Altered neurovascular coupling in neuromyelitis optica

Abstract

Neurovascular coupling reflects the close relationship between neuronal activity and cerebral blood flow (CBF), providing a new mechanistic insight into health and disease. Neuromyelitis optica (NMO) is an autoimmune inflammatory demyelinating disease of the central nervous system and shows cognitive decline‐related brain gray matter abnormalities besides the damage of optic nerve and spinal cord. We aimed to investigate neurovascular coupling alteration and its clinical significance in NMO by using regional homogeneity (ReHo) to measure neuronal activity and CBF to measure vascular response. ReHo was calculated from functional MRI and CBF was computed from arterial spin labeling (ASL) in 56 patients with NMO and 63 healthy controls. Global neurovascular coupling was assessed by across‐voxel CBF‐ReHo correlations and regional neurovascular coupling was evaluated by CBF/ReHo ratio. Correlations between CBF/ReHo ratio and clinical variables were explored in patients with NMO. Global CBF‐ReHo coupling was decreased in patients with NMO relative to healthy controls (p = .009). Patients with NMO showed decreased CBF/ReHo ratio (10.9%–17.3% reduction) in the parietal and occipital regions and increased CBF/ReHo ratio (8.0%–13.3% increase) in the insular, sensorimotor, temporal and prefrontal regions. Some of these abnormalities cannot be identified by a single CBF or ReHo analysis. Both abnormally decreased and increased CBF/ReHo ratios were correlated with more severe clinical impairments and cognitive decline in patients with NMO. These findings suggested that patients with NMO show abnormal neurovascular coupling, which is associated with disease severity and cognitive impairments.

Peer Review #1 of "Disturbed neurovascular coupling in hemodialysis patients (v0.1)"

“…Consistent with our hypothesis, we found a significant across-voxel correlation between CBF and ALFF in healthy subjects, which was also reported in previous studies (Guo et al 2019;Liang et al 2013;Zhu et al 2017), indicating the physiological neurovascular coupling in healthy brain. Additionally, across-voxel correlation between CBF and ALFF was also observed in hemodialysis patients, which was lower than that in healthy controls at the global level, presumably indicating global neurovascular decoupling in hemodialysis patients.…”

“…This abnormality may at least partly account for the emotional and cognitive dysfunction in hemodialysis patients. The CBF/ALFF ratio maintains the balance between two aspects in the healthy brain (Guo et al 2019). One aspect is vascular response and the other aspect is neuronal activity.…”

“…Thus, multimodal neuroimaging techniques were expected to detect cerebral coupling abnormalities in hemodialysis patients in this study. Several studies have investigated the close neurovascular coupling between CBF and neuronal activity in the normal brain (Phillips et al 2016) and abnormal pathological conditions including Alzheimer's disease (Tarantini et al 2017), neuromyelitis optica (Guo et al 2019), schizophrenia (Zhu et al 2017)…”

Acute Endotheliitis (Type 3 Hypersensitivity Vasculitis) in Ten COVID-19 Autopsy Brains

“…Uncoupling of these units causes a decline in neuronal activity. [36][37][38] *Highest elevated D-dimer level above the amount of the reference level as noted in test units according to the laboratory test method employed, using either the D-dimer unit reference range (<250 ng/mL DDU), or the fibrinogen-related reference range (<0.5 mg/L FEU). A microvessel in the H-1 zone of the right hippocamin the mid-level medulla has acute endotheliitis.…”

Neurovascular coupling alterations in type 2 diabetes: a 5-year longitudinal MRI study

“…Therefore, a combination of ReHo and CBF images (ReHo:CBF) reflecting the NVC may serve as a valuable in vivo method to elucidate the neural mechanisms of T2DM-related cognitive decline. Actually, the MRI method combining quantified neural activities and CBF has been successfully used for evaluating NVC changes in neuromyelitis optica 19 and schizophrenia. 18 …”