Dredla, Brynn K.

AbstractThe immune system and sleep are inextricably linked in both health and pathological conditions. Tightly regulated neuroimmune processes are critical for the physiological maintenance of healthy sleep. Reciprocally, sleep disturbances can detrimentally affect immune homeostasis and predispose to increased risk of autoimmune conditions, which themselves are bidirectionally associated with a higher risk of sleep disturbances. Autoimmune diseases of the central nervous system (CNS), particularly conditions that affect neuroanatomical regions involved in sleep homeostasis and nocturnal respiration, are associated with an increased risk sleep disorders that may impact diagnosis, clinical course, and management. This review summarizes the bidirectional relationship between sleep and immunity and highlights several exemplar autoimmune conditions of the CNS that include sleep disorders as a consequence or diagnostic feature of the disorder.

Abstract Introduction Quantitative rapid eye movement (REM) sleep without atonia (RSWA) recorded during polysomnography (PSG) represents loss of normal REM sleep atonia. RSWA is the neurophysiologic signature of REM sleep behavior disorder (RBD). Visually scored RSWA is a candidate biomarker for synucleinopathies. However, visual RSWA scoring requires expert scoring, limiting widespread application. We comparatively analyzed RSWA in DLB and iRBD using the automated Ferri REM Atonia Index (RAI). Methods We quantitatively analyzed the RAI in 17 DLB and 20 iRBD patients, compared to 20 controls using Hypnolab Software for Sleep Analysis (SWS Soft, Colognola ai Colli, Italy). PSG data were converted to European Data Format (.EDF), and the submentalis surface electromyogram (EMG) signal was notch-filtered at 60 Hertz and rectified. Automatically calculated RAI scores were comparatively analyzed across groups (DLB, iRBD, controls) using Kruskal Wallis H tests for group comparisons, and regression analyses determined relationships between diagnosis, age, and sex. Logistic regression ROC determined optimal RAI for distinguishing iRBD from DLB. When interpreting RAI, lower values represent greater amounts of RSWA, and higher values represent more normal REM atonia. Results Median age was no different between DLB (72.6 years), iRBD (69.4 years), and controls (68.0 years). The DLB group consisted of 16 men and one woman, the iRBD group had 18 men and 2 women, and controls were comprised of 16 men and 4 women. Median RAI was lowest in DLB (0.32), intermediate in iRBD (0.84) and highest in controls (0.96), indicating a gradient in RSWA amounts from DLB patients (highest) to controls (lowest). Regression demonstrated diagnosis independently predicted RAI, controlling for age and sex (adjusted R2=0.64, p=0.0001). The RAI that optimally distinguished iRBD from DLB was 0.48 (specificity 85%, sensitivity 76%, AUC=0.88). Conclusion The RAI demonstrated a clear gradient throughout the Lewy body spectrum; highest (indicating lowest RSWA amounts) in controls, intermediate in iRBD, and lowest (indicating greatest RSWA) in DLB. The RAI is a promising, time efficient and broadly applicable candidate biomarker for DLB and iRBD. Automated quantitative RSWA could be a valuable tool for deep phenotyping throughout the Lewy body disease spectrum. Support (if any) This study was supported by: U01NS100620, R34AG056639, U19AG071754, and P30AG62677.

Abstract Introduction Restless legs syndrome (RLS) is a common disorder of unpleasant sensations during inactivity, an urge to move the legs, and hyperarousal. The pathophysiology is incompletely understood. Treatments are not always successful or carry side effects. Methods (Case Report) Results A 45-year-old woman presented with over a decade of RLS and sleep-onset insomnia. The diagnosis was based on the International RLS Study Group criteria. The severity was assessed by the nightly occurrence and Insomnia Severity Index (ISI) of 25. Interfering neurologic or sleep disorders, medications, and abnormal blood work were ruled out. Different dopamine agonists resulted in augmentation. Caffeine was stopped. Polysomnography revealed periodic limb movement with sleep fragmentation. Gabapentin was partially effective and poorly tolerated at high doses, but continued at 600 mg. While using Dextromethorphan (DXM) for an upper respiratory infection, the patient found dramatic improvement of her RLS symptoms. Independently, she discontinued Gabapentin, and continued DXM 30 mg for 6 months, with consistent improvement. ISI decreased to 10. Ultimately, considering its expense, DXM was tapered, and Tramadol initiated. The pathophysiology of RLS is partially understood. Studies showed abnormalities in iron regulation, low adenosine tone, enhanced glutamatergic activity, inflammation, and a genetic predisposition, as contributing factors. Alpha-2-delta calcium channel ligands inhibit the presynaptic glutamate release. Central nervous system iron deficiency may increase glutamatergic tone. Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, inhibits the activation of NMDA receptor by glutamate and decreases glutamate presynaptic release. Ketamine was reported to effectively treat RLS. DXM, another NMDA receptor antagonist, has not been reported to treat RLS in the literature. Additionally, an association between inflammation and RLS was described, and limited data showed anti-inflammatory effect of DXM. Conclusion Patients with RLS suffer from their symptoms’ burden. Approved medications could carry side effects, or augmentation. We report a case of severe RLS with dramatic and sustained improvement with DXM. Support (if any)

AbstractBackgroundQuantitative rapid eye movement (REM) sleep without atonia (RSWA) recorded during polysomnography (PSG) represents loss of normal REM sleep atonia. RSWA is the neurophysiologic signature of REM sleep behavior disorder (RBD). Visually scored RSWA is a candidate biomarker for synucleinopathies. However, visual RSWA scoring requires expert scoring, limiting widespread application. We comparatively analyzed RSWA in DLB and iRBD using the automated Ferri REM Atonia Index (RAI).MethodWe quantitatively analyzed the RAI in 12 DLB and 20 iRBD patients, compared to 20 controls using Hypnolab Software for Sleep Analysis (SWS Soft, Inc, Colognola ai Colli, Italy). PSG data were converted to European Data Format (.EDF), and the submentalis surface electromyogram (EMG) signal was notch‐filtered at 60 Hertz and rectified. Automatically calculated RAI scores were comparatively analyzed across groups (DLB, iRBD, controls) using Kruskal Wallis H tests for group comparisons, and regression analyses determined relationships between diagnosis, age, and sex. Logistic regression ROC determined optimal RAI for distinguishing iRBD from DLB. When interpreting RAI, lower values represent greater amounts of RSWA, and higher values represent more normal REM atonia.ResultMean age was older in DLB than in iRBD or controls (72.6 vs. 68.7 vs. 66.5 years). All 12 DLB participants were men, the iRBD group had 18 men and 2 women, and controls were comprised of 16 men and 4 women. Mean RAI was lowest in DLB (0.46), intermediate in iRBD (0.71) and highest in controls (0.96), indicating a gradient in RSWA amounts from DLB patients (highest) to controls (lowest) (Figure). Regression demonstrated diagnosis independently predicted RAI, controlling for age and sex (adjusted R2 = 0.49, p = 0.0001). The RAI that optimally distinguished iRBD from DLB was 0.46 (specificity 85%, sensitivity 58%, AUC = 0.75).ConclusionThe RAI demonstrated a clear gradient throughout the Lewy body spectrum; highest (indicating lowest RSWA amounts) in controls, intermediate in iRBD, and lowest (indicating greatest RSWA) in DLB. The RAI is a promising, time efficient and broadly applicable candidate biomarker for DLB and iRBD. Automated quantitative RSWA could be a valuable tool for deep phenotyping throughout the Lewy body disease spectrum.

AbstractIntroductionWe examined the temporal sequence of the core features in probable dementia with Lewy bodies (DLB).MethodsIn 488 patients with probable DLB, the onset of each core feature and time to diagnosis was determined for men and women, and a pathologic subgroup (n = 209).ResultsREM sleep behavior disorder (RBD) developed before the other core features in men and women. Men were more likely to have RBD and were diagnosed with probable DLB earlier than women. Visual hallucinations developed after the other core features in men, but in women, they appeared earlier and concurrently with fluctuations and parkinsonism. Women were older and more cognitively impaired at first visit, were less likely to have RBD, more likely to be diagnosed with probable DLB later than men, and more likely to have neocortical tangles.DiscussionAn earlier latency to probable DLB was associated with men, RBD, and Lewy body disease without neocortical tangles.