Jeong Gil Leem

Treatment of chronic lumbosacral radicular pain using adjuvant pulsed radiofrequency: a randomized controlled study.

OBJECTIVES The objective of this study was to determine the effects of combining pulsed radiofrequency (PRF) treatment and transforaminal epidural injection (TFEI) to treat patients with chronic refractory lumbar radicular pain caused by lumbar spinal stenosis. STUDY DESIGN Randomized control trial. SETTINGS Interventional pain management practice. METHOD Sixty-two patients were assigned to the study groups (PRF group = 31; control group = 31). Under fluoroscopic guidance, the RF needle was positioned close to the lumbar dorsal root ganglion. The PRF group received 3 cycles of PRF treatment, and sensory stimulation without RF lesioning was applied to the control group. After PRF or sham lesioning, a local anesthetic with steroid was injected. The primary outcome of a successful response was defined as: 1) ≥50% or 4-point pain reduction in the numerical rating scale (NRS) without an increase in the Oswestry disability index (ODI) or medication quantification scale (MQS), or mean score <4 in the global perceived effect (GPE) scale; or 2) ≥30% or 2-point pain reduction in NRS with a simultaneous decrease in ODI, MQS, or ≥6 points in the GPE scale. RESULT The number of patients with successful treatment results was higher in the PRF group at 2 months (P = 0.032) and 3 months (P = 0.018). No significant differences were observed in terms of the secondary outcome variables between the 2 groups. CONCLUSION The TFEI provided significant short-term pain relief and PRF can be applied in conjunction with TFEI to achieve higher treatment efficacy compared with TFEI alone.

Effects of Nefopam on Streptozotocin-Induced Diabetic Neuropathic Pain in Rats

Background Nefopam is a centrally acting non-opioid analgesic agent. Its analgesic properties may be related to the inhibitions of monoamine reuptake and the N-methyl-D-aspartate (NMDA) receptor. The antinociceptive effect of nefopam has been shown in animal models of acute and chronic pain and in humans. However, the effect of nefopam on diabetic neuropathic pain is unclear. Therefore, we investigated the preventive effect of nefopam on diabetic neuropathic pain induced by streptozotocin (STZ) in rats. Methods Pretreatment with nefopam (30 mg/kg) was performed intraperitoneally 30 min prior to an intraperitoneal injection of STZ (60 mg/kg). Mechanical and cold allodynia were tested before, and 1 to 4 weeks after drug administration. Thermal hyperalgesia was also investigated. In addition, the transient receptor potential ankyrin 1 (TRPA1) and TRP melastatin 8 (TRPM8) expression levels in the dorsal root ganglion (DRG) were evaluated. Results Pretreatment with nefopam significantly inhibited STZ-induced mechanical and cold allodynia, but not thermal hyperalgesia. The STZ injection increased TRPM8, but not TRPA1, expression levels in DRG neurons. Pretreatment with nefopam decreased STZ-induced TRPM8 expression levels in the DRG. Conclusions These results demonstrate that a nefopam pretreatment has strong antiallodynic effects on STZ-induced diabetic rats, which may be associated with TRPM8 located in the DRG.

Tumor Necrosis Factor-alpha and Apoptosis Following Spinal Nerve Ligation Injury in Rats

Background Spinal nerve ligation (SNL) injury in rats produces a pain syndrome that includes mechanical and thermal allodynia. Previous studies have indicated that proinflammatory cytokines such as tumor necrosis factor-α (TNF-α) play an important role in peripheral mediation of neuropathic pain, and that altered dorsal root ganglion (DRG) function and degree of DRG neuronal apoptosis are associated with spinal nerve injury. The present study was conducted to evaluate the expression of TNF-α and the extent of apoptosis in the dorsal root ganglion after SNL in rats. Methods Sprague-Dawley rats were subjected to SNL of the left L5 and L6 spinal nerves distal to the DRG and proximal to the formation of the sciatic nerve. At postoperative day 8, TNF-α protein levels in the L5-6 DRG were compared between SNL and naive groups using ELISA. In addition, we compared the percentage of neurons injured in the DRG using immunostaining for apoptosis and localization of activated caspase-3. Results SNL injury produced significant mechanical and cold allodynia throughout the 7-day experimental period. TNF-α protein levels were increased in the DRG in rats that had undergone SNL (12.7 ± 3.2 pg/100 µg, P < 0.001) when compared with naïve rats (4.1 ± 1.4 pg/100 µg). The percentage of neurons or satellite cells co-localized with activated caspase-3 were also significantly higher in rats with SNL than in naïve rats (P < 0.001, P < 0.05, respectively). Conclusions SNL injury produces mechanical and cold allodynia, as well as TNF-α elevation and apoptosis in the DRG.

Clinical Experiences of Transforaminal Balloon Decompression for Patients with Spinal Stenosis

Lumbar spinal stenosis is a commonly treated with epidural injections of local anesthetics and corticosteroids, however, these therapies may relieve leg pain for weeks to months but do not influence functional status. Furthermore, the majority of patients report no substantial symptom change over the repeated treatment. Utilizing balloon catheters, we successfully treated with three patients who complained persistent symptoms despite repeated conventional steroid injections. Our results suggest that transforaminal decompression using a balloon catheter may have potential in the nonsurgical treatment of spinal stenosis by modifying the underlying pathophysiology.

Adenosine triphosphate-sensitive potassium channel blockers attenuate the antiallodynic effect of R-PIA in neuropathic rats.

BACKGROUND: Nerve injury can generate neuropathic pain. The accompanying mechanical allodynia may be reduced by the intrathecal administration of adenosine. The neuroprotective effects of adenosine are mediated by the adenosine triphosphate (ATP)-sensitive potassium (KATP) channel. We assessed the relationship between the adenosine A1 receptor agonist, N6-(R)-phenylisopropyl adenosine (R-PIA), and KATP channels to determine whether the antiallodynic effects of R-PIA are also mediated through KATP channels in a rat nerve ligation injury model of neuropathic pain. METHODS: Mechanical allodynia was induced by tight ligation of the left lumbar fifth and sixth spinal nerves. Mechanical allodynia in the left hindpaw was evaluated using von Frey filaments to measure withdrawal thresholds. R-PIA (0.5, 1, or 2 &mgr;g) was administered intrathecally to induce antiallodynia. We assessed whether pretreatment with the KATP channel blockers glibenclamide or 5-hydroxydecanoate reversed the antiallodynic effect of R-PIA. Also, we evaluated whether diazoxide, a KATP channel opener, had an antiallodynic effect and promoted the antiallodynic effect of R-PIA. Lastly, we investigated whether the voltage-activated K channel blocker 4-aminopyridine attenuated the effect of R-PIA. RESULTS: Intrathecal R-PIA produced maximal antiallodynia at 2 &mgr;g (P < 0.05). Intrathecal pretreatment with glibenclamide and intraperitoneal pretreatment 5-hydroxydecanoate significantly reduced the antiallodynic effect of R-PIA. Diazoxide produced an antiallodynic effect and also enhanced the antiallodynic action of R-PIA. 4-Aminopyridine had no effect on the antiallodynic action of R-PIA. CONCLUSIONS: The antiallodynic effects of adenosine A1 receptor stimulation may be related to KATP channel activity in a rat model of nerve ligation injury.

Smoking May Increase Postoperative Opioid Consumption in Patients Who Underwent Distal Gastrectomy With Gastroduodenostomy for Early Stomach Cancer: A Retrospective Analysis

Objectives: Although nicotine has an analgesic effect, the incidence and severity of chronic pain is higher in smokers than nonsmokers. Acute pain is more intense in smokers during the perioperative period. This study evaluated whether smokers require higher doses of opioid to reduce pain when they undergo surgery. Methods: A retrospective review of 236 patients who had intravenous patient-controlled analgesia after distal gastrectomy with gastroduodenostomy between October 2013 and September 2014 was performed to analyze the difference in postoperative opioid requirements between smokers and nonsmokers. Total opioid consumption was observed from the day of operation to postoperative day 2. Patients were grouped into smokers (N=117) and nonsmokers (N=119) for comparison. Simple and multiple regression analyses were performed to identify predictors of postoperative opioid requirements. Results: Opioid consumption by male smokers was higher than nonsmokers. Multiple regression analysis showed that age, smoking, and amount of intraoperative remifentanil were the only significant factors for postoperative opioid requirements. Discussion: Our results suggest that smokers undergoing distal gastrectomy with gastroduodenostomy required more opioid than nonsmokers for postoperative pain. Old age, smoking status, and increment of remifentanil use seemed to be predictors of postoperative opioid consumption.