The Neural Correlates of Shoulder Apprehension: A Functional MRI Study

Abstract

Although shoulder apprehension is an established clinical finding and is important for the prevention of shoulder dislocation, how this subjective perception is evoked remains unclear. We elucidated the functional neuroplasticity associated with apprehension in patients with recurrent anterior shoulder instability (RSI) using functional magnetic resonance imaging (fMRI). Twelve healthy volunteers and 14 patients with right-sided RSI performed a motor imagery task and a passive shoulder motion task. Brain activity was compared between healthy participants and those with RSI and was correlated with the apprehension intensity reported by participants after each task. Compared to healthy volunteers, participants with RSI exhibited decreased brain activity in the motor network, but increased activity in the hippocampus and amygdala. During the passive motion task, participants with RSI exhibited decreased activity in the left premotor and primary motor/somatosensory areas. Furthermore, brain activity was correlated with apprehension intensity in the left amygdala and left thalamus during the motor imagery task (memory-induced), while a correlation between apprehension intensity and brain activity was found in the left prefrontal cortex during the passive motion task (instability-induced). Our findings provide insight into the pathophysiology of RSI by identifying its associated neural alterations. We elucidated that shoulder apprehension was induced by two different factors, namely instability and memory.

Structural white matter and functional connectivity alterations in patients with shoulder apprehension

“…This study extends previous works 3 6 7 , showing that beside functional changes, WM changes are also present in patients with shoulder apprehension compared to controls affecting notably the motor tract in the internal capsule and bilateral thalamus. These structural alterations affect dimensions of shoulder apprehension as performance in daily life.…”

“…This indicates a strong effect of shoulder apprehension on cerebral networks. These results were not extensively discussed here as they resemble findings from previous studies 3 7 . Moreover, a limitation regarding the methods should be highlighted: we used DTI sequence with 30 diffusion directions.…”

“…Recent arising new interest in shoulder apprehension has helped disentangle its different cognitive and physical components combining functional magnetic resonance (fMRI) with clinical examination 6 . Previous fMRI findings have indeed indicated that apprehension is more complex than a purely mechanical problem of the shoulder, suggesting a direct implication of cerebral networks including motor, interoceptive awareness, and emotional regulation 6 7 . These results demonstrate functional differences at the brain level in patients with shoulder apprehension compared to normal population.…”

Shoulder apprehension

“…5,6 Another recent study published by Shitara et al analysed cerebral changes induced by shoulder dislocation in 14 patients. 18 Although results were similar to our study, they observed a larger and less specific spectrum of activated cerebral areas, which may be explained by the fact that they projected static and abstract images during fMRI acquisition that may be prone to vaguer and subjective interpretation, and that, moreover, did not convey the dynamic component inherent to apprehension.…”

A functional Magnetic Resonance Imaging study of patients with Polar Type II/III complex shoulder instability

“…Little fMRI work has been done on shoulder movement and its disorders. One study found decreased brain activity in the motor network and different areas of activations in patients with recurrent anterior shoulder instability 38 . Two studies on shoulder apprehension have demonstrated structural changes in the sensorimotor areas using a visual task to evoke shoulder apprehension 39,40 , and abnormalities in task-correlated functional connectivity, measured in the resting state, related to viewing images of shoulder movement 39,40 .…”