Abstracts

Rationale: A study in Mexican population found that IGE constitutes 20% of epilepsies. Typical absence seizures (TAS) are a group of IGE with onset before 18-20 years in 65% and are the second leading cause of IGE. We report EEG and VideoEEG of 10 adult patients with epilepsy and TAS emphasizing focal or different findings to those reported in childhood. Methods: Forty-one patients with epilepsy and TAS were identified from January to October 2013. Ten accepted to participate in the study. A descriptive, cross-sectional analytical study; medical history, neurological exam, brain MRI, EEGs and videoEEGs were evaluated. In all patients we performed an 8 hour prolonged videoEEG. Results: Among 171 patients with IGE 41 had AS and 10 accepted to participate. Four males and 6 females mean age 29.6 years. Age of onset for generalized seizures (GS) was 10.9 and for typical AS 11.9; 1 started after 20; 4 (40%) picnoleptic and persisted in 2 (20%). Generalized tonic-clonic seizures (GTCS)in 80% and myoclonus in 60%. All had normal development and exam. None were seizure free. Family history and febrile seizures in relatives was found in 4 (40%) and 3 (30%) respectively. Eight (80%) used a contraindicated AED or one which wouldn't benefit (CBZ 60% and PHT 50%). Three (30%) monotherapy (VPA) and the remaining had an average of 2 AEDs (range 1-3). Two of ten MRI showed mesial temporal sclerosis. Previous EEGs: 27 interictal EEGs were collected with 14 abnormal: dysfunction (2); focal epileptic activity (3) with paroxysms of polyspike slow wave (PSW) and slow wave (SW); focal and generalized epileptic activity but independent. Just 5 had generalized epileptic activity (regular PSW complexes). VideoEEGs: 3/14 ictal (average duration 8.4hrs) with typical absences: 39 total (range 1-25 in each EEG-video); all with normal basal rhythm, average duration of 5.35 seconds. Initial discharge generalized in 28/39 and focal in 11/39. The main clinical features were behavioral arrest (39/39), eye flashing (31/39) and stare (27/39). Regular PSW in 16/39, PS (2-4) in 18/39 and PS (> 4) in 5/39. Recent videoEEG: All were no ictal. Interictally with focal epileptic activity in 40%. All had PSW. During hyperventilation one patient showed focal frontotemporal activity that generalized. Conclusions: The criteria for the diagnosis of IGE and subsyndromes was gathered according to the ILAE, 4 met criteria for AE and 6 for JME. Absences were accompanied by other seizure types, GTCS 80%; agreeing with the 4 risk factors for developing them: male sex, age of onset > 8 years, no response to initial therapy or to monotherapy; thus presence of GTCS in absence epilepsy could predicts drug resistance. Half had focal findings on EEG. The present study shows that characteristics of typical absences in the evolution of IGE in adulthood have distinct patterns from childhood and those may suggest drug resistance and lower probability of remission. Focal findings such as those found in this series are common and should be taken into account to avoid erroneous diagnosis and treatment.