ABSTRACT
Symptomatic epilepsies and syndromes are considered to be consequences of known or strongly suspected disorders of the CNS.1 They include both location-related epilepsies, in which seizure semiology or findings at investigation disclose a localized origin of the seizures, and generalized epilepsies, in which the first clinical changes indicate initial involvement of both hemispheres and the ictal EEG patterns are apparently bilateral. They are a heterogeneous group of epilepsies with different pathophysiologic mechanisms, causes, and clinical manifestations, including syndromes of great individual variability. Their diagnoses lie not only in the correct identification of seizure types and clinical and EEG features, but also in the anatomic localization of the structural causes and in their etiology, when known (Chapter 6). Nonetheless, epilepsies symptomatic of structural lesions share some common characteristics, including uncertain prognoses, frequent associations with neurologic and/or mental abnormalities, and, often, some degree of resistance to drug treatment. Factors associated with more favorable outcomes include absence of neurologic and mental abnormalities, a limited number of seizures, the presence of a single type of seizure; absence of tonic, atonic and secondarily generalized seizures and of episodes of status epilepticus; a relatively late onset of seizures (i.e. after the age of 3 years); and absence of secondary bilateral synchrony on EEG. The prognoses for children with epilepsies symptomatic of structural lesions are generally poor and depend mainly on the type, extension and topography of brain abnormalities. Therefore, prognostic studies should be performed on etiologically homogeneous cohorts of individuals. Epidemiologic studies examining the strength of the
association between a probable cause of epilepsy and the time of onset of the condition could provide clues to the major and minor etiologic agents and their potential interaction. Systematic study of the etiologies of epilepsy is the key to prevention. Furthermore, epilepsy, intellectual disability and/or cerebral palsy are often associated in the same child, as a result of the same underlying brain abnormalities. Therefore, prognostic studies should stratify different homogeneous groups that present with only epilepsy, or, concurrent epilepsy and intellectual disability and/or cerebral palsy.
