Use of rsfMRI-fALFF for the detection of changes in brain activity in patients with normal-tension glaucoma

We know little about the changes of brain activity in patients with normal-tension glaucoma (NTG).

To investigate the altered spontaneous brain activity in patients with NTG through the resting state functional magnetic resonance imaging-fractional amplitude of low-frequency fluctuation (rsfMRI-fALFF) technique, and to explore the relationship with optical coherence tomography (OCT) and field of vision.

Twenty patients with NTG and 20 healthy controls (HCs) (matched for sex, age, and level of education) were enrolled. Spontaneous cerebral activity variations were investigated using the rsfMRI-fALFF technique in all individuals. The average fALFF values of patients with NTG and HCs were compared.

Compared with HCs, patients with NTG had significantly lower fALFF values in the right angular gyrus and precuneus; however, higher fALFF values in the brain regions were not observed. The values showed statistically significant negative correlation with those of the retinal nerve fiber layer (right angular gyrus: r = -0.607, P = 0.010; right precuneus: r = -0.504, P = 0.020). There was no significant correlation between the fALFF value and cup-disc ratio (right angular gyrus: r = 0.158, P = 0.494; right precuneus: r = -0.087, P = 0.706), mean deviation (right angular gyrus: r = 0.096, P = 0.468; right precuneus: r = 0.026, P = 0.845), and pattern SD value (right angular gyrus: r = 0.064, P = 0.626; right precuneus: r = -0.145, P = 0.268).

Abnormal spontaneous activities were detected in numerous brain regions of patients with NTG, which may provide useful information for understanding the dysfunction in NTG. These activity changes in brain regions may be used as effective clinical indicators for NTG.