Part of the book: Neuroimaging for Clinicians
Part of the book: Neuroimaging
Part of the book: Cerebral Palsy
Symptoms of inattention and hyperactivity, features of attention-deficit/hyperactivity disorder (ADHD), have been frequently documented in children with autism spectrum disorders (ASDs) and often co-occur. Evidence indicates that 20-50% of children with ADHD meet criteria for ASD, and 30-80% of ASD children meet criteria for ADHD.
Part of the book: ADHD
Early infantile epileptic encephalopathy (EIEE) and early myoclonic encephalopathy (EME) are catastrophic epilepsies starting in the neonatal period. The International League Against Epilepsy classifies both of them as generalized symptomatic epilepsies of nonspecific etiology, characterized by early onset, presence of burst-suppression EEG pattern and serious prognosis. The critical difference lies in their presumed etiologies and the prevailing clinical seizure type at onset: EIEE (known as Ohtahara syndrome) usually manifests with tonic seizures, while EME is mainly associated with myoclonic seizures. However, the distinction between those two pathologies is not always easy due to clinical and etiological overlap. Both mutations in the ARX gene for EIEE (OMIM 308350) and disruption in the neuregulin receptor ErbB4 for EME (OMIM 609304) impair interneuron migration and alter the number of GABAergic interneurons in the postnatal cortex. These findings could explain the occurrence of severe epileptic encephalopathy with a burst-suppression pattern and represent a continuum of progressive pathology. In the present chapter we review the genes involved in EIEE and EME including their possible mechanisms of action, particularly via GABAegic interneurons. Their clinical manifestations are myoclonic or tonic seizures, which represent the expression of the underlying pathology and correlate with degree of brain damage.
Part of the book: Epileptology
The prevalence of autism has increased in an exponential way in the past few years. Many monogenetic mutations as well as copy number variants and single nucleotide polymorphisms have been associated with autism spectrum disorders (ASD), a large proportion of which occur in genes associated with synaptogenesis and synaptic function. However, the increase in appearance of genetic alterations does not explain the etiology of an elevated number of ASD cases. Recent research is now focusing on the role of environmental/epigenetic factors, which by themselves and/or in combination with classical genetic factors, may be the root cause of a large number of ASDs. In this chapter we review the current literature regarding the epigenetic changes involved in ASD, including their possible mechanisms of action such as oxidative stress, altered fatty acid metabolism, mitochondrial dysfunction, DNA methylation and histone methylation (via the one‐carbon metabolism cycle), histone variants, and ATP‐dependent chromatin remodeling. We discuss possible new biochemical markers related to autism as well as new lines of research for therapeutic targets.
Part of the book: Autism