Search

Introduction: The perisylvian areas, located around the Sylvian fissure, are constituted by frontal, temporal and parietal brain regions. These are connected forming specialized neural networks and play a primary role in the development of linguistic skills and social cognition. These areas are a possible neuronal substrate of cognitive and behavioral impairments in patients with autism spectrum disorders (ASD)., Aim: To locate and quantify epileptiform activity sources through magnetoencephalography in frontal perisylvian areas in children with idiopathic ASD., Patients and Methods: Sixty-eight children with idiopathic ASD were studied by magnetoencephalography. The children were classified into two groups: a group of 41 children with autistic disorder and a combined group of 27 children with Asperger syndrome and children with pervasive developmental disorder not otherwise specified. The sources of magnetoencephalografic epileptiform activity detected in the frontal perisylvian were localized and quantified., Results: The amount of epileptiform activity in frontal perisylvian region was significantly higher in children with autistic disorder., Conclusions: The amount of epileptiform activity in frontal perisylvian areas differed significantly between children with autistic disorder and those with Asperger syndrome and pervasive developmental disorder not otherwise specified.

Autism spectrum disorders (ASD) have been associated with physiopathology in cerebral organization and function. Electroencephalography is a noninvasive technique that provides information about brain electrocortical activity. Electroencephalographic (EEG) studies using power spectra have documented differences associated with ASD, particularly in frontal areas that have been functionally linked to cognitive functions that are disrupted in individuals with ASD. Furthermore, EEG studies confirm coherence changes in individuals with ASD. Many studies have also reported high rates of interictal epileptiform EEG abnormalities in children with ASD with or without history of seizures. Several polysomnography studies have confirmed the presence of disrupted sleep architecture in children with ASD. Polysomnographic abnormalities include reduction of REM sleep, longer sleep latency, increased arousals, lower sleep efficiency, increased stage 1 sleep and decreased slow wave sleep as well as decreased density of spindle activity. The objective of this review is to present research data on the EEG findings in patients with ASD, with emphasis on their power EEG, coherence EEG, epileptiform EEG abnormalities and sleep disorders.

Introduction: Recent studies have investigated functional and structural brain connectivity in patients with autism spectrum disorders (ASD). Neuroimaging and electroencephalographic studies have found evidences suggesting that connectivity patterns are altered in ASD., Aims: To review recent works from structural and functional neuroimaging and neurophysiological studies, and to provide a summary of advances in research implicating disordered connectivity in ASD., Development: Functional findings reveal that patients with ASD have deficit in long-distance connections (under-connectivity), with a most prominent deficit in fronto-posterior connections. With regard to structural connectivity there is evidence of disruption to inter-hemispheric white matter structures. Less functional studies reveal that patients with ASD also have an excess of local connections (over-connectivity), but findings from structural studies are considerably more inconsistent., Conclusions: The converging findings of functional connectivity abnormalities and white matter abnormalities in autism suggest that alterations in neural connectivity and the communication between different brain regions may be involved in behavioral and cognitive deficits associated with autism.

INTRODUCTION. The steady increase in the number of children with autism spectrum disorders, has led to a better social awareness but also to a higher demand for specific interventions. This has questioned what the most appropriate and effective procedures for detection, diagnosis and treatment are. AIM. To review different approaches and classifications of interventions with individuals with autism spectrum disorders based on scientific evidence. DEVELOPMENT. According to the latest revisions, there are three types of classifications to categorize evidence-based interventions: practice-based intervention, comprehensive models of treatment and drug treatments. There are difficulties in comparing results of different methods of intervention, however, some common elements to prove their effectiveness have been identified. CONCLUSIONS. All intervention models should include functional communication skills, meaningful learning, carried out in various contexts, addressing challenging behaviors through positive behavioral support, promoting activities with peers and emphasize the role of parents in the planning and implementation of the objectives.

Electroencephalographic studies of subjects with autism spectrum disorders (ASD) provide evidences of brain functional aspects in this pathology. Mu rhythm can be reactive in normal population (mu suppression) to both self-movements and to movements performed by others. These reactivities are considered to be related to mirror neurons activity. Subjects with ASD show significant mu suppression to self-movements but they fail to react to the movements performed by others. These findings support the hypothesis of a dysfunctional mirror neurons system in individuals with ASD. Moreover, dysfunction of mirror neurons would be related to social and communicative impairments, cognitive deficits and impairment imitation skills associated with ASD.

Introduction and Development: Impairments in language and communication are a defining feature of autism spectrum disorders. There is significant variability in linguistic abilities in autism spectrum disorders. They have difficulties with certain aspects of language such as semantics functions, syntax, prosody and phonology, although the most evident language deficits concern to pragmatics functioning. These language difficulties can cause serious problems in social interaction., Conclusions: The neural bases underlying this failure to develop language are unknown. Several functional and structural imaging studies have identified irregularities in language-related regions in autism spectrum disorders, such as morphometric differences in Broca's area and Wernicke's area, and patterns of reduced or reversed laterality in frontal and temporal cortex. There is also decreased functional connectivity between anterior and posterior language regions.

Introduction and Development: Autism spectrum disorders (ASD) are characterised by the alteration of three basic areas of behaviour, qualitative alterations in reciprocal social interaction, qualitative alterations in communication and patterns of behaviour, and stereotyped, repetitive and restrictive activities and interests. Specific language impairment (SLI) is a disorder in which language is slow and retarded with respect to the patient's chronological age, and which is not related to a sensory-auditory or motor deficit or to a pervasive developmental disorder. In both disorders, epilepsy has an important role. Dr. Muñoz Yunta's researches were focused in studying ASD and SLI using magnetoencephalography in order to look for epileptiform activity in precise cerebral areas., Conclusions: Patients with ASD showed specific epileptiform activity predominantly distributed in the perisylvian areas. In patients with Asperger's syndrome, epileptiform activity was mostly found in the right hemisphere. In patients with autism, no lateralized epileptiform activity was observed, although there was predominant activity in the left hemisphere. Subclinical epileptiform activity was found in the perisylvian areas in patients with ASD. Patients with SLI displayed epileptiform activity in the frontal and middle temporal regions of both hemispheres. Magnetoencephalography can be used to distinguish between patients with ASD and patients with SLI.

Objective: To provide further data around magnetoencephalographic (MEG) findings in early-onset autism spectrum disorders (ASD)., Methods: Thirty-six children (mean age 7 years) diagnosed of PDD (DSM-IV, ICD-10) were studied. There were 22 children with autistic disorder, 9 with Asperger's syndrome, and 5 with pervasive developmental disorder not otherwise specified (PDD-NOS). According to the Childhood Autism Rating Scale (CARS), the autistic disorder was mild to moderate in 11, and severe in 11. Neuroimaging studies using three-dimensional MRI as well as simultaneous MEG-EEG and fusion techniques through magnetic source imaging (MSI) were performed, with the aid of anesthesia in non-cooperative patients., Results: Most patients had no EEG abnormalities. All ASD children showed common specific abnormalities in the shape of low amplitude monophasic and biphasic spikes (isolated or short bursts) as well as acute waves, predominantly distributed in the perisylvian areas. In Asperger's syndrome, epileptiform spikes were mostly found in the right hemisphere. No lateralized epileptiform activity was observed in non-Asperger's autistic patients., Conclusions: MEG epileptiform activity is frequently documented in children with early-onset ASD., Significance: Subclinical epileptiform activity is present especially in the perisylvian regions for many patients with ASD.

Introduction: The rate of epilepsy in autism is higher than in other developmental disorders and estimates point to a frequency range of between 7% and 42%. Between 40% and 47% of autistic children suffer from clinical epilepsy. Onset of epilepsy may occur at any age., Development: During the ontogenesis of the nervous system, if the maturing process is upset by some epileptogenic phenomenon, the consequences on the consolidation of the emerging cognitive functions can be severe. Epileptiform discharges can occur although clinical seizures are absent, but nevertheless they still have an effect on the maturing process. Between 10% and 50% of autistic children undergo a regression of acquired behaviour following a period of normal development. The absence of clinical seizures during regression does not rule out the epileptogenic origin of the regressive process., Conclusions: The relation between pervasive developmental disorders and epilepsy, epileptiform activity and subclinical seizures can be explained from a neurobiological point of view, on the one hand, by an imbalance between the excitatory system -glutamate- and the inhibitory system -gamma-aminobutyric acid (GABA)- in key points in the cerebral cortex and, on the other, by means of molecular genetic studies and studies of candidate genes (FOXP2, WNT2, subunits of GABA receptors, neuroligins, ARX, SCN1A, SCN2A, MECP2, CDKL5 and DLX5).

Introduction: Pragmatics refers to the social use of language; its precursors are already present during the process of maturing, during the preverbal stage, and become manifest when the child starts to point and to share his or her attention with another person. In cases of specific language impairment (SLI) and autism spectrum disorders (ASD) it can be altered to varying degrees., Patients and Methods: Due to the difficulties involved in diagnosis from a clinical point of view, we carried out a study by means of magnetoencephalography (MEG) on a series of 11 patients who had SLI and another series of 9 patients with ASD, in order to determine whether MEG is capable of distinguishing these diagnoses., Results: Patients with SLI displayed pathological activity in the frontal and middle temporal regions of both hemispheres. Patients with ASD showed pathological activity in the perisylvian area. Expressive-receptive SLI with pragmatic language disorder showed pathological activity that was similar to that seen in autism., Conclusion: MEG can be used to distinguish between SLI and ASD by studying the epileptiform activity that occurs in pervasive developmental disorders. MEG helps us to understand the continuum that exists between SLI or expressive-receptive SLI and autism.

Introduction: Autism spectrum disorders cover a continuum of disorders ranging from severe autism to mild autism and Asperger's syndrome. They are considered to be a subgroup of the pervasive development disorders and are characterised by the alteration of three basic areas of behaviour, qualitative alterations in reciprocal social interaction, qualitative alterations in communication and patterns of behaviour, and stereotyped, repetitive and restrictive activities and interests. These alterations are expressed to a greater or lesser degree depending on the level of severity of the disorder and can be detected and quantified by clinical instruments such as the ADI-R (Autism Diagnostic Interview-Revised) and the CARS (Childhood Autism Rating Scale). AIMS. Our aim was to establish a relationship between the specific behavioural characteristics of autism (evaluated by ADI-R and CARS) and brain structures and functions., Patients and Methods: The sample was made up of 10 subjects (9 boys and 1 girl) diagnosed with pervasive development disorder., Results: We obtained statistically significant Spearman correlations between the ADI-R item restricted, repetitive and stereotyped behaviour patterns and the area of the right inferior precentral gyrus. A positive correlation was also found between the item for abnormality or apparent deviation in development before the age of 36 months and the right supramarginal gyrus area, while the correlation was negative between the former and the left postcentral gyrus. There was also a significant correlation between the number of perisylvian areas and epileptiform activity and qualitative incapacity in communication on the ADI-R, and some items on the CARS with areas of the perisylvian zone., Conclusions: Our findings confirm the relation between functional alterations of the different areas that make up the perisylvian region and the distinct behavioural features that define and characterise autism.

Introduction: Specific language disorder (SLD) is defined as a disorder in which language is slow and retarded with respect to the patient's chronological age, and which is not related to a sensory-auditory or motor deficit or to a pervasive development disorder; in other words, structural and functional neurological developmental disorders must be excluded. After many studies and attempts to reach an agreement, specific language disorders have been broadly classified into two groups: specific expressive language disorder and specific receptive-expressive language disorder., Aims: Our objective was to study SLD using magnetoencephalography (MEG) in order to look for epileptiform manifestations in precise language areas., Patients and Methods: We studied a sample made up of 11 patients with SLD, one of whom had Landau-Kleffner syndrome and one with cryptogenic-type SLD. The criteria used were age-dependent autism exclusion tests and specific language tests for SLD. The MSI technique was carried out on all the patients, by magnetic resonance and MEG., Results: A characteristic pattern is obtained for SLD in the form of irregular spike and polyspike-wave discharges in bilateral frontal channels. The dipoles were situated mainly in the left perisylvian areas., Conclusions: The study of specific language disorders using MEG enables us to identify the SLD included in a proposed classification as primary-type specific language disorder, cryptogenic-type specific language disorder and secondary-type type specific language disorder, like Landau-Kleffner syndrome.

Introduction: We understand the term ontogenesis to mean the process that begins from the moment the ovule is fertilised up to the second year of postnatal life, which is a process that plays a key role in the organisation of the central nervous system., Development: In this paper we describe the stages of micromaturation (glial cell proliferation, neuronal migration, synaptogenesis, selective apoptosis and general myelination) and the theories of neuronal plasticity are also explained., Conclusions: The best known ontogenic process is the acquisition of motor maturity, while other areas such as the social and cognitive dimensions are less well known, and this would explain how autistic spectrum disorders remain undetected in the early stages. The somatogram is a valuable tool in the process of maturing that constitutes the foundation for understanding how the cognitive brain is constructed.

Introduction: Autistic spectrum disorders (ASD) is a term that is not included in DSM IV or in ICD 10, which are the diagnostic tools most commonly used by clinical professionals but can offer problems in research when it comes to finding homogenous groups., Development: From a neuropaediatric point of view, there is a need for a classification of the generalised disorders affecting development and for this purpose we used Wing's triad, which defines the continuum of the autistic spectrum, and the information provided by magnetoencephalography (MEG) as grouping elements. Specific generalised developmental disorders were taken as being those syndromes that partially expressed some autistic trait, but with their own personality so that they could be considered to be a specific disorder. ASD were classified as being primary, cryptogenic or secondary. The primary disorders, in turn, express a continuum that ranges from Savant syndrome to Asperger's syndrome and the different degrees of early infantile autism. MEG is a functional neuroimaging technique that has enabled us to back up this classification.

Savant syndrome is currently still very mysterious, yet, thanks to the progress made in neuroimaging studies and especially MSI (Magnetic Source Imaging) techniques, a little more is now known about it. The theory, formulated many years ago, about damage to the left hemisphere of the brain has been supported by functional neuroimaging. Its relation to developmental disorders or to autism spectrum disorders is far more justified today and can be explained on the basis of its neuropathology. We present a study based on a review of the scientific literature concerning the syndrome, from the first time it was described back in 1789 by Benjamin Rush up to the present day. We comment on its epidemiology and positive clinical manifestations, involving brilliant artistic talent and dazzling memory, but also the negative aspects suffered by these autistic patients. The most important theories are discussed together with the clinical coincidence with frontotemporal dementia and the responsibility of the right hemisphere when there are alterations in the contralateral hemisphere. The latest contributions made by Positron Emission Tomography and magnetoencephalography will be discussed and a mini-video of a personal case will be projected.

Autism is a rare disease, but is currently in vogue. An incidence of 1/1,000 has been estimated for early childhood autism, but in autism spectrum the incidence can reach 30/1,000. The clinical characteristics of autism are cognitive language disorders, lack of social interaction, obsessive behaviours with stereotypic movements and epilepsy. For some authors it is an associated symptom while for others it is a cardinal symptom of the disease. Epilepsy in autism, as an association, was reported as early as 1944 by Leo Kanner, in describing his initial work involving 11 cases and how one of them suffered from epilepsy. In 1960, the prevalence of epilepsy among autistic patients was evaluated and found to be much higher than in the normal population. The figures differ from author to author, but really they depend on age: the higher the age, the greater the prevalence of epilepsy. It was in fact this detail that drew our attention to this issue, and triggered the first questions in our research into autism and epilepsy. The series vary from 4 to 86%, depending on the methodology used to confirm the epilepsy. In our casuistics, between the ages of 1 and 18 years, 20% of these children with autism spectrum disorders suffer some kind of epileptic seizures, and 80% suffer what other researchers call subclinical seizures . In this paper, the symptomatology of the most important subclinical seizures that have been observed in these children is presented; the diseases associated with autism are commented on; the concept of primary and secondary autism is discussed; we explain why seizures occur in autism and their consequences as a neurodevelopmental disorder, and we put forward an interesting hypothesis within our general theory of autism. We also comment on the importance that the use of functional magnetic images in the study of autism has in our research.