Prevalence and severity of fatigue in adolescents and young adults with acquired brain injury: A nationwide study.

Objective: To investigate the prevalence and severity of fatigue in adolescents and young adults with acquired brain injury (ABI) compared with healthy controls (HCs) and to examine associations between fatigue and gender, age and level of education. Methods: This cross-sectional study included 15-30 year old patients with ABI and a convenience sample of 15-30 year old HCs. All participants completed the 20-item Multidimensional Fatigue Inventory (MFI-20). Pathological fatigue was defined as "General Fatigue" ≥12. Adjusted mean differences between groups were calculated using multivariate analysis of covariance (MANCOVA). The adjusted prevalence proportion ratio (PPRadj) of pathological fatigue was calculated using Poisson regression. Results: The patients (n = 334) had higher scores than the HCs (n = 168) on all MFI-20 subscales with adjusted mean differences ranging from 1.7 to 4.7 and a higher prevalence of pathological fatigue (73% versus 29%), PPRadj 2.7 (95% confidence interval 2.1-3.5). Female patients experienced more fatigue than males on the "General Fatigue" and "Reduced Activity" subscales, while no gender differences were found in the HC group. Patients and HCs with elementary education had elevated scores on the "Reduced Activity" and "Mental Fatigue" subscales. Age was not associated with any of the subscale scores. Conclusion: Young patients with ABI had markedly higher prevalence and severity of fatigue than HCs. Age (15-30 years) was not associated with fatigue. No clear patterns of associations were evident with gender and level of education. Abbreviations: ABI: acquired brain injury; CI: confidence interval; GF: general fatigue; GOSE: Glasgow Outcome Scale Extended; HC: healthy control; MANCOVA: multivariate analysis of covariance; MF: mental fatigue; MFI-20: Multidimensional Fatigue Inventory-20; PF: physical fatigue; RA: reduced activity; RM: reduced motivation; TBI: traumatic brain injury.

Equal effects of typical environmental and specific social enrichment on posttraumatic cognitive functioning after fimbria-fornix transection in rats.

Enriched environment (EE) has been shown to have beneficial effects on cognitive recovery after brain injury. Typical EE comprises three components: (i) enlarged living area providing physical activation, (ii) sensory stimulation, and (iii) social stimulation. The present study assessed the specific contribution of the social stimulation. Animals were randomly divided into groups of (1) a typical EE, (2) pure social enrichment (SE), or (3) standard housing (SH) and subjected to either a sham operation or transection of the fimbria-fornix (FF). The effect of these conditions on acquisition of a delayed alternation task in a T-maze was assessed. The sham control groups were not affected by housing conditions. In the lesioned groups, both typical EE and SE improved the task acquisition, compared to SH. A baseline one-hour activity measurement confirmed an equal level of physical activity in the EE and SE groups. After delayed alternation testing, pharmacological challenges (muscarinergic antagonist scopolamine and dopaminergic antagonist SKF-83566) were used to assess cholinergic and dopaminergic contributions to task solution. Scopolamine led to a marked impairment in all groups. SKF-83566 significantly enhanced the performance of the lesioned group subjected to SE. The results demonstrate that housing in a typical as well as atypical EE can enhance cognitive recovery after mechanical injury to the hippocampus. The scopolamine challenge revealed a cholinergic dependency during task performance in all groups, regardless of lesion and housing conditions. The dopaminergic challenge revealed a difference in the neural substrates mediating recovery in the lesioned groups exposed to different types of housing.