Sandness, David J.

Abstract Study Objectives To analyze cognitive deficits leading to unsafe driving in patients with REM Sleep Behavior Disorder (RBD), strongly associated with cognitive impairment and synucleinopathy-related neurodegeneration. Methods Twenty isolated RBD (iRBD), 10 symptomatic RBD (sRBD), and 20 age- and education-matched controls participated in a prospective case-control driving simulation study. Group mean differences were compared with correlations between cognitive and driving safety measures. Results iRBD and sRBD patients were more cognitively impaired than controls in global neurocognitive functioning, processing speeds, visuospatial attention, and distractibility (p < .05). sRBD patients drove slower with more collisions than iRBD patients and controls (p < .05), required more warnings, and had greater difficulty following and matching speed of a lead car during simulated car-following tasks (p < .05). Driving safety measures were similar between iRBD patients and controls. Slower psychomotor speed correlated with more off-road accidents (r = 0.65) while processing speed (−0.88), executive function (−0.90), and visuospatial impairment (0.74) correlated with safety warnings in sRBD patients. Slower stimulus recognition was associated with more signal-light (0.64) and stop-sign (0.56) infractions in iRBD patients. Conclusions iRBD and sRBD patients have greater selective cognitive impairments than controls, particularly visuospatial abilities and processing speed. sRBD patients exhibited unsafe driving behaviors, associated with processing speed, visuospatial awareness, and attentional impairments. Our results suggest that iRBD patients have similar driving-simulator performance as healthy controls but that driving capabilities regress as RBD progresses to symptomatic RBD with overt signs of cognitive, autonomic, and motor impairment. Longitudinal studies with serial driving simulator evaluations and objective on-road driving performance are needed.

AbstractStudy ObjectivesRapid eye movement (REM) sleep behavior disorder (RBD) and other sleep disturbances are frequent in leucine-rich, glioma inactivated protein 1-IgG (LGI1) and contactin-associated protein 2-IgG (CASPR2) autoimmunity, yet polysomnographic analyses of these disorders remain limited. We aimed to characterize clinical presentations and analyze polysomnographic manifestations, especially quantitative REM sleep without atonia (RSWA) in LGI1/CASPR2-IgG seropositive (LGI/CASPR2+) patients.MethodsWe retrospectively analyzed clinical and polysomnographic features and quantitative RSWA between LGI1+/CASPR2+ patients and age-sex matched controls. Groups were compared with Wilcoxon rank-sum and chi-square tests. Combined submentalis and anterior tibialis (SM + AT) RSWA was the primary outcome.ResultsAmong 11 (LGI1+, n = 9; CASPR2+, n = 2) patients, Morvan syndrome sleep features were present in seven (63.6%) LGI1+/CASPR2+ patients, with simultaneous insomnia and dream enactment behavior (DEB) in three (27.3%), and the most common presenting sleep disturbances were DEB (n = 5), insomnia (n = 5), and sleep apnea (n = 8; median apnea-hypopnea index = 15/hour). Median Epworth Sleepiness Scale was nine (range 3–24; n = 10), with hypersomnia in four (36.4%). LGI1+/CASPR2+ patients had increased N1 sleep (p = .02), decreased REM sleep (p = .001), and higher levels of SM + AT any RSWA (p < .001). Eight of nine (89%) LGI1+ exceeded RBD RSWA thresholds (DEB, n = 5; isolated RSWA, n = 3). RSWA was greater in AT than SM. All 10 LGI1+/CASPR2+ patients treated with immunotherapy benefitted, and 5/10 had improved sleep disturbances.ConclusionsLGI1/CASPR2-IgG autoimmunity is associated with prominent dream enactment, insomnia, RSWA, sleep apnea, and shallower sleep. Polysomnography provides objective disease markers in LGI1+/CASPR2+ autoimmunity and immunotherapy may benefit associated sleep disturbances.

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):