Multimodality Predictive Diagnostic Characterization of Chronic Regional Pain Syndrome an Observational Study with Clinical and Imaging Correlation

Author(s):

Rammohan Vadapalli*, Vikas Rao and Ramesh Tippani

Complex regional pain syndrome or CRPS, its subtypes CRPS I: no nerve injury, CRPS II: definitive nerve injury, characterized clinically by pain, vasomotor disturbances, trophic skin changes, and radiographically by regional osteoporosis and bone resorption poses diagnostic challenges. Objective: Multimodality Imaging characterization of CRPS, and clinical and imaging phenotypes. Materials and methods:Fifty-seven patients in the age range of 33-65, the mean age of 49, 35 men (61.40%), 22 Women (38.60%) underwent this observational diagnostic accuracy study at Pratima Institute of Medical Sciences(Karimnagar Telangana, India). The multimodality imaging protocol on Radiography (Diagnox 302, Philips), Ultrasound Doppler (Infinity Philips), Low dose Multi-slice CT(Ingenuity), MRI (1.5T Achieva, PHILIPS Health care) ) for characterization of CRPS phenotypes after IRB approval. The imaging findings from all the modalities were analysed using descriptive statistics. Results: Patients with upper limb involvement (n=18), lower limb involvement(n=32), Pelvic involvement (6). CRPs Type 1-: 27, CRPS Type 2 -:23, Mixed pattern: 7 1.Juxta regional osteopenia(n=17) 2. Patterns of bone resorption on radiography and CT :Pattern A: Mild (n=31) , B: -Aggressive (19) Pattern C- No significant radiological changes(7);Locations of bone loss on radiography /CT.-Periarticular:18, sub Periosteal:8, subchondral/endosteal:11-Intracortical :7 -Mixed pattern: 12 ,Bone marrow edema:32 ,Soft tissue edema: 31.Pattern A : positive predictive value(PPV) of 91%, a concordance rate of 94% with clinical diagnosis of CRPS. Pattern B: PPV of 98% , a concordance rate of 97% . Conclusion: The multimodality imaging approach predicts the accurate diagnosis of CRPS evolving from early acute to late atrophic stages.