Background Peripheral neuropathies (PN), are peripheral nervous system disorders associated to several causes. According to distribution are classified as: Local (mononeuropathy [MNP]) or Systemic (Multiple mononeuropathy [MNPM] and polyneuropathy [PNP]). PN in gout has been scarcely described. Previous reports only consider MNP of median nerve at the wrist and MNP of the ulnar nerve at the elbow, due to tophus compression.
Objectives To describe the frequency and characteristics of PN in patients with gout and its association to gout related variables, co-morbidity and treatment.
Methods Consecutive patients from GRESGO, a cohort of 450 gout (ARA/CGD/ACR-EULAR) patients seen for the first time at Rheumatology department and treated according to published guidelines for gout. Variables included: demographic, clinical, biochemical data, HAQ and 3 questionnaires for PN (DN4, LANSS and MNSI) previously translated and validated in our country. We performed Nerve Conduction Studies (NCS) following AAME guidelines (Include:Sensory action potential [sural, ulnar and median nerves], Compound muscle action potential [peroneal, tibial, median and ulnar nerves] and late F-wave [tibial and ulnar nerves]). This protocol was approved by the local IRB and the patients signed an informed consent. Statistical analysis: Student's t test, Mann–Whitney U test and X2.
Results We included 162 gout patients, 98% males, 72% tophaceous gout, 48% severe tophaceous gout (STG), mean age 49.4±12 years, 14±10 years of disease duration, educational level 8±4 years, BMI 27.9±4.6kg/m2.
According to questionnaires: 56% DN4, 45% MNSI and 36% LANSS could be classified as PN. Sixty five percent had abnormal NCS: MNP: 52%, most of them (58%) neuropraxia. PNP 35% and 13% MNPM in them, axonal damage was reported in 88%. MNP localization: Median nerve/carpal tunnel (89%); peroneal nerve/fibula head (7.4%); ulnar nerve/elbow (1.8%) and tibial nerve/ankle (1.8%).
For associated factors, Gout+Local PN (L-PN) patients were compared with Gout without PN as well as Gout+Systemic PN (S-PN) (see table). Hypertriglyceridemia and dyslipidemia were significantly more frequent among L-PN patients; in other hand, frequency of tophi, STG and mean HAQ values were significantly more frequent in S-PN patients, there were no significant differences among other clinical data associated with gout itself.
Conclusions PN is common among gout patients, PN could be diagnosed by questionnaires (particularly DN4) and NCS in 65%. L-PN (median nerve most of them) explain 52% of the cases, in 48% S-PN was found, in these group PNP is more frequent. Hypertriglyceridemia is associated with L-PN and STG to S-PN. The role of uric acid and/or crystals needs to be evaluated.
Disclosure of Interest None declared