Showing papers by "Michael H. Silber published in 2020"

REM sleep atonia loss distinguishes synucleinopathy in older adults with cognitive impairment

Abstract: Objective To determine whether quantitative polysomnographic REM sleep without atonia (RSWA) distinguishes between cognitive impairment phenotypes. Background Neurodegenerative cognitive impairment in older adults predominantly correlates with tauopathy or synucleinopathy. Accurate antemortem phenotypic diagnosis has important prognostic and treatment implications; additional clinical tools might distinguish between dementia syndromes. Methods We quantitatively analyzed RSWA in 61 older adults who underwent polysomnography including 46 with cognitive impairment (20 probable synucleinopathy), 26 probable non-synucleinopathy (15 probable Alzheimer disease, 11 frontotemporal lobar dementia), and 15 age- and sex-matched controls. Submentalis and anterior tibialis RSWA metrics and automated REM atonia index were calculated. Group statistical comparisons and regression were performed, and receiver operating characteristic curves determined diagnostic RSWA thresholds that best distinguished synucleinopathy phenotype. Results Submentalis—but not anterior tibialis RSWA—was greater in synucleinopathy than nonsynucleinopathy; several RSWA diagnostic thresholds distinguished synucleinopathy with excellent specificity including submentalis tonic, 5.6% (area under the curve [AUC] 0.791); submentalis any, 15.0% (AUC 0.871); submentalis phasic, 10.8% (AUC 0.863); and anterior tibialis phasic, 31.4% (AUC 0.694). In the subset of patients without dream enactment behaviors, submentalis RSWA was also greater in patients with synucleinopathy than in those without synucleinopathy. RSWA was detected more frequently by quantitative than qualitative methods (p = 0.0001). Conclusion Elevated submentalis RSWA distinguishes probable synucleinopathy from probable nonsynucleinopathy in cognitively impaired older adults, even in the absence of clinical dream enactment symptoms. Classification of evidence This study provides Class III evidence that quantitative RSWA analysis is useful for distinguishing cognitive impairment phenotypes. Further studies with pathologic confirmation of dementia diagnoses are needed to confirm the diagnostic utility of RSWA in dementia.

Autonomic dysfunction and phenoconversion in idiopathic REM sleep behavior disorder.

Abstract: REM sleep behavior disorder (RBD) is a common finding among patients with synucleinopathies. We aimed to determine the degree of autonomic dysfunction in patients presenting with idiopathic RBD (iRBD), and the predictive value of autonomic dysfunction for phenoconversion to a defined neurodegenerative disease. We searched our electronic medical record for patients diagnosed with iRBD who also underwent standardized autonomic function testing within 6 months of iRBD diagnosis, and who had clinical follow-up of at least 3 years following iRBD diagnosis. The composite autonomic severity score (CASS) was derived and compared between phenoconverters and non-converters using chi-square and Wilcoxon rank-sum tests. We identified 18 patients who fulfilled inclusion and exclusion criteria. Average age at autonomic testing was 67 ± 6.6 years. Twelve (67%) patients phenoconverted during the follow-up period; six developed Parkinson’s disease (PD), and the other six, dementia with Lewy bodies (DLB). Fifteen (83%) patients had at least mild autonomic dysfunction. There were no significant differences between overall converters and non-converters in total CASS or CASS subscores. However, iRBD patients who developed DLB had significantly higher total and cardiovagal CASS scores compared with those who developed PD (p < 0.05), and a trend for higher adrenergic CASS scores compared to those who developed PD and those who did not phenoconvert. Autonomic dysfunction was seen in 83% of iRBD patients, and more severe baseline cardiovagal autonomic dysfunction in iRBD was associated with phenoconversion to DLB but not PD. Prospective studies are needed to confirm the value of autonomic testing for predicting phenoconversion and disease phenotype in iRBD.

Advance taper of antidepressants prior to multiple sleep latency testing increases the number of sleep-onset rapid eye movement periods and reduces mean sleep latency

Abstract: Study Objectives:Patients presenting with excessive sleepiness are frequently using antidepressant medication(s). While practice parameters recommend discontinuation of antidepressants prior to mul...

0003 LGI1 and CASPR2 Autoimmunity: Sleep Symptoms, Polysomnography, and Quantitative REM Sleep without Atonia

Abstract: Sleep disturbances, including rapid eye movement (REM) behavior disorder (RBD), are known manifestations of voltage-gated-potassium-channel-complex VGKC-IgG seropositivity (VGKC+). Discovery of leucine-rich, glioma inactivated protein 1 (LGI1) and contactin-associated protein 2 (CASPR2) have refined our understanding of VGKC+. VGKC+ without LGI1/CASPR2-IgG (“double-negative”) has lost its clinical significance. Previous detailed sleep analysis of these subtypes has been limited. We performed a retrospective study to characterize clinical and polysomnographic features of LGI1/CASPR2 seropositive (LGI1+/CASPR2+) and VGKC double-negative patients, including quantitative REM sleep without atonia (RSWA). Quantified RSWA was compared to matched controls and normative RSWA percentiles. Eleven LGI1+/CASPR2+ (LGI1+, 9) and twelve VGKC double-negative patients were analyzed. Insomnia was seen in 55% of LGI1+/CASPR2+ and 8% of VGKC double-negative patients (p=0.05). The LGI1+/CASPR2+ group had reduced slow wave sleep compared to the VGKC double-negative group. Five LGI1+ patients had clinical dream enactment behavior (DEB). Eight LGI1+ patients met quantitative diagnostic levels of RSWA. Higher RSWA levels were seen in the LGI1+/CASPR2+ group. Ten LGI1+/CASPR2+ patients received immunotherapy; all ten neurologically benefited with sleep benefits in 6/10. Sleep disorders such as insomnia and RBD are part of the LGI1/CASPR2 autoimmune phenotype. Objective sleep manifestations can be seen on polysomnogram in the form of reduced N3 and elevated RSWA as compared to controls. Quantitative RSWA analysis identified RBD in more LGI1+ patients than clinical report or qualitative RSWA. In this study, RBD was only seen with LGI1+, not CASPR2+. The intermediate RSWA levels of the VGKC double-negative patients may suggest a spectrum of abnormal motor activity in these related antibodies. Additional studies are needed to further explore the biomarker potential of quantitative RSWA in autoimmune neurological conditions. This project was supported by the National Center forResearch Resources, National Institutes of Health, through Grant Number 1 UL1 RR024150- 01.