title: Spontaneous slow hemodynamic oscillations are impaired in cerebral microangiopathy.
abstract: Small-vessel disease or cerebral microangiopathy (CMA) is a common finding in elderly people. It is related to a variety of vascular risk factors and may finally lead to subcortical ischemic vascular dementia. Because vessel stiffness is increased, we hypothesized that slow spontaneous oscillations are reduced in cerebral hemodynamics. Accordingly, we examined spontaneous oscillations in the visual cortex of 13 patients suffering from CMA, and compared them with 14 age-matched controls. As an imaging method we applied functional near-infrared spectroscopy, because it is particularly sensitive to the microvasculature. Spontaneous low-frequency oscillations (LFOs) (0.07 to 0.12 Hz) were specifically impaired in CMA in contrast to spontaneous very-low-frequency oscillations (0.01 to 0.05 Hz), which remained unaltered. Vascular reagibility was reduced during visual stimulation. Interestingly, changes were tightly related to neuropsychological deficits, namely executive dysfunction. Vascular alterations had to be attributed mainly to the vascular risk factor arterial hypertension. Further, results suggest that the impairments might be, at least partly, reversed by medical treatment such as angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers. Results indicate that functional near-infrared spectroscopy may detect changes in the microvasculature due to CMA, namely an impairment of spontaneous LFOs, and of vascular reagibility. Hence, CMA accelerates microvascular changes due to aging, leading to impairments of autoregulation.
authors.affiliation: Max-Planck-Institute for Human Cognitive and Brain Sciences, University of Leipzig, Leipzig, Germany. schroet@cbs.mpg.de
authors.forename: Matthias L
authors.initials: ML
authors.lastname: Schroeter
authors.forename: Markus M
authors.initials: MM
authors.lastname: Bücheler
authors.forename: Christoph
authors.initials: C
authors.lastname: Preul
authors.forename: Rainer
authors.initials: R
authors.lastname: Scheid
authors.forename: Ole
authors.initials: O
authors.lastname: Schmiedel
authors.forename: Thomas
authors.initials: T
authors.lastname: Guthke
authors.forename: D Yves
authors.initials: DY
authors.lastname: von Cramon
mesh_terms: D000368:Aged; D002545:Brain Ischemia / Q000473:pathology / Q000503:physiopathology*; D002533:Cerebral Angiography; D002560:Cerebrovascular Circulation; D015140:Dementia, Vascular / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D009483:Neuropsychological Tests; D010507:Periodicity; D019265:Spectroscopy, Near-Infrared