Mortality of the Danish Nationwide AQP4 Antibody-Seropositive Neuromyelitis Optica Spectrum Disorder Patient Cohort.

BACKGROUND AND OBJECTIVES: We aimed to evaluate the mortality of patients with AQP4 antibody-seropositive (AQP4-Ab+) neuromyelitis optica spectrum disorder (NMOSD) in Denmark compared with that in the general population. METHODS: We identified patients with AQP4-Ab+ NMOSD fulfilling the 2015 International Panel for Neuromyelitis Optica Diagnosis (IPND) criteria from multiple sources (laboratories and the Danish Multiple Sclerosis Registry). We obtained detailed information about patients from hospital records and about the general population matched on age, sex, and calendar year from Statistics Denmark. We calculated standardized mortality ratio (SMR), excess number of deaths per 1,000 person-years (EDR), and life expectancies compared with those of the matched general population. We examined predictive factors of mortality and the cause of death. RESULTS: Of 66 patients with AQP4-Ab+ NMOSD between 2008 and 2020, 15 died. Overall, the SMR was 2.54 (95% CI 1.47-4.09), and the EDR was 16.8 (95% CI 4.6-34.3). The median life expectancy for patients with AQP4-Ab+ NMOSD was 64.08 years (95% CI 53.02-83.9), compared with 83.07 years for the general population. Risk of death over time was increased in the patient population with a hazard ratio (HR) of 2.22 (1.34-3.68; p = 0.002). The cause of death was directly related to NMOSD in 93% of the cases. The age at disease onset was an independent predictor of death (HR 1.042; 95% CI 1.006-1.079; p = 0.02). DISCUSSION: AQP4-Ab+ NMOSD is associated with increased mortality and shorter life expectancy compared with that in the general population, underlining the need for highly effective treatment approaches.

Microglial Activation and Progression of Nigrostriatal Dysfunction in Isolated REM Sleep Behavior Disorder.

BACKGROUND: Using 11 C-(R)-PK11195-PET, we found increased microglia activation in isolated REM sleep behavior disorder (iRBD) patients. Their role remains to be clarified. OBJECTIVES: The objective is to assess relationships between activated microglia and progression of nigrostriatal dysfunction in iRBD. METHODS: Fifteen iRBD patients previously scanned with 11 C-(R)-PK11195 and 18 F-DOPA-PET underwent repeat 18 F-DOPA-PET after 3 years. 18 F-DOPA Ki changes from baseline were evaluated with volumes-of-interest and voxel-based analyses. RESULTS: Significant 18 F-DOPA Ki reductions were found in putamen and caudate. Reductions were larger and more widespread in patients with increased nigral microglia activation at baseline. Left nigral 11 C-(R)-PK11195 binding at baseline was a predictor of 18 F-DOPA Ki reduction in left caudate (coef = -0.0426, P = 0.016). CONCLUSIONS: Subjects with increased baseline 11 C-(R)-PK11195 binding have greater changes in nigrostriatal function, suggesting a detrimental rather than protective effect of microglial activation. Alternatively, both phenomena occur in patients with prominent nigrostriatal dysfunction without a causative link. The clinical and therapeutic implications of these findings need further elucidation. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Progression of brain cholinergic dysfunction in patients with isolated rapid eye movement sleep behavior disorder.

BACKGROUND: Reduced cortical acetylcholinesterase activity, as measured by 11 C-donepezil positron emission tomography (PET), has been reported in patients with isolated rapid eye movement (REM) sleep behavior disorder (iRBD). However, its progression and clinical implications have not been fully investigated. Here, we explored the relationship between longitudinal changes in brain acetylcholinesterase activity and cognitive function in iRBD. METHODS: Twelve iRBD patients underwent 11 C-donepezil PET at baseline and after 3 years. PET images were interrogated with statistical parametric mapping (SPM) and a regions of interest (ROI) approach. Clinical progression was assessed with the Movement Disorder Society-Unified Parkinson's Disease Rating Scale-Part III (MDS-UPDRS-III). Cognitive function was rated using the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). RESULTS: From baseline to follow-up, the mean 11 C-donepezil distribution volume ratio (DVR) decreased in the cortex (p = 0.006), thalamus (p = 0.013), and caudate (p = 0.013) ROI. Despite no significant changes in the group mean MMSE or MoCA scores being observed, individually, seven patients showed a decline in their scores on these cognitive tests. Subgroup analysis showed that only the subgroup of patients with a decline in cognitive scores had a significant reduction in mean cortical 11 C-donepezil DVR. CONCLUSIONS: Our results show that severity of brain cholinergic dysfunction in iRBD patients increases significantly over 3 years, and those changes are more severe in those with a decline in cognitive test scores.