Role of CT angiography in thrombolysis decision-making for patients with presumed seizure at stroke onset

Background and Purpose - The presence of seizure at stroke onset is a contraindication for intravenous tissue plasminogen activator treatment. A significant proportion of these patients' deficits are not attributable to Todd's paralysis and could be attributable to reversible ischemia. Currently there are no established methods of differentiating Todd's paralysis from ischemic stroke/early seizure. We sought to determine whether computed tomographic angiography (CTA) can be helpful in differentiating the 2. Methods - Three hundred and twenty six patients underwent noncontrast CT and CTA for acute stroke at our institution over 3 years (June 2002 to April 2005). Of them, 116 had disabling deficits and presented within 3 hours. We reviewed the clinical data, noncontrast CT, CTA, electroencephalogram and outcome of these patients and identified those who presented with presumed seizure activity at stroke onset ( seizure or altered consciousness at stroke onset). Results - Nine (7.7%) patients had a concern of seizure at stroke onset. Median age 73 years ( range, 31 to 85 years), median National Institutes of Health Stroke Scale (NIHSS) score 12 ( range, 5 to 29). CTA showed proximal middle cerebral artery occlusion in 2 and distal middle cerebral artery occlusion in 3 patients. All 5 of these patients had evidence of infarction on follow-up (stroke + early seizure group-intracranial occlusion present). Three of these patients received intravenous tissue plasminogen activator because they were deemed to have "ischemic tissue at risk". Four patients had normal CT and CTA studies and recovered completely in 24 hours ( Todd's paralysis only group-intracranial occlusion negative). Conclusion - Seizure at stroke onset was relatively uncommon in a consecutive cohort of acute stroke patients. CTA was a useful modality in differentiating Todd's paralysis from early seizure and ischemia by detection of intracranial occlusion and may contribute to decision-making for thrombolysis.