Background: Rheumatoid arthritis (RA) is an inflammatory, long-term systemic autoimmune disease with extra-articular manifestations(EAMs). One of the most common EAMs associated with rheumatoid arthritis is median nerve entrapment at wrist (Carpal Tunnel Syndrome), occurring in about 30% of rheumatoid arthritis patients.
Aims: This study aimed to determine the prevalence of Carpal Tunnel Syndrome among rheumatoid arthritis patients in Basrah, south of Iraq, and to assess its clinical and electrophysiological changes.
Methods: A cross-sectional study was carried out in Basrah governorate, south of Iraq on patients with confirmed diagnosis of rheumatoid arthritis. Their clinical, and electrophysiological characteristics using nerve conduction studies were documented.
Results: Out of 110 individuals with rheumatoid arthritis, 44 (40%) were diagnosed with carpal tunnel syndrome. The CTS and non-CTS groups exhibited no significant differences in age, sex, BMI, RA duration, disease activity, treatment, or laboratory parameters (all P>0.05), however, smoking was much more common among CTS patients (P=0.003). Bilateral involvement was predominant (72.7%). Nerve conduction examinations revealed markedly prolonged median motor and sensory latencies, diminished conduction velocities, and decreased sensory amplitudes in patients with CTS (all P<0.01), but median motor amplitudes remained unchanged. Ulnar nerve parameters exhibited considerable variation (all P≤0.006). Needle electromyography of the abductor pollicis brevis demonstrated neurogenic alterations in about one-third of patients bilaterally, accompanied by rare spontaneous activity.
Conclusions: Carpal tunnel syndrome impacts 40% of rheumatoid arthritis patients, with a significant 72.7% exhibiting bilateral involvement, and is mostly a localized entrapment neuropathy not associated with systemic inflammation or disease activity. Cigarette consumption shown a notable correlation with CTS (P=0.003). Electrophysiological assessment revealed bilateral median nerve demyelination accompanied by varying degrees of axonal involvement and neurogenic EMG alterations in one-third patients. we recommend routine CTS screening in all RA patients, early electrophysiological evaluation, cessation of smoking, local wrist assessment, and future studies on synovitis control and CTS prevention.