Fatigue after neurosurgery in patients with a brain tumor: The role of autonomic dysregulation and disturbed sleep.

Background Fatigue is prevalent in patients with a brain tumor and high levels of fatigue persist after neurosurgical tumor resection. The underlying mechanisms are insufficiently understood and this study examines the role of autonomic nervous system dysregulation and objective sleep characteristics in fatigue among post-surgical patients. Methods Patients undergoing craniotomy (N = 52; age 52.1 ± 15.0 years; 44% women) were evaluated at 3 months after surgery (median = 86 days). Fatigue was measured using the Multidimensional Fatigue Inventory. Autonomic nervous system indices were based on 24-h heart rate variability (HRV) analysis. Sleep parameters were measured using actigraphy: total sleep duration, efficiency, onset latency and wake after sleep onset (WASO). Data analyses of this cross-sectional study included correlation and multiple regression analysis. Results Fatigue scores were significantly elevated in tumor resection patients compared to healthy reference norms (p's < 0.05) with no differences between patients with glioma (N = 32) versus meningioma (N = 20). Associations between HRV indices and fatigue were non-significant (r values <0.16, p values > 0.25). Sleep duration was associated with physical fatigue (r = 0.35, p = 0.02), whereas WASO was associated with mental fatigue levels (r = 0.40, p = 0.006). Disturbed sleep measures were associated with HRV indices of reduced parasympathetic nervous system activity in glioma patients but not in meningioma patients. Conclusions Multiple nocturnal awakenings may result in mental fatigue and longer sleep time was associated with physical fatigue, which may reflect compensatory sleep patterns. Future intervention studies addressing sleep quality may be beneficial in treating fatigue in patients following neurosurgery for tumor resection.