• The Korean Journal of Pain
• /
• v.35 no.4
• /
• pp.468-474
• /
• 2022

Background: The new type of corona virus has a wide range of symptoms. Some people who have COVID-19 can experience long-term effects from their infection, known as post-COVID conditions. The authors aimed to investigate prolonged musculoskeletal pain as a symptom of the post-COVID-19 condition. Methods: This is a descriptive study on the patients who were diagnosed with COVID-19 in a university hospital, between March 2020 and March 2021. Patient records and an extensive questionnaire were used to obtain relevant demographic and clinical characteristics, including hospitalization history, comorbidities, smoking history, duration of the pain, the area of pain, and the presence of accompanying neuropathic symptoms. Results: Of the diagnosed patients, 501 agreed to participate in the study. Among the participants, 318 had musculoskeletal pain during COVID-19 infection, and 69 of them reported prolonged pain symptoms as part of their a post-COVID condition which could not be attributed to any other cause. The mean duration of pain was 4.38 ± 1.73 months, and the mean pain level was 7.2 ± 4.3. Neuropathic pain symptoms such as burning sensation (n = 16, 23.2%), numbness (n = 15, 21.7%), tingling (n = 10, 14.5%), stinging (n = 4, 5.8%), freezing (n = 1, 1.4%) were accompanied in patients with prolonged musculoskeletal pain. Conclusions: Patients with COVID-19 may develop prolonged musculoskeletal pain. In some patients, neuropathic pain accompanies it. Awareness of prolonged post-COVID-19 pain is crucial for its early detection and management.

• Journal of Korean Neurosurgical Society
• /
• v.65 no.2
• /
• pp.276-286
• /
• 2022

Objective : Spinal cord stimulation (SCS) is an effective treatment for chronic neuropathic pain. However, its clinical efficacy in regard to specific types of pain has not been well studied. The primary objective of this study was to retrospectively analyze the clinical outcomes of paddle-type SCS according to the type of neuropathic pain. Methods : Seventeen patients who underwent paddle-lead SCS at our hospital were examined. Clinical outcomes were evaluated pre- and postoperatively (3 months, 1 year, and last follow-up) using the Neuropathic Pain Symptom Inventory (NPSI). The NPSI categorizes pain as superficial, deep, paroxysmal, evoked, or dysesthesia and assess the duration of the pain (pain time score). Changes in NPSI scores were compared with change in Visual analogue scale (VAS) scores. Results : After SCS, the pain time score improved by 45% (independent t-test, p=0.0002) and the deep pain score improved by 58% (independent t-test, p=0.001). Improvements in the pain time score significantly correlated with improvements in the VAS score (r=0.667, p=0.003, Spearman correlation). Additionally, the morphine milligram equivalent value was markedly lower after vs. before surgery (~49 mg, pared t-test, p=0.002). No preoperative value was associated with clinical outcome. Conclusion : The NPSI is a useful tool for evaluating the therapeutic effects of SCS. Chronic use of a paddle-type spinal cord stimulation improved the deep pain and the pain time scores.

• Korean Journal of Acupuncture
• /
• v.30 no.1
• /
• pp.56-63
• /
• 2013

Objectives : Effects of repetitive electroacupuncture(EA) on the pain behavior and activation of spinal glial cells were examined in the rat model of neuropathic pain. Methods : Twenty one adult male Sprague-Dawley rats were randomly assigned into 3 groups(control group, SP6 group, ST36+GB34 group). Neuropathic pain was induced by tight ligation of L5 spinal nerve. Mechanical and thermal hypersensitivity of hind paw were tested. Immunohistochemistry was performed in spinal cord L5/6 of all groups. EA was treated once in a day from the $5^{th}$ day after surgery. Results : EA treatments applied to ST36 and GB34 reduced significantly both of mechanical and thermal hypersensitivity after 3 times of treatment throughout the experiments. In the SP6 group, the analgesic effect was also shown after 7 times of treatment. Immunohistochemistry demonstrated inhibition of microglia and astrocyte activation in the spinal cord L5/6 dorsal horn in the ST36+GB34 group. Conclusions : The present results suggest that repetitive EA exert strong analgesic effect on neuropathic pain. These analgesic effects in neuropathic pain are associated with suppressing the activation of microglia and astrocyte.

• The Korean Journal of Pain
• /
• v.13 no.2
• /
• pp.156-163
• /
• 2000

Background: Peripheral nerve injury sometimes leads to chronic neuropathic pain such as causalgia. A subset of patients with causalgia have a sympathetically maintained pain which is often evoked by cooling stimuli. However, our knowledge on adrenergic receptor types responsible for cold-evoked pain that is sympathetically dependent is lacking. The present study was conducted to investigate subtypes of adrenoceptors involved in mediating cold-evoked pain that developed following peripheral nerve injury. Methods: Neuropathic surgery was performed by a unilateral ligation of L5 and L6 spinal nerves of rats. Behavioral sign of cold-evoked pain was examined for 5 min by measuring cumulative duration of time that the rat lifted its foot off a metal plate held at cold temperature ($5^{\circ}C$). Whether cold-evoked pain behavior was affected by antagonists of various subtypes of adrenoceptors, which were administered intraperitoneally before and after the ligation, was investigated. Results: After ligation, duration of foot lifting on the ligated side at cold temperature increased as compared to the pre-operative period. This increase maintained for the entire 40-day test period. Pretreatment with alpha-antagonist phentolamine produced a suppression of cold-evoked pain behavior that was not affected by beta-antagonist propranolol pretreatment. Prazosin, alpha-1 antagonist, suppressed cold- evoked pain behavior when treated either before or after nerve ligation. On the other hand, alpha-2 antagonist yohimbine was without effect on cold-evoked pain behavior whether it was treated before or after the ligation. Conclusions: The results suggest that peripheral nerve injury develops cold-evoked pain that is sympathetically dependent, and that alpha-1 adrenoreceptor plays a critical role for the generation of this type of pain in its initiation as well as maintenance.

• The Korean Journal of Pain
• /
• v.31 no.3
• /
• pp.155-173
• /
• 2018

Chronic postsurgical pain (CPSP) is an unwanted adverse event in any operation. It leads to functional limitations and psychological trauma for patients, and leaves the operative team with feelings of failure and humiliation. Therefore, it is crucial that preventive strategies for CPSP are considered in high-risk operations. Various techniques have been implemented to reduce the risk with variable success. Identifying the risk factors for each patient and applying a timely preventive strategy may help patients avoid the distress of chronic pain. The preventive strategies include modification of the surgical technique, good pain control throughout the perioperative period, and preoperative psychological intervention focusing on the psychosocial and cognitive risk factors. Appropriate management of CPSP patients is also necessary to reduce their suffering. CPSP usually has a neuropathic pain component; therefore, the current recommendations are based on data on chronic neuropathic pain. Hence, voltage-dependent calcium channel antagonists, antidepressants, topical lidocaine and topical capsaicin are the main pharmacological treatments. Paracetamol, NSAIDs and weak opioids can be used according to symptom severity, but strong opioids should be used with great caution and are not recommended. Other drugs that may be helpful are ketamine, clonidine, and intravenous lidocaine infusion. For patients with failed pharmacological treatment, consideration should be given to pain interventions; examples include transcutaneous electrical nerve stimulation, botulinum toxin injections, pulsed radiofrequency, nerve blocks, nerve ablation, neuromodulation and surgical management. Physical therapy, cognitive behavioral therapy and lifestyle modifications are also useful for relieving the pain and distress experienced by CPSP patients.

• The Korean Journal of Pain
• /
• v.34 no.2
• /
• pp.217-228
• /
• 2021

Background: The purpose of this study was to assess the effectiveness of transcutaneous electrical nerve stimulation (TENS) in chronic low back pain and neuropathic pain. Methods: Seventy-four patients aged 18-65 with chronic low back pain were included in the study. Baseline measurements were performed, and patients were randomized into three groups. The first group received burst TENS (bTENS), the second group conventional TENS (cTENS), and the third group placebo TENS (pTENS), all over 15 sessions. Patients' visual analogue scale (VAS) scores were evaluated before treatment (preT), immediately after treatment (postT), and in the third month after treatment (postT3). Douleur Neuropathique 4 Questions (DN4), the Modified Oswestry Low Back Pain Disability Questionnaire (MOS), the Beck Depression Inventory (BDI), and sympathetic skin response (SSR) values were also evaluated preT and postT3. Results: A statistically significant improvement was observed in mean VAS scores postT compared to preT in all three groups. Intergroup comparison revealed a significant difference between preT and postT values, that difference being assessed in favor of bTENS at multiple comparison analysis. Although significant improvement was determined in neuropathic pain DN4 scores measured at postT3 compared to preT in all groups, there was no significant difference between the groups. No statistically significant difference was also observed between the groups in terms of MOS, BDI, or SSR values at postT3 (P > 0.05). Conclusions: bTENS therapy in patients with low back pain is an effective and safe method that can be employed in short-term pain control.

• The Korean Journal of Pain
• /
• v.35 no.4
• /
• pp.391-402
• /
• 2022

Background: The mechanism of peripheral axon transport in neuropathic pain is still unclear. Chemokine ligand 13 (CXCL13) and its receptor (C-X-C chemokine receptor type 5, CXCR5) as well as GABA transporter 1 (GAT-1) play an important role in the development of pain. The aim of this study was to explore the axonal transport of CXCL13/CXCR5 and GAT-1 with the aid of the analgesic effect of botulinum toxin type A (BTX-A) in rats. Methods: Chronic constriction injury (CCI) rat models were established. BTX-A was administered to rats through subcutaneous injection in the hind paw. The pain behaviors in CCI rats were measured by paw withdrawal threshold and paw withdrawal latencies. The levels of CXCL13/CXCR5 and GAT-1 were measured by western blots. Results: The subcutaneous injection of BTX-A relieved the mechanical allodynia and heat hyperalgesia induced by CCI surgery and reversed the overexpression of CXCL13/CXCR5 and GAT-1 in the spinal cord, dorsal root ganglia (DRG), sciatic nerve, and plantar skin in CCI rats. After 10 mmol/L colchicine blocked the axon transport of sciatic nerve, the inhibitory effect of BTX-A disappeared, and the levels of CXCL13/CXCR5 and GAT-1 in the spinal cord and DRG were reduced in CCI rats. Conclusions: BTX-A regulated the levels of CXCL13/CXCR5 and GAT-1 in the spine and DRG through axonal transport. Chemokines (such as CXCL13) may be transported from the injury site to the spine or DRG through axonal transport. Axon molecular transport may be a target to enhance pain management in neuropathic pain.

• Journal of Acupuncture Research
• /
• v.27 no.5
• /
• pp.13-24
• /
• 2010

Objectives : This study was designed to investigate the effects of bee venom acupuncture at Shinsu($BL_{23}$) and Daejangsu($BL_{25}$) on neuropathic pain induced by tibial and sural nerve injury in rats. Methods : Neuropathic pain model was made by partial resection of tibial and sural nerve. Three weeks after the neuropathic surgery, bee venom acupuncture was firstly injected at $BL_{23}$ and $BL_{25}$, then we measured withdrawal responses induced by von Frey filament and acetone stimulation. Bee venom acupunctures were injected 6times on every 2days. Measurement of withdrawal responses were conducted on the same days. After bee venom acupuncture injection, expression levels of c-Fos, nocieptin and KOR-3 were observed through using immunohistochemistry. Results : In this experiment, bee venom acupunctures at $BL_{23}$ and $BL_{25}$ decreased levels of withdrawal responses induced by von Frey filament and acetone stimulation respectively. In addtion, expression levels of c-Fos, nociceptin and KOR-3 in central gray part of brain in rats were decreased by bee venom acupuncture. Conclusions : These results imply that bee venom acupuncture was useful to treat patients with neuropathic pain, and related mechanisms were involved in opioid and their receptors such as nociceptin and KOR-3.

• The Korean Journal of Pain
• /
• v.30 no.3
• /
• pp.183-191
• /
• 2017

Background: Current therapy for the treatment of neuropathic pain is often unsatisfactory. Considerable variation in treatment pattern still exists in spite of availability of sufficient literature from various guidelines. Recent Indian market data suggested that the utilization (sale) of drugs such as amitriptyline, pregabalin, and gabapentin was more for low-dose unit packs than that of the high-dose unit packs, raising the belief that these drugs are prescribed at a lower dose than is actually recommended in the guidelines. To test this hypothesis, a survey was conducted across speciality throughout the country to observe the prescription pattern of these drugs amongst the health care providers in India. Methods: Three hundred fifty survey forms were distributed of which 281 forms were included for analysis. Results: It was observed that the commonly used initiation and maintenance dose for amitriptyline, pregabalin, and gabapentin was 5-10 mg/day, 50-75 mg/day, and 100-300 mg/day, respectively. The reason to select the lower dosages was to have a balancing effect to achieve good efficacy with minimum side effects. Care-givers reported no side effects/not many side effects as a reason in 22.2%, 16.88%, and 23.86% patients with amitriptyline, pregabalin, and gabapentin, respectively. Sedation and giddiness were commonly reported with all three drugs. Conclusions: Commonly prescribed drugs for management of neuropathic pain, such as amitriptyline, pregabalin, and gabapentin are preferred at lower doses in Indian clinical settings. Acceptable efficacy and low tolerance to the standard dosage is believed to be the reason behind the prescribed dose.

• Journal of Korean Academy of Nursing
• /
• v.40 no.5
• /
• pp.611-619
• /
• 2010

The purpose of this study was to examine the effects of exercise on muscle weight and Type I and II fiber cross-sectional area of affected and unaffected hindlimb muscles in rats with neuropathic pain induced by unilateral peripheral nerve injury. Methods: Neuropathic pain was induced by ligation and cutting of the left L5 spinal nerve. Adult male Sprague-Dawley rats were randomly assigned to one of two groups: The Pain+Exercise (PE) group (n=21) and the Sham+Exercise (SE) group (n=20). All rats had 28 sessions of treadmill exercise at grade 10 for 30 minutes, twice/day at 10 m/min for 14 days. Body weight, food intake and activity were measured every day. At 15 days all rats were anesthetized and soleus, plantaris and gastrocnemius muscles were dissected. Muscle weight and Type I, II fiber cross-sectional area of the dissected muscles were measured. Results: The PE group showed significant increases (p<.05), as compared to the SE group for body weight and total diet intake, muscle weight of the unaffected soleus and plantaris, and in Type I and II fiber cross-sectional area of unaffected three muscles and affected plantaris. Conclusion: Exercise for 14 days attenuates unaffected soleus, plantaris and gastrocnemius muscle atrophy in neuropathic pain model.