Diffusion imaging of cerebral diaschisis in neonatal arterial ischemic stroke

Abstract

Background: Neonatal arterial ischemic stroke (NAIS) is a leading cause of brain injury and cerebral palsy. Diffusion-weighted imaging (DWI) has revolutionized NAIS diagnosis and outcome prognostication. Diaschisis refers to changes in brain areas functionally connected but structurally remote from primary injury. We hypothesized that acute DWI can demonstrate cerebral diaschisis and evaluated associations with outcome. Methods: Subjects were identified from a prospective, population-based research cohort (Calgary Pediatric Stroke Program). Inclusion criteria were unilateral middle cerebral artery NAIS, DWI MRI within 10 days of birth, and >12-month follow-up (Pediatric Stroke Outcome Measure, PSOM). Diaschisis was quantified using a validated software method. Diaschisis-scores were corrected for infarct size and compared to outcomes (Mann-Whitney). Results: From 20 eligible NAIS, 2 were excluded for image quality. Of 18 remaining, 16 (89%) demonstrated diaschisis. Thalamus (88%) was most often involved. Age at imaging was not associated with diaschisis. Long-term outcomes available on 13 (81%) demonstrated no association between diaschisis score and PSOM categories. Conclusion: Cerebral diaschisis occurs in NAIS and can be quantified with DWI. Occurrence is common and should not be mistaken for additional infarction. Determining additional clinical significance will depend on larger samples with long-term outcomes.