Inflamed shoulder structures in polymyalgia rheumatica with normal erythrocyte sedimentation rate.

OBJECTIVE: To investigate the inflammatory involvement of shoulder articular and extraarticular structures in polymyalgia rheumatica (PMR) patients with a normal erythrocyte sedimentation rate (ESR) at diagnosis. METHODS: This was a case-control study. All consecutive, untreated new outpatients diagnosed as having PMR with a normal ESR (<40 mm/hour) during a 6-month period were included in the study (case patients). Controls were 12 consecutive, untreated PMR outpatients with an ESR of >40 mm/hour who were observed after the case patients. Before starting corticosteroid therapy, all case patients and controls underwent bilateral shoulder ultrasonography (US) and magnetic resonance imaging (MRI). US and MRI scans were evaluated independently by two radiologists who were blinded to the reciprocal results. RESULTS: Six case patients (4 men and 2 women) and 12 controls (4 men and 8 women) were studied. Both US and MRI demonstrated bilateral subacromial/subdeltoid bursitis in all 6 case patients and in 11 of the 12 (92%) controls (P not significant [NS]). One control had unilateral bursitis. Glenohumeral joint synovitis was found in 4 of 6 case patients (67%) by MRI and in 3 of 6 case patients (50%) by US (P NS), as well as in 8 of 12 controls (67%) by MRI and in 7 of 12 controls (58%) by US (P NS). Both MRI and US detected biceps tenosynovitis in 5 of 6 case patients (83%) and in 8 of 12 controls (67%) (P NS). The severity of bursitis did not differ significantly between the groups. US was as effective as MRI in detecting inflammatory changes of the shoulder. CONCLUSION: MRI and US studies showed that PMR patients with normal or high ESRs have similar inflammatory shoulder lesions. Moreover, bilateral subacromial/subdeltoid bursitis represents the imaging hallmark in PMR patients with a high or normal ESR. MRI or US of the shoulder may facilitate the proper diagnosis in patients with the typical proximal symptoms of PMR who also have normal ESRs.

Shoulder ultrasonography in the diagnosis of polymyalgia rheumatica: a case-control study.

OBJECTIVE: Magnetic resonance imaging (MRI) showed that subacromial/subdeltoid bursitis is the most frequent shoulder lesion in polymyalgia rheumatica (PMR). We evaluated whether shoulder ultrasonography (US) was as effective as MRI in the detection of this lesion and assessed the sensitivity and specificity of bilateral subacromial/subdeltoid bursitis in the diagnosis of PMR. METHODS: A case-control study of 57 consecutive case patients with untreated PMR and 114 controls seen over a 6 month period in 3 secondary referral rheumatology centers. Control patients consisted of the next 2 consecutive patients with bilateral shoulder aching and stiffness observed after the case patient. In all case and control patients the glenohumeral joint space, bursae, and long head biceps tendon were assessed by bilateral shoulder US. The first 24 case patients were also examined by bilateral shoulder MRI. RESULTS: US showed subacromial/subdeltoid bursitis in 55/57 (96%) patients with PMR and in 25/114 (22%) controls (p < 0.001). The lesion was bilateral in 53/55 (96%) case patients and in 1/25 (4%) controls (p < 0.001). The frequency of glenohumeral joint synovitis and biceps tenosynovitis did not differ significantly between case patients and controls. In 100% of case patients MRI showed subacromial/subdeltoid bursitis confirming US findings. The sonographic evidence of bilateral bursitis had a sensitivity of 92.9%, specificity of 99. 1%, and positive predictive value of 98. 1% for the diagnosis of PMR. CONCLUSION: US and MRI were equally effective in confirming bilateral subacromial and subdeltoid bursitis in PMR. This finding, in view of its high sensitivity and specificity, could be used as a new diagnostic criterion for PMR.