Instabilità del sonno NREM: implicazioni cognitivo-comportamentali in pazienti con Sleep-related Hypermotor Epilepsy (SHE) e Parasonnie NREM

Background: good sleep architecture, particularly of the NREM phase, is fundamental for the development and maintenance of various cognitive functions. A fragmentation in this specific phase could be responsible for the reported cognitive difficulties in patients with Sleep-related Hypermotor Epilepsy (SHE) as perception of non-restorative sleep, daytime sleepiness and negative impact on cognitive functions, showing the fundamental role of frontal lobe in structuring the subject's personality and its processes higher mental. Also NREM sleep Parasomias is characterezed by an instability in this phase which may be responsible for daytime symptoms reported by patients such as excessive daytime sleepiness and mood changes. In this case, cognitive functioning is generally conserved; although patients may report concentration difficulties and decreasing performances attention-demanding task. Our study has as objectives to evaluate the behavioral-cognitive functioning of patients with SHE and NREM Parasomnias and to study the possible role of pharmacological treatments on cognitive functioning in SHE patients. Participants: This cohort study was conducted in the Center for the Diagnosis and Treatment of Sleep Disorders at the University Hospital of Monserrato (Cagliari) between March 2016 and June 2019. We recruited 16 patients, (9 Male and 7 Female, average age 33.56 ± 12.23, average education 12.5 ± 3.10), with SHE video-PSG confirmed. To evaluate the possible role of pharmacological treatments on cognitive functioning, we identified 13 patients in drug treatment with SHE video-PSG confirmed between 2013-2015 (6 M and 7 F, average age 42 ± 14.96, average education 12.38 ± 3.45). We then recruited 11 patients, 3 males and 8 Females with NREM parasomnias video-PSG confirmed (average age 32, 91 ± 10.82, average education 13.55 ± 3.33). To verify statistic differences, we recruited a control group of healthy volunteers matched by age, sex and education with each patient. Materials and methods: a battery of standardized neuropsychological tests was used to explore the cognitive functions as attention, executive functions, visual-constructive and visuo-spatial skills, memory, language and logical reasoning skills. Subjective behavioral questionnaires were administered to evalue quality of night's sleep, daytime sleepiness, comorbidity with other sleep disorders, depressive symptoms and anxiety. Discussion: SHE patients show an implication in executive and memory functions with an inhibiting interference, cognitive flexibility, ability to recover informations based on effective research strategies, verbal and visuo-spatial episodic memory. Behavioral assessment shows an involvement of state anxiety on the initial performance which is reduced as the evaluation proceeds. The perception of “acting" during sleep and the unpleasant sensation in the lower limbs that inevitably affect the affective area, as demonstrated by the presence of depressive symptoms. Compared to the role of antiepileptic therapy on cognitive functioning in patients with SHE, results obtained show an involvement of the verbal episodic memory. Compared behavioral-cognitive NREM Parasomnia profile, in accordance with the literature, the subjects don’t show , an impairment of the cognitive functions investigated, despite the reported attentional difficulties, it was found that all patients with Parasonnie NREM had a positive outcome on the RBD test. Conclusions: results show an executive and memory implication in SHE patients. Presence of a mood deflection confirm the negative impact of nighttime crises on a relational and social level reported by patients. Antiepileptic therapy in SHE could induce positive effects on the cognitive functions, depending on the characteristics of the individual patient. Compared to NREM Parasomnias, it is not possible to assert a cognitive involvement.