Brain Tumours Involving the Areas of the Circadian System Result in Disturbances in Melatonin Secretion, Fatigue and Poor Quality of Life

Background: Sleep disturbances, circadian abnormalities and poor health are often reported in children with brain tumours. The objective of this study was to examine circadian function, sleep pattern, fatigue and mental health in these children. We hypothesized that children with tumours involving the areas of the circadian system have altered melatonin secretion. Design: Cross-sectional study. Methods: 309 children diagnosed with a tumour in the brain or cervical medulla and aged ≤18 years were identified, 174 met the inclusion criteria, and 68 consented to participate. They were divided according to their tumour location into 1) location involving the areas of the circadian system, i.e. diencephalon, pineal gland, brain stem and cervical medulla and 2) other areas. Sleep-wake patterns were assessed by two weeks of sleep diary recordings and actigraphy in 66 and 61 children, respectively. Diurnal saliva-melatonin levels were measured in 51 children. Sleep quality, fatigue and mental health were assessed in 65 children by Children’s Sleep Habits Questionnaire, Strengths and Difficulties Questionnaire and Pediatric Quality of Life Inventory, Multidimensional Fatigue Scale and Generic Core Scale. Results: All children had normal sleep-wake patterns without significant between-group differences. The children with tumours involving the areas of the circadian system had lower melatonin peak levels (p=0.03) and a tendency of lower levels at 00 h and 04 h (all p=0.06). Three patterns of diurnal melatonin profiles were observed: Normal, low peak and phase-shifted peak. In comparison of the two patient groups, more children with tumours involving the areas of the circadian system had melatonin profiles with low peak values (29% vs 13%) and one had phase-shifted peak (3% vs 0%), although not significant. These children were more affected by mental problems (p<0.01), more cognitive fatigued (p=0.03) and had poorer quality of life (p=0.01) than children with tumours located elsewhere. Conclusion: Children with tumours affecting the areas of the circadian system including the diencephalon, pineal gland, brain stem and cervical medulla have altered melatonin secretion, are fatigued, have poor mental health and poor quality of life. Circadian disturbances may adversely affect health and have negative psychological impact.