To evaluate the analgesic effect of intrathecal gabapentin therapy on secondary hyperalgesia in a rat model of persistent muscle pain.
Intrathecal catheters were implanted into rats. Mechanical secondary hyperalgesia was induced by repeated intramuscular injections of acidic solution into the gastrocnemius muscle. Gabapentin was administrated intrathecally. Rats were allocated to control and experimental (gabapentin 30, 100, 300, and 1,000 µg) group. After gabapentin administration, mechanical withdrawal threshold was measured every 15 minutes and the motor function was measured 30 minutes later.
Mechanical hyperalgesia was evoked after the second acidic buffer injection. There was a significant improvement on the mechanical threshold after administration of 100, 300, and 1,000 µg gabapentin compared to pre-injection and the control group. The analgesic effect continued for 105, 135, and 210 minutes, respectively. To discern side effects, motor function was measured. Motor function was preserved in both groups after gabapentin administration, except for rats who received 1,000 µg gabapentin.
Intrathecal gabapentin administration produces dose-dependent improvements in mechanical hyperalgesia in a persistent muscle pain rat model. This implicates the central nervous system as having a strong influence on the development of persistent mechanical hyperalgesia. These results are helpful in understanding the pathophysiology of secondary hyperalgesia and in the treatment of patients with chronic muscle pain.
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To compare the treatment effects of epidural neuroplasty (NP) and transforaminal epidural steroid injection (TFESI) for the radiating pain caused by herniated lumbar disc.
Thirty-two patients diagnosed with herniated lumbar disc through magnetic resonance imaging or computed tomography were included in this study. Fourteen patients received an epidural NP and eighteen patients had a TFESI. The visual analogue scale (VAS) and functional rating index (FRI) were measured before the treatment, and at 2 weeks, 4 weeks and 8 weeks after the treatment.
In the epidural NP group, the mean values of the VAS before the treatment, and at 2 weeks, 4 weeks and 8 weeks after the treatment were 7.00±1.52, 4.29±1.20, 2.64±0.93, 1.43±0.51 and those of FRI were 23.57±3.84, 16.50±3.48, 11.43±2.44, 7.00±2.15. In the TFESI group, the mean values of the VAS before the treatment, and at 2 weeks, 4 weeks and 8 weeks after the treatment were 7.22±2.05, 4.28±1.67, 2.56±1.04, 1.33±0.49 and those of FRI were 22.00±6.64, 16.22±5.07, 11.56±4.18, 8.06±1.89. During the follow-up period, the values of VAS and FRI within each group were significantly reduced (p<0.05) after the treatment. But there were no significant differences between the two groups statistically.
Epidural NP and TFESI are equally effective treatments for the reduction of radiating pain and for improvement of function in patients with a herniated lumbar disc. We recommend that TFESI should be primarily applied to patients who need interventional spine treatment, because it is easier and more cost-effective than epidural NP.
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To identify risk factors for developing a vertebral refracture after percutaneous vertebroplasty.
A retrospective analysis of 60 patients who had undergone percutaneous vertebroplasty between January 2008 and April 2010 was conducted. All patients were observed for a 1 year follow-up period, and fracture was defined when it was both clinically reported and radiographically confirmed. Twenty-seven patients with a refractured vertebra and 33 patients without a refracture were included. Of the 60 patients, 20 presented with a refracture from a cemented vertebra, whereas the remaining 40 patients did not. Clinical, imaging and procedure-related factors for each group were analyzed by the Fisher's exact, chi-square, and the Mann-Whitney
Local kyphotic angle and sagittal index were significant as a result of researching various risk factors related to vertebral refracture (p<0.001, p<0.001, respectively) and refracture from a cemented vertebra itself (p=0.004, p<0.001, respectively). Other factors were not significant.
Patients who had a high preoperative local kyphotic angle and a high sagittal index required a close follow-up and attention.
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