AUTHOR=Hu Hui-Min , Liu Wen-Hui , Li Chen , Shi Qing , Liu Chun-Hua , Liu An-Xiang , Li Yi-Fan , Zhang Yi , Mao Peng , Fan Bi-Fa TITLE=Efficacy and safety of interferon-alpha 1b injection into the intervertebral foramen with ultrasonic guidance in patients with postherpetic neuralgia: study protocol for a randomized, double-blind, placebo-controlled, multicenter clinical trial JOURNAL=Frontiers in Neurology VOLUME=15 YEAR=2025 URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2024.1516262 DOI=10.3389/fneur.2024.1516262 ISSN=1664-2295