RESUMEN
OBJECTIVES: Autism is a severe neurodevelopmental disorder with a high rate of epilepsy and subclinical epileptiform activity. High physical connectivity on a microcolumnar level leading to epileptiform activity and low functional informational connectivity are assumed in autism. The aim of this study was to investigate nonlinear EEG brain dynamics in terms of synchronization in a group of children with autism spectrum disorders compared to a control group. We expected a lower degree of synchronization in autistic subjects. METHODS: The autistic group consisted of 27 patients with autism spectrum disorders diagnosed according to ICD-10. The mean age of the sample was 7.1 (SD 3.6) years, 14 of them were mentally retarded. Normal EEG was found in 9 patients, epileptiform EEG in 18 autistic patients. Four patients had a history of epileptic seizures, fully compensated in long term. The control group consisted of 20 children (mean age of 8.4, SD 2.3 years) with normal intelligence, without an epileptic history, investigated within the frame of the research program for cochlear implantation. They had normal neurological examination and suffered from perceptive deafness. Normal EEG was found in 17 of the control subjects, epileptiform EEG was in 3 control subjects. We analyzed night sleep EEG recordings from 10 channels (F3, F4, F7, F8, C3, C4, T3, T4, P3 and P4) with the inclusion of sleep stages NREM 2, 3 and 4 in the subsequent analyses. Coarse-grained entropy information rates between neighbouring electrodes were computed, expressing the synchronization between 11 selected electrode couples. RESULTS: Synchronization was significantly lower in the autistic group in all three examined NREM stages even when age and intelligence were taken into account as covariates. CONCLUSIONS: The results of the study confirmed the validity of the underconnectivity model in autism.
Asunto(s)
Trastorno Autístico/fisiopatología , Electroencefalografía , Sueño/fisiología , Niño , Preescolar , Humanos , Discapacidad Intelectual/fisiopatología , PolisomnografíaRESUMEN
The aim of our study was to subcategorize Autistic Spectrum Disorders (ASD) using a multidisciplinary approach. Sixty four autistic patients (mean age 9.4+/-5.6 years) were entered into a cluster analysis. The clustering analysis was based on MRI data. The clusters obtained did not differ significantly in the overall severity of autistic symptomatology as measured by the total score on the Childhood Autism Rating Scale (CARS). The clusters could be characterized as showing significant differences: Cluster 1: showed the largest sizes of the genu and splenium of the corpus callosum (CC), the lowest pregnancy order and the lowest frequency of facial dysmorphic features. Cluster 2: showed the largest sizes of the amygdala and hippocampus (HPC), the least abnormal visual response on the CARS, the lowest frequency of epilepsy and the least frequent abnormal psychomotor development during the first year of life. Cluster 3: showed the largest sizes of the caput of the nucleus caudatus (NC), the smallest sizes of the HPC and facial dysmorphic features were always present. Cluster 4: showed the smallest sizes of the genu and splenium of the CC, as well as the amygdala, and caput of the NC, the most abnormal visual response on the CARS, the highest frequency of epilepsy, the highest pregnancy order, abnormal psychomotor development during the first year of life was always present and facial dysmorphic features were always present. This multidisciplinary approach seems to be a promising method for subtyping autism.
Asunto(s)
Trastorno Autístico/diagnóstico , Encéfalo/anomalías , Imagen por Resonancia Magnética , Niño , Análisis por Conglomerados , HumanosRESUMEN
The aim of the study was to investigate the potential association of epilepsy and EEG abnormalities with autistic regression and mental retardation. We examined a group of 77 autistic children (61 boys, 16 girls) with an average age of 9.1 +/- 5.3 years. Clinical interview, neurological examination focused on the evaluation of epilepsy, IQ testing, and 21-channel EEG (including night sleep EEG recording) were performed. Normal EEGs were observed in 44.4% of the patients, non-epileptiform abnormal EEGs in 17.5%, and abnormal EEGs with epileptiform discharges in 38.1% of the patients. Epilepsy was found in 22.1% of the subjects. A history of regression was reported in 25.8% of the patients, 54.8% of the sample had abnormal development during the first year of life, and 79.7% of the patients were mentally retarded. Autistic regression was significantly more frequent in patients with epilepsy than in non-epileptic patients (p = 0.003). Abnormal development during the first year of life was significantly associated with epileptiform EEG abnormalities (p = 0.014). Epilepsy correlated significantly with mental retardation (p = 0.001). Although the biological basis and possible causal relationships of these associations remain to be explained, they may point to different subgroups of patients with autistic spectrum disorders.
Asunto(s)
Trastorno Autístico , Encéfalo/fisiopatología , Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/epidemiología , Electroencefalografía , Epilepsia , Regresión Psicológica , Adolescente , Adulto , Trastorno Autístico/diagnóstico , Trastorno Autístico/epidemiología , Trastorno Autístico/fisiopatología , Niño , Preescolar , Epilepsia/diagnóstico , Epilepsia/epidemiología , Epilepsia/fisiopatología , Femenino , Humanos , Masculino , Pruebas NeuropsicológicasRESUMEN
A uniquely successful neurosurgical intervention in a four-month-old child suffering from status epilepticus (SE) caused by focal cortical dysplasia is reported. Seizures appeared at postnatal day 10 and culminated as medically intractable focal motor SE three months later. The first MRI scan at postnatal week 2 was inconclusive; electroclinical features typical of malformations of cortical development led to the repetition of MRI at the age of 3 months that confirmed the correct diagnosis. Since all medical trials including thiopental anaesthesia have been unsuccessful in treatment of SE, urgent resection of the right frontal and parietal lobes was performed at 4 months of age. One month later, the child had become seizure-free and her psychomotor development is proceeding well. Histopathological analysis of the resected brain tissue revealed abnormalities typical of the Taylor's type of focal cortical dysplasia. The aim of the report is to encourage considering surgery in selected patients suffering from medically intractable SE early in life.