Abstracts

Rationale: Patients with neurofibromatosis type 1 (NF1) may present cerebral tumors and epilepsy. Seizures in NF1 are not so prevalent as in other neurocutaneous syndromes but are more frequent than in general population, especially with focal dyscognitive symptoms and infantile spasms. Most times neoplastic cerebral lesions in NF1 are not related to epileptogenic foci. This may be a prototypical form of neocortical epileptogenesis not related to tumours in the context of a microscopic diffuse brain pathology or seizures may initiate in other extracortical areas such as brainstem and cerebellum. The latter can be present in other structural epilepsies and not only in those with clear genetic etiology. Methods: Description of two children with clinical diagnosis of NF1 and extracortical and brainstem lesions on brain MRI who were submitted to video-EEG with ictal recording in a tertiary epilepsy center in Sao Paulo, Brazil.Results: Both female patients with abnormal developmental milestones acquisition, visual deficit, multiple caf -au-lait macules, freckling in axillary areas and epilepsy. Patient 1: age 8 years (twin brother also with clinical NF1) epilepsy onset at age 3 years, consisting of focal dyscognitive seizures, refractory to drug therapy; interictal EEG revealed right occipital continuous activity and video-EEG, focal seizures originating in right mesial temporal area; brain MRI showed: FLAIR hypersignal globoid lesions in cerebellar peduncles, multiple unidentified bright objects (UBOs) in globum pallidum and cerebellum, blurred cortical grey/white matter junction which was intense in right posterior area and mild in right temporal region. Also asymmetric hippocampi, smaller at right and malrotated at left. Patient 2: age 2 years and 5 months, infantile spasms with hypsarrhythmia at 5 months totally controlled with vigabatrin (150 mg/kg/d); brain MRI revealed: multiple globoid hypersignal focal lesions in cerebellar and cerebral peduncles, pons, midbrain and optic tracts as well as a small dysplastic lesion in right hippocampus. At age 1 year 10 months when withdrawing VGB she started having oculoversive seizures with tonic posture in both arms which improved after association of valproic acid. Video-EEG showed multifocal epileptiform activity and electrographical seizures originated in right centroparietal region.Conclusions: Non cortical lesions in these cases may be surrogate markers of a diffuse pathologic process with focal structural accentuation. Some of these lesions may generate extracortical epileptic seizures such as those in cerebellum and brainstem. Acknowledgements: FAPESP, Instituto Nacional de Ci ncia e Tecnologia em Neuroci ncia Translacional (Brazil).