Backround and purpose: Shoulder apprehension is defined as anxiety and resistance in patients with a history of anterior glenohumeral instability. It remains unclear whether shoulder apprehension is the result of true recurrent instability or a memorized subjective sensation. We tested whether visual presentation of apprehension videos modifies functional brain networks associated with motor resistance and anxiety.
Materials and methods: This prospective study includes 15 consecutive right-handed male patients with shoulder apprehension (9 with right shoulder apprehension, 6 with left shoulder apprehension; 27.5 ± 6.4 years) and 10 healthy male right-handed age-matched control participants (29.0 ± 4.7 years). Multimodal MR imaging included 1) functional connectivity tensorial independent component analysis, 2) task-related general linear model analysis during visual stimulation of movies showing typical apprehension movements vs control videos, 3) voxel-based morphometry analysis of GM, and 4) tract-based spatial statistics analysis of WM.
Results: Patients with shoulder apprehension had significant (P < .05 corrected) increase in task-correlated functional connectivity, notably in the bilateral primary sensory-motor area and dorsolateral prefrontal cortex and, to a lesser degree, the bilateral dorsomedial prefrontal cortex, anterior insula, and dorsal anterior cingulate cortex (+148% right, +144% left). Anticorrelated functional connectivity decreased in the higher-level visual and parietal areas (-185%). There were no potentially confounding structural changes in GM or WM.
Conclusions: Shoulder apprehension induces specific reorganization in apprehension-related functional connectivity of the primary sensory-motor areas (motor resistance), dorsolateral prefrontal cortex (cognitive control of motor behavior), and the dorsal anterior cingulate cortex/dorsomedial prefrontal cortex and anterior insula (anxiety and emotional regulation).