Epileptic seizures result from paroxysmal, uncontrolled discharges of electricity

from the brain that arise predominantly from the cerebral cortex. It is not surprising therefore that MCDs are often associated with recurrent, seizures, and that these seizures may be difficult, to control. The seizures in MCDs arise as a consequence of either malpositioning of normal cortical neurons or the presence Inhibitors,research,lifescience,medical of abnormal cortical neurons which results in abnormal cortical circuitry and a subsequent imbalance between the excitatory (glutaminergic) and inhibitory (y-aminobutyric acid [GABA]ergic) systems which would normally control electrical discharges Inhibitors,research,lifescience,medical and prevent, spontaneous abnormal electrical discharges and seizures. The precise incidence of MCDs is not known; however, they have been diagnosed with increased frequency since the use of magnetic resonance imaging (MRI) to investigate patients with epilepsy, mental retardation, and congenital neurological deficits.

It is estimated that 25% to 40% of intractable or medication-resistant childhood epilepsy is attributable to MCDs,1,2 and that at least 75% of patients with MCDs will have epilepsy.3 A large number of MCDs have now been identified and classified using embryologie, genetic, and imaging criteria.4 Contrary to previous Inhibitors,research,lifescience,medical assumptions, the majority of these disorders Inhibitors,research,lifescience,medical are now thought to have a genetic basis, although environmental causes such as in utero infection or ischemia are still possible. At the time of preparation of this manuscript, mutations in over 30 genes have been

identified as causes of MCDs. MCD syndromes with specific clinical, imaging, and genetic criteria are being defined and delineated. The aim of this review is to discuss the main types of MCDs encountered in Inhibitors,research,lifescience,medical clinical practice, highlighting those MCDs in which epilepsy is a frequent accompaniment. The different. MCDs shall be discussed in the order in which they arc currently classified, based on the presumed timing of the “insult,” be it genetic or environmental, within the overlapping stages of cortical development. Each MCD shall be discussed in terms of its pathological, Drug_discovery clinical, imaging, and etiological features. MCDs as a consequence of abnormal neuronal and glial proliferation or differentiation Tuberous sclerosis Tuberous sclerosis complex (TSC) is a multisystem syndrome characterized by hamartomata in multiple organ systems, including abnormal proliferation of neurons and glia in the central nervous system. The brain is the most frequently affected organ, but other organs including skin, eyes, heart, and kidneys may be involved.5 Typical brain abnormalities include cortical tubers, Y-27632 2HCL subependymal nodules, and subependymal giant cell astrocytoma.