Data from: Can perfusion CT unmask postictal stroke mimics? A case-control study of 133 patients

OBJECTIVE: To study the diagnostic value of volume perfusion CT (VPCT) in
patients with transient focal neurological deficits following and during
epileptic seizures, that mimic symptoms of stroke. METHODS: a
retrospective case-control study was performed on 159 patients that
presented with a seizure and received an emergency VPCT within the first
3.5 hours of admission, after being misjudged to have an acute stroke. The
reference test was a clinical-based, EEG-supported diagnostic algorithm
for seizure. RESULTS: We included 133 patients: 94 stroke-mimicking cases
with postictal focal neurological deficits (“Todd’s phenomenon”, n=67) or
ongoing seizure on hospital admission (“ictal patients”, n=27), and 39
postictal controls without focal neurological deficits. Patients with
Todd’s phenomenon showed normal (64%), hypo (21%)- and hyperperfusion
(14%) on early VPCT. Ictal patients displayed more hyperperfusion compared
to postictal patients (p=0.015). Test sensitivity of hyperperfusion for
ictal patients is 38% CI [20.7-57.7], specificity 86% CI [77.3-91.7],
positive predictive value (ppv) is 42% CI [27.5-58.7], the negative
predictive value (npv) 83% CI [78.6-86.9]. A cortical distribution was
seen in all hyperperfusion scans, compared to a cortico-subcortical
pattern in hypoperfusion (p<0.001). A history of complex focal
seizure and age were associated with hyperperfusion (p= 0.046 and 0.038,
respectively). CLASSIFICATION OF EVIDENCE: This study provides Class IV
evidence that VPCT accurately differentiates ictal stroke mimics from
acute ischemic stroke. CONCLUSION: VPCT can differentiate ictal stroke
mimics with hyperperfusion from acute ischemic stroke, but not postictal
patients who display perfusion patterns overlapping with ischemic stroke.