Cognitive Fatigue and Processing Speed in Children Treated for Brain Tumours

Objective: The relationship between fatigue and cognition has not been fully elucidated in children and adolescent survivors of brain tumours. The aim of the present study was to investigate the potential relationship between fatigue and cognitive impairments in these survivors, as this group is at risk for both types of deficits. Methods: Survivors of paediatric brain tumours (n = 45) underwent a neuropsychological testing on average 4 years after diagnosis. Mean age at follow-up was 13.41 years. Cognition was assessed with neuropsychological tests, and fatigue with the Pediatric Quality of Life (PedsQL (TM)) Multidimensional Fatigue Scale. Regression analysis, adjusted for cranial radiotherapy and age at diagnosis, was used to investigate the associations between cognitive variables and fatigue subscales. Cognitive variables associated with fatigue were subsequently exploratively assessed. Results: Significant associations were found for cognitive fatigue and measures of cognitive processing speed; Coding: p = .003, r = .583, 95% CI [9.61; 22.83] and Symbol Search: p = .001, r = .585, 95% CI [10.54; 24.87]. Slower processing speed was associated with poorer results for cognitive fatigue. Survivors with the largest decrease in processing speed from baseline to follow-up also experienced the most cognitive fatigue. Survivors expressed more cognitive fatigue compared to other types of fatigue. Conclusions: The association between cognitive fatigue and cognitive processing speed in children and adolescents treated for brain tumours is in concordance with the results previously reported in adults. Some survivors experience fatigue without impairment in processing speed, indicating the need for comprehensive assessments. Moreover, the study supports that fatigue is a multidimensional concept which should be measured accordingly.