Abstracts

Rationale: There are some suggestions that treatment of acute ischaemic stroke with IV thrombolysis (rtPA) can be associated with epileptiform activity and seizures. We aimed to compare the frequency of EEG abnormalities and clinical seizures in patients with acute ischaemic stroke treated or not with rtPA. Methods: Prospective study of anterior circulation acute ischaemic stroke patients consecutively admitted to a stroke unit during a period of two years, with a follow-up time of one year. All patients had to be previously independent, have a NIHSS higher than 4 upon hospital admission, an acute ischaemic lesion in brain imaging and no previous history of epileptic seizures. They were submitted to standardized cerebrovascular disease investigation and medical care, during admission and after discharge. Video-EEG was performed with a maximum duration of 60 minutes in different time frames after stroke: in the first 24 to 72h; daily, in the first 7 days; whenever there was clinical worsening; at discharge and one year after. We used the American Clinical Neurophysiology Society EEG terminology, and ASPECTS in the acute brain CT scan performed after the first 24 hours of an isolate middle cerebral artery stroke. Results: A total of 151 patients were included, of which 101 were submitted to IV thrombolysis. A middle cerebral artery infarct was documented in 99 rtPA patients and 49 non-rtPA patients. No differences between treatment groups were found, neither in ASPECTS score [7(4) vs. 5(4)], number of cortical territories of ASPECTS with infarct [5(4) vs. 4(3)], percentage of patients with islands of preserved cortex within the infarct [20.6% vs. 18.8%], nor regarding hemorrhagic transformation [17.5% vs. 18.8%]. In the first EEG, rtPA patients had more often background EEG slowing [43.6% vs. 26.0%, p=0.036]. This difference was no longer observed at discharge [24.0% vs. 19.1%] or one year after stroke [11.8% vs. 10.0%]. No other EEG differences (in the background symmetry, presence of EEG suppression, focal slow wave or rhythmic slow wave activity, periodic discharges or epileptiforme activity) were found. Clinical paroxysmal phenomena during rtPA perfusion were observed in 5 (5%) patients. This occurrence was associated to suppression of background activity in the first EEG. No significant differences between rtPA treated and non-treated patients were found in the frequency of acute symptomatic seizures [13.9% vs. 16.0%] or remote symptomatic seizures [16,7% vs. 14.6%]. Functional prognosis of patients with post-stroke seizures was not different between treatment groups. Conclusions: The frequency of EEG and clinical epileptic phenomena, in patients with anterior circulation acute ischaemic stroke, was similar in patients treated and non-treated with rtPA. Functional prognosis of patients with post-stroke seizures was not influenced by rtPA treatment. Funding: This work was supported by the 2012 Research Grant in Cerebrovascular Diseases (Scientific Promoter: Stroke Portuguese Society (SPAVC) and Sponsor: Tecnifar)