Erector spinae plane block in the management of post-herpetic thoracic neuralgia: a retrospective observational study

Post-herpetic neuralgia (PHN) is a debilitating neuropathic pain condition that often persists despite optimized pharmacologic therapy and markedly impairs quality of life. The erector spinae plane (ESP) block has emerged as a minimally invasive interfascial technique for thoracic neuropathic pain, but evidence in established PHN remains limited. This retrospective observational study evaluated the effectiveness of thoracic ESP block combined with pregabalin compared with pregabalin alone in patients with severe thoracic PHN. Forty-six patients treated between 2018 and 2022 were included: 22 received pregabalin alone, and 24 received pregabalin plus two ultrasound-guided ESP blocks performed 7 days apart. Pain intensity (Numeric Rating Scale [NRS]), sleep disturbance (Insomnia Severity Index [ISI]), and pregabalin dosage were assessed at baseline and at 2 weeks, 1 month, 3 months, and 6 months. Baseline characteristics were comparable between groups (p>0.05). Although both groups demonstrated progressive improvement over time, the ESP group showed significantly greater reductions in NRS at 2 weeks (p<0.001), 1 month (p=0.0001), 3 months (p=0.016), and 6 months (p=0.004), with pain decreasing from moderate-severe to mild intensity within 2 weeks. Sleep quality improved significantly more in the ESP group at 2 weeks, 1 month, and 3 months (all p<0.05). At 6 months, pregabalin reduction was significantly greater in the ESP group (p=0.004). Thoracic ESP block appears to provide clinically meaningful and sustained analgesia, improve sleep quality, and reduce pharmacologic burden in severe thoracic PHN, supporting its role as an effective adjunct within multimodal pain management strategies. These findings support its role as an effective adjunct in multimodal pain management and warrant confirmation in prospective randomized trials.