Several connectivities are reduced in the brains of patients with neuromyelitis optica spectrum disorder (NMOSD) who are cognitively impaired, a new study published in Multiple Sclerosis and Related Disorders found.

More precisely, the functional connectivities within the posterior default mode network and between the salience network and the posterior default mode network or right frontoparietal network were decreased in cognitively impaired patients with NMOSD.

These findings could help explain the underlying mechanism of how NMOSD leads to cognitive impairment, a common symptom among patients.


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A team of researchers from China investigated functional connectivity abnormalities within and between the main cognitive networks in NMOSD patients who were cognitively impaired and studied their correlations with cognitive performance.

Read more about the symptoms of NMOSD

The study included 34 patients with NMOSD and 39 healthy controls. The researchers neuropsychologically evaluated the participants and performed resting-state functional magnetic resonance imaging on them, a technique that shows the patterns of brain activity.

The neuropsychological evaluation revealed that 16 of the 24 NMOSD patients were cognitively impaired, while 18 had normal cognition. 

The researchers then selected 7 components representing 6 main cognitive networks and assessed the differences in intra- and internetwork functional connectivities between the 3 groups. They found that the intranetwork connectivity in the posterior default mode network was decreased in cognitively impaired NMOSD patients compared to that of the controls. 

When they compared the NMOSD patients with no cognitive impairment with controls, the researchers found that there were still decreases in the internetwork connectivity between the salience network and posterior default mode network as well as the connectivity between the salience network and right frontoparietal network. 

The team reported that altered functional connectivity values were significantly correlated with cognitive performance in all patients with NMOSD.

They concluded that the disconnections within the posterior default mode network and between the salience network and posterior default mode network or right frontoparietal network “might suggest the neural substrates underlying cognitive impairment in NMOSD.”

Reference

Yang Y, Rui Q, Wu X, et al. Altered functional connectivity associated with cognitive impairment in neuromyelitis optica spectrum disorder. Mult Scler Relat Disord. Published online August 13, 2022. doi:10.1016/j.msard.2022.104113