Carvalho, Diego Z.

Abstract Introduction Accurate, early diagnosis of isolated rapid eye movement (REM) sleep behavior disorder (iRBD) is crucial given its injury potential and neurological prognosis. We aimed to analyze visual and automated REM sleep without atonia (RSWA) diagnostic thresholds in a current cohort of iRBD patients using submentalis (SM) and individual four limb electromyography (EMG) recordings, including bilateral flexor digitorum superificialis (FDS) and anterior tibialis (AT) during polysomnography. Methods We analyzed RSWA in 20 iRBD patients and 20 age-sex-AHI matched controls who underwent polysomnography between 2017-2021 for phasic burst durations, phasic, tonic, and "any" muscle activity, and automated REM atonia index (RAI). Group RSWA metrics were analyzed with non-parametric comparisons, logistic regression, and receiver operating characteristic (ROC) curves to determine optimal diagnostic cutoff thresholds for iRBD. Correlation explored associative relationships between RSWA metrics, and principal components analysis (PCA) defined determinants of RSWA metric variance. Results All mean RSWA metrics were higher in iRBD patients than controls (p<0.05), except for left and bilateral AT phasic density and duration. RSWA(phasic%, AUC; "any"%, AUC) cutoffs were: SM (6.5%, AUC=90.2; 6.5%, AUC=92.5); L FDS (7.3%, AUC=95.8; 7.3%, AUC=95.8%); R FDS (5.4%, AUC=93.5; 5.8%, AUC=93.2%); Bilateral FDS (10.7%, AUC=96; 15.3%, AUC=95.8); L AT (6.7%, AUC=74.5; 6.7%, AUC=74.8%); R AT (4.7%, AUC=76.8; 4.7%, AUC=76.8%); Bilateral AT (7.5%, AUC=77.5; 7.5%, AUC=77.5%), combined SM/FDS (15.0%, AUC=95.5; 15.1%; AUC=95.8), combined SM/AT (16.5%, AUC=85.8; 21.0%; AUC=88.8),tonic (0.5%; AUC=85.9), and RAI (0.90; AUC=91.4). Phasic burst duration cutoffs were: SM=0.7s (AUC=90.2), L FDS=0.5 s (AUC=83.2), R FDS=0.6 (AUC=85.2), L AT=0.3 s (AUC=65.0) and R AT=0.4 s (AUC=77.0). PCA demonstrated that FDS and combined SM/FDS and SM/AT RSWA metrics best explained RSWA variance and differentiated controls from RBD, while SM and AT alone were less explanatory. Conclusion This study provides evidence for quantitative RSWA diagnostic thresholds applicable in current iRBD populations, and confirms the key importance of FDS to assure accurate iRBD diagnosis. Interestingly, these RSWA diagnostic thresholds are lower than previously determined thresholds, suggesting secular trends toward earlier iRBD detection and heterogeneous disease duration relative to polysomnography acquisition, underscoring the necessity of future large scale prospective, multicenter polysomnographic analyses to determine definitive iRBD diagnostic RSWA thresholds. Support (If Any)

Abstract Introduction Orexin deficiency in cerebrospinal fluid (CSF) was first reported in human narcolepsy in 2001, included in diagnostic criteria for narcolepsy in 2014, and made clinically available at the Mayo Clinic in 2019. The purpose of this publication is to report orexin test utilization and results, and other clinically relevant findings from patients evaluated at Mayo Clinic. Methods We retrospectively reviewed CSF orexin samples and clinical records from patients evaluated at Mayo Clinic from 2019 to 2021. Results A total of 98 internal samples (Rochester, n=56; Arizona, n=25, and Florida, n=17) from 95 patients (mean age 32.4 +/- 16.6 years with 20 %, 52 %, and 28 % of patients < 18, 18 – 40, and > 40 years, respectively, at time of CSF collection; 62 % female) have been submitted for CSF orexin measurement (mean CSF orexin 335.17 +/- 158.3 pg/ml; deficient < 110 pg/ml, n=11, 64 % <=40 years with mean age 32.9 +/- 17.0 years; intermediate 110 – 200 pg/ml, n=8, 100 % <= 40 years with mean age 21.1 +/- 12.8 years; normal > 200 pg/ml, n=79, 57 % <=40 years with mean age 33.5 +/- 16.7). No significant correlation was found between orexin levels, and time of collection (i.e., diurnal variation), gender, or age. Repeat testing was performed on three individuals (ages 10, 14, and 19 years) with a change in category of orexin level found in one patient from an intermediate to a normal level. Conclusion Orexin deficiency was found in 12 % of the patients (64 % of the deficient samples were found at ages <= 40 years). This result may reflect the fact that this test is frequently pursued in clinical patients presenting with inconclusive findings and/or comorbidities. Intermediate orexin levels found in 8 % of the samples (100 % <= 40 years). Although most of the patients tested were female (62.2%) and most were 40 years or younger (72%), no significant correlation was found between orexin levels, and time of collection (i.e., diurnal variation), gender, or age. Support (If Any) none

Abstract Introduction We have previously shown that older adults with excessive daytime sleepiness (EDS) appear to be more vulnerable to longitudinal amyloid PET accumulation before the onset of the dementia. It remains unclear whether this vulnerability is specific to amyloid or extends to other biomarkers of Alzheimer’s disease pathology, or axonal integrity and inflammation, which can also contribute to neurodegeneration and cognitive changes. Methods For this cross-sectional analysis, we identified 260 cognitively unimpaired adults (>60 years old) without neurologic disorder who underwent CSF quantification of AD biomarkers (CSF Aβ-42, p-tau181, p-tau217) along with at least one other biomarker of interest (neurofilament light chain [NfL], IL-6, IL-10, and TNF-α) from the Mayo Clinic Study of Aging – a longitudinal population-based cohort in Olmsted County, Minnesota. CSF biomarkers were available in 251-260 individuals, depending on the biomarker. We fit linear regression models to assess whether the CSF biomarkers were associated with sleepiness as measured by the Epworth Sleepiness Scale (ESS), after controlling for age, sex, APOE4 genotype, BMI, hypertension, dyslipidemia, and OSA diagnosis (by chart review). Results Higher ESS scores were independently associated with higher CSF IL-6 and NfL, but not with the other biomarkers in the whole sample. For every single-point increase in the ESS score, there was a .008 ([95% CI .001-.016], p=0.033) increase in the log of IL-6 and .01 ([95% CI .002-.018], p=0.016) increase in the log of NfL. A sensitivity analysis showed a correlation between ESS scores and log of p-tau/Aβ-42 ratio only in participants with abnormal ratio (>0.023), after controlling for APOE4 (partial r=.27, p=039). Conclusion Our results corroborate previous literature suggesting that higher inflammatory milieu reflected by increased CSF IL-6 is associated with sleepiness. The association between NfL and sleepiness suggests that sleepiness may be related to disturbed connectivity due to axonal damage. Alternatively, NfL may be a surrogate of active axonal injury associated with more disrupted sleep. A correlation between sleepiness and CSF p-tau/ab-42 ratio was only seen in patients with abnormal ratio, suggesting a stronger association between sleepiness and AD pathology as the disease progresses, possibly because AD pathology worsens sleep quality and/or vice-versa. Support (If Any) NIH/NIA

Abstract Introduction REM sleep behavior disorder (RBD) is characterized by disruptive, violent dream enactment behaviors (DEB), necessitating symptomatic treatment to prevent injury and reduce DEB frequency and severity. Melatonin and clonazepam are regarded as RBD therapeutic mainstays, although outcomes data remains limited. We surveyed RBD patients to determine their outcomes following melatonin, clonazepam, and melatonin-clonazepam combination therapy. Methods Mayo Clinic RBD Patient Registry participants received an electronic survey concerning treatment type(s) and dose(s), efficacy, and adverse effects. The primary outcome was treatment efficacy, determined by comparing DEB frequency/severity ratings on a visual analog scale (VAS). Adverse effects severity was assessed by Likert scales. We comparatively analyzed VAS before and after treatment and adverse effects between treatments using non-parametric statistical tests. Results Sixty-eight of 109 patients responded (62.3%; 64 had analyzable data) with a mean age of 67.7 years. Fifty-seven (85%) were men, with mean RBD symptom duration of 13.9 years. Patients receiving each treatment were: melatonin=30, clonazepam=8, and combination=12; 14 received other or no treatment. Baseline VAS ratings were similar between groups. Only melatonin (p=0.003) and combination therapy (p=0.039) improved VAS ratings; clonazepam monotherapy did not improve VAS. Only melatonin monotherapy was reported to lower VAS compared to untreated patients (p=0.02). Optimally effective mean dosages were melatonin 9.95±5.06 mg and clonazepam 0.81±0.48 mg. Patient frequencies reporting one or more moderately-severe side effect(s) were similar between melatonin (15%), clonazepam (7%), and combination therapies (9%). Twenty-five (36.8%) patients had received only one medication trial, while 41.2% required more than one medication. Of these, 15 (22.1%) tried 2 and 13 (19.1%) tried 3 or more treatments. Conclusion Melatonin therapy at an approximate mean 10 mg dosage improved patient-reported DEB frequency/severity on VAS, compared between both previous intraindividual baseline ratings and with untreated patients, while clonazepam monotherapy did not, without differential adverse effects. Clonazepam monotherapy data were limited. These data inform future prospective melatonin symptomatic therapy trials for RBD. Additionally, 41.2% required more than one RBD pharmacological treatment, suggesting a current therapeutic gap and unmet need for future development of biologically-informed, evidence-based symptomatic RBD therapeutics. Support (if any):