Impact of lesion metrics and neurological functions on long-term cognitive outcome in childhood stroke

The prevalence of cognitive impairment after childhood stroke is high and various risk factors influence long-term cognitive outcome. Whether and how risk factors are associated with cognitive outcome is still incompletely understood. This study investigated how lesion volume, lesion location and neurological functions at discharge, 6 months and 2 years after childhood stroke contribute to long-term cognitive outcome. This observational study included patients after childhood arterial ischemic stroke. Long-term cognitive outcome (intelligence, processing speed, working memory) was assessed at least one year after stroke (Md = 3.52, IQR = 5.57). Neurological functions were measured using the pediatric stroke outcome measure at discharge, at 6-month and 2-year follow-up. Magnetic resonance imaging at stroke manifestation was applied to analyze acute to subacute lesion metrics (volume & location). 43 patients aged 6-23 years (Md = 6.17, IQR = 7.58) were enrolled in the study. Cognitive functions significantly correlated with lesion volume (processing speed: r = -.423, p = .005; working memory: r = -.478, p = .002). Working memory was worse if the left caudate nucleus was involved (U = 284.5, p < .001, d = 1.43). Long-term cognitive outcome correlated with neurological functions at discharge, 6-month and 2-year follow-up, although effects varied depending on the cognitive domain measured (discharge: r = .449, p = .003; 6-month; r = .509 to .538, p <.001; 2-year follow-up: r = .588 to .744, p <.001). Long-term cognitive outcome was associated with lesion volume, lesion location and neurological functions. Our study adds to the determination of risk factors for long-term cognitive rehabilitation and highlights the need for the combined evaluation of neurological and cognitive outcome.