Neonatal seizures are usually considered of epileptic origin, although some may be generated by non-epileptic mechanisms. Neonatal seizures may be classified by clinical features: focal clonic, focal tonic, myoclonic, spasms, generalized tonic and motor automatisms. The main categories of etiological factors of neonatal seizures include hypoxic- ischemic encephalopathy, central nervous system (CNS) infections, structural brain abnormalities, and metabolic disturbances. Early neuroimaging studies, particularly magnetic resonance imaging (MRI) with diffusion imaging, should show acute diffuse abnormalities consistent with hypoxia/ischemia. Some neonatal seizures result from long-standing disorders. These disorders include cerebral dysgenesis, neurocutaneous syndromes, genetic disorders, or very early onset epilepsy in association with well-defined epileptic syndromes. Clinical examination and seizure characterization are initial points of reference in the evaluation of infants suspected of early myoclonic encephalopathy (EME). Benzodiazepines are frequently used as alternative secondline antiepileptic drugs (AEDs), although more often they are given following phenobarbital and in place of phenytoin.

This chapter talks about the neurocutaneous syndromes such as hypomelanosis of Ito (HI), incontinentia pigmenti (IP), nevus sebaceous (NS) syndrome and unilateral somatic intracranial hypoplasia. Chromosomal mosaicism is recognized as the pathogenic basis of many cases of HI and related disorders. It can explain the protean clinical manifestations of this condition and their often asymmetrical expression. Cerebral lesions of IP patients commonly extend radially through cortical and subcortical zones, involving cortex, subcortical and deep white matter, ependymal and subependymal zones of one or both cerebral hemispheres. Epilepsy usually appears after a variable period of evolution when the subcortical lesions are apparent in the cerebral hemisphere ipsilateral to the facial hemiatrophy. Unilateral hypoplasia of a polymicrogyric cerebral hemisphere, of the brainstem, cerebellum, and of the intracranial arteries on the same side and a hypoplastic hemibody commonly occur.