Examining the Relationships Among Motor, Cognitive, and Mental Health Outcomes after Pediatric Arterial Ischemic Stroke

Pediatric arterial ischemic stroke (AIS) is an important cause of neurological disability in children with motor, cognitive, and behavioural sequelae. Motor impairments are one of the most common adverse outcomes after pediatric AIS, yet little is known about the impact of motor functioning on neuropsychological functioning. This dissertation consists of three studies examining relationships between motor functioning and neuropsychological outcomes after pediatric AIS. Study 1 examined relationships between motor functioning assessed with the Pediatric Stroke Outcome Measure at two timepoints and intellectual abilities. Results showed that motor functioning assessed during early recovery was associated with aspects of intellectual functioning, whereas later motor functioning was not. Different patterns of associations between motor functioning and intellectual abilities were observed in perinatal and childhood AIS groups. Features associated with poor motor outcome were combined cortical+subcortical lesions, hemiparesis, seizures, and utilizing rehabilitation services. Studies 2 and 3 focused on children with acquired dystonia, a movement disorder characterized by involuntary muscle contractions, after AIS involving subcortical regions. Study 2 compared symptoms of anxiety and depression between children with subcortical AIS, with and without dystonia, as well as associations among motor functioning and cognitive and mental health outcomes. Results supported the presence of greater levels of symptoms of anxiety and depression in children with post-stroke dystonia. There were no significant associations between motor and neuropsychological outcomes in the dystonia group, whereas motor and cognitive outcomes were associated in the no dystonia group. Study 3 examined whether there were differences in infarct characteristics on acute neuroimaging between children with and without dystonia and subcortical AIS. There was a significantly higher proportion of children with dystonia with lesions involving the putamen, caudate nucleus, and anterior limb of the internal capsule. More children with dystonia had severe cortical involvement and infarct volumes were significantly larger. Regression analyses showed involvement of the putamen significantly predicted dystonia and intellectual outcome. Overall, results support an association between motor and neuropsychological functioning after pediatric AIS that may be related to maladaptive neural reorganization involving cortico-subcortical networks. Clinical implications and suggestions for future research are discussed.