Sex differences exist in stroke epidemiology, acute presentation, treatment, and post-stroke clinical outcome. Neuroimaging can objectively identify potential pathological therapeutic targets and is reflective clinical observations. MCA occlusion (MCAO) is measurable by angiography and the presence of penumbra by diffusion-perfusion mismatch. We present evaluation of sex differences in the Lesion Evolution in Stroke and Ischemia On Neuroimaging (LESION) Project to determine if the probability of MCAO and penumbra depend on sex.
We hypothesize imaging-based evidence is consistent with clinical observations of sex differences in severity and interactions with age and race.
Methods: Patients included in the LESION study were diagnosed with acute ischemic cerebrovascular syndrome, had a brain MRI obtained within 24 hours from last known well and NIHSS>3 or were treated with acute intervention with a pre-treatment MRI. MR imaging included DWI, FLAIR, MRA and PWI, which were co-localized over the entire brain. Patients with M1 or M2 abnormalities were graded as MCAO. The probability of having an MCAO or measurable pathological target was qualitatively evaluated as a function of sex with adjustment for age and race.
Results: Women were more likely than men (all p<0.05) to have a measurable of MCAO (OR [CI’s]) = (1.43 [1.08-1.89]), perfusion defect (1.42 [1.02-2.0]), or a diffusion-perfusion mismatch (1.35 [1.02-1.80]) (Table). This sex difference remained after adjusting for time from onset, NIHSS and age. Women over 70 years are most likely to have a measurable therapeutic target and white women are more likely to have a penumbral pattern than men or non-white women (p<0.05).
Conclusion: This preliminary imaging-based evidence is encouraging that sex differences in imaging biomarkers exist in a representative sample of acute stroke patients. This study shows that sex differences exist not only in the clinical phenotype, but in presence of a biological target.