Abstracts

Rationale: Post-stroke seizures (PSS) affect 10% of stroke patients and account for the majority of epilepsy diagnoses in the elderly. CT perfusion (CTP) is a functional imaging modality with high sensitivity for diagnosis of acute ischemic stroke and is faster and more readily available in emergency settings than MRI. Since CTP is used for early stroke prognostication, it would be ideal for prognostication of PSS. While Cerebral Blood Flow was identified to have a high specificity and a positive predictive value for PSS,¹ there have not been sufficient data on other parameters including mismatch ratio and mismatch volume. We hypothesized that a lower mismatch ratio and volume could lead to a higher likelihood of PSS given the increased area of irreversibly damaged brain tissue.

_x000D_ Methods: This was a retrospective electronic chart review of patients 18 years or older admitted with acute stroke to Temple University Hospital from February 2015 to February 2020. Data was extracted on stroke and PSS diagnoses, CTP, EEG and antiseizure medications. Demographic data was analyzed for patients with ischemic or hemorrhagic stroke who underwent CTP at admission.  Patients with prior history of epilepsy, brain tumor, or traumatic brain injury were excluded. Groups were divided into non-PSS and PSS.
Patients with anterior circulation ischemic stroke were included for analysis of CTP parameters of mismatch ratio and mismatch volume. Continuous variables were compared using Wilcoxon Mann–Whitney U test, and categorical variables were compared using Fisher’s exact test.

Results: Of 400 records reviewed, 35 met all criteria for statistical analysis. The median age  was 73 years (inter-quartile range, 61-85), 63% were female. Demographic data are presented in Table 1. Six patients had PSS (17%). Comparison of mismatch ratio and mismatch volume on CTP between PSS and PSS groups was not significant (Table 2). Cerebral Blood Volume was not consistently reported. Of those who did have PSS, all had partial anterior circulation strokes. In the non-PSS group, 21 had a partial anterior circulation stroke (79%), 2 subjects had total anterior circulation (7%) strokes, 2 subjects had posterior circulation strokes, and 2 subjects had lacunar strokes (7%). One patient out of six in the PSS group (33%) had hemorrhagic stroke, whereas 15% of patients in the non-PSS group had hemorrhagic strokes.

Conclusions: Our study did not demonstrate a significant association of mismatch volume or mismatch ratio on CTP with development of PSS. Limitations of this study included a small sample size, retrospective design and available data on multiple CTP parameters. Our results are consistent with previous findings that anterior circulation strokes and hemorrhagic strokes are associated with PSS. A prospective design with a larger sample size and direct imaging review is suggested to define the role of multiple CTP parameters in PSS prognostication.
_x000D_ Reference:_x000D_ 1. Koome M, Churilov L, Chen Z, et al. Computed tomography perfusion as a diagnostic tool for seizures after ischemic stroke. Neuroradiology. 2016;58:577-584.

Funding: None