Altered neurovascular coupling in neuromyelitis optica

Area of Science:

• Neuroscience
• Radiology
• Immunology

Background:

• Neurovascular coupling links neuronal activity and cerebral blood flow (CBF), crucial for brain function.
• Neuromyelitis optica (NMO) is an autoimmune disease affecting the central nervous system, often leading to cognitive decline.
• Existing research highlights gray matter abnormalities in NMO but lacks detailed understanding of neurovascular coupling.

Purpose of the Study:

• To investigate alterations in neurovascular coupling in NMO patients.
• To explore the clinical significance of these neurovascular coupling changes.
• To correlate neurovascular coupling abnormalities with disease severity and cognitive impairment.

Main Methods:

• Used functional MRI for regional homogeneity (ReHo) to assess neuronal activity.
• Employed arterial spin labeling (ASL) to measure cerebral blood flow (CBF).
• Analyzed global CBF-ReHo correlations and regional CBF/ReHo ratios in 56 NMO patients and 63 controls.

Main Results:

• Global neurovascular coupling (CBF-ReHo correlation) was significantly decreased in NMO patients.
• Regional CBF/ReHo ratios showed decreased values in parietal/occipital lobes and increased values in insular/sensorimotor/temporal/prefrontal regions.
• These regional abnormalities were often undetectable by analyzing CBF or ReHo alone.

Conclusions:

• NMO patients exhibit widespread neurovascular coupling dysfunction.
• Abnormalities in neurovascular coupling are associated with more severe clinical impairments and cognitive decline in NMO.
• Assessing neurovascular coupling provides deeper insights into NMO pathophysiology beyond individual CBF or ReHo measures.