High prevalence of neuropathic pain in the hand of patients with traumatic brachial plexus injury: a cross-sectional study

Pulsed radiofrequency to stellate ganglion for brachial plexus injury-induced complex regional pain syndrome: A case series

Brachial plexus injury (BPI) occurs commonly in young adults following trauma. This may result in the development of complex regional pain syndrome (CRPS) following injury, which is difficult to treat. We present a group of patients with CRPS secondary to BPI. These patients were managed with neuromodulation of the stellate ganglion (SG) with pulsed radiofrequency (PRF) and followed up for a period of 3 months to assess for pain relief and a decrease in the intake of medications after the intervention. PRF to SG was found to have significant pain relief lasting around three months.

Inducing Ulnar Nerve Function while Eliminating Claw Hand and Reducing Chronic Neuropathic Pain

Ulnar nerve injury induces chronic neuropathic pain and is frequently devastating due to loss of cupping the hand around objects (finger clawing) and diminished grip strength. There is little chance of restoring good function, eliminating finger clawing, or reducing the pain. A novel technique was tested for its efficacy in promoting ulnar nerve function and reducing finger clawing and chronic neuropathic pain. A 25-year-old subject presented 5.7 months after a wrist gunshot that created three nerve gaps proximal to the deep ulnar nerve branch. He sought restoration of function due to developing ulnar nerve injury-induced claw hand and increasingly severe chronic neuropathic pain. After resection of the scarred nerve tissue, each gap was 10 cm long. The gaps were bridged with two nonreversed sural nerve grafts within a PRP-filled NeuroMend collagen tube (Collagen Matrix, Oakland, N.J.). Some axons regenerated entirely across all three 10-cm-long repaired nerve gaps, restoring excellent topographically correct sensitivity of S4, including two-point discrimination of 4 mm, good M4 motor function, and full ROM. The ulnar nerve injury-induced finger clawing was eliminated, and the chronic neuropathic pain of 7 was reduced to 0 on a 0-10 validated scale and did not return over the following 3.75 years. Thus, this novel technique induces good sensory and motor function, despite repairing three 10-cm-long nerve gaps while eliminating ulnar nerve injury-induced hand clawing and chronic neuropathic pain. Further studies are required to determine whether the effects were due to PRP.

Pregabalin in patients with post-traumatic peripheral neuropathic pain: A meta-analysis of randomized controlled trials

OBJECTIVE

The aim of the study was to investigate the safety and efficacy of pregabalin versus placebo in post-traumatic peripheral neuropathic pain (PTNP).

METHODS

PubMed, Cochrane Library, Web of Science, and Google Scholar were searched for relevant evidence up to January 2022. The Cochran tool was used to assess the quality of randomized clinical trials (RCTs). Data analysis was performed using Comprehensive Meta-Analysis software.

RESULTS

Three RCTs involving 821 patients were included in the meta-analysis. A significant difference was observed between pregabalin and placebo in terms of the pain score (the standardized mean difference [SMD] = -0.14, 95% CI: 0.28 to -0.006, p = 0.04) and sleep interference (MD = -0.25, 95% CI: -0.39 to -0.11, p = 0.00). There was also a significant difference between pregabalin and placebo regarding somnolence (risk ratio [RR] = 2.78; 95% CI: 1.64-4.71, p = 0.00), dizziness (RR = 4.13; 95% CI: 2.71-6.28, p = 0.00), and disturbance in attention (RR: 2.97; 95% CI: 1.02-8.65, p = 0.04). However, no significant difference was observed between pregabalin and placebo in terms of headache (RR = 1.20; 95% CI: 0.70-2.06, p = 0.50), fatigue (RR = 1.42; 95% CI: 0.82-2.47, p = 0.20), nausea (RR = 1.52; 95% CI: 0.88-2.62, p = 0.13), constipation (RR = 1.84; 95% CI: 0.78-4.29, p = 0.15), and discontinuation (RR = 1.52; 95% CI: 0.45-5.06, p = 0.49).

CONCLUSION

Compared with placebo, pregabalin showed better efficacy in reducing PTNP and improving sleep interference. However, it was associated with higher adverse events. Further RCTs are needed to confirm these findings.

Functional capacity of individuals with brachial plexus injury

BACKGROUND

To enable (pain free) functioning, individuals with brachial plexus injury (BPI) may require a higher functional capacity compared to two-handed individuals, because the load on unaffected structures is greater.

OBJECTIVE

This study compared the functional capacity of individuals with BPI and healthy controls and explored differences in the functional capacity of BPI-affected individuals with respect to: those with and without hand function; affected and unaffected sides; with and without musculoskeletal complaints (MSCs).

METHODS

Six functional capacity tests adjusted for one-handed function were performed by 23 BPI-affected individuals and 20 healthy controls. Hand function was assessed through physical examination and the Dutch Musculoskeletal Questionnaire was used to assess MSCs.

RESULTS

Individuals with BPI scored lower for the two-handed tests, compared with the controls (p≤0.01, effect size (r) ≤-0.41 for both tests). However, both groups performed similar in the one-handed tests. On average individuals with BPI met the physical demands to perform sedentary to light physical work. Among BPI-affected individuals, two-handed overhead lifting capacity was higher in those with hand function than in those without hand function (p = 0.02; r = 0.33). Functional capacity tended to be lower for the unaffected side than for the affected side (4 tests; p≤0.05, r≤-0.36). Test results of BPI-affected Individuals with and without MSCs were similar.

CONCLUSION

Individuals with BPI demonstrated lower two-handed functional capacity than healthy controls. Effect sizes were medium. Capacity of their unaffected side was similar to the dominant side of controls. No association was found between MSCs and functional capacity.

Nerve pathology and neuropathic pain after whiplash injury: a systematic review and meta-analysis

ABSTRACT

There is no clear understanding of the mechanisms causing persistent pain in patients with whiplash-associated disorder (WAD). The aim of this systematic review was to assess the evidence for nerve pathology and neuropathic pain in patients with WAD. EMBASE, PubMed, CINAHL (EBSCO), and MEDLINE were searched from inception to September 1, 2020. Study quality and risk of bias were assessed using the Newcastle-Ottawa Quality Assessment Scales. Fifty-four studies reporting on 390,644 patients and 918 controls were included. Clinical questionnaires suggested symptoms of predominant neuropathic characteristic in 34% of patients (range 25%-75%). The mean prevalence of nerve pathology detected with neurological examination was 13% (0%-100%) and 32% (10%-100%) with electrodiagnostic testing. Patients independent of WAD severity (Quebec Task Force grades I-IV) demonstrated significantly impaired sensory detection thresholds of the index finger compared with controls, including mechanical (SMD 0.65 [0.30; 1.00] P < 0.005), current (SMD 0.82 [0.25; 1.39] P = 0.0165), cold (SMD -0.43 [-0.73; -0.13] P = 0.0204), and warm detection (SMD 0.84 [0.25; 1.42] P = 0.0200). Patients with WAD had significantly heightened nerve mechanosensitivity compared with controls on median nerve pressure pain thresholds (SMD -1.10 [-1.50; -0.70], P < 0.0001) and neurodynamic tests (SMD 1.68 [0.92; 2.44], P = 0.0004). Similar sensory dysfunction and nerve mechanosensitivity was seen in WAD grade II, which contradicts its traditional definition of absent nerve involvement. Our findings strongly suggest a subset of patients with WAD demonstrate signs of peripheral nerve pathology and neuropathic pain. Although there was heterogeneity among some studies, typical WAD classifications may need to be reconsidered and include detailed clinical assessments for nerve integrity.

Surgical Management of Traumatic Brachial Plexus Injuries in the Pediatric Population

OBJECTIVE

The aim of this study was to evaluate the demographics, treatment options, and outcomes of pediatric age traumatic brachial plexus injuries (BPI).

METHODS

Traumatic brachial plexus reconstructions in patients aged 17 years or younger were reviewed. Patients were stratified into pan-plexus and incomplete plexus injuries. Functional outcomes (modified British Medical Council Grade -mBMRC) were reviewed after a minimum of 9 months follow-up.

RESULTS

Seventy-one patients underwent brachial plexus reconstruction at an average age of 13.9 years (Range 2-17 years). Approximately half of patients had a pan-brachial plexus injury (n=33, 46.5%) with 59.2% having at least one preganglionic avulsion injury. Twenty-five patients with pan-brachial plexus injuries had follow-up greater than 9 months, of which 12 (48%), 24 (96%), and 17 (68%) had reconstruction surgery for shoulder, elbow, and grasp function, respectively. At last follow-up, 50%, 83%, and 29% of these patients had grade 3 or greater mBMRC in shoulder abduction, elbow flexion, and grasp, respectively. Of the 31 patients with incomplete BPI, 28 (90%) underwent reconstruction for shoulder function, and 13 (42%) had surgery for elbow flexion. At last follow=up, 71% and 100% of patients had grade 3 mBMRC testing in shoulder abduction and elbow flexion.

CONCLUSIONS

Pediatric traumatic BPI are often high energy injuries resulting in nerve root avulsions. Most patients were able to regain anti-gravity elbow flexion or stronger after brachial plexus reconstruction, and over half had similar improvement in shoulder function. Treatment should be directed with goals of elbow flexion, shoulder stability/external rotation, and rudimentary grasp.

Effects of rTMS and tDCS on neuropathic pain after brachial plexus injury: a randomized placebo-controlled pilot study

Neuropathic pain after brachial plexus injury (NPBPI) is a highly disabling clinical condition and is increasingly prevalent due to increased motorcycle accidents. Currently, no randomized controlled trials have evaluated the effectiveness of non-invasive brain stimulation techniques such as repetitive transcranial magnetic stimulation (rTMS) and transcranial direct-current stimulation (tDCS) in patients suffering from NPBPI. In this study, we directly compare the efficacy of 10-Hz rTMS and anodal 2 mA tDCS techniques applied over the motor cortex (5 daily consecutive sessions) in 20 patients with NPBPI, allocated into 2 parallel groups (active or sham). The order of the sessions was randomised for each of these treatment groups according to a crossover design and separated by a 30-day interval. Scores for "continuous" and "paroxysmal" pain (primary outcome) were tabulated after the last stimulation day and 30 days after. Secondary outcomes included the improvement in multidimensional aspects of pain, anxiety state and quality of life from a qualitative and quantitative approach. Active rTMS and tDCS were both superior to sham in reducing continuous (p < 0.001) and paroxysmal (p = 0.002; p = 0.02) pain as well as in multidimensional aspects of pain (p = 0.001; p = 0.002) and anxiety state (p =  < 0.001; p = 0.005). Our results suggest rTMS and tDCS are able to treat NPBPI with little distinction in pain and anxiety state, which may promote the use of tDCS in brachial plexus injury pain management, as it constitutes an easier and more available technique.Clinical Trial Registration: http://www.ensaiosclinicos.gov.br/, RBR-5xnjbc - Sep 3, 2018.

Transcranial Direct Current Stimulation and Mirror Therapy for Neuropathic Pain After Brachial Plexus Avulsion: A Randomized, Double-Blind, Controlled Pilot Study

Introduction: Although transcranial direct current stimulation (tDCS) and mirror therapy (MT) have benefits in combating chronic pain, there is still no evidence of the effects of the simultaneous application of these techniques in patients with neuropathic pain. This study aims to assess the efficacy of tDCS paired with MT in neuropathic pain after brachial plexus injury. Methods: In a sham controlled, double-blind, parallel-group design, 16 patients were randomized to receive active or sham tDCS administered during mirror therapy. Each patient received 12 treatment sessions, 30 min each, during a period of 4 weeks over M1 contralateral to the side of the injury. Outcome variables were evaluated at baseline and post-treatment using the McGill questionnaire, Brief Pain Inventory, and Medical Outcomes Study 36-Item Short-Form Health Survey. Long-term effects of treatment were evaluated at a 3-month follow-up. Results: An improvement in pain relief and quality of life were observed in both groups (p ≤ 0.05). However, active tDCS and mirror therapy resulted in greater improvements after the endpoint (p ≤ 0.02). No statistically significant differences in the outcome measures were identified among the groups at follow-up (p ≥ 0.12). A significant relationship was found between baseline pain intensity and outcome measures (p ≤ 0.04). Moreover, the results showed that state anxiety is closely linked to post-treatment pain relief (p ≤ 0.05). Conclusion: Active tDCS combined with mirror therapy has a short-term effect of pain relief, however, levels of pain and anxiety at the baseline should be considered. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT04385030.

Electroacupuncture-Related Metabolic Brain Connectivity in Neuropathic Pain due to Brachial Plexus Avulsion Injury in Rats

Objective: The present study aimed to investigate the analgesic effect of electroacupuncture (EA) in neuropathic pain due to brachial plexus avulsion injury (BPAI) and related changes in the metabolic brain connectivity. Methods: Neuropathic pain model due to BPAI was established in adult female Sprague-Dawley rats. EA stimulations (2/15 Hz, 30 min/day, 5-day intervention followed by 2-day rest in each session) were applied to the fifth-seventh cervical "Jiaji" acupoints on the noninjured side from 1st to 12th weeks following BPAI (EA group, n = 8). Three control groups included sham EA (nonelectrical acupuncture applied to 3 mm lateral to the real "Jiaji" acupoints), BPAI-only, and normal rats (no particular intervention; eight rats in each group). Thermal withdrawal latency (TWL) of the noninjured forepaw was regularly tested to evaluate the threshold of thermalgesia. Small animal [fluorine-18]-fluoro-2-deoxy-_D-glucose (¹⁸F-FDG) PET/CT scans of brain were conducted at the end of 4th, 12th, and 16th weeks to explore metabolic alterations of brain. Results: In the EA group, the TWL of the noninjured forepaw significantly decreased following BPAI and then increased following EA stimulation, compared with sham EA (P < 0.001). The metabolic brain connectivity among somatosensory cortex (SC), motor cortex (MC), caudate putamen (Cpu), and dorsolateral thalamus (DLT) in bilateral hemispheres decreased throughout the 16 weeks' observation in the BPAI-only group, compared with the normal rats (P < 0.05). In the EA group, the strength of connectivity among the above regions were found to be increased at the end of 4th week following BPAI modeling, decreased at 12th week, and then increased again at 16th week (P < 0.05). The changes in metabolic connectivity were uncharacteristic and dispersed in the sham EA group. Conclusion: The study revealed long-term and extensive changes of metabolic brain connectivity in EA-treated BPAI-induced neuropathic pain rats. Bilateral sensorimotor and pain-related brain regions were mainly involved in this process. It indicated that modulation of brain metabolic connectivity might be an important mechanism of analgesic effect in EA stimulation for the treatment of neuropathic pain.

Comparison of neuropathic pain characteristics associated with total brachial plexus injury before and after surgical repair: A retrospective study

OBJECTIVES

The goal of this study was to compare clinical characteristics of neuropathic pain associated with total brachial plexus injury before and after surgeries and to correlate possible contributing factors concerning to the pain prognosis.

PATIENTS AND METHODS

Thirty patients with both total brachial plexus injury and neuropathic pain were included. Neuropathic pain was evaluated in terms of pain intensities, symptoms and regions. Pain intensities were evaluated by a visual analogue scale. The Neuropathic Pain Symptoms Inventory questionnaire and body maps were used to compare the pain symptoms and regions. Demographic data, injury and repair information were evaluated to analyze the possible factors influencing the prognosis.

RESULTS

The average pain score of all participants was 7.13 ± 2.46 preoperatively and 5.40 ± 2.08 postoperatively. All patients were divided into Pain Relief Group and Pain Aggravation Group. Older age (p = 0.042), machine traction injury (p = 0.019)and nerve transplantation(p = 0.015) seemed to be related with pain aggravation. Paroxysmal pain was aggravated after surgical repairs (p = 0.041), while paresthesia/dysesthesia improved after surgery (p = 0.003). The permanent component of the pain (spontaneous pain) did not show any significant change (p = 0.584). Pain in C5 (p < 0.001) and C6 (p = 0.031) dermatomes got relieved after surgery.

CONCLUSION

This study revealed the neuropathic pain of most patients with total brachial plexus injury was alleviated after neurosurgery, and the pain prognosis of different symptoms and regions varied after the nerve repair.

A Comparative Study of Two Modalities in Pain Management of Patients Presenting with Chronic Brachial Neuralgia

Objectives: The study aims to assess, evaluate, and compare the efficacy of acupressure and hypnotherapy in the management of pain in patients presenting with chronic brachial neuralgia (CBN). Design: Randomized controlled trial. Settings/location: Department of Orthopaedic Surgery, University Malaya Medical Centre, Kuala Lumpur, Malaysia. Subjects: Forty patients with CBN following traumatic brachial plexus injury from 2012 to 2017. Intervention: Therapy for a duration of 1 month in two groups; subjects in the hypnotherapy group received a weekly session of clinical hypnotherapy (total of four times) using a standardized protocol, while subjects in the acupressure group were guided by an acupuncturist during the initial session, received 2 month take home supply of acupressure patches, and were reviewed fortnightly. Outcome measures: The Visual Analog Scale, the Brief Pain Inventory, and the SF-36v2^® Health Survey were recorded at different time points; 1 month pretreatment (week 0), pretreatment (week 4), post-treatment (week 8), and 4 months post-treatment (week 20). Results: There was a statistically significant improvement in the average pain intensity from pretreatment to post-treatment score in both groups. The pain intensity increased 4 months later; however, the pain intensity was still significantly reduced in comparison with pretreatment scores. The study suggests that both treatment outcomes are effective in terms of alleviating pain and improving quality of life in subjects with CBN, to a different degree. Conclusion: Overall, both therapies were able to improve the pain intensity and quality of life significantly during the treatment period. Hypnotherapy was observed to have a better carryover effect compared to acupressure, especially in terms of improving quality of life and the mental component score.

Mechanisms, Treatment, and Patient Outcome of Iatrogenic Injury to the Brachial Plexus-A Retrospective Single-Center Study

BACKGROUND

Injury to the brachial plexus is a devastating condition, with severe impairment of upper extremity function resulting in distinct disability. There are no systematic reports on epidemiology, causative mechanisms, treatment strategies. or outcomes of iatrogenic brachial plexus injury (iBPI).

METHODS

We screened all cases of iatrogenic nerve injuries recorded between 2007 and 2017 at a single specialized institution. Mechanism of iBPI, type of previous causative intervention, location and type of the lesion as well as the type of revision surgery and functional patient outcome were analyzed.

RESULTS

We identified 14 cases of iBPI, which all presented with significant impairment of upper extremity motor function (at least 1 muscle Medical Research Council grade 0). Neuropathic pain was present in most patients (11/14). Orthopedic shoulder procedures such as rotator cuff fixation, arthroplasty, and repositioning of a clavicle fracture accounted for iBPI in 7 of 14 patients. Other reasons for iBPI were resection or biopsy of a peripheral nerve sheath tumor in 3 patients or lymph node situated at the cervicomediastinal area in 2 patients. Mechanisms also included transaxillary rib resection in one and sternotomy in another patient. The treatment of iBPI was conducted according to each individual's needs and included neurolysis in 4, nerve grafting in 9, and nerve transfers in 1 patient. We found improved symptoms after treatment in most patients (11/14).

CONCLUSIONS

Most common causes for iBPI were shoulder surgery and resection or biopsy of peripheral nerve sheath tumor and lymph nodes. Early referral to specialized peripheral nerve centers may help to improve functional patient outcome.

Prevalence of pain and its socio-demographic and clinical correlates among heroin-dependent patients receiving methadone maintenance treatment

To date there have been no studies investigating the characteristics of pain in Chinese heroin-dependent patients (HDPs) receiving methadone maintenance treatment (MMT). This study examined the frequency and socio-demographic and clinical correlates of pain in HDPs under MMT. A consecutive sample of 603 HDPs was recruited from three MMT clinics in Wuhan, China. These patients completed a standardized questionnaire concerning socio-demographic and clinical data. Pain intensity was assessed with the 5-point Verbal Rating Scale (“Overall, how intense is your pain now?”) with responses of: 1 = none, 2 = mild, 3 = moderate, 4 = severe, 5 = very severe. A pain score of three or higher was used to denote clinical significant pain (CSP). The prevalence of CSP in HDPs receiving MMT was 53.6%. Factors significantly associated CSP in multiple logistics regression analysis were old age, marital status of “non-married”, unemployment, having religious beliefs, a history of injecting heroin, a high dose of methadone, and more depressive symptoms. Over a half of Chinese HDPs receiving MMT have CSP. Services for HDPs in MMT settings should include periodic screening for pain, psychosocial supports, and professional treatment for pain.