Median nerve swelling in RA patients: an 8-year longitudinal MRI-based study

Area of Science:

• Rheumatology
• Radiology
• Orthopedics

Background:

• Rheumatoid arthritis (RA) patients frequently develop carpal tunnel syndrome (CTS).
• Magnetic Resonance Imaging (MRI) is effective for diagnosing CTS and assessing RA-related wrist pathologies.
• Median nerve cross-sectional area (CSA) > 15 mm² is a key MRI criterion for CTS diagnosis.

Purpose of the Study:

• To determine the prevalence of median nerve swelling in early RA patients.
• To investigate the relationship between median nerve swelling, inflammation, and structural damage.
• To evaluate the long-term outcomes of median nerve swelling following RA treatment.

Main Methods:

• Retrospective analysis of 81 early RA patients.
• Assessment of clinical, serological, and radiological data.
• Dynamic contrast-enhanced MRI of the wrist at baseline, year 1, and year 8, evaluating median nerve CSA, enhancement, retinacular bowing, synovitis, and structural damage.

Main Results:

• Median nerve swelling was present in 31% at baseline and 46% at year 8.
• Swelling correlated with tenosynovitis volume at baseline but not with synovitis or structural damage long-term.
• Median nerve swelling did not regress with treatment and was associated with increased functional impairment at year 8.

Conclusions:

• Undue median nerve swelling is a common, persistent finding in RA patients.
• It is not directly related to synovitis or structural damage.
• Median nerve swelling is linked to long-term functional impairment in RA patients.