Introduction
Sleep problems are known to be highly prevalent in pediatric cancer patients and can be caused by biological and/or psychosocial factors such as treatment toxicity, pain, and anxiety1,2. In the short term, sleep problems can lead to distress, cognitive problems, and lower quality of life in pediatric cancer patients2-6. In the long term, it is clear from studies in the general population, that sleep problems are associated with obesity, cardiovascular disease and lower life expectancy2. Sleep also plays a critical role in neuroimmune function and neuronal recovery in pediatric cancer patients. Moreover, fragmented sleep has increasingly been linked to tumor growth in mice7-9. Children with a brain tumor are especially prone to develop sleep problems. Neurosurgery, hydrocephalus, cranial radiation therapy and hypothalamic damage may further contribute to the onset of disturbances in sleeping patterns1,10,11.
Currently, little is known about the prevalence and extent of sleep problems in children with a newly diagnosed brain tumor. Previous studies have mainly focused on patients with all types of cancer diagnoses, causing heterogeneity, or included only patients with hematologic malignancies, the most common type of pediatric cancer12. In addition, most studies focus on sleep at the end of treatment or further into survivorship. Multiple physical, psychological, and therapeutic factors related to the period around diagnosis may impact sleep, such as high levels of distress or the requirement of one or multiple hospitalizations, which are characterized by frequent nightly awakenings13,14. Poor sleeping habits and maladaptive strategies may emerge in this period and persist over the course of the disease. Lastly, sleep is most often assessed by questionnaires only, which provide information on sleep behaviors and consequences of disrupted sleep. However, questionnaires do not measure sleep duration and sleep efficiency, and do not correlate well with polysomnography, the gold standard for measuring sleep15. Some questionnaire studies only assess parent-reported sleep16,17, and this inherently poses some reporting bias. Using several modes of sleep assessment is important as it provides complementary information and contributes to our understanding of sleep15,17,18.
Sleep in the early phases of treatment in pediatric brain tumor patients has thus far not been studied comprehensively, even though this has been strongly recommended by researchers and clinicians6,7,19. Identifying which children are at risk to develop sleep problems is important, in order to provide effective, targeted sleep interventions in a timely manner, with the aim to improve long-term negative health outcomes associated with poor sleep. In adult cancer patients, treatment of sleep problems by using non-pharmacological interventions such as cognitive behavioural therapy has shown favorable results20,21. In contrast, in children with central nervous system tumors, a multicomponent sleep intervention consisting of cognitive and behavioral interventions modestly improved sleep outcomes22. Therefore, more insight into disrupted sleep and contributing factors in the earliest phase after brain tumor diagnosis is needed.
We performed a prospective, observational study into sleep shortly after primary pediatric brain tumor diagnosis. Our primary goal was to describe patient and parent reported sleep problems and daytime consequences, and sleep estimates within three months after diagnosis. Secondly, we defined biological and psychological risk factors of poor sleep. This study is part of a larger longitudinal study into sleep, post-traumatic stress, and neurocognitive functioning (SuSPeCT-study).