Mental versus physical fatigue after subarachnoid hemorrhage: differential associations with outcome

Fatigue is a major consequence of subarachnoid hemorrhage (SAH), but the specific characteristics are unclear. Our objective was to investigate the nature of post-SAH fatigue (mental or physical) and to determine the relationship with functional outcome in the chronic stage. Also, the possible influence of mood disorders and acute SAH-related factors [SAH type and external cerebrospinal fluid (CSF) drainage] on the presence of fatigue was investigated.

Patients with an aneurysmal SAH (aSAH) or angiographically negative SAH (anSAH) were assessed 3-10 years post-SAH (N = 221). Questionnaires were used to investigate mental and physical fatigue and mood. Functional outcome was examined with the Glasgow Outcome Scale Extended. Between-group comparisons and binary logistic regression analysis were performed.

Frequencies of mental and physical fatigue were 48.4% and 38.5%, respectively, with prevalence of mental fatigue being significantly higher. A two-way anova with SAH type and external CSF drainage as independent variables and mental fatigue as dependent variable showed a significant main effect of CSF drainage only (P < 0.001). Only mental fatigue explained a significant part of the variance in long-term functional outcome (model χ² = 52.99, P < 0.001; Nagelkerke R² = 0.32).

Mental fatigue after SAH is a serious burden to the patient and is associated with impaired long-term functional outcome. Distinguishing different aspects of fatigue is relevant as mental post-SAH fatigue might be a target for treatment aimed to improve long-term outcome.