Abstract
INTRODUCTION: Functional neurological disorders (FND) are conditions marked by disruptions in brain network function without structural abnormalities. Sleep disturbances, though under-researched, are commonly observed in FND patients and may worsen symptoms and overall health. METHODS: This systematic review had been registered prospectively in PROSPERO with the registration number: CRD42023446306. Search of PubMed, MEDLINE, Embase, and Cochrane databases identified 218 articles. After removing duplicates and applying exclusion criteria, 9 studies were included in the final analysis. RESULTS: The analysis showed a significant prevalence of sleep disorders among FND patients, with 58% reporting sleep disturbances, similar to other neuropsychiatric conditions. Studies on psychogenic non-epileptic seizures (PNES) indicated poorer subjective sleep quality and higher insomnia rates compared to epilepsy controls. Limited data on specific measures such as wake after sleep onset (WASO) and Epworth Sleepiness Scale (ESS) scores prevented definitive conclusions. DISCUSSION: This review is the first systematic examination of sleep disorders in FND. The findings reveal a high prevalence of sleep disturbances, especially among PNES patients, correlating with lower quality of life and increased symptom severity. However, the heterogeneity of studies and limited reporting of specific sleep metrics weaken these conclusions. Further research is needed to investigate the direct impact of sleep quality on FND pathogenesis and management. CONCLUSION: Sleep disturbances are prevalent in FND patients and can significantly affect their quality of life. Increased awareness and routine evaluation of sleep in FND patients are recommended. Future studies should explore the relationship between sleep deprivation and FND to develop targeted therapeutic interventions.