Background The aim of this study was to evaluate peripheral nervous system involvement and prevalence of neuropathic pain in ankylosing spondylitis (AS).
Objectives The aim of this study was to evaluate peripheral nervous system involvement in ankylosing spondylitis (AS). Nerve conduction methods that were not previously used in other studies (i.e. superficial peroneal nerve (MDSP) sensory conduction studies, F-wave responses, soleus H reflex responses) were used to define peripheral neuropathy in patients with AS. Clinical evaluation was also integrated to show pathologies of peripheral nervous system and to interpret the presence of neuropathic pain
Methods Fifty-three AS patients and 40 healthy controls were enrolled in this study. On physical examination of the patients;Schober, hand-floor distance, occiput-wall distance, and chest expansion were evaluated. Visual analogue scale (VAS) for pain, Bath AS Disease Activity Index (BASDAI), Bath AS Functional Index (BASFI), Bath AS Metrology Index (BASM) was used. In all cases, quality of life was assessed by Short Form-36 (SF-36) and neuropathy was evaluated with neurological examination, clinical neuropathy classification and Leeds Assessment of Neuropathic Symptoms Score (LANSS). In all cases, electrophysiological examination included dominant hand median, ulnar, bilateral tibial and peroneal motor nerve conduction studies; dominant hand median, ulnar, radial, and bilateral sural and superficial peroneal sensory nerve conduction studies along with the dominant hand median, bilateral tibial F waves, and bilateral soleus H-reflex latencies.
Results In this study, clinical peripheral neuropathy (PNP) was found in 6 (11.3%) AS patients using clinical neuropathy classification.Thirty-three patients (62%)had neuropathic pain symptoms. LANSS score of patients was significantly higher than control group (p<0.01). In the electrophysiological examination of the patient group, there was carpal tunnel syndrome (CTS) in 5 patients, ulnar neuropathy (UN) in 2 patients, sensory PNP in 5 patients and sensorymotor PNP in 5 patients; a total of 17 patients (32.1%) were affected. In the asymptomatic healthy control group, 2 (5%) showed UN. In the patient group, the distal latencies in all the motor nerve conduction studies were longer than the control group (p<0.05, p<0.01). All sensory nerve conduction velocities were slower, and the distal latencies were longer than those of the control group, respectively. F-wave latencies and H-reflex latencies showed no significant differences between the groups (p 0.05).
Conclusions Peripheral neuropathy is seen more frequently in patients with AS than the normal population.In our study, incidence of PNP is higher than other studies without MDSP nerve conduction study in patients with AS. The reason of this result could be due to MDSP nerve testing in this study, which is a more sensitive test of nerve conduction studies.Although F-wave latencies and the H-reflex responses have not turned out to be significant in our study and the presence of the MDSP nerve conduction study in the detection and routine work of the late responses is recommended. Also in patients with neuropathic pain, clinical PNP evaluation and LANSS must be used to have an accurate and easy diagnosis.
Gündüz OH, Kıralp MZ, Ozçakar L, Çakar E, Yıldırım P, Akyüz G. Nerve conduction studies in patients withAnkylosing Spondylitis. J Natl Med Assoc 2010;102:243-6.
Disclosure of Interest None declared