Clinical and Ultrasound Evaluation of Hemiplegic Shoulder Pain in Stroke Patients: A Longitudinal Observational Study Starting in the First Hours After Stroke

<i>Background and Objectives</i>: Hemiplegic shoulder pain (HSP) is a common and disabling complication in stroke patients, yet its pathogenesis remains unclear. This longitudinal study aimed to investigate the clinical and ultrasound characteristics of HSP emerging within the first 72 h (T0) post-stroke, with follow-ups at one month (T1) and three months (T2). <i>Materials and Methods</i>: A total of 28 stroke patients with hemiparesis were assessed for HSP. Evaluations included pain severity during passive shoulder mobilization, passive and active range of motion, muscle strength, spasticity, and functional disability. Ultrasound examinations were conducted to assess tendon disorders, bursitis, effusion, glenohumeral subluxation, and adhesive capsulitis. <i>Results</i>: HSP prevalence increased over time, affecting 11% of patients at T0, 32% at T1, and 57% at T2. Higher baseline scores on the National Institutes of Health Stroke Scale (NIHSS), an established marker of stroke severity, were significantly associated with HSP (<i>p</i> < 0.05). At T2, patients with HSP exhibited greater impairment, including restricted passive and active range of movement, pronounced muscle weakness, and increased spasticity (<i>p</i> < 0.05). Ultrasound findings at T2 revealed that adhesive capsulitis and glenohumeral subluxation were significantly more frequent in HSP patients (<i>p</i> < 0.05). Adhesive capsulitis showed a significant increase from 0% at T0 to 21% at T2 (<i>p</i> = 0.031), while glenohumeral subluxation exhibited a non-significant rise from 4% to 21% (<i>p</i> = 0.063). Patients with these conditions experienced significantly greater pain progression (<i>p</i> < 0.001). <i>Conclusions</i>: These findings suggest that capsular pathology plays a key role in the development of HSP within the first three months after stroke. The results highlight the need for targeted interventions addressing glenohumeral subluxation and adhesive capsulitis to alleviate pain and improve rehabilitation outcomes.