Enhanced-MRI and ultrasound evaluation of painful shoulder in patients after stroke: a pilot study

Epidemiological and radiological studies have previously been performed to identify the possible causes of hemiplegic shoulder pain (HSP). Many different etiologies have been postulated, though no clear correlations have emerged, and a multifactorial pathogenesis of HSP has been proposed. Recently, two MRI-based studies have described different shoulder findings as possible causes of pain in chronic stroke survivors.

The aim of this study was to describe the structural abnormalities of the painful shoulder in the first months after stroke by ultrasound and enhanced MRI. The secondary aims were to identify possible predisposing factors for HSP and to evaluate its impact on motor recovery.

One hundred and fifty-three first-time stroke patients, admitted to the Santa Lucia Foundation for rehabilitation, were investigated for HSP. Twenty-five stroke patients with HSP and 16 stroke patients without shoulder pain were included. An ultrasound evaluation and enhanced shoulder MRI were performed for all the patients.

Among the shoulder abnormalities detected by both imaging studies, only capsulitis, which was detected by enhanced shoulder MRI in 88% of the HSP patients, was independently associated with pain (p < 0.001) and proven to be predictive of pain intensity as expressed by the VAS score (p < 0.003). HSP correlated with a worse global recovery (p < 0.05) as well as with male sex (p = 0.006), neglect (p = 0.02) and subluxation (p = 0.03), although none of these features were found to be independent predictors of pain.

Adhesive capsulitis was found to be a possible cause of HSP. However, MRI, which is more expensive than other diagnostic tools, may be considered the gold standard tool for understanding the etiology of HSP.