Nerve conduction and electromyography in rheumatoid arthritis patients : a case-control study

Abstract EN

Objectives : This study aims to assess peripheral nerve conduction and electromyographic function abnormalities in patients with rheumatoid arthritis.

Subjects and methods : One hundred normal subjects and rheumatoid arthritis patients for each were included in this study, the normal subjects were matched regarding the age and sex with rheumatoid arthritis patients, rheumatoid arthritis patients were diagnosed according to American revised criteria (ARC) 1987 ; at the Department of Rheumatology in Ibn-Sina Teaching Hospital in Mosul city during the period of 15th of November 2009-15th of May 2010.

Nerve conduction study for median, ulnar, radial (motor and sensory), posterior tibial and common peroneal nerves were done for all normal subjects and rheumatoid arthritis patients by using system 98-MyoQuik (micromed) EMG.

Electromyography for tibialis anterior, gastrocnemius and quadriceps muscles were done for normal subjects and rheumatoid arthritis patients by using Dantec-Neuromatic 2000M-EMG.

Results: In this study, peripheral neuropathy was detected in 54 patients (54 %) ; mononeuritis simplex was the commonest lesion and detected in 36 patients (66.6 %) out of the 54 patients.

The entrapment neuropathy was found in 25 patients (46.74 %), affecting the median (24.07 %), posterior tibial (14.81 %) and ulnar (7.40 %) nerves.

Mononeuritis multiplex was detected in 11 patients (20.37 %), and symmetrical polyneuropathy found in 7 patients (12.90 %).

In the present study, the axonopathy (due to vasculitis mainly), and local demylination (due to entrapment mainly), were the common types of nerve injury seen in rheumatoid arthritis patients.

Muscle involvement could be detected by electromyography in rheumatoid arthritis patients in this study.

Conclusion : Neurogenic lesions were present, while no myogenic lesion was detected in patients with rheumatoid arthritis.