Cerebrovascular regulation in patients with vasovagal syncope and autonomic failure due to familial amyloidotic polyneuropathy

•Pursuit Projection Regression is a nonlinear method to study myogenic and neurogenic mechanisms of cerebral autoregulation•Healthy controls, syncope, and autonomic failure groups were studied with head-up tilt test· In healthy subjects, tilt did not change the range or effectiveness of cerebral autoregulation.•During tilt, syncope group showed augmentation of range/effectiveness of cerebral autoregulation Autonomic failure showed an abnormally absent response of cerebral autoregulation during tilt