Abstracts

Rationale: Unilateral ictal dystonic posturing (DP) occurring in 15-70% of patients is a reliable lateralizing sign in temporal lobe epilepsy (TLE). Diagnostic criteria stringency, epilepsy etiology and mesial as opposed to lateral TLE account for the wide variability. Contralateral DP associated with ipsilateral upper limb automatisms present high lateralizing value. Unilateral ictal akinesia, dystonic automatisms , as RINCH (Rhythmic Ictal Nonclonic Hand) motions and nonmanipulative proximal upper extremity automatisms (NMUEAs), and ipsilateral head turning (HT) are associated symptoms, probably with similar pathophysiology. DP could be the expression of an attempt of the brain to avoid imminent generalization. Predictive value of DP in post-operative seizure-outcome remains controversial. Methods: Four-hundred ninety-one seizures of 151 patients with unilateral mesial temporal sclerosis (MTS), who underwent temporal lobectomy at UNIFESP, with at least one year of follow up, were reviewed without knowledge of clinical data. Patients under 15 years, or with other lesions besides MTS in MRI, were excluded. Surgical outcome with respect to seizures was assessed in the first anniversary of surgery and in the last visit, according to Engel Scale. All patients gave consent for analysis of their seizures for research purposes. Results: DP was observed in 134 seizures (27.3%) of 53 patients (35%), 90% contralateral to the operated side. The mean DP latency from ictal onset was 33.6 s, and DP mean duration was 42.2 s. Upper limb automatisms occurred in 89.5% of seizures. Ipsilateral to DP, ictal akinesia occurred in 31.5%; RINCH in 5%, and NMUEAs in 6.7%. HT occurred in 70.2%, 90% contralateral to DP. RINCH without DP occurred in 22 seizures (6.2%) of eight patients, contralateral to the operated side in 75%. NMUEAs without DP, in seven seizures (2%) of four patients, contralateral in 50%. Seventy-two seizures evolved into secondarily generalized tonic-clonic seizures (14.4%). Sixty-one of these (84.7%) were not preceded by DP, whilst only 11 of them (15.3%) occurred after DP (p=0.03). Considering all seizures with DP, 8.2% evolved into secondary generalization. Regarding seizure outcome, the mean of follow up was 45.6 months (range 12-84). At the first anniversary after surgery, 51.0% of patients without and 45.0% of those with DP were free of all seizures (Engel IA; p=0.5). At last visit, 57 patients were between two and five years of follow up. In this group, 17.5% without (p=0.008), and 22.2% with DP (p=0.63) restarted having seizures. Among patients with more than five years of follow up (n=53), 30.3% without (p=0.01) and 15.5% with DP (p=0.12), restarted having seizures. Conclusions: Unilateral or predominantly unilateral DP occurred in 35% of patients, 90% contralateral to the operated side. RINCH and NMUEAs without DP were less frequently observed, and contralateral to the operated side in 75% and 50%, respectively. DP was associated with a lesser probability of generalization of seizures. Finally, DP was not related to worse surgical outcome.