Brain Microvasculature Involvement in ANCA Positive Vasculitis

Objective: Endothelial dysfunction is associated with arterial stiffness, a factor that is increasingly recognised as an important determinant of cardiovascular risk. High-flow organs such as the brain and kidneys are particularly sensitive to excessive pressure and flow pulsatility. High, local blood flow is associated with low microvascular impedance, which facilitates the penetration of excessive pulsatile energy into the microvascular bed leading to tissue damage. Systemic endothelial dysfunction and arterial stiffness have been demonstrated in peripheral vessels in associated vasculitis (AAV). Although, the brain involvement is not infrequent in AAV, it has not been evaluated previously. Our aim is to evaluate the involvement of the brain microvasculature in AAV. Methods: Twenty-three patients with inactive AAV were studied. Brain blood flow was assessed by transcranial Doppler (TCD) and single-photon positron emission tomography (SPECT), structural brain involvement by brain MRI and cognitive scores by Montreal Cognitive Assessment (MoCA) test. Results: Lower mean flow velocity (MFV) was associated to altered SPECT perfusion, higher white matter changes (WMC), lower MoCA scores and younger age (p Conclusions: The alterations in brain perfusion SPECT, the presence of white matter lesions on MRI, as well as increased PI and RI with lower MFV of the cerebral vessels in TCD suggest the presence of microangiopathy in asymptomatic AAV that could lead to cognitive impairment.