Influence of centrally mediated symptoms on functional outcomes after carpal tunnel release

Towards comprehensive management of symptomatic endometriosis: beyond the dichotomy of medical versus surgical treatment

Except when surgery is the only option because of organ damage, the presence of suspicious lesions, or the desire to conceive, women with endometriosis-associated pain often face a choice between medical and surgical treatment. In theory, the description of the potential benefits and potential harms of the two alternatives should be standardized, unbiased, and based on strong evidence, enabling the patient to make an informed decision. However, doctor's opinion, intellectual competing interests, local availability of specific services and (mis)information obtained from social media, and online support groups can influence the type of advice given and affect patients' choices. This is compounded by the paucity of robust data from randomized controlled trials, and the anxiety of distressed women who are eager to do anything to alleviate their disabling symptoms. Vulnerable patients are more likely to accept the suggestions of their healthcare provider, which can lead to unbalanced and physician-centred decisions, whether in favour of either medical or surgical treatment. In general, treatments should be symptom-orientated rather than lesion-orientated. Medical and surgical modalities appear to be similarly effective in reducing pain symptoms, with medications generally more successful for severe dysmenorrhoea and surgery more successful for severe deep dyspareunia caused by fibrotic lesions infiltrating the posterior compartment. Oestrogen-progestogen combinations and progestogen monotherapies are generally safe and well tolerated, provided there are no major contraindications. About three-quarters of patients with superficial peritoneal and ovarian endometriosis and two-thirds of those with infiltrating fibrotic lesions are ultimately satisfied with their medical treatment although the remainder may experience side effects, which may result in non-compliance. Surgery for superficial and ovarian endometriosis is usually safe. When fibrotic infiltrating lesions are present, morbidity varies greatly depending on the skill of the individual surgeon, the need for advanced procedures, such as bowel resection and ureteral reimplantation, and the availability of expert colorectal surgeons and urologists working together in a multidisciplinary approach. The generalizability of published results is adequate for medical treatment but very limited for surgery. Moreover, on the one hand, hormonal drugs induce disease remission but do not cure endometriosis, and symptom relapse is expected when the drugs are discontinued; on the other hand, the same drugs should be used after lesion excision, which also does not cure endometriosis, to prevent an overall cumulative symptom and lesion recurrence rate of 10% per postoperative year. Therefore, the real choice may not be between medical treatment and surgery, but between medical treatment alone and surgery plus postoperative medical treatment. The experience of pain in women with endometriosis is a complex phenomenon that is not exclusively based on nociception, although the role of peripheral and central sensitization is not fully understood. In addition, trauma, and especially sexual trauma, and pelvic floor disorders can cause or contribute to symptoms in many individuals with chronic pelvic pain, and healthcare providers should never take for granted that diagnosed or suspected endometriosis is always the real, or the sole, origin of the referred complaints. Alternative treatment modalities are available that can help address most of the additional causes contributing to symptoms. Pain management in women with endometriosis may be more than a choice between medical and surgical treatment and may require comprehensive care by a multidisciplinary team including psychologists, sexologists, physiotherapists, dieticians, and pain therapists. An often missing factor in successful treatment is empathy on the part of healthcare providers. Being heard and understood, receiving simple and clear explanations and honest communication about uncertainties, being invited to share medical decisions after receiving detailed and impartial information, and being reassured that a team member will be available should a major problem arise, can greatly increase trust in doctors and transform a lonely and frustrating experience into a guided and supported journey, during which coping with this chronic disease is gradually learned and eventually accepted. Within this broader scenario, patient-centred medicine is the priority, and whether or when to resort to surgery or choose the medical option remains the prerogative of each individual woman.

Explaining Personalized Activity Limitations in Patients With Hand and Wrist Disorders: Insights from Sociodemographic, Clinical, and Mindset Characteristics

OBJECTIVES

To investigate the association of sociodemographic, clinical, and mindset characteristics on outcomes measured with a patient-specific patient-reported outcome measure (PROM); the Patient Specific Functional Scale (PSFS). Secondly, we examined whether these factors differ when a fixed-item PROM, the Michigan Hand Outcome Questionnaire (MHQ), is used as an outcome.

DESIGN

Cohort study, using the aforementioned groups of factors in a hierarchical linear regression.

SETTING

Twenty-six clinics for hand and wrist conditions in the Netherlands.

PARTICIPANTS

Two samples of patients with various hand and wrist conditions and treatments: n=7111 (PSFS) and n=5872 (MHQ).

INTERVENTIONS

NA.

MAIN OUTCOME MEASURES

The PSFS and MHQ at 3 months.

RESULTS

The PSFS exhibited greater between-subject variability in baseline, follow-up, and change scores than the MHQ. Better PSFS outcomes were associated with: no involvement in litigation (β[95% confidence interval=-0.40[-0.54;-0.25]), better treatment expectations (0.09[0.06;0.13]), light workload (0.08[0.03;0.14]), not smoking (-0.07[-0.13;-0.01]), men sex (0.07[0.02;0.12]), better quality of life (0.07[0.05;0.10]), moderate workload (0.06[0.00;0.13]), better hand satisfaction (0.05[0.02; 0.07]), less concern (-0.05[-0.08;-0.02]), less pain at rest (-0.04[-0.08;-0.00]), younger age (-0.04[-0.07;-0.01]), better comprehensibility (0.03[0.01;0.06]), better timeline perception (-0.03[-0.06;-0.01]), and better control (-0.02[-0.04;-0.00]). The MHQ model was highly similar but showed a higher R2 than the PSFS model (0.41 vs 0.15), largely due to the R2 of the baseline scores (0.23 for MHQ vs 0.01 for PSFS).

CONCLUSIONS

Health care professionals can improve personalized activity limitations by addressing treatment expectations and illness perceptions, which affect PSFS outcomes. Similar factors affect the MHQ, but the baseline MHQ score has a stronger association with the outcome score than the PSFS. While the PSFS is better for individual patient evaluation, we found that it is difficult to explain PSFS outcomes based on baseline characteristics compared with the MHQ. Using both patient-specific and fixed-item instruments helps health care professionals develop personalized treatment plans that meet individual needs and goals.

Central Sensitization in Patients with Chronic Pain Secondary to Carpal Tunnel Syndrome and Determinants

Purpose

Central sensitization (CS) is commonly seen in chronic pain disorders, including neuropathic pain. However, there exist inconsistencies concerning the presence of CS in chronic pain secondary to carpal tunnel syndrome (CTS). CS and neuropathic pain manifestations in CTS remain not well established. Therefore, this study aims to investigate the CS and pain profiles in patients with CTS and to explore the potential determinants associated with CS.

Patients and Methods

Patients with suspected CTS symptoms lasting 3 months or above and healthy controls were enrolled. History, physical examinations, and nerve conduction studies were employed to confirm the diagnosis and severity of median nerve dysfunction. The central sensitization inventory (CSI) was used to screen CS. Other outcomes included neuropathic pain, CTS-specific symptom severity and functions, emotion, and health-related quality of life. Between-group comparisons were conducted in terms of the CS presence. Logistic regression analysis was performed to identify determinants associated with CS.

Results

Over 60% of participants with CTS were found with clinical CS, significantly higher than that in the control group. More than 70% of the CTS participants were identified to have possible or very likely neuropathic pain components. In addition, one-fourth of CTS cases had depression or anxiety. Anxiety was associated with an increased risk of developing CS in CTS (adjusted OR=1.31, 95% CI 1.08-1.59), whereas higher self-perceived general health rating was negatively associated with the presence of CS (adjusted OR=0.92, 95% CI 0.88-0.97) in the multivariate adjusted regression model.

Conclusion

CS is prevalent in patients with CTS. Predominant neuropathic pain characteristics were uncovered in CTS patients as well as comorbid psychological distress. Significant association was found between anxiety and CS presence. Self-perceived general health was inversely related to CS. Further research is warranted to explore the mechanisms of anxiety and central pain processing in painful entrapment neuropathy.

Carpal Tunnel Syndrome: Neuropathic Pain Associated or Not with a Nociplastic Condition

Carpal tunnel syndrome (CTS) has been traditionally classified as primarily a neuropathic condition with or without pain. Precision medicine refers to an evidence-based method of grouping patients based on their susceptibility to biology, prognosis of a particular disease, or in their response to a specific treatment, and tailoring specific treatments accordingly. In 2021, the International Association for the Study of Pain (IASP) proposed a grading system for classifying patients into nociceptive, neuropathic, or nociplastic phenotypes. This position paper presents data supporting the possibility of subgrouping individuals with specific CTS related-pain into nociceptive, neuropathic, nociplastic or mixed-type phenotypes. Carpal tunnel syndrome is a neuropathic condition but can also be comorbid with a nociplastic pain condition. The presence of extra-median symptoms and the development of facilitated pain processing seem to be signs suggesting that specific CTS cases can be classified as the nociplastic pain phenotype. The clinical responses of therapeutic approaches for the management of CTS are inconclusive. Accordingly, the ability to identify the predominant pain phenotype in patients with CTS could likely be problematic for producing efficient treatment outcomes. In fact, the presence of a nociplastic or mixed-type pain phenotype would explain the lack of clinical effect of treatment interventions targeting the carpal tunnel area selectively. We propose a clinical decision tree by using the 2021 IASP classification criteria for identifying the predominant pain phenotype in people with CTS-related pain, albeit CTS being a priori a neuropathic pain condition. The identification of a nociplastic-associated condition requires a more nuanced multimodal treatment approach to achieve better treatment outcomes.

Association of Central Sensitization Inventory Scores With Pain Outcomes After Endometriosis Surgery

IMPORTANCE

A subset of people who undergo surgery for endometriosis have persistent pain, suggesting that other factors besides the endometriosis, such as central sensitization, may play a role in this pain. The Central Sensitization Inventory, a validated self-reported questionnaire of central sensitization symptoms, may identify individuals with endometriosis who have more pain after surgery due to pain sensitization.

OBJECTIVE

To examine whether greater baseline Central Sensitization Inventory scores are associated with postsurgical pain outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This prospective, longitudinal cohort study performed at a tertiary center for endometriosis and pelvic pain in British Columbia, Canada, included all patients aged 18 to 50 years with diagnosed or suspected endometriosis and a baseline visit between January 1, 2018, and December 31, 2019, who underwent surgery after the baseline visit. Individuals who were menopausal, had a prior hysterectomy, or were missing data for outcomes or measures were excluded. Data analysis was performed from July 2021 to June 2022.

MAIN OUTCOMES AND MEASURES

The primary outcome was chronic pelvic pain at follow-up measured on a scale of 0 to 10, with 0 to 3 indicating no pain or mild pain, 4 to 6 indicating moderate pain, and 7 to 10 indicating severe pain. Secondary outcomes were deep dyspareunia, dysmenorrhea, dyschezia, and back pain at follow-up. The main variable of interest was baseline Central Sensitization Inventory score (measured from 0 to 100, consisting of 25 self-reported questions rated from 0 to 4 [never, rarely, sometimes, often, and always, respectively]).

RESULTS

A total of 239 patients (mean [SD] age, 34 [7] years; 189 [79.1%] White [11 (5.8%) identified as White mixed with another ethnicity], 1 [0.4%] Black or African American, 29 [12.1%] Asian, 2 [0.8%] Native Hawaiian or Pacific Islander, 16 [6.7%] other, and 2 [0.8%] mixed race or ethnicity) with follow-up data at more than 4 months after surgery were included in this study (71.0% follow-up rate). The mean (SD) baseline Central Sensitization Inventory score was 43.8 (18.2), and the mean (SD) follow-up was 16.1 (6.1) months. Higher baseline Central Sensitization Inventory scores were significantly associated with higher chronic pelvic pain (odds ratio [OR], 1.02; 95% CI, 1.00-1.03; P = .02), deep dyspareunia (OR, 1.03; 95% CI, 1.01-1.04; P = .004), dyschezia (OR, 1.03; 95% CI, 1.01-1.04; P < .001), and back pain (OR, 1.02; 95% CI, 1.00-1.03; P = .02) at follow-up, when controlling for baseline pain scores. The Central Sensitization Inventory scores themselves decreased slightly from baseline to follow-up (mean [SD] score, 43.8 [18.2] vs 41.7 [18.9]; P = .05); however, individuals with high baseline Central Sensitization Inventory scores still had high scores at follow-up.

CONCLUSIONS AND RELEVANCE

In this cohort study of 239 patients with endometriosis, higher Central Sensitization Inventory scores at baseline were associated with worse pain outcomes after endometriosis surgery, when controlling for baseline pain scores. The Central Sensitization Inventory could be used to counsel patients with endometriosis on their expected outcomes after surgery.

A Systematic Review of the Outcomes of Carpal Ligament Release in Severe Carpal Tunnel Syndrome

PURPOSE

Indications for surgical treatment of severe carpal tunnel syndrome (CTS) are controversial. The aim of this study was to review the outcomes reported in the literature of carpal tunnel release in patients with severe CTS.

METHODS

A systematic review of the outcomes of carpal tunnel release in patients with severe CTS was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Outcome measures included change in symptoms, sensation (2-point discrimination, light touch), thenar atrophy, strength (power and pinch grip), electrophysiology, median nerve morphology, and patient-reported outcome measures. Outcomes are reported by ranges of the percentage of patients/hands improved in the included studies.

RESULTS

Thirty-eight papers were selected, representing 2,531 patients and 2,712 hands. Demographic information on age and sex were available for a total of 1,542 patients. Mean age ranged from 49.8 to 83 years and 72% were female. All studies that assessed patient-reported outcome measures before and after surgery reported significant improvements. Complete resolution of paresthesia occurred in 55%-98% of hands across different studies. Resolution of numbness occurred in between 39% and 94% of hands. Pain completely resolved in 64%-100% and weakness in 60%-75% of hands. Two-point discrimination and light touch improved postoperatively. Power grip, key, tripod, index-thumb pulp pinch, and thumb opposition increased. Motor and sensory amplitudes, distal motor latencies, and sensory conduction velocities improved. Patient-reported outcomes indicated symptomatic improvement and reduced disability.

CONCLUSIONS

Symptomatic improvement following carpal tunnel release in patients with severe CTS can occur. Patients should be counseled about the unpredictability of the outcomes and factors that might affect outcomes.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Pain mechanisms in carpal tunnel syndrome: a systematic review and meta-analysis of quantitative sensory testing outcomes

ABSTRACT

Carpal tunnel syndrome (CTS) is the most common nerve compression in the arm. A mix of peripheral and central contributions on quantitative sensory testing (QST) has been reported in the literature. Thus, this systematic review or meta-analysis aimed to identify the dominant sensory phenotype and draw conclusive evidence about the presence of central sensitization (CS) in CTS. Based on an a priori published protocol and using PRISMA guidelines, 7 databases were searched (Embase, Web of Science, Scopus, PubMed, SAGE, EBSCOhost, and ProQuest). Eligible studies compared the QST findings of individuals with subacute and chronic CTS with those of healthy controls through thermal, mechanical, and vibration detection thresholds; thermal, pressure, and mechanical pain thresholds; mechanical pain sensitivity; presence of allodynia; wind-up ratio; and conditioned pain modulation. Thirty-seven studies were included in the qualitative analysis. Results showed a significant loss of all detection thresholds of hand median nerve territories and hand extramedian areas (little finger and hand dorsum) in CTS (P < 0.05) but no significant difference (P > 0.05) in wind-up ratio, cold, heat, or mechanical pain thresholds of the median nerve territories. Furthermore, there was a significant increase in mechanical pain sensitivity in median nerve territories and remotely in the forearm (P < 0.05) and a significant gain in pressure and heat pain thresholds in the carpal area (P < 0.05). Conditioned pain modulation was impaired in CTS. Hypoesthesia and increased thermal and mechanical pain ratings are the dominant sensory phenotype with inconclusive evidence about CS in CTS due to the heterogenous results of thermal and mechanical pain thresholds.

Application of digital infrared thermography for carpal tunnel syndrome evaluation

We investigated the thermographic findings of carpal tunnel syndrome (CTS). We enrolled 304 hands with electrodiagnostically identified CTS and 88 control hands. CTS hands were assigned to duration groups (D1, < 3 months; D2, 3‒6 months; D3, 6‒12 months; D4, ≥ 12 months) and severity groups (S1, very mild; S2, mild; S3, moderate; S4, severe). The temperature difference between the median and ulnar nerve territories (ΔM-U territories) decreased as CTS duration and severity increased. Significant differences in ΔM-U territories between the D1 and D3, D1 and D4, D2 and D4, and S1 and S4 groups (P = 0.003, 0.001, 0.001, and < 0.001, respectively) were observed. Thermal anisometry increased as CTS duration and severity increased. Significant differences in thermal anisometry between the D1 and D4 as well as the D2 and D4 groups (P = 0.005 and 0.04, respectively) were noted. Thermal anisometry was higher in the S4 group than in the S1, S2, and S3 groups (P = 0.009, < 0.001, and 0.003, respectively). As CTS progresses, skin temperature tends to decrease and thermal variation tends to increase in the median nerve-innervated area. Thermographic findings reflect the physiological changes of the entrapped median nerve.

Understanding the Psychophysiological Mechanisms Related to Widespread Pressure Pain Hyperalgesia Underpinning Carpal Tunnel Syndrome: A Network Analysis Approach

OBJECTIVE

Current evidence suggests that carpal tunnel syndrome (CTS) involves widespread pressure pain sensitivity as manifestion of central sensitization. This study aimed to quantify mechanisms driving widespread pressure pain hyperalgesia in CTS by using network analysis.

DESIGN

Cross-sectional.

SETTING

Urban hospital.

SUBJECTS

120 women with CTS who participated in a previous randomized clinical trial.

METHODS

Pain intensity, related-function, symptom's severity, depressive levels, and pressure pain threshold (PPTs) over median, radial and ulnar nerves, the cervical spine, the carpal tunnel, and the tibialis anterior were collected. Network analysis was used to quantify the adjusted correlations between the modelled variables, and to determine the centrality indices of each variable (i.e., the degree of connection with other symptoms in the network).

RESULTS

The estimated network showed several local associations between clinical variables and the psychophysical outcomes separately. The edges with the strongest weights were between PPT over the median and radial nerves (ρ: 0.34), function and depressive levels (ρ: 0.30), and PPT over the carpal tunnel and tibialis anterior (ρ: 0.29). The most central variables were PPT over the tibialis anterior (the highest Strength centrality), and PPT over the carpal tunnel (the highest Closeness and Betweenness centrality).

CONCLUSIONS

This is the first study to apply network analysis to understand the multivariate mechanisms of individuals with CTS. Our findings support a model where clinical, depression, and widespread pressure pain sensitivity are connected, albeit within separate clusters. Clinical implications of current findings, such as developing treatments targeting these mechanisms, are also discussed.

Spectral Clustering Reveals Different Profiles of Central Sensitization in Women with Carpal Tunnel Syndrome

Identification of subgroups of patients with chronic pain provides meaningful insights into the characteristics of a specific population, helping to identify individuals at risk of chronification and to determine appropriate therapeutic strategies. This paper proposes the use of spectral clustering (SC) to distinguish subgroups (clusters) of individuals with carpal tunnel syndrome (CTS), making use of the obtained patient profiling to argue about potential management implications. SC is a powerful algorithm that builds a similarity graph among the data points (the patients), and tries to find the subsets of points that are strongly connected among themselves, but weakly connected to others. It was chosen due to its advantages with respect to other simpler clustering techniques, such as k-means, and the fact that it has been successfully applied to similar problems. Clinical (age, duration of symptoms, pain intensity, function, and symptom severity), psycho-physical (pressure pain thresholds—PPTs—over the three main nerve trunks of the upper extremity, cervical spine, carpal tunnel, and tibialis anterior), psychological (depressive levels), and motor (pinch tip grip force) variables were collected in 208 women with clinical/electromyographic diagnosis of CTS, whose symptoms usually started unilaterally but eventually evolved into bilateral symmetry. SC was used to identify clusters of patients without any previous assumptions, yielding three clusters. Patients in cluster 1 exhibited worse clinical features, higher widespread pressure pain hyperalgesia, higher depressive levels, and lower pinch tip grip force than the other two. Patients in cluster 2 showed higher generalized thermal pain hyperalgesia than the other two. Cluster 0 showed less hypersensitivity to pressure and thermal pain, less severe clinical features, and more normal motor output (tip grip force). The presence of subgroups of individuals with different altered nociceptive processing (one group being more sensitive to pressure pain and another group more sensitive to thermal pain) could lead to different therapeutic programs.

Clinical evidence and mechanisms of growth factors in idiopathic and diabetes-induced carpal tunnel syndrome

Carpal tunnel syndrome (CTS) is an entrapment neuropathy caused by compression and irritation of the median nerve, which travels through the carpal tunnel in the wrist. Increased fibrosis is a hallmark of the development and pathology of CTS. Different growth factors have been demonstrated to play a potential role in the development of CTS. Studies have described an increase in the expression of growth factors, including Transforming Growth Factor (TGF-β), Vascular Endothelial Growth Factor (VEGF) and interleukins (growth factors for immune and inflammatory cells) in SSCT (sub-synovial connective tissue) in CTS patients. Additionally, SSCT fibrosis is also marked by increased activation of canonical TGF-β second messenger Smads, increased expression of downstream fibrotic mediators such as connective tissue growth factor (CTGF), increased production of collagen type I, II, III and IV, and decreased expression of matrix metalloproteinases. Anti-fibrotic such as anti-TGF treatment may prove beneficial in idiopathic patients, however, anti VEGF therapy can be successful in the diabetic CTS patients. The present review describes the clinical evidence stating the role of different growth factors in the development of fibrosis in idiopathic and diabetes induced CTS.