Lina Jeantin

Background and objectives: Although sleep disorders of neurological origin have been documented extensively in cases of autoimmune encephalitis, the impact and clinical significance of sleep disordered breathing remain underexplored. We aimed at determining the prevalence of sleep disordered breathing in autoimmune encephalitis. Methods: A cohort study of consecutive patients with autoimmune encephalitis referred to a tertiary centre for sleep pathology was conducted over a period of 4.5 years. Patients underwent an overnight video-polysomnography with capnography. We investigated the presence of sleep-related breathing disorders, including sleep-related hypoventilation, sleep apnoea–hypopnoea syndrome, central hyperventilation, irregular breathing and excessive sighing. Results: 46 participants with autoimmune encephalitis were included, with a median (interquartile range) age of 60 (40–69) years, of whom three were previously treated with noninvasive ventilation after acute respiratory failure and three were previously treated with positive airway pressure. A total of 26 (56.5%) out of 46 participants had sleep disordered breathing, including 19 (41.3%) out of 46 participants with moderate to severe apnoea–hypopnoea syndrome. Capnography revealed sleep-related hypoventilation in 12 (36%) out of 33 cases, including four (80%) out of five anti-IgLON5, one (25%) out of four anti-glutamic acid decarboxylase-65, one (25%) out of four anti-CASPR2, and six (42.8%) out of 14 antibody-negative cases. Nocturnal stridor was observed in two (40%) out of five anti-IgLON5 cases. Overall, 20 (43%) out of 46 subjects required respiratory support, including positive airway pressure (n=13) and noninvasive ventilation (n=7). Conclusion: More than one-third of participants with autoimmune encephalitis required nocturnal mechanical ventilation. Particular attention should be paid to sleep-related hypoventilation (assessed by nocturnal capnography) in patients with autoimmune encephalitis to guide timely respiratory support and reduce morbidity and mortality.

Electroencephalography (EEG) signal complexity reflects the richness of brain activity and is considered a marker of consciousness. However, its normative values across physiological conscious states using intracranial EEG (iEEG) across cortical areas remain poorly defined. We aimed at referencing iEEG complexity in the human brain and its links with global states of consciousness. We analyzed 5,703 iEEG recordings from healthy cortices in 106 participants during wakefulness, N2, N3, and REM sleep, using complementary markers: Kolmogorov complexity, permutation entropy, and spectral entropy. An independent dataset comprising 474 recordings was used for validation and added data on epileptic cortices and propofol anesthesia. iEEG complexity decreased with reduced consciousness, with the highest values in wake/REM and the lowest under propofol. Complexity was more variable during N2/N3 sleep. Frontoparietal regions exhibited the highest complexity in conscious states. Epileptic cortex showed lower complexity than healthy cortex during wake and REM. A random forest classifier reliably classified sleep stages using complexity markers. Markers of iEEG signal complexity reliably index global states of consciousness. These normative data support the use of complexity as a marker of physiological consciousness, cortical integrity, and sleep-stage detection.

Background: While neurological sleep disorders have been described in auto-immune encephalitis (AE), little is known about sleep-related breathing disorders (SRBD) in patients with AE although it may carry significant morbi-mortality. We aimed to describe the prevalence of SRBD and their management in a cohort of patients with AE. Methods: Cohort study including patients with AE, who underwent sleep interviews and nighttime video-polysomnography (V-PSG) with respiratory setup between 06/2019 and 10/2023. Results: Forty-six patients with AE were included, with a median age of 60 [40, 69] years and a BMI of 25.7 [23, 29]kg/m² at the time of V-PSG recording. Overall, 32 (70%) patients had SRBD. Identified SRBD were: sleep apnea syndrom (SAS) (n:22; 51%) with 15 having moderate/severe SAS (68%), nocturnal hypoventilation (n:12; 36%), irregular breathing (n;8; 17%), stridor (n:2; 4%), central hypoventilation (n=1; 2%) with overlaps between patients. Type of SRBD varied significantly between AE type (cf. figure 1). Nocturnal alveolar hypoventilation, was particularly prevalent in anti-IgLON5 (80%) and seronegative (43%) encephalitis. Positive airway pressure or noninvasive ventilation were initiated in 20 patients (43%). Death or AE relapse occured in 6 (13%) patients. Conclusion: Two-thirds of patients with AE have SRBD. Thorough overnight respiratory assessment during sleep including overnight capnography is needed in all patients with patients with AE erj;64/suppl_68/PA2677/F1 F1 F1

Background: Epidemiologic studies on coronavirus disease 2019 (COVID-19) in patients with multiple sclerosis (pwMS) have focused on the first waves of the pandemic until early 2021. Objectives: We aimed to extend these data from the onset of the pandemic to the global coverage by vaccination in summer 2022. Methods: This retrospective, multicenter observational study analyzed COVISEP registry data on reported COVID-19 cases in pwMS between January 2020 and July 2022. Severe COVID-19 was defined as hospitalization or higher severity. Results: Among 2584 pwMS with confirmed/highly suspected COVID-19, severe infection rates declined from 14.6% preomicron wave to 5.7% during omicron wave ( p < 0.001). Multivariate analysis identified age (odds ratio (OR) = 1.43, 95% confidence interval (CI) = [1.25–1.64] per 10 years), male sex (OR = 2.01, 95% CI = [1.51–2.67]), obesity (OR = 2.36, 95% CI = [1.52–3.68]), cardiac comorbidities (OR = 2.36, 95% CI = [1.46–3.83]), higher Expanded Disability Status Scale (EDSS) scores (OR = 2.09, 95% CI = [1.43–3.06] for EDSS 3–5.5 and OR = 4.53, 95% CI = [3.04–6.75] for EDSS ⩾6), and anti-CD20 therapies (OR = 2.67, 95% CI = [1.85–3.87]) as risk factors for COVID-19 severity. Vaccinated individuals experienced less severe COVID-19, whether on (risk ratio (RR) = 0.64, 95% CI = [0.60–0.69]) or off (RR = 0.32, 95% CI = [0.30–0.33]) anti-CD20. Discussion: In pwMS, consistent risk factors were anti-CD20 therapies and neurological disability, emerging as vital drivers of COVID-19 severity regardless of wave, period, or vaccination status.

Background: Fungal infections of the central nervous system usually affect immunocompromised patients. Primary Aspergillus myelitis has never been described. Report: A 45-year-old immunocompetent male with subacute paraplegia was treated for inflammatory myelitis before clinical deterioration requiring mechanical ventilation. Purulent meningitis preceded the formation of a paraspinal nodule biopsied by neurosurgery. Histopathological analysis revealed the presence of fungal hyphae, and polymerase chain reaction was positive for Aspergillus fumigatus. No cause of immunodeficiency was identified in this patient. Discussion: Primary Aspergillus myelitis may be confused with inflammatory myelitis and should be considered even in the absence of apparent immunosuppression.

Background and purpose: Despite their detrimental impact on the quality of life in autoimmune encephalitis, sleep disorders have not been investigated in anti‐glutamic acid decarboxylase (GAD65) associated neurological syndromes.Methods: Six consecutive adult patients diagnosed with anti‐GAD65‐associated neurological syndromes (four with limbic encephalitis and two with stiff‐person syndrome) and 12 healthy controls were enrolled. Participants underwent sleep interviews and sleep studies including night‐time video‐polysomnography, followed by five daytime multiple sleep latency tests (MSLTs, to assess propensity to fall asleep) and an 18 h bed rest polysomnography (to assess excessive sleep need).Results: Patients reported the need for daily naps and that their cognition and quality of life were altered by sleepiness, but they had normal scores on the Epworth sleepiness scale. Compared with controls, sleep latencies during the MSLT were shorter in the patient group (median 5.8 min, interquartile range [IQR] 4.5, 6.0 vs. 17.7 min, IQR 16.3, 19.7, p = 0.001), and the arousal index was reduced (2.5/h, IQR 2.3, 3.0 vs. 22.3/h, IQR 13.8, 30.0, p = 0.002), although total sleep time was similar between groups (621 min, IQR 464, 651 vs. 542.5 min, IQR 499, 582, p = 0.51). Remarkably, all six patients had MSLT latencies ≤8 min, indicating severe sleepiness. No parasomnia or sleep‐disordered breathing was detected.Conclusion: Central hypersomnia is a relevant characteristic of anti‐GAD65‐associated neurological syndromes.

Background Although vaccination against SARS-CoV-2 is recommended prior to introducing anti-CD20 therapies, limited data are available regarding the evolution of post-vaccinal immunity. Methods This retrospective study compared anti-Spike antibody titres at 6 and 12 months from SARS-CoV-2 vaccination between patients vaccinated before switching to anti-CD20 (‘Switch’) and two control groups: (1) patients vaccinated under disease-modifying therapies (DMTs) other than fingolimod and anti-CD20 (‘Other DMTs’); (2) patients vaccinated on anti-CD20 (‘Anti-CD20’). Anti-Spike-specific T-cell responses were compared between ‘Switch’ and ‘Anti-CD20’ groups. Results Fifty-three patients were included in the ‘Switch’ group, 54 in the ‘Other DMTs’ group and 141 in the ‘Anti-CD20’ group. At 6 months, in the subset of patients who received a booster dose, the ‘Switch’ group had lower anti-Spike titres compared with the ‘Other DMTs’ group (median 241.0 IQR (88.0; 504.0) BAU/mL vs 2034 (1155; 4634) BAU/mL, pConclusions Despite a primary vaccination performed before the first anti-CD20 cycle, our results suggest weaker immune responses at 6 and 12 months and decreased booster efficacy after introducing anti-CD20. Patients vaccinated prior to anti-CD20 introduction might falsely be considered as fully protected by vaccination.