Initial exploration on clinical application of resting-state functional magnetic resonance imaging amplitude of low-frequency fluctuation method on cognitive impairment in amyotrophic lateral sclerosis

Objective To explore diagnostic value of amplitude of low-frequency fluctuation (ALFF) on cognitive impairment in amyotrophic lateral sclerosis (ALS) using resting-state functional magnetic resonance imaging (MRI). Methods Sixteen ALS patients from neurological clinic in Peking Union Medical College Hospital were enrolled between November 2013 and April 2015. The patients were divided into two groups by the presence (ALSi, n=7) or absence (ALSu, n=9) of cognitive impairment. Routine MRI structural images and resting-state functional MRI were collected for comparison between groups through voxel-based morphometry (VBM) and ALFF. Results (1) Neuropsychological analysis showed significant differences in Montreal Cognitive Assessment score (22.9±2.0 vs 25.8±2.3, t=2.622, P=0.020), Frontal Assessment Battery score (12.4±1.6 vs 15.1±1.4, t=3.600, P=0.003), animal listing test (13.6±1.8 vs 16.7±2.9, t=2.482, P=0.026), naming test (2(1) vs 0(1), Z=-2.746, P=0.006), similarity test (7.9±3.7 vs 17.3±2.8, t=5.846, P=0.000)and clock drawing test (2(2) vs 3(0), Z=2.516, P=0.012). (2) VBM analysis showed no significant differences in both gray matter and white matter density between the two groups. (3) ALFF analysis showed significantly increased signals in widespread areas of bilateral cerebrum and cerebellum in ALSi group compared to ALSu group. Conclusion ALFF value has the potential to provide more valuable imaging basis for early diagnosis on cognitive impairment in ALS. Key words: Amyotrophic lateral sclerosis; Cognition disorders; Magnetic resonance imaging; Diagnosis