Background: Neuropathic pain, a chronic and debilitating condition caused by damage to the nervous system, remains challenging to treat due to its complex pathophysiology and resistance to analgesics. This study investigated the analgesic effects of Panaphix (PAX-1), a novel pharmacological agent, in a rat model of neuropathic pain induced by spinal nerve ligation (SNL). Methods: Male Sprague–Dawley rats underwent SNL to induce neuropathic pain. PAX-1 (0.1, 1, or 10 mg/kg) or vehicle was administered orally once daily for seven consecutive days starting on postoperative day 8. Mechanical allodynia was evaluated using the von Frey filament test, and the dorsal root ganglia were analyzed using an enzyme-linked immunosorbent assay and immunofluorescence to evaluate tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) expression levels.Results: PAX-1 significantly alleviated mechanical allodynia induced by SNL in a dose-dependent manner, and 1 mg/kg was selected as the optimal dose for subsequent analyses. PAX-1 markedly reduced IL-1β expression in microglia and partially decreased TNF-α immunoreactivity within the dorsal root ganglion, while showing minimal effects on the expression of astrocytic cytokines.Conclusions: PAX-1 demonstrated potent anti-allodynic and anti-inflammatory effects in an SNL-induced neuropathic pain model. These findings indicate that PAX-1 may exert analgesic effects primarily through modulation of IL-1β-mediated microglial activation, suggesting its therapeutic potential for neuropathic pain management.

Background and Objectives: Ultrasound-guided stellate ganglion block is a promising alternative intervention for cervical radicular pain. However, factors associated with treatment responses remain unknown. This single-center, retrospective study aimed to identify clinical and radiological factors associated with treatment response to stellate ganglion block in patients with cervical radicular pain. Materials and Methods: This study included patients with cervical radicular pain who underwent ultrasound-guided stellate ganglion block. Successful response was defined as a ≥4-point or ≥50% reduction in the numerical rating scale score at 3 months post-procedure compared with the pre-procedural baseline. Patients who did not meet these criteria or underwent additional interventional procedures for persistent cervical radicular pain within 3 months were classified as unsuccessful responders. Logistic regression analysis was performed to identify factors associated with treatment response. Results: Multivariable logistic regression analysis demonstrated that substantial cervical multifidus fatty degeneration, defined as Goutallier grade ≥2 of the cervical multifidus muscles (vs. minimal fatty degeneration, odds ratio (OR) 0.23, 95% confidence interval (CI): 0.08–0.66, p = 0.007) and bony hypertrophy at the uncovertebral or facet joint as the primary etiology of foraminal stenosis (vs. disc herniation, OR 0.35, 95% CI: 0.14–0.87, p = 0.024) were independently associated with lower odds of a successful response to stellate ganglion block. Steroid use was not significantly associated with treatment response (OR 0.52, 95% CI: 0.18–1.49, p = 0.223). The successful response rate declined progressively with the number of risk factors: 94.7% (18/19), 50.0% (22/44), and 40.7% (11/27) for zero, one, and two factors, respectively (p < 0.001). Conclusions: Substantial cervical multifidus fatty degeneration and foraminal stenosis attributable to bony hypertrophy may be associated with lower odds of a successful response to stellate ganglion block in patients with cervical radicular pain. These factors require prospective validation before routine clinical implementation.