Abstracts

Rationale: Frontal lobe epilepsy (FLE) represents the second most common form of focal epilepsies, occurring in approximately 20% of patients admitted to epilepsy surgery programs. Valuable information about the location of the epileptogenic zone (EZ) and seizure spread pathways can be obtained by the ictal semiology analysis. In temporal lobe epileptic patients, detailed and systematic observation of behavioral sequences (neuroethology) suggested localizing and lateralizing signs, and the coupling of neuroethology and SPECT data also contributed to the understanding of epileptic networks (Dal-Cól et al, 2006, Epilepsy Behav; Bertti et al, 2010, Epilepsy Behav). Our goal in the current study was to apply the neuroethology method to epileptic seizures in FLE. Methods: We retrospectively studied a group of pharmacoresistant FLE patients successfully operated (Engel's class I; Engel, 1993) in our institution (CIREP/FMRP-USP). Behavioral sequences of each of the seizures, and also one minute of the preictal and postictal periods, underwent statistical analysis with ETHOMATIC software. The results were represented as flowcharts, with frequency, mean duration and statistical interaction between behaviors calculated by a chi-square test (X2 < 3.84, P < 0.05). Approved by Ethics Committee (13528/2010). Results: Eighteen patients, 9 adults (50%), 3 teenagers (16.6%) and 6 children older than 6 years (33.3%) were selected. A total of 120 seizures were observed and three major types were present: tonic (supplementary motor area), focal clonic or complex partial seizures. Sleep preceded the seizure onset in 34 seizures (28.33 %; p<0.001). Behavioral arrest was related with the seizure onset in 39 seizures (32.5 %; p<0.01). A series of behaviors were identified, such as automatisms, behavioral arrest, head deviation or version, dystonic, tonic and clonic postures, among others. Tonic postures were the most common, with unilateral or bilateral expressions, involving the extension or flexion or even abduction of the upper, lower or both upper and lower limbs. Head and eye version, unilateral tonic posture, speech arrest and vocalization had localizing or lateralizing significance. The postictal facial wiping (FW) was observed in 11 patients (61.1%) and with the exception of two, it was not executed exclusively ipsi or contralaterally to the EZ. Conclusions: The neuroethology of FLS detected semiological types, evidenced behavioral sequences and showed items with lateralizing and localizing values, such as the presence of tonic postures, the head and eyes versions, in addition to complex movements. The statistical interactions, frequency and duration of signs proved to be suggestive of potential spread pathways. The pre and postictal analysis detected events previously described in literature, like sleep before the seizure onset, the rapid postictal recovery and also the lack of lateralizing value of postictal FW. Further studies involving a larger sample and also the association with electroencephalographic and neuroimaging data will be coupled by computational approach. Financial support: CNPq, CINAPCE-FAPESP, PROEX-CAPES, FAEPA.