Neuropathic pain in superficial radial neuropathy: neurophysiological correlations in a retrospective series of 20 patients

BACKGROUND: Superficial radial neuropathy (SRN) is an uncommon sensory mononeuropathy, and data on neuropathic pain in SRN are limited. This study aimed to determine the frequency of neuropathic pain in patients with SRN and to evaluate its associations with neurophysiological severity. METHODS: We retrospectively reviewed adult patients diagnosed with SRN. Neuropathic pain was evaluated using the Douleur Neuropathique 4 Questions (DN4) and the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS). Neurophysiological severity was categorized as mild, moderate, or severe according to the superficial radial sensory nerve action potential (SNAP) amplitude. Associations between neuropathic pain and SRN severity, etiology, and coexisting upper-limb neuropathies were examined. RESULTS: Twenty patients were included (mean age 36.2 ± 11.9 years; 75% male). SRN was trauma-related in 18 patients and entrapment-related in 2. Ten patients (50%) met screening criteria for neuropathic pain according to DN4 and 9 (45%) according to LANSS. Screening positivity tended to be more frequent in severe SRN than in mild-moderate SRN (DN4: 6/7 vs. 4/13, p = 0.057) and was significantly higher according to LANSS (6/7 vs. 3/13, p = 0.012). Screening positivity was also observed in 3/4 patients with coexisting median or ulnar neuropathies. CONCLUSION: Approximately half of patients with SRN met screening criteria for neuropathic pain. Higher screening positivity was observed in electrophysiologically severe SRN and in patients with coexisting median or ulnar neuropathies; these findings warrant confirmation in larger prospective cohorts.