NEFL and Alzheimer disease: Grey matter atrophy has been associated with cerebral hypoperfusion in Alzheimer’s disease,30,31 while NFL, elevated in axonal damage, is a recognized marker of the amyloid-beta-tau-neurodegeneration classification in Alzheimer’s disease.32 In addition, bradycardia displayed a striking association with higher levels of pTau-181 and pTau-217, robust markers of cerebral tau and Aß pathologies.33 This association with neurodegeneration could be explained by several mechanisms.