Amplitude of low-frequency oscillations in blepharospasm: a resting-state functional MRI study

Abstract

Objective To explore the possible pathophysiology of blepharospasm by comparing differences of brain functional activities between patients with blepharospasm and healthy controls with the resting-state functional magnetic resonance imaging (fMRI). Methods Twenty-four patients with blepharospasm and 24 age- and sex-matched healthy controls were enrolled in the study. The fractional amplitude of low-frequency fluctuation (fALFF) method was used to analyze the data. Two-sample t test was applied to compare differences of fALFF between patients with blepharospasm and healthy controls. Pearson correlation was used to examine the correlation between the fALFF values in brain regions with abnormal fALFF and symptom severity of blepharospasm, anxiety, and depression in patients. Results The whole brain analysis indicated that patients with blepharospasm had significantly increased fALFF in the left postcentral gyrus, bilateral supplementary motor area, left cerebellum anterior lobe and significantly decreased fALFF in the bilateral superior medial frontal gyrus, bilateral middle cingulum, right angular gyrus, bilateral precuneus compared with healthy controls (t=-5.2495-5.3675, all P<0.01). There was no significant correlation between abnormal fALFF and symptom severity of blepharospasm, anxiety, and depression in patients. Conclusion Dysfunction of the sensational and supplementary motor area, cerebellum and default-mode network may underlie the pathophysiology of blepharospasm. Key words: Blepharospasm; Magnetic resonance imaging; Resting state