Perfusion-CT imaging in epileptic seizures

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).

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.

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).

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.