Video electroencephalographic diagnosis of epileptic and non-epileptic paroxysmal episodes in infants and children at the pre-school age

The main usefulness of video electroencephalographic (video-EEG) monitoring lies in the fact that it allows proper classification of the type of epileptic seizure and epileptic syndrome, identification of minor seizures, location of the epileptogenic zone and differentiation between epileptic seizures and non-epileptic paroxysmal manifestations (NEPM). In infants and pre-school age children, the clinical signs with which epileptic seizures are expressed differ to those of older children, seizures with bilateral motor signs such as epileptic spasms, tonic and myoclonic seizures predominate, and seizures with interruption of activity or hypomotor seizures, and no prominent automatisms are observed. In children with focal epilepsies, focal and generalised signs are often superposed, both clinically and in the EEG. NEPM may be benign transitory disorders or they can be episodic symptoms of different neurological or psychopathological disorders. NEPM are often observed in children with mental retardation, neurological compromise or autism spectrum disorders, who present epileptic seizures and epileptiform abnormalities in the baseline EEG. It then becomes necessary to determine which episodes correspond to epileptic seizures and which do not. The NEPM that are most frequently registered in the video-EEG in infants and pre-school age children are unexpected sudden motor contractions ('spasms'), introspective tendencies, motor stereotypic movements and paroxysmal sleep disorders.