Delayed onset sleep-related stridor due to radiation for thyroid cancer.

Radiation therapy is the mainstay of treatment for head and neck cancers with both acute and delayed complications. While obstructive sleep apnea is common in the few series of patients undergoing radiation therapy to the neck, the development of sleep-related stridor is exceedingly rare and has typically been reported in the acute treatment setting. We describe a 65-year-old female with 1 year of nocturnal groaning beginning 2 years after radiation therapy for thyroid carcinoma. Polysomnography revealed mild obstructive sleep apnea and sleep-related stridor responsive to nasal continuous positive airway pressure. Our case highlights the importance of screening patients with a history of head and neck radiation for sleep-related breathing complaints at each follow-up visit and consideration of both obstructive sleep apnea and stridor in these patients. Identification of sleep-disordered breathing in these patients may lead to timely treatment and improvement in quality of life. CITATION: McCarter SJ, Mansukhani MP, Herold DL, Kolla BP. Delayed onset sleep-related stridor due to radiation for thyroid cancer. J Clin Sleep Med. 2022;18(9):2327-2329.

Association Between Plasma Biomarkers of Amyloid, Tau, and Neurodegeneration with Cerebral Microbleeds.

BACKGROUND: Cerebral microbleeds (CMBs) are a common vascular pathology associated with future intracerebral hemorrhage. Plasma biomarkers of amyloid, tau, and neurodegeneration may provide a screening avenue to identify those with CMBs, but evidence is conflicting. OBJECTIVE: To determine the association between plasma biomarkers (Aß40, Aß42, t-tau, p-tau181, p-tau217, neurofilament light chain (NfL)) and CMBs in a population-based study of aging and whether these biomarkers predict higher signal on Aß-PET imaging in patients with multiple CMBs. METHODS: 712 participants from the Mayo Clinic Study of Aging with T2* GRE MRI and plasma biomarkers were included. Biomarkers were analyzed utilizing Simoa (Aß40, Aß42, t-tau, NfL) or Meso Scale Discovery (p-tau181, p-tau217) platforms. Cross-sectional associations between CMBs, plasma biomarkers and Aß-PET were evaluated using hurdle models and multivariable regression models. RESULTS: Among the 188 (26%) individuals with≥1 CMB, a lower plasma Aß42/Aß40 ratio was associated with more CMBs after adjusting for covariables (IRR 568.5 95% CI 2.8-116,127). No other biomarkers were associated with risk or number CMBs. In 81 individuals with≥2 CMBs, higher plasma t-tau, p-tau181, and p-tau217 all were associated with higher Aß-PET signal, with plasma p-tau217 having the strongest predictive value (r2 0.603, AIC -53.0). CONCLUSION: Lower plasma Aß42/Aß40 ratio and higher plasma p-tau217 were associated with brain amyloidosis in individuals with CMBs from the general population. Our results suggest that in individuals with multiple CMBs and/or lobar intracranial hemorrhage that a lower plasma Aß42/Aß40 ratio or elevated p-tau217 may indicate underlying cerebral amyloid angiopathy.

Objective sleep profile in LGI1/CASPR2 autoimmunity.

STUDY OBJECTIVES: Rapid 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. METHODS: We 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. RESULTS: Among 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. CONCLUSIONS: LGI1/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.

The Mary Walker effect: Mary Broadfoot Walker.

Mary Broadfoot Walker (1888-1974) was the first to demonstrate the 'Mary Walker effect' describing the weakness of other muscle groups following release of the arteriovenous occlusion of an unrelated exercising muscle group in patients with myasthenia gravis, which led to the search for a circulating causative agent for myasthenia gravis. She was the first to clearly demonstrate that strength temporarily improved in patients with myasthenia gravis with physostigmine or Prostigmin (neostigmine). This dramatic treatment response has been erroneously termed the 'Mary Walker effect'. Further, she noted hypokalaemia during attacks of weakness in familial periodic paralysis, pioneering treatment with potassium chloride. Although Mary Walker practiced in a nonacademic setting and trained at a time when women were not allowed to train alongside men, she was the first to convincingly demonstrate three life-changing treatments in the field of neuromuscular medicine, a feat that few physicians of any era can claim.

Risk Factor Profile in Parkinson's Disease Subtype with REM Sleep Behavior Disorder.

BACKGROUND: Numerous large-scale studies have found diverse risk factors for Parkinson's disease (PD), including caffeine non-use, non-smoking, head injury, pesticide exposure, and family history. These studies assessed risk factors for PD overall; however, PD is a heterogeneous condition. One of the strongest identifiers of prognosis and disease subtype is the co-occurrence of rapid eye movement sleep behavior disorder (RBD).In previous studies, idiopathic RBD was associated with a different risk factor profile from PD and dementia with Lewy bodies, suggesting that the PD-RBD subtype may also have a different risk factor profile. OBJECTIVE: To define risk factors for PD in patients with or without associated RBD. METHODS: In a questionnaire, we assessed risk factors for PD, including demographic, medical, environmental, and lifestyle variables of 189 PD patients with or without associated polysomnography-confirmed RBD. The risk profile of patients with vs. without RBD was assessed with logistic regression, adjusting for age, sex, and disease duration. RESULTS: PD-RBD patients were more likely to have been a welder (OR = 3.11 (1.05-9.223), and to have been regular smokers (OR = 1.96 (1.04-3.68)). There were no differences in use of caffeine or alcohol, other occupations, pesticide exposure, rural living, or well water use. Patients with RBD had a higher prevalence of the combined family history of both dementia and parkinsonism (13.3% vs. 5.5% , OR = 3.28 (1.07-10.0). CONCLUSION: The RBD-specific subtype of PD may also have a different risk factor profile.

Neuroimaging-evident lesional pathology associated with REM sleep behavior disorder.

BACKGROUND/RATIONALE: Rapid eye movement (REM) sleep behavior disorder (RBD) is a potentially injurious parasomnia characterized by dream enactment behavior and polysomnographic REM sleep without atonia (RSWA). Recently, RBD not only has been shown to be strongly associated with synucleinopathy neurodegeneration but has also been rarely reported to be associated with structural lesions involving the brainstem or limbic system. The aim of this study was to describe the clinical, neuroimaging, and outcome characteristics in a case series of patients with lesional RBD. METHODS: This is a retrospective case series from a tertiary care referral center. RESULTS: A total of 10 patients with lesional RBD were identified. Seven (70%) were men, with an average age of sleep symptom onset of 53.7 ± 17.0 years. Structural pathology evident on neuroimaging included four extraaxial (three meningiomas and one basilar fusiform aneurysm with brainstem compression) and six intraaxial (encephalomalacia, multiple sclerosis, vasculitis, autoimmune limbic encephalitis, and leukodystrophy) lesions. No patient developed parkinsonian features or cognitive impairment suggestive of synucleinopathy over an average of 45.4 ± 35.2 months of follow-up. CONCLUSIONS: RBD is rarely associated with non-synuclein structural lesions affecting the pons, medulla, or limbic system. The spectrum of lesional RBD comprises tumors, aneurysms, leukodystrophy, and autoimmune/inflammatory/demyelinating brain lesions.