Ultrasonographic characteristics of peripheral neuropathy in systemic lupus erythematosus

Abstract

Objective

To explore the ultrasonographic characteristics of SLE-related peripheral neuropathy (PN) using nerve ultrasound.

Methods

Patients with SLE were recruited consecutively between December 2022 and June 2023. Detailed clinical assessment and nerve ultrasound were conducted on each SLE patient and healthy control (HC) at predetermined sites of peripheral nerves. The upper limit of the CSA for each nerve location was defined as 95th percentile in healthy controls for the identification of nerve enlargement. Nerve conduction studies (NCS) and relevant ancillary examinations were conducted on all SLE patients for comparisons.

Results

A total of 32 SLE female patients and age- and gender-marched 52 HC were finally recruited. At M6 (P = 0.041) point of median nerve, U1 (P < 0.001) and U6-10 (P < 0.001, =0.008, <0.001, <0.001, <0.001, respectively) points of ulnar nerve, the CSA in SLE patients were remarkably higher than that in HC. Mild and moderate nerve enlargement were detected in 12 and 20 SLE patients, respectively. Only 12 tested nerves showed both axonal damage in electrophysiological studies and nerve enlargement under ultrasound.

Conclusion

Nerve enlargement was extremely common in SLE patients, mainly in the forms of mild to moderate and focal thickening in upper limbs. There was significant inconsistency between NCS and ultrasound in detecting peripheral nerve involvement and a combined examination using NCS and nerve ultrasound might be more effective in detecting SLE-related PN.