Correlation between Lesion Location and EEG Findings in Post-stroke Epilepsy

Objectives: Stroke is an important etiological factor in seizures and epilepsies of advanced age. In this study, it was planned to determine the location of lesions and EEG findings in 106 patients with post-stroke seizures, who were followed in the Neurology Department of Uludag University, Faculty of Medicine, retrospectively. Methods: Archive files of 4221 patients diagnosed with epilepsy admitted to the Neurology Department of Uludag University, Faculty of Medicine were screened, and one hundred and six patients, with stroke as the etiology of epilepsy, were included into the study. Information on the demographical features of patients and past histories, stroke type, age at stroke, etiology of stroke, and stroke localization according to neuro-imaging, seizure on set date after stroke, seizure type, and anti-epileptic treatment were all recorded. Neuro-imaging findings were identified according to the arteries involved such as ACA (anterior cerebral artery), MCA (middle cerebral artery), PCA (posterior cerebral artery) and others. Moreover, EEG findings were classified as normal, slow wave activity and epileptiform activity. Data was compared statistically. Results: Sixty-three of 106 patients were male (59%) and 43 were female (41%). Fifty-eight patients (54.7%) had early-onset seizures (first 15 days after stroke), whereas 48 patients (45.3%) had late-onset seizures. Arterial stroke regions were categorized as MCA for 52 patients (49.1%), PCA for 28 patients (26.4%), ACA for 14 patients (13.2%) and others for 12 patients (11.3%). EEG findings were recorded as normal for 13 patients (12.3%). EEG features were corresponding to location of lesions on neuro-imaging in 54 patients (51%), not corresponding in 39 patients (36.7%). Concordance of EEG findings was especially significant in strokes of the MCA region (p< 0.05). Conclusion: EEG findings after infarctions were usually recorded as slow wave activity corresponding to the location of the lesion, and sometimes epileptiform activities can accompany. In cases with stroke, EEG has a limited place; however, if evaluated with clinical findings and neuro-imaging data, EEG is important as a supporting diagnostic test.