Is this a case of PMR?
Dr. Adriana Ramona Valea, Dr. SA Ramakrishnan
Rheumatology Department, Our Lady's Hospital, Navan, Co. Meath
Polymyalgia rheumatica is a relatively common inflammatory rheumatic condition characterized clinically by pain and morning stiffness involving shoulders, neck and hips. It is affecting almost exclusively adults over the age of 50 with a peak incidence between 70 and 80.
There is no pathognomonic test to diagnose PMR therefore the diagnosis process in guided by ACR/EULAR provisional classification criteria published in 2012. These criteria included ultrasound findings of subdeltoid bursitis and/or biceps tenosynovitis and/or glenohumeral synovitis and synovitis and/or trochanteric bursitis.
Imaging techniques like MRI or PET CT are not routinely indicated for diagnostic purposed but may be useful in cases of unclear diagnosis or suspicion of subclinical vascular involvement.
We are presenting two of our PMR cases in which these imaging techniques have proven useful for elucidation of diagnosis.
Case 1 : 59 yrs old woman referred by GP with pain and 4 hour morning stiffness involving shoulder and hip girdle. Despite her typical symptoms inflammatory markers were normal from her initial presentation in absence of steroid therapy. To confirm diagnosis she completed MRI whole body which reported bilateral shoulder joint effusion and bilateral trochanteric bursitis. Patient met classification criteria after imaging. She was started on Methotrexate from baseline due to her background of osteoporosis and had complete resolution of symptoms.
Case 2 : 67 yrs old woman referred to rheumatology after having a PET CT for investigation of lung nodule, showing increased uptake bilateral shoulders and to a lesser extent hips. On enquiry patient had history of shoulder pain and stiffness with reduced range of movement for a few months. Her inflammatory markers were elevated and after initiating steroid therapy returned to normal along with resolution of symptoms.
Although not routinely recommended, imaging including MRI can prove to be a useful tool in some cases of PMR, particularly those with normal inflammatory markers. PET CT is mostly valuable in assessing for vascular involvement in patients with symptoms of GCA but in our patient has identified changes suggestive of PMR triggering a referral to rheumatology for proper diagnosis and management.