Shoulder apprehension is a commonly reported complaint in shoulder instability, which may lead to patient morbidity and impede shoulder function. It is the result of a cognitively complex mechanism, which includes anxiety, salience, fear and anticipation.

The primary aim of this study were to correlate 5 clinically established scores that assess these different aspects of apprehension to brain activation patterns from fMRI in patients with a positive apprehension. The second study aim was to correlated functional connectivity networks and task-related brain activation to these 5 different clinical scores.

Prospective case-control study.

This study includes 28 consecutive right-handed, male patients (26.8±1.2years) with positive shoulder apprehension test and 10 healthy matched control participants. Task-related and functional connectivity fMRI activation patterns during apprehension video cue stimulation were correlated to 5 clinical tests and scores: Visual Analog Scale (VAS), Rowe, Simple Shoulder Test (SST), Subjective Shoulder Value (SSV) and Western Ontario Shoulder Instability (WOSI).

Rowe, pain VAS and WOSI correlated with pre-frontal, dorsolateral/dorsomedial pre-frontal cortex, somatosensory areas and parieto-occipital and temporal areas (default mode network). Rowe additionally correlated with frontal pole, anterior mid-cingulate cortex and visual areas. Moreover, SSV correlated with task-related brain activity of bilateral pre- and post-central gyrus, and bilateral superior parietal lobe.

Overall, the Rowe score provides the strongest link between shoulder apprehension and brain level alterations as it correlated with the highest number of ICs involving areas responsible for both motor and cognitive functions, while the pain VAS and WOSI occupy an intermediately strong link recruiting less brain networks. Finally, SST and SSV have the weakest link at the brain level. Raising interest in this particular field may allow development of a whole new therapeutic approach to shoulder instability, as well as other joint instabilities or orthopedic conditions.