Abstracts

Rationale: Since the beginning of the epidemic of Zika virus-associated microcephaly in several countries, especially in Brazil, the clinical picture of this new clinical entity, called Congenital Zika Virus Infection Syndrome (CZVIS) has been delineated. However, most studies have focused on developmental aspects and neuroimaging findings. Epilepsy and electroencephalographic findings continue to be poorly addressed. Our study aimed to analyze the electroclinical profile of patients with CZVIS throughout the first three years of life. Methods: We selected 33 patients (23 with serological confirmation by IgM and 10 considered probable by the serological exclusion of other etiologies and clinical and suggestive neuroimaging patterns) with CZVIS who underwent serial EEG recordings. The clinical evaluation of epilepsy was performed through directed anamnesis, a detailed questionnaire and analysis of cell phone videos made by the parents. The EEGs were analyzed by two independent certified neurophysiologists. Results: The mean age of the 33 patients was 18 months (7 - 31 months). Thirty (91%) had epilepsy. The mean age of seizure onset was 5.5 months (1 - 18 months). The most frequent initial seizure type was epileptic spasms in 9 (30%), generalized tonic in 8 (26.7%), focal clonic in 5 (16.7%), generalized myoclonic in 3 (10%). In two patients (6.7%) there was an association of epileptic spasms and generalized tonic seizures, in one (3.3%) the association of epileptic spasms and generalized myoclonic seizures, and generalized tonic and myoclonic seizures in another one  (3,3%). In one patient it was not possible to establish with certainty the type of seizure (unknown onset). During evolution, epileptic spasms predominated as the most commonly encountered seizure type in 13 children (43.3%), while generalized tonic occurred in 7 (23.3%), focal clonic in 5 (16.7%) and generalized myoclonic in 4 (13.3%). One patient (3,3%) with unknown onset seizures. In 50% of the patients with epilepsy, it was possible to obtain seizure control with monotherapy in 10 (33.3%) and polytherapy in 5 (16.7%). Fifteen patients remain drug-resistant despite polytherapy. Of the drug-resistant patients, twelve (80%) had epileptic spasms as the main seizure type. The most used antiepileptic drugs were valproic acid, vigabatrin, phenobarbital and levetiracetam. Of the 33 cases (including 3 patients without epilepsy), only two (6%) had normal EEGs. Abnormalities of the background activity, such as disorganization, slowing or asymmetries were observed in 22 cases (66.7%), while epileptiform abnormalities occurred in 27 exams (81.8%). Hypsarrhythmia was present in two cases (6%) (suppressed in one of them after use of ACTH). Focal epileptiform abnormality (one or two foci) was the most common interictal pattern in 19 cases (70.4%), whereas the multifocal pattern was seen in five (18,5%) and generalized in three (11.1 %). Conclusions: Follow-up studies of the electroclinical profile of patients with CZVIS show that both clinical characteristics of epilepsy and EEG abnormalities change according to the children's age and degree of central nervous system maturity. Knowledge of these evolution patterns is essential for immediate recognition of the epileptic seizure types and consequently effectiveness of treatment, such as the choice of more appropriate antiepileptic drugs, according to the patient's electroclinical profile. Funding: None