Abstracts

Seizure semiology is known to vary as a function of age. Certain seizure types such as spasms are seen mainly during infancy, while other seizure types such as automotor seizures are rare in small children. Differences in seizure semiology according to age have been described in temporal lobe epilepsy with mesial temporal sclerosis (Mohamed et al, 2001) and frontal lobe epilepsy due to cortical dysplasia (Fogarasi et al, 2001). The aim of our study was to analyze seizure semiology and EEG patterns in adults and children under 11 years with lesional frontal lobe epilepsy.
We retrospectively reviewed 249 video-taped seizures from 10 pediatric patients (mean age, 5 years, range 9 months-11) and 10 adults (mean age, 30 years, range 21-58) with intractable lesional frontal lobe epilepsy admitted to the Epilepsy Monitoring Unit for presurgical evaluation. Seizures were classified according to the semiological seizure classification. Localization of the epileptogenic zone within the frontal lobe was based on congruent interictal and ictal EEG findings, seizure semiology and presence of a MRI lesion.
Most frequently seen seizures types included focal motor seizures (with tonic or clonic motor phenomenon contralateral to the lesion), in 2 children and 3 adults; hypomotor/dialeptic(complex partial seizures with arrest of activity without automatisms), in 4 children and 3 adults; and bilateral asymmetric seizures suggestive of activation of supplementary sensorimotor area, in 3 children and 3 adults. Less frequent seizures included primary versive seizures, seen only in 3 adults, and epileptic spasms, seen only in 3 children. Hypermotor seizures were seen in 2 children and 1 adult. Auras were rare, seen only in one adult (epigastric) and one child (somatosensory). Automotor seizures were seen only in 1 adult. Lateralizing signs were seen during seizure evolution in 4 children (mainly Todd[acute]s paresis and late unilateral clonic movements) and 4 adults (mainly Todd[acute]s paresis and postictal aphasia). Generalized ictal EEG patterns in addition to focal patterns were seen in 3 children and 4 adults. MRI in children showed mainly cortical dysplasia (9/10), while MRI lesions in adults included porencephalic cysts due to head trauma, remote hemorraghe or previous tumor resection (5/10) and also cortical dysplasia (4/10).
Seizure semiology differs in children and adults with lesional frontal lobe epilepsy. Although some seizure types (focal motor seizures, hypomotor/dialeptic seizures and bilateral asymmetric tonic seizures) are common in both populations, epileptic spasms are mainly seen in children and versive seizures in adults. Hypermotor seizures not reported in previous studies were seen in pediatric patients, with features similar to the adults. Lateralizing signs during seizure evolution and generalized ictal EEG patterns are equally frequent in both populations. Cortical dysplasia in MRI was more frequently found in children.