#7203 Examining the role of sleep and dreaming in functional neurological disorder

<h3>Objectives</h3> Patients with Functional Neurological Disorder (FND) frequently report experiencing sleep disturbance. The impact of sleep and dreams on FND symptoms is not well described. This study investigated self-reported characteristics of sleep and dreaming in this group, and their relationship with FND symptoms. <h3>Methods</h3> An online questionnaire was designed by multiple experts in collaboration with FND charities. A total of 373 participants aged over 18 with a self-reported diagnosis of FND were included in the analysis. 67 participants who reported no dream recall were excluded from the dream-related questions. Most participants were female (86.1%). The relationship between FND symptoms, sleep, and dream parameters was evaluated. <h3>Results</h3> The majority (72.6%) perceived their sleep quality ‘over the last 3 months’ as ‘poor’. A large proportion of participants (41%) reported the option of least amount of time asleep (&lt;6 hours). Almost all (92.5%) reported non-positive dream content, with 78.4% experiencing nightmares ‘at least once per week’. Notably, in the period ‘before the onset of FND symptoms’ to ‘the last 3 months’, self-rated good sleep quality decreased by 21.8%, and the frequency of nightmares increased by 14%. With regards to symptom variation, many (45.7%) noticed symptom improvement after a good night’s sleep. Generally, participants reported negative changes related to sleep and dreams, with a large majority (88.2%) describing worsening of functional symptoms when falling asleep, during sleep and when waking up. Just over a quarter (28.4%) of participants noted changes following specific dreams or nightmares, and almost all (99%) were negative changes, such as worsening of seizures, pain, and fatigue. These negative changes were more common in people with poor sleep quality. We noted a high prevalence of obesity in the cohort (41%), which is a known risk factor for sleep apnoea. However, formally diagnosed sleep breathing disorders were rare at rates (7.8%) and much lower than found in a study assessing sleep apnoea in FND (49%) (Nepo&amp;zcaron;itek et al., 2023). <h3>Conclusions</h3> Our findings support the common perception of poor sleep quality, nightmares, and negative dreams in FND patients. Further, we demonstrated that self-reported sleep and dream content may also influence symptoms of FND. Finally, we identify further areas of interest such as the role of specific, or recurrent dreams. There is likely also a huge underdiagnosis of formal sleep disorders, which have established treatments. These findings together may help to encourage more treatments targeting sleep for FND patients. <h3>Reference</h3> Nepo&amp;zcaron;itek J, Dostálová S, V&amp;ecaron;chetová G, Sieger T, Forejtová Z, Nováková L, Galušková K, Milata M, Varga Z, Tanaka H, R&amp;uring;&amp;zcaron;i&amp;ccaron;ka E, Šonka K, Edwards M, Serranová T. Sleepiness and comorbid sleep disorders in functional motor disorders: A comparative study with central hypersomnia. <i>Journal of Sleep Research</i>, 2023;e14098. https://doi.org/10.1111/jsr.14098