Alterations in regional functional coherence within the sensory-motor network in amyotrophic lateral sclerosis

Alteration of brain activity synchrony has been shown in amyotrophic lateral sclerosis (ALS) using seed-based functional connectivity analysis. However, regional activity synchrony has not been characterized in ALS. The purpose of this study was to assess regional brain synchrony by calculating regional data coherence of resting state functional MRI (rsfMRI), as well as its correlations to clinical indices. Twelve ALS patients and 12 age- and sex-matched healthy controls underwent rsfMRI scans. Coherence measurement was performed in the sensory-motor network (SMN), a key brain network impaired by ALS. Decreased coherence was found in the superior medial SMN, which was surrounded by increased coherence in the peripheral SMN areas. Decreased regional coherence in the right postcentral gyrus/precentral gyrus/superior frontal gyrus was correlated with high disease severity as indicated by lower ALSFRS-r scores; meanwhile, enhanced regional coherence in left postcentral gyrus and inferior parietal cortex was related to longer disease duration. Finally, increased coherence in left postcentral gyrus corresponds to fast disease progression rate. These ALS-related SMN regional coherence alterations suggest using regional coherence as a potential marker for studying ALS and its progression.