Abstract TMP96: Maladaptive Plasticity In Dystonia Following Pediatric Basal Ganglia Stroke: Associations Between Structural Connectivity And Cognitive Functioning

Background: Dystonia is one of the most common movement disorders after pediatric basal ganglia stroke, causing significant disability. It presents several months post stroke suggesting a role of maladaptive neuroplasticity in its manifestation. Children with dystonia show additional difficulties in intelligence (IQ), academics, and cognitive inhibition, beyond those associated with stroke. Objective: To examine structural connectivity in children with post-stroke dystonia and its relationship with cognitive outcomes. Method: A prospective study of children with unilateral basal ganglia stroke and dystonia and healthy controls. Diffusion tensor imaging was used to assess white matter integrity in the cingulum and superior longitudinal fasciculus (SLF) using fractional anisotropy (FA) and mean diffusivity (MD). Participants completed measures of IQ and cognitive inhibition and flexibility. Results: Six children with basal ganglia stroke and dystonia (6 female; Median age= 15.98, IQR= 4.32) and 6 neurotypical controls (3 male; Median age= 18.01, IQR= 5.13) were included. Participants were age-matched within 1-3 years. Hemispheres were matched by dominance such that if the stroke was in the dominant hemisphere the control’s dominant hemisphere was matched to the ipsilateral side and vice versa. Mann Whitney-U tests showed children with dystonia had poorer performance on measures of IQ (U= 0, p=. 002, η 2 = .69) and inhibition (U= 4.5, p= .026, η 2 = .39). FA was lower in the ipsilateral cingulum (U= 5, p= .041, η 2 = .36) and MD was higher in the ipsilateral SLF (U= 32, p= .026, η 2 = .42) in the dystonia participants. Significant associations (p< .05) were found between ipsilateral cingulum FA and IQ (r= .56), inhibition (r= .76), and flexibility (r= .60); contralateral cingulum FA and inhibition (p= .59); ipsilateral SLF FA and inhibition (r= .51) and flexibility (r= .58); and ipsilateral SLF MD and inhibition (r= -.54) and flexibility (r= -.55). Associations between the contralateral cingulum FA and IQ (r= .47, p= .060) and flexibility (r= .50, p= .051) trended to significance. Conclusion: Findings support the hypothesis that post-stroke dystonia reflects maladaptive reorganization after injury that is associated with motor and cognitive outcome.