"S ylvian SEIZURES" is a term proposed for one of the partial epilepsies of childhood, with a relatively elementary symptomatology, yet one that may be confused within the protean group of temporal lobe epilepsy. Their age incidence, the peripheral manifestations, the clinical and electrographic correlates, the mode of propagation, prognosis are all sufficiently homogenous to justify a special subgrouping. The most characteristic peripheral features can be summarized as follows. First, there is almost always some somatosensory involvement, most often of the tongue, but occasionally of inner cheeks, lips or gums, or even of a single tooth, while typical visceral aurae are rare. The sensory involvement is usually contralateral to the electroencephalographic focus but may be ipsilateral. More rarely a vertiginous component may be present. Second, speech arrest, not due to dysphasia but to motor interference, or anarthria. Third, preservation of consciousness, in most cases. Fourth, excessive pooling of saliva. Fifth,