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

Abstract

Previous functional magnetic resonance imaging (fMRI) findings indicate that shoulder apprehension is more complex than a pure mechanical problem of the shoulder, showing a direct modification in functional brain networks associated with motor inhibition and emotional regulation. The current study extends these findings by investigating further structural alterations in patients with shoulder apprehension compared to controls. 14 aged patients with shoulder apprehension (27.3 ± 2.0 years) and 10 matched healthy controls (29.6 ± 1.3 years) underwent clinical and fMRI examination including fMRI and diffusion tensor imaging (DTI). Tract-based spatial statistics procedure was used to analyze white matter (WM) alterations. Functional images were analyzed investigating resting state network connectivity. DTI results were correlated with different shoulder clinical scores and functional connectivity networks. Fractional anisotropy (FA), representing white matter integrity, is increased in the left internal capsule and partially in the thalamus in patients compared to controls. Moreover, FA correlates negatively with simple shoulder test (SST) scores (p < .05) and positively with a functional connectivity network qualitatively replicating previous results (p < .01). This study extends previous findings, showing that in addition to functional changes, structural white matter changes are also present in patients with shoulder apprehension.

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

“…Further, there has been some therapeutic translation, where constraint-induced movement therapy has been deployed to attempt motor cortex reorganisation 74–76 . fMRI has never previously been applied to shoulder instability, although cortical activation abnormalities have been explored in shoulder apprehension 40 .…”

“…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 . No studies have considered patients with complex shoulder instability.…”

Shoulder apprehension

“…In a subsequent study, our group extended these findings by investigating further structural alterations in patients with shoulder apprehension. 12 We found that fractional anisotropy, representing white matter integrity, was increased in the left internal capsule and partially in the thalamus in patients compared with healthy controls. Fractional anisotropy correlated positively with pain visual analogue scale (VAS) scores (p < 0.05) and negatively with simple shoulder test (SST) scores (p < 0.05).…”

“…Fractional anisotropy correlated positively with pain visual analogue scale (VAS) scores (p < 0.05) and negatively with simple shoulder test (SST) scores (p < 0.05). 12 This suggests an abnormal increased axonal integrity and therefore pathological structural plasticity due to the over-connection of white matter fibres in the motor pathway. These structural alterations affect several dimensions of shoulder apprehension as pain perception and performance in daily life.…”

Dynamic Anterior Stabilization Using the Long Head of the Biceps for Anteroinferior Glenohumeral Instability

“…Initially, no physiotherapy is recommended. Nevertheless, if persistent apprehension is observed, 34 , 35 , 36 a multidisciplinary approach can be recommended. This can include (1) a “reafferentation” of the shoulder based on a neuromuscular and proprioceptive work, 37 (2) a neurofeedback therapy, 38 (3) a cognitive behavioral approach to decondition the pathological residual apprehension by highlighting to the patients that residual micromotion does not necessarily lead to recurrent instability, 39 and finally with (4) a rotator cuff reinforcement to avoid further dysfunction due to muscle fatigue.…”