Perfusion-CT imaging in epileptic seizures.

Introduction: PCT is used in the diagnosis of acute neurological syndromes, particularly stroke. We aimed to evaluate PCT abnormalities in patients with acute epileptic seizures or status epilepticus (SE).
Methods: We collected patients undergoing acute PCT for the suspicion of acute ischemic stroke (AIS), who received a final diagnosis of focal seizures or generalised seizures with a post-ictal deficit, with or without concomitant AIS. PCTs were retrospectively analysed for the presence of hyper- and hypoperfusion, and results correlated with delay from seizure onset, aetiology, type of seizures and the presence of electrical SE.
Results: Half of the 43 consecutively identified patients had regional PCT abnormalities-hyperperfusion in 13 (30%) and hypoperfusion in 8 (19%)-and 4 (9%) had AIS. Among patients with hyperperfusion, six (46%) had a focal deficit during imaging acquisition (two a normal clinical status, one altered consciousness and four ongoing seizure); nine (69%) of these patients had a SE; none had a stroke. All patients with hypoperfusion had focal neurological deficit; three (37%) of them a simultaneous ischemic stroke (in the remaining five, hypoperfusion was considered to be related to the seizure post-ictal phase). In the 22 with normal perfusion, 9 had a focal deficit (10 a normal clinical status, 2 altered consciousness and 1 ongoing seizure); 3 had a SE, and 1 had a stroke. Patients with SE featured a higher prevalence of hyperperfusion (9/13 [69%] vs. 4/30 [13%] without SE, p = 0.00).
Conclusion: In patients with acute epileptic seizures, regional hyperperfusion on PCT may suggest an ongoing or recently resolved SE, whereas hypoperfusion may be due to post-ictal state or simultaneous AIS. These observations might help attributing focal deficits to epileptic seizures rather than stroke, allowing for targeted therapy.