Long-term Pain Outcomes Research Articles

Perioperative Analgesic Interventions for Reduction of Persistent Postsurgical Pain After Total Hip and Knee Arthroplasty: A Systematic Review and Meta-analysis.

High pain levels immediately after surgery have been associated with persistent postsurgical pain. Still, it is uncertain if analgesic treatment of immediate postsurgical pain prevents the development of persistent postsurgical pain. We searched MEDLINE, CENTRAL, and Embase up to September 12, 2023, for randomized controlled trials investigating perioperative analgesic interventions and with reported pain levels 3 to 24 months after total hip or knee arthroplasty in patients with osteoarthritis. The primary outcome was pain score 3 to 24 months after surgery, assessed at rest and during movement separately. Two authors independently screened, extracted data, and assessed risk of bias using the Cochrane Risk of Bias 2 tool. We conducted meta-analyses and tested their robustness with trial sequential analyses and worst-best and best-worst case analyses. We included 49 trials with 68 intervention arms. All but 4 trials were at high risk of bias for the primary outcome. Moreover, the included trials were heterogeneous in terms of exclusion criteria, baseline pain severity, and which cointerventions the participants were offered. For pain at rest, no interventions demonstrated a statistically significant difference between intervention and control. For pain during movement, perioperative treatment with duloxetine (7 trials with 641 participants) reduced pain scores at 3 to 24 months after surgery (mean difference -4.9 mm [95% confidence interval {CI}, -6.5 to -3.4] on the 0-100 visual analog scale) compared to placebo. This difference was lower than our predefined threshold for clinical importance of 10 mm. We found no perioperative analgesic interventions that reduced pain 3 to 24 months after total hip or knee arthroplasty for osteoarthritis. The literature on perioperative analgesia focused little on potential long-term effects. We encourage the assessment of long-term pain outcomes.

ID: 343080 A Report on Interim Long-term Pain Outcomes from the COMFORT Peripheral Nerve Stimulation RCT

ID: 343080 A Report on Interim Long-term Pain Outcomes from the COMFORT Peripheral Nerve Stimulation RCT

Impact of the Disc Vacuum Phenomenon on Surgical Outcomes in Lumbar Spinal Stenosis: A Comparative Study between Endoscopic Decompression and Minimally Invasive Oblique Lateral Interbody Fusion.

Objective: This study investigated the influence of the vacuum phenomenon (VP) on surgical outcomes in patients with lumbar spinal stenosis, comparing minimally invasive oblique lateral interbody fusion (MIS OLIF) and endoscopic decompression. Methods: A cohort of 110 patients diagnosed with lumbar spinal stenosis underwent either endoscopic decompression or MIS OLIF. Patients were classified into two groups based on the presence or absence of the VP on preoperative CT scans, non-VP (n = 42) and VP (n = 68). Radiologic and clinical outcomes, including back and leg pain assessed using the visual analogue scale (VAS), the Oswestry Disability Index (ODI), and the EuroQol-5 Dimension (Eq5D), were compared pre- and postoperatively over a 2-year follow-up period. Results: Preoperatively, the VP group exhibited significantly greater leg pain (p = 0.010), while no significant differences were observed in back pain or the ODI between the groups. In the non-VP group, decompression and fusion yielded similar outcomes, with decompression showing a better ODI score at 1 month (p = 0.018). In contrast, in the VP group, patients who underwent fusion showed significantly improved long-term leg pain outcomes compared to those who underwent decompression at both 1-year (p = 0.042) and 2-year (p = 0.017) follow-ups. Conclusions: The VP may indicate segmental instability and may play a role in the persistence of radiculopathy. Fusion surgery appears to offer better long-term relief in patients with the VP, whereas decompression alone is a viable option in non-VP cases. These findings suggest that the VP may be a useful factor in guiding surgical decision-making.

People with short symptom duration of knee osteoarthritis benefit more from exercise therapy than people with longer symptom duration: An individual participant data meta-analysis from the OA trial bank

ObjectiveTo investigate whether duration of knee symptoms influenced the magnitude of the effect of exercise therapy compared to non-exercise control interventions on pain and physical function in people with knee osteoarthritis (OA). MethodWe undertook an individual participant data (IPD) meta-analysis utilizing IPD stored within the OA Trial Bank from randomised controlled trials (RCTs) comparing exercise to non-exercise control interventions among people with knee OA. IPD from RCTs were analysed to determine the treatment effect by considering both study-level and individual-level covariates in the multilevel regression model. To estimate the interaction effect (i.e., treatment x duration of symptoms (dichotomized)), on self-reported pain or physical function (standardized to 0-100 scale) a one-stage multilevel regression model was applied. ResultsWe included IPD from 1767 participants with knee OA from 10 RCTs. Significant interaction effects between study arm and symptom duration (≤1 year vs >1 year, and ≤2 years vs>2 years) were found for short- (~3 months) (Mean Difference (MD) -3.57, 95%CI -6.76 to -0.38 and -4.12, 95% CI-6.58 to -1.66, respectively) and long-term (~12 months) pain outcomes (MD -8.33, 95%CI -12.51 to -4.15 and -8.00, 95%CI -11.21 to -4.80, respectively), and long-term function outcomes (MD -5.46, 95%CI -9.22 to -1.70 and -4.56 95%CI -7.33 to-1.80, respectively). ConclusionsThis IPD meta-analysis demonstrated that people with a relatively short symptom duration benefit more from therapeutic exercise than those with a longer symptom duration. Therefore, there seems to be a window of opportunity to target therapeutic exercise in knee OA.

Long-term pain outcomes after serial lidocaine infusion in participants with recent onset of peripheral neuropathic pain: A pilot double-blind, randomized, placebo-controlled trial.

This study investigated the outcomes up to 12 weeks after serial lidocaine infusion for early-onset peripheral neuropathic pain. This pilot double-blind, randomized, 2-arm placebo-controlled trial recruited 50 participants with onset of peripheral neuropathic pain within the past 6 months and randomized them to either receive lidocaine (3 mg/kg) in normal saline (50 mL) intravenous infusion over 1 hour (lidocaine group) once a week for 4 weeks or 50 mL of normal saline infusion (placebo group) once a week for 4 weeks. Twenty-nine participants completed the protocol; 15 participants were assigned to the lidocaine group and 14 to the placebo group. The outcomes were pain intensity assessed using a numerical rating scale (NRS), quality of life assessed using EuroQol-Five Dimensions-Five Levels questionnaire (EQ-5D-5L), psychological function using the Thai version of the 21-item Depression Anxiety Stress Scales (DASS-21), pain medication use, and adverse effects, all assessed at baseline (BL) and again at 4, 8, and 12 weeks following randomization. The reported tramadol use at 8 and 12 weeks following the first infusion was significantly lower in the lidocaine group (P = .023). No other significant between-group differences were observed at any time point or for any other outcome, and no serious adverse events were observed. Multiple lidocaine infusions of 3 mg/kg once a week for 4 weeks in participants with recent onset of peripheral neuropathic pain demonstrated no significant benefits in pain intensity, quality of life, or psychological outcomes. At most, this treatment may result in less tramadol use.

Predicting long-term outcomes in patients with classical trigeminal neuralgia following microvascular decompression with an MRI-based radiomics nomogram: a multicentre study.

This study aimed to develop a clinical-radiomics nomogram to predict the long-term outcomes of patients with classical trigeminal neuralgia (CTN) following microvascular decompression (MVD). This retrospective study included 455 patients with CTN who underwent MVD from three independent institutions A total of 2030 radiomics features from the cistern segment of the trigeminal nerve were extracted computationally from the three-dimensional steady-state free precession and three-dimensional time-of-flight magnetic resonance angiography sequences. Using the least absolute shrinkage and selection operator regression, 16 features were chosen to develop radiomics signatures. A clinical-radiomics nomogram was subsequently developed in the development cohort of 279 patients via multivariate Cox regression. The predictive performance and clinical application of the nomogram were assessed in an external cohort consisting of 176 patients. Sixteen highly outcome-related radiomics features extracted from multisequence images were used to construct the radiomics model, with concordance indices (C-index) of 0.804 and 0.796 in the development and test cohorts, respectively. Additionally, a clinical-radiomics nomogram was developed by incorporating both radiomics features and clinical characteristics (i.e., pain type and degree of neurovascular compression) and yielded higher C-indices of 0.865 and 0.834 in the development and test cohorts, respectively. K‒M survival analysis indicated that the nomogram successfully stratified patients with CTN into high-risk and low-risk groups for poor outcomes (hazard ratio: 37.18, p < 0.001). Our study findings indicated that the clinical-radiomics nomogram exhibited promising performance in accurately predicting long-term pain outcomes following MVD. This model had the potential to aid clinicians in making well-informed decisions regarding the treatment of patients with CTN. Trigeminal neuralgia recurs in about one-third of patients after undergoing MVD. The clinical-radiomics nomogram stratified patients into high- and low-risk groups for poor surgical outcomes. Using this nomogram could better inform patients of recurrence risk and allow for discussion of alternative treatments.

The influence of prior percutaneous rhizotomy on outcomes following microvascular decompression for trigeminal neuralgia.

Microvascular decompression (MVD) is an effective intervention in patients with trigeminal neuralgia (TN). How prior rhizotomy can impact long-term pain outcomes following MVD is not well understood. In this study, the authors sought to compare pain outcomes in patients who had undergone primary MVD versus those who had undergone secondary MVD after a single or multiple rhizotomies. The authors retrospectively reviewed the data on all patients who had undergone MVD at their institution from 2007 to 2020. Patients were included in the study if they had undergone primary MVD or if their surgical history was notable for past rhizotomy. Barrow Neurological Institute (BNI) pain scores were assigned at preoperative and final follow-up appointments. Perioperative complications were noted for each patient, and evidence of pain recurrence was recorded as well. A history of rhizotomy as well as other variables that might influence TN pain recurrence were evaluated using a Cox proportional hazards model. The impact of prior rhizotomy on TN pain recurrence following MVD was further assessed using Kaplan-Meier survival analysis. Of 1044 patients reviewed, 947 met the study inclusion criteria. Of these, 796 patients had undergone primary MVD, 84 had a history of a single rhizotomy before MVD, and 67 had a history of ≥ 2 rhizotomies prior to MVD. Patients in the single rhizotomy and multiple rhizotomies cohorts exhibited a greater frequency of preoperative numbness (p < 0.001), higher preoperative BNI pain scores (p < 0.005), and higher rates of postoperative numbness (p = 0.04). However, final follow-up BNI pain scores were not significantly different between the primary MVD and prior rhizotomy groups (p = 0.34). Cox proportional hazards analysis revealed that younger age, multiple sclerosis, and female sex independently predicted an increased risk of pain recurrence following MVD. Neither a history of a single prior rhizotomy nor a history of multiple prior rhizotomies independently increased the risk of pain recurrence. Furthermore, Kaplan-Meier analysis of pain-free survival among the 3 groups revealed no relationship between a history of prior rhizotomy and pain recurrence following MVD (p = 0.57). Percutaneous rhizotomy does not complicate outcomes following subsequent MVD for TN pain. However, patients undergoing rhizotomy before MVD may have an increased risk of postoperative facial numbness compared to that in patients undergoing primary MVD.

Pain after combat injury in male UK military personnel deployed to Afghanistan

BackgroundChronic pain after injury poses a serious health burden. As a result of advances in medical technology, ever more military personnel survive severe combat injuries, but long-term pain outcomes are unknown. We aimed to assess rates of pain in a representative sample of UK military personnel with and without combat injuries. MethodsWe used data from the ADVANCE cohort study (ISRCTN57285353). Individuals deployed as UK armed forces to Afghanistan were recruited to include those with physical combat injuries, and a frequency-matched uninjured comparison group. Participants completed self-reported questionnaires, including ‘overall’ pain intensity and self-assessment of post-traumatic stress disorder, anxiety, and depression. ResultsA total of 579 participants with combat injury, including 161 with amputations, and 565 uninjured participants were included in the analysis (median 8 yr since injury/deployment). Frequency of moderate or severe pain was 18% (n=202), and was higher in the injured group (n=140, 24%) compared with the uninjured group (n=62, 11%, relative risk: 1.1, 95% confidence interval [CI]: 1.0–1.2, P<0.001), and lower in the amputation injury subgroup (n=31, 19%) compared with the non-amputation injury subgroup (n=109, 26%, relative risk: 0.9, 95% CI: 0.9–1.0, P=0.034). Presence of at least moderate pain was associated with higher rates of post-traumatic stress (RR: 3.7, 95% CI: 2.7–5.0), anxiety (RR: 3.2, 95% CI: 2.4–4.3), and depression (RR: 3.4, 95% CI: 2.7–4.5) after accounting for injury. ConclusionCombat injury, but not amputation, was associated with a higher frequency of moderate to severe pain intensity in this cohort, and pain was associated with adverse mental health outcomes.

Long-term Functional and Pain Outcomes Following Arthroscopic Partial-Thickness Rotator Cuff Tear Completion and Repair

Objective: There remains little consensus on the optimal treatment approach for partial-thickness rotator cuff tears and few studies have examined the long-term outcomes of different surgical repair techniques. The purpose of this study is to identify the long-term functional and pain outcomes of arthroscopic tear completion followed by repair. The authors hypothesize that this technique will allow patients to have long-term pain relief and return to a pre-injury level of function. Methods: Patients (n=16) who underwent arthroscopic tear completion and repair for a partial-thickness rotator cuff tear were included in this case series. Each patient returned for a one-time follow-up visit, with an average follow-up time of 7.09 years, at which time physical and neurological exams were performed, quality of life was assessed through subjective questionnaires, American Shoulder and Elbow Society (ASES) and the University of California at Los Angeles (UCLA) shoulder scores were obtained, and magnetic resonance imaging was performed. Results: The average ASES score was 85.3, with 81% of patients reporting that they were able to return to a pre-injury level of function. Half of the patients reported the highest possible UCLA shoulder score of 35. Physical examination showed that patients had excellent strength and range of motion. Magnetic resonance imaging demonstrated continuity of the repair in all but one patient. However, 25% of patients reported return of symptoms since surgery, including pain and limited mobility. Conclusion: At an average of 7.09 years follow-up, most patients were found to have full mobility, pre-injury level of activity, and maintenance of rotator cuff integrity in the surgically treated shoulder. However, one fourth of patients reported return of symptoms. The authors conclude that the tear completion and repair technique can lead to long-term functional improvement, but has less favorable results in terms of subjective pain level and quality of life.

Efficacy and Complications of Percutaneous Balloon Compression for Patients With Trigeminal Neuralgia With and Without Concomitant Continuous Pain

BACKGROUND: Percutaneous balloon compression (PBC) has become one of the most common and effective minimally invasive treatments for trigeminal neuralgia (TN). However, the initial and long-term pain outcomes, as well as the complication rates of PBC for patients with TN with concomitant continuous pain (CCP) have yet to be specifically documented. OBJECTIVE: In this clinical study, we aimed to evaluate and compare the results of PBC in treating TN with and without CCP. STUDY DESIGN: Retrospective study. METHODS: This research retrospectively analyzed the pain outcomes and complications of 57 patients with TN with CCP and 118 patients with TN without CCP who had undergone PBC at our institution from January 2019 through June 2022. Procedures were performed by one senior neurosurgeon in a single center. The postdischarge follow-up and the collection of clinical data, including immediate and long-term pain relief, time to recurrence, and complications, were completed through phone contact by an independent neurosurgeon blind to the patients’ information. Then, the results of the 2 groups were compared; demographic and clinical data were evaluated for possible predictive factors for poor pain outcomes. RESULTS: In this study, PBC immediately resulted in complete pain relief in 70.2% of patients with CCP and significant pain relief in 84.2% of patients with CCP. For patients without CCP, the rates were 73.7% for complete pain relief and 85.6% for significant pain relief. After a minimum 6-month follow-up period, the rates decreased to 52.6% for complete pain relief and 73.7% for significant pain relief in patients with CCP, compared to 54.2% and 75.4% in those without CCP. The initial and long-term pain control rates in patients without CCP were slightly higher than those with CCP, but the differences were not statistically significant (P = 0.878, P = 0.968, respectively). The incidences of postoperative complications were similar between patients with and without CCP (21.1% vs 22.0%, P = 0.883), whereas the remission rate of complications in patients with CCP was significantly lower than that in patients without CCP (25.0% vs 69.2%, P = 0.011). A longer symptoms duration and having a history of neurodestructive procedures were predictive factors for poor outcomes following PBC. LIMITATIONS: The study was performed in a single-center. The nature of this research is retrospective instead of prospective and randomized, with the inability to control completely for variables. Additionally, the follow-up duration was not long enough to observe recurrence in some patients. CONCLUSIONS: This is the first specifically reported experience treating TN with CCP with PBC. PBC can result in significant relief of both episodic and constant pain from TN with CCP. Patients with a longer duration of pain and prior neurodestructive procedures have a higher risk of poor outcomes. The presence of CCP is not associated with pain outcomes and should not be considered a contraindication to PBC. KEY WORDS: Percutaneous balloon compression, trigeminal neuralgia, concomitant continuous pain, pain relief, comparison, efficacy, complication, predictive factor

Frailty Predicts Worse Pain Outcomes for Older TN Patients Treated with Microvascular Decompression

Trigeminal neuralgia (TN) is a debilitating orofacial pain disorder. Recent data from a national database suggest that microvascular decompression (MVD) in frail patients is associated with more postoperative complications. However, the long-term pain outcomes for frail TN patients are not known. We aimed to elucidate the relationship between frailty and long-term pain outcomes after MVD for TN. From 2007 to 2020, 368 TN patients aged ≥60 years underwent MVD at our institution. Patient demographics, clinical characteristics, postoperative complications, and long-term pain outcomes were recorded. Frailty was assessed using the modified 5-item frailty index (mFI-5) score, and the patients were dichotomized into nonfrail (mFI-5 <2) and frail (mFI-5 >1). Differences were assessed via the t test, χ2 test, multivariate ordinal regression, and Cox proportional hazards analysis. Of the 368 patients analyzed, 9.8% were frail. The frail patients were significantly older (P= 0.02) with a higher body mass index (P= 0.01) and a greater incidence of comorbidities (P < 0.001). Frail patients presented with significantly higher pain levels at the final follow-up (P= 0.04). On multivariate analysis, frailty was independently associated with more pain at follow-up (P= 0.01), as was younger age, female sex, and black race. The relationship between frailty and postoperative pain recurrence showed a trend toward significance (P= 0.06), and younger age and black race were significantly associated with recurrence. Frail patients undergoing MVD are at risk of worse long-term pain outcomes. Our results provide clinicians with useful information pertaining to the influence of frailty on the long-term efficacy of MVD in treating TN.

A Systematic Review on Long-Term Postsurgical Pain Outcomes; What Is the Effect of Upper Extremity Regional Anesthesia?: Erratum.

A Systematic Review on Long-Term Postsurgical Pain Outcomes; What Is the Effect of Upper Extremity Regional Anesthesia?: Erratum.

Long-term pain outcomes in trigeminal neuralgia patients with concomitant continuous pain: a comparison of first-time microvascular decompression and percutaneous balloon compression.

Long-term pain outcomes in trigeminal neuralgia patients with concomitant continuous pain: a comparison of first-time microvascular decompression and percutaneous balloon compression.

A Systematic Review on Long-Term Postsurgical Pain Outcomes; What Is the Effect of Upper Extremity Regional Anesthesia?

Chronic pain is a recognized complication of surgery, and it has been hypothesized that regional anesthesia might reduce the risk of development of chronic pain after upper extremity surgery. A systematic literature review was performed to assess whether in patients undergoing elective upper extremity surgery (P), regional anesthesia (I), compared to general anesthesia (C), would result in lower long-term (>3 months) postoperative pain intensity (O). We included randomized and nonrandomized controlled trials (RCTs). Our primary outcome was numerical rating score or visual analogue scale for pain, at >3 months postoperatively. The Embase, Medline ALL, Web of Science Core Collections, Cochrane Central Register of Controlled Trials, and Google Scholar databases were searched for all reports assessing pain at >3 months after upper extremity surgery under general versus regional anesthesia. Secondary outcomes were: opioid prescription filling, complex regional pain syndrome (CRPS) incidence, the Mayo Wrist Score (MWS), and scores on the Disability of the Arm, Shoulder and Hand (DASH) questionnaire. Quality (or certainty) of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Risk-of-bias was assessed using the Cochrane tool for randomized trials (RoB 2.0) and nonrandomized trials (ROBINS-I). This review included 14 studies, comprising 7 RCTs and 7 nonrandomized studies. Six of the 7 studies (4 RCTs, N = 273; 2 nonrandomized studies, N = 305) using a pain score, our primary outcome, report comparable long-term postoperative pain scores after regional and general anesthesia. Six of the 7 studies using our secondary outcomes report comparable long-term outcomes in terms of opioid prescription filling (2 retrospective cohort studies [RCSs], N = 89,256), CRPS incidence (1 RCT, N = 301), MWS (1 RCT and 1 RCS, N = 215), and DASH score (1 RCT, N = 36). Comparable outcomes were reported in all 7 RCTs (N = 778) and in 5 of the 7 nonrandomized studies, comprising 5 RCSs (N = 89,608). Two prospective observational studies (POSTs), comprising 279 patients, report a statistically significant difference in outcomes, with less pain and better DASH scores after brachial plexus anesthesia. All 14 studies provided moderate to very low certainty evidence, and there was a serious risk of bias due to confounding bias in 5 of the 7 nonrandomized studies (N = 631). The results of this review indicate that upper extremity regional anesthesia, compared to general anesthesia, is unlikely to change pain intensity at >3 months postoperatively.

ID: 208120 Spinal Cord Stimulation Trialing: Is Trialing Predictive of Short, Intermediate, and Long-Term Pain Outcomes?

Increased attention has surrounded spinal cord stimulation’s (SCS) long-term effectiveness and methods to improve patient selection. SCS trialing with documentation of pain relief ≥ 50% as a prerequisite for implantation is commonly utilized, which was reinforced by government agencies (e.g., FDA).1 However, the utility, reporting protocols, and evidence surrounding the long-term prognostic value of trialing are questioned.2,3 The purpose of this study is to analyze the influence of SCS trial reported pain results to accurately predict short, intermediate, and long-term pain outcomes, as well as identify possible patient-specific confounding variables.

SP06. Regenerative Peripheral Nerve Interface Surgery and its Four-year Pain and Medication Intake Outcomes for Treatment or Prevention of Postamputation Pain

PURPOSE: Regenerative peripheral nerve interface (RPNI) surgery is a validated method for mitigating pain in postamputation patients. However, the long-term efficacy of RPNI surgery has yet to be fully characterized. The purpose of this clinical study was to assess long-term pain outcomes and opioid medication intake in amputation patients who have undergone RPNI surgery for the treatment or prevention of postamputation pain. METHODS: Patients included in this study underwent RPNI surgery between 2014 and 2021 for the treatment or prevention of postamputation pain and had at least one-year follow-up. A retrospective review was performed to collect preoperative demographic and clinical information. Outcomes for neuroma pain and PLP were assessed from the medical records at both the 1-year and the most recent follow-up visits. Postoperative pain was compared to preoperative pain and categorized into the following outcomes: no symptoms, improved symptoms, stable symptoms, or worsened symptoms. Opioid prescriptions were obtained through the EMR at preoperative and follow-up visits and converted to morphine milliequivalents (MME) based on dosage and type of opioid medication. RESULTS: Seventy-seven patients met inclusion criteria in this study. Thirty-seven patients underwent RPNI surgery to treat preexisting postamputation pain (treatment group) and 40 patients underwent prophylactic RPNI surgery at the time of amputation (prophylactic group). Fifty-five patients (26 in the treatment group and 29 in the prophylactic group) had additional follow-up visits after the one-year postop time frame. Average time from surgery at most recent follow-up was 50 months (4.2 years). For the treatment group, at time of most recent follow-up, favorable neuroma pain and PLP outcomes (no reported symptoms or improved symptoms) were seen in 77% and 61% of patients, respectively. For patients treated prophylactically, 97% of patients had no recorded neuroma pain or PLP at time of most recent follow-up visit. Average MME at time of most recent follow-up was also lower for both the treatment group (-12 +/- 83) and prophylactic group (-40 +/- 103). CONCLUSIONS: This study demonstrates the long-term clinical benefits of RPNI surgery on improving neuroma pain and PLP as well as a reduction of opioid intake for amputation patients who underwent the procedure. These findings suggest that the benefits of RPNI surgery on pain outcomes are highly favorable, and thus this surgery should be considered for all amputation patients.

Prospective Blood Transcriptomics Study in a Motor Vehicle Collision Cohort Identified a Protective Function of the SAMD15 Gene Against Chronic Pain

Traumatic brain injuries following motor vehicle collisions (MVCs) are ubiquitous. Surprisingly, there are no correlates between concussion impact force and long-term pain outcomes. To study the molecular underpinnings of chronic pain after MVC, we assembled a prospective cohort of 36 subjects that experienced MVC and suffered documented mild traumatic brain injuries. For each participant, a first blood sample was drawn within 72 hours of the collision, then a second one at the 6-month mark. Pain was also assessed at the second blood draw to determine if pain became chronic or resolved. Blood samples enabled transcriptomics analyses for immune cells. At the transcriptome-wide level, we found that Sterile Alpha Motif Domain Containing 15 (SAMD15) mRNA was significantly upregulated with time in subjects who resolved their pain whereas unregulated in those with persistent pain. Using several large publicly available datasets, such as the UK Biobank and the GTeX portal, we then linked elevated SAMD15 gene expression, elevated neutrophils cell counts, and decreased risk for chronic pain to increased dosage of the T allele at SNP rs4903580, situated within SAMD15’s gene locus. The causality between the components of our model was established and supported by Mendelian randomization. Overall, our results support the role of SAMD15 as a potential gene effector for neutrophil-dependent chronic pain development. PerspectiveThis article highlights the potential protective role of the SAMD15 gene against chronic pain following a mild traumatic brain injury. The expression of the gene is associated with a SNP rs4903580, which is itself associated with neutrophils counts as well as chronic pain in large genetic studies.

Patients’ and clinicians’ perspectives towards primary care consultations for shoulder pain: qualitative findings from the Prognostic and Diagnostic Assessment of the Shoulder (PANDA-S) programme

BackgroundClinical management of musculoskeletal shoulder pain can be challenging due to diagnostic uncertainty, variable prognosis and limited evidence for long-term treatment benefits. The UK-based PANDA-S programme (Prognostic And Diagnostic Assessment of the Shoulder) is investigating short and long-term shoulder pain outcomes. This paper reports linked qualitative research exploring patients’ and clinicians’ views towards primary care consultations for shoulder pain.MethodsSemi-structured interviews were conducted with 24 patients and 15 primary care clinicians. Twenty-two interviews (11 patients, 11 clinicians) were conducted as matched patient-clinician ‘dyads’. Data were analysed thematically.ResultsClinicians reported attempts to involve patients in management decisions; however, there was variation in whether patients preferred treatment choice, or for decisions to be clinician-led. Some patients felt uncertain about the decisions made, due to a lack of discussion about available management options. Many General Practitioners expressed a lack of confidence in diagnosing the underlying cause of shoulder pain. Patients reported either not being given a diagnosis, or receiving different diagnoses from different professionals, resulting in confusion. Whilst clinicians reported routinely discussing prognosis of shoulder pain, patients reported that prognosis was not raised. Patients also expressed concern that their shoulder pain could be caused by serious pathology; however, clinicians felt that this was not a common concern for patients.ConclusionsFindings showed disparities between patients’ and clinicians’ views towards shoulder pain consultations, indicating a need for improved patient-clinician communication. Findings will inform the design of an intervention to support treatment and referral decisions for shoulder pain that will be tested in a randomised controlled trial.

Internal neurolysis versus intraoperative glycerin rhizotomy for trigeminal neuralgia.

Internal neurolysis (IN) and intraoperative glycerin rhizotomy (ioGR) are emerging surgical options for patients with trigeminal neuralgia without neurovascular contact. The objective of this study was to compare the neurological outcomes of patients who underwent IN with those of patients who underwent ioGR. The authors retrospectively reviewed all patients who underwent IN or ioGR for trigeminal neuralgia at our institution. Patient demographic characteristics and immediate postoperative outcomes, as well as long-term neurological outcomes, were compared. Of 1044 patients who underwent open surgical treatment for trigeminal neuralgia, 56 patients underwent IN and 91 underwent ioGR. Of these 147 patients, 37 had no evidence of intraoperative neurovascular conflict. All patients who underwent IN and 96.7% of patients who underwent ioGR had immediate postoperative pain relief. At last follow-up, patients who underwent IN had lower Barrow Neurological Institute (BNI) pain intensity scores (p = 0.05), better BNI facial numbness scores (p < 0.01), and a greater degree of pain improvement (p = 0.05) compared with those who underwent ioGR. Patients who underwent IN also had significantly lower rates of symptomatic pain recurrence (p < 0.01) at last follow-up over an average of 9.5 months. IN appears to provide patients with a greater degree of pain relief, lower rates of facial numbness, and lower rates of pain recurrence compared with ioGR. Future prospective studies will better characterize long-term pain recurrence and outcomes.

Treatment of Ulnar Neuropathic Pain with Peripheral Nerve Stimulation: Two Case Reports.

Ulnar neuropathy is a condition that manifests with symptoms of neuropathic pain, numbness, tingling, and even possible motor deficits in the ulnar distribution of the arm. This debilitating painful condition may be refractory to conservative, pharmacologic, and surgical interventions. Peripheral nerve stimulation (PNS) technology has advanced significantly in recent years allowing for conditions such as ulnar neuropathy to be treated in a minimally invasive manner. Here we report the first case reports in the literature (to our knowledge) of two patients with intractable ulnar neuropathy who underwent minimally invasive PNS Bioventus implants. Both patients experienced at least 75% pain relief based on NRS scores at 6 months after ulnar nerve PNS implantation. The patients also experienced significant improvement in functional outcomes, including return to employment, ability to perform activities of daily living without any impairment, and improved quality of life measures. While the results presented in our two case reports are promising, we only provide observational data over a 6 to 15-month period post-implantation. Future well-powered, large-scale, and long-term randomized controlled trials are warranted to determine efficacy and long-term pain and functional outcomes from PNS therapy for treatment of ulnar neuropathy.