Nerve conduction studies in patients with ankylosing spondylitis

Area of Science:

• Neurology
• Rheumatology
• Neurophysiology

Background:

• Ankylosing spondylitis (AS) is a chronic inflammatory disease primarily affecting the axial skeleton.
• The involvement of the peripheral nervous system (PNS) in AS, particularly in asymptomatic patients, is not well-understood.

Purpose of the Study:

• To investigate the relationship between peripheral neuropathy and ankylosing spondylitis (AS).
• To evaluate the PNS in AS patients and identify correlations between neuropathy and disease parameters.

Main Methods:

• Prospective recruitment of 32 AS patients without neuropathy symptoms across two centers.
• Comprehensive evaluation for AS and peripheral neuropathy, including motor and sensory nerve conduction studies (median, ulnar, common peroneal, tibial, sural nerves).
• Comparison of nerve conduction study results with 30 healthy controls.

Main Results:

• 18.8% of AS patients showed PNS involvement (5 sensory, 1 sensorimotor).
• 21.9% had focal nerve involvements, including prolonged median distal sensory latency and slowed ulnar nerve motor conduction velocity.
• Correlations were found between tibial nerve motor conduction velocity and Schober/chest expansion tests, and between sural nerve sensory action potential amplitude and age/disease duration.

Conclusions:

• The PNS may be affected in asymptomatic AS patients, similar to the central nervous system.
• Further research with larger cohorts and longer follow-up is needed to confirm these findings and elucidate clinical relevance.
• The role of other neuropathy types and medication effects on PNS in AS requires further investigation.