening (GTCS). The limits between these subsyndromes are not well defined, supporting the existence of only one major syndrome. Visual assessment of routine magnetic resonance imaging (MRI) in patients with IGE is normal. MRI voxel-based morphometry (VBM) uses automatically segmented gray and white matter for comparisons, eliminating the investigator bias. We used VBM to study 120 individuals (47 controls, 44 with JME, 24 with AE and 15 with GTCS) to investigate the presence of subtle structural abnormalities in IGE subsyndromes. VBM was performed searching for abnormalities on gray matter concentration (GMC) between patients groups and controls. Compared to controls, JME presented increased GMC in frontobasal region and AE showed increased GMC in the superior mesiofrontal region. The GTCS group did not differ from controls. There were no areas of reduced GMC with the statistical level selected. Region of interest analysis showed increased GMC in the anterior portion of the thalamus in patients with absence seizures. Our results support subtle GMC abnormalities in patients with JME and AE when compared to controls. These findings suggest the existence of different patterns of cortical abnormalities in IGE subsyndromes.