Conservative Management of Occipital Neuralgia Supported by Physical Therapy: A Review of Available Research and Mechanistic Rationale to Guide Treatment

PURPOSE OF REVIEW

Conservative management is consistently recommended as a first line intervention for occipital neuralgia (ON); however, there is limited clinical research regarding conservative intervention for ON. This lack of research may lead to underutilization or unwarranted variability in conservative treatment. This article provides mechanism-based guidance for conservative management of ON as a component of a multimodal treatment approach, and discusses the role of the physical therapist in the care team. It also highlights opportunities for further research to refine conservative management of this condition.

RECENT FINDINGS

Published research on conservative interventions specific to ON is limited to very low-quality evidence for the use of TENS. The contemporary shift toward precision pain management emphasizing treatment based on a patient's constellation of clinical features-a phenotype-rather than solely a diagnosis provides more personalized and specifically targeted pain treatment. This paradigm can guide treatment in cases where diagnosis-specific research is lacking and can be used to inform conservative treatment in this case. Various conservative interventions have demonstrated efficacy in treating many of the symptoms and accepted etiologies of ON. Conservative interventions provided by a physical therapist including exercise, manual therapy, posture and biomechanical training, TENS, patient education, and desensitization have mechanistic justification to treat symptoms and causes of ON. Physical therapists have adequate time and skill to provide such progressive and iterative interventions and should be included in a multimodal treatment plan for ON. Further research is required to determine appropriate dosing, sequencing, and progression of conservative treatments.

The effectiveness of nerve mechanical interface treatment for entrapment neuropathies in the limbs: A systematic review with metanalysis

BACKGROUND

Neurodynamic approach employs neural mobilization and mechanical nerve interface techniques. While published studies investigated the efficacy of neural mobilization, it is currently unknown whether manual treatment of the nerve mechanical interface is effective in the treatment of people with entrapment neuropathies.

OBJECTIVES

Assess the effectiveness of mechanical interface treatment, including joint and soft tissue techniques, on pain and function in people with peripheral entrapment neuropathies.

DESIGN

Intervention systematic review with metanalysis.

METHODS

the databases MEDLINE, CINAHL, AMED, APA PsycINFO, SPORTDiscus, PubMed and ScienceDirect were searched from their inception to October 2022. Randomized controlled trials investigating mechanical interface treatment in isolation in patients with peripheral entrapment neuropathies were included. Two independent reviewers performed study selection, data extraction and risk of bias assessment using the Cochrane RoB 2.0 tool. Certainty of evidence for each outcome was judged using the GRADE framework.

RESULTS

11 studies were included in the review, all investigating carpal tunnel syndrome (CTS). Due to high heterogeneity of interventions and comparators, only five studies were pooled in a random-effects meta-analysis. There was evidence of mechanical interface techniques being more effective in reducing pain than sham (MD -2.47 [-3.94;-0.99]) and similarly effective as neural mobilization (MD -0.22 [-0.76; 0.33]) in CTS, albeit with low to very low certainty in the results.

CONCLUSION

mechanical interface techniques are effective for improving pain and function in people with CTS. However, the marked heterogeneity of included interventions and comparators prevents clinical recommendation of specific treatments.

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.

Motor Imagery and Pain Processing in Patients With Entrapment Neuropathies: A Cross-sectional Study

OBJECTIVES

(1) To assess the ability to generate both kinesthetic and visual motor imagery in participants with carpal tunnel syndrome (CTS), compared with asymptomatic participants. (2) To assess the influence of psychophysiological and functional variables in the motor imagery process.

METHODS

Twenty patients with unilateral CTS and 18 pain-free individuals were recruited. An observational case-control study with a nonprobability sample was conducted to assess visual and kinesthetic movement imagery ability and psychophysiological variables in patients with CTS compared with asymptomatic participants in a control group. The trial was conducted in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology statement.

RESULTS

CTS patients have more difficulties in generating visual motor images compared with asymptomatic individuals ( t =-2.099; P <0.05; d=0.70). They need more time to complete the mental tasks (visual t =-2.424; P <0.05 and kinesthetic t =-2.200; P <0.05). A negative correlation was found between the ability to imagine and functional deficits ( r =-0.569; P =0.021) for the kinesthetic subscale and temporal summation ( r =-0.515; P <0.5). A positive correlation was found between pain pressure threshold homolateral (homolateral) and time to generate the visual mental images ( r =0.537; P <0.05).

DISCUSSION

CTS patients have greater difficulty generating motor images than asymptomatic individuals. Patients also spend more time during mental tasks. CTS patients present a relationship between temporal summation and the capacity to generate kinesthetic images. In addition, the CST patients presented a correlation between chronometry mental tasking and mechanical hyperalgesia.

A systematic review of the psychometric properties of pressure pain detection threshold in evaluating mechanical pain threshold in people with hand or wrist injuries

PURPOSE

The aim of this study was to conduct a systematic review of the psychometric properties of Pressure Pain Detection Threshold (PPDT) measures in people with hand or wrist injuries.

STUDY DESIGN AND METHODS

MEDLINE, Embase, and CINAHL databases were searched to identify eligible studies evaluating psychometric properties of PPDT in samples composed of at least 50% of people with hand or wrist injury. The Consensus-based Standards for the Measurement of Health Instruments' risk of bias checklist was used to critically appraise the included studies, and qualitative synthesis was performed by pooling the results of all studies that presented the same measurement property using Grading of Recommendations, Assessment, Development, and Evaluation.

RESULTS

From 415 studies, 11 relevant studies were identified. Of the 11 studies, four hand or wrist injuries were represented; carpal tunnel syndrome, distal radius fractures, osteoarthritis, and complex regional pain syndrome. Intra-rater reliability was considered sufficient (intraclass correlation coefficient 0.64-0.94), with small reported standard error of the mean values (5.3-39.2 kPa). Results of validity and responsiveness could not be synthesized due to heterogeneity. Risk of bias for reliability and measurement error was assessed as very good or adequate, whereas validity and responsiveness were doubtful or inadequate. Overall quality of evidence was low or very low for all measurement properties.

CONCLUSIONS

Inconsistent results and low quality evidence provide little confidence in the overall measurement properties of PPDT in a hand or wrist injury population. No criterion standard for pain further highlights complexities around pain measurement such that the results obtained from PPDT measures in clinical practice cannot be compared to a gold standard measure.

Microglial Depletion does not Affect the Laterality of Mechanical Allodynia in Mice

Mechanical allodynia (MA), including punctate and dynamic forms, is a common and debilitating symptom suffered by millions of chronic pain patients. Some peripheral injuries result in the development of bilateral MA, while most injuries usually led to unilateral MA. To date, the control of such laterality remains poorly understood. Here, to study the role of microglia in the control of MA laterality, we used genetic strategies to deplete microglia and tested both dynamic and punctate forms of MA in mice. Surprisingly, the depletion of central microglia did not prevent the induction of bilateral dynamic and punctate MA. Moreover, in dorsal root ganglion-dorsal root-sagittal spinal cord slice preparations we recorded the low-threshold Aβ-fiber stimulation-evoked inputs and outputs of superficial dorsal horn neurons. Consistent with behavioral results, microglial depletion did not prevent the opening of bilateral gates for Aβ pathways in the superficial dorsal horn. This study challenges the role of microglia in the control of MA laterality in mice. Future studies are needed to further understand whether the role of microglia in the control of MA laterality is etiology-or species-specific.

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.

Identification of brain-to-spinal circuits controlling the laterality and duration of mechanical allodynia in mice

Mechanical allodynia (MA) represents one prevalent symptom of chronic pain. Previously we and others have identified spinal and brain circuits that transmit or modulate the initial establishment of MA. However, brain-derived descending pathways that control the laterality and duration of MA are still poorly understood. Here we report that the contralateral brain-to-spinal circuits, from Oprm1 neurons in the lateral parabrachial nucleus (lPBNOprm1), via Pdyn neurons in the dorsal medial regions of hypothalamus (dmHPdyn), to the spinal dorsal horn (SDH), act to prevent nerve injury from inducing contralateral MA and reduce the duration of bilateral MA induced by capsaicin. Ablating/silencing dmH-projecting lPBNOprm1 neurons or SDH-projecting dmHPdyn neurons, deleting Dyn peptide from dmH, or blocking spinal κ-opioid receptors all led to long-lasting bilateral MA. Conversely, activation of dmHPdyn neurons or their axonal terminals in SDH can suppress sustained bilateral MA induced by lPBN lesion.

Chronic pain and local pain in usually painless conditions including neuroma may be due to compressive proximal neural lesion

It has been unexplained why chronic pain does not invariably accompany chronic pain-prone disorders. This question-driven, hypothesis-based article suggests that the reason may be varying occurrence of concomitant peripheral compressive proximal neural lesion (cPNL), e.g., radiculopathy and entrapment plexopathies. Transition of acute to chronic pain may involve development or aggravation of cPNL. Nociceptive hypersensitivity induced and/or maintained by cPNL may be responsible for all types of general chronic pain as well as for pain in isolated tissue conditions that are usually painless, e.g., neuroma, scar, and Dupuytren's fibromatosis. Compressive PNL induces focal neuroinflammation, which can maintain dorsal root ganglion neuron (DRGn) hyperexcitability (i.e., peripheral sensitization) and thus fuel central sensitization (i.e., hyperexcitability of central nociceptive pathways) and a vicious cycle of chronic pain. DRGn hyperexcitability and cPNL may reciprocally maintain each other, because cPNL can result from reflexive myospasm-induced myofascial tension, muscle weakness, and consequent muscle imbalance- and/or pain-provoked compensatory overuse. Because of pain and motor fiber damage, cPNL can worsen the causative musculoskeletal dysfunction, which further accounts for the reciprocity between the latter two factors. Sensitization increases nerve vulnerability and thus catalyzes this cycle. Because of these mechanisms and relatively greater number of neurons involved, cPNL is more likely to maintain DRGn hyperexcitability in comparison to distal neural and non-neural lesions. Compressive PNL is associated with restricted neural mobility. Intermittent (dynamic) nature of cPNL may be essential in chronic pain, because healed (i.e., fibrotic) lesions are physiologically silent and, consequently, cannot provide nociceptive input. Not all patients may be equally susceptible to develop cPNL, because occurrence of cPNL may vary as vary patients' predisposition to musculoskeletal impairment. Sensitization is accompanied by pressure pain threshold decrease and consequent mechanical allodynia and hyperalgesia, which can cause unusual local pain via natural pressure exerted by space occupying lesions or by their examination. Worsening of local pain is similarly explainable. Neuroma pain may be due to cPNL-induced axonal mechanical sensitivity and hypersensitivity of the nociceptive nervi nervorum of the nerve trunk and its stump. Intermittence and symptomatic complexity of cPNL may be the cause of frequent misdiagnosis of chronic pain.

Comparison of characteristics between neuropathic pain and non-neuropathic pain in patients with diabetic carpal tunnel syndrome: A cross-sectional study

Background

The aim of the study was to compare the clinical characteristics of diabetic carpal tunnel syndrome between patients with neuropathic pain (NeuP) and non-NeuP.

Methods

We enrolled 276 patients with diabetic carpal tunnel syndrome. Pain symptoms were evaluated using a visual analog scale. Douleur Neuropathique 4, the Neuropathic Pain Symptoms Inventory questionnaire, and the body map were used to assess neuropathic symptoms. Baseline information, clinical manifestations, electrophysiological test results, and psychological status were compared between the neuropathic pain (NeuP) and non-NeuP to identify the risk factor for NeuP occurrence.

Results

Results showed that the degree of pain was more severe in NeuP patients than in nociceptive pain patients (p = 0.025). The frequencies of light touch and pinprick were more pronounced in the NeuP group than in the non-NeuP group (light touch: p = 0.001; pinprick: p = 0.004). There were 48 and 27 NeuP patients with extramedian and proximal spread, respectively, whereas in the non-NeuP group, there were 11 and 9 patients, respectively (p = 0.03). Electrophysiological results showed that patients in the NeuP group exhibited greater sensory nerve conduction velocity impairment compared with the non-NeuP group (p = 0.033). Pain Catastrophizing Scale total scores of the NeuP group were significantly higher than those of the non-NeuP group (p = 0.006).

Conclusion

Of the 276 diabetic carpal tunnel syndrome patients studied, the majority had NeuP. Furthermore, light touch, electrophysiological test results, and psychological factors were found to be related to NeuP occurrence in patients with diabetic carpal tunnel syndrome.

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.

Interhemispheric Inhibition Between Primary Sensory Cortices is not Influenced by Acute Muscle Pain

Bilateral deficits in sensorimotor function have been observed in unilateral musculoskeletal pain conditions. Altered interhemispheric inhibition (IHI) between primary sensory cortices (S1s) is one mechanism that could explain this phenomenon. However, IHI between S1s in response to acute muscle pain, and the relationship between IHI and pressure pain sensitivity in the unaffected limb have not been examined. In 21 healthy individuals, IHI was assessed using somatosensory evoked potentials in response to paired median nerve electrical stimulation at: 1) baseline; 2) immediately following pain resolution; and 3) at 30-minutes follow-up. Acute muscle pain was induced by injection of hypertonic saline into the right abductor pollicis brevis (APB) muscle. Pressure pain thresholds were assessed at the right and left APB muscles before and 30-minutes after pain resolution. Compared to baseline, IHI from the affected to unaffected S1 was unaltered in response to acute muscle pain immediately following pain resolution, or at 30-minutes follow-up. Pressure pain thresholds were reduced over the right (P = .001) and left (P = .001) APB muscles at 30-minutes follow-up. These findings suggest IHI between S1s is unaffected by acute, short-lasting muscle pain, despite the development of increased sensitivity to pressure in the unaffected APB muscle. PERSPECTIVE: IHI from the affected S1 (contralateral to the side of pain) to unaffected S1 is unaltered following the resolution of acute muscle pain. This finding suggests that IHI between S1s may not be relevant in the development of bilateral sensorimotor symptoms in unilateral pain conditions.

Signs Indicative of Central Sensitization Are Present but Not Associated with the Central Sensitization Inventory in Patients with Focal Nerve Injury

Objective: Carpal tunnel syndrome (CTS) is the most common focal nerve injury. People with CTS may show alterations in central processing of nociceptive information. It remains unclear whether the central sensitization inventory (CSI) is capable of detecting such altered central pain processing. Methods: Thirty healthy volunteers were matched with 30 people with unilateral CTS from the orthopaedic waitlist. Changes to central pain processing were established through psychophysical sensory testing (bilateral pressure pain thresholds (PPT), conditioned pain modulation, temporal summation) and pain distribution on body charts. Patients also completed pain severity and function questionnaires, psychological questionnaires and the CSI. Results: Compared to healthy volunteers, patients with CTS have lower PPTs over the carpal tunnel bilaterally (t = −4.06, p < 0.0001 ipsilateral and t = −4.58, p < 0.0001 contralateral) and reduced conditioned pain modulation efficacy (t = −7.31, p <0.0001) but no differences in temporal summation (t = 0.52, p = 0.60). The CSI was not associated with psychophysical measures or pain distributions indicative of altered central pain processing. However, there was a correlation of the CSI with the Beck Depression Inventory (r = 0.426; p = 0.019). Conclusion: Patients with CTS show signs of altered central pain mechanisms. The CSI seems unsuitable to detect changes in central pain processing but is rather associated with psychological factors in people with focal nerve injuries.

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.

[Entrapment neuropathies: a contemporary approach to pathophysiology, clinical assessment, and management : German version]

Entrapment neuropathies such as carpal tunnel syndrome, radiculopathies, or radicular pain are the most common peripheral neuropathies and also the most common cause for neuropathic pain. Despite their high prevalence, they often remain challenging to diagnose and manage in a clinical setting. Summarising the evidence from both preclinical and clinical studies, this review provides an update on the aetiology and pathophysiology of entrapment neuropathies. Potenzial mechanisms are put in perspective with clinical findings. The contemporary assessment is discussed and diagnostic pitfalls highlighted. The evidence for the noninvasive and surgical management of common entrapment neuropathies is summarised and future areas of research are identified.

The Effects of Gender, Functional Condition, and ADL on Pressure Pain Threshold in Stroke Patients

Background

Somatosensory impairments and pain are common symptoms following stroke. However, the condition of perception and pain threshold for pressure stimuli and the factors that can influence this in individuals with stroke are still unclear. This study aimed to investigate the gender differences in pressure pain threshold (PPT) and positive somatosensory signs for pressure stimuli, and explore the effects of joint pain, motor function, and activities of daily living (ADL) on pain threshold in post-stroke patients.

Design

A cross-sectional study.

Methods

A total of 60 participants with stroke were recruited, and their pain condition, motor functions, and ADL were evaluated by the Fugl-Meyer assessment of joint pain scale, motor function scale, and Barthel index, respectively. PPTs in eight tested points at the affected and unaffected sides were assessed.

Results

Significant differences in PPTs were found between male and female patients in all measured muscles (p < 0.05). Positive somatosensory signs for pressure stimuli, including hypoalgesia and hyperalgesia, were frequently found at the affected side, particularly in the extremity muscles, but such signs were not significantly influenced by gender (p > 0.05). More equal PPTs between both sides and relatively lower PPTs at the affected side in the trunk and medial gastrocnemius muscles (p < 0.05) were observed in patients with less pain, better motor functions, and ADL.

Conclusion

Gender differences widely exist in post-stroke survivors either at the affected or unaffected side, which are multifactorial. Sensory loss and central and/or peripheral sensitization, such as hypoalgesia and hyperalgesia for pressure stimuli, caused by a brain lesion are common signs in male and female stroke patients. Moreover, patients who are in a better condition show a more symmetrical pain sensitivity between both sides in the trunk and in female lower extremities, indicating the bidirectional improvement of somatosensory abnormalities caused by a possible neural plasticity.

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.

Static and Dynamic Pain Sensitivity in Adults With Persistent Low Back Pain: Comparison to Healthy Controls and Associations With Movement-evoked Pain Versus Traditional Clinical Pain Measures

OBJECTIVES

Despite its impact, individual factors associated with persistent low back pain (LBP) remain poorly understood. This study investigated static and dynamic pain sensitivity in adults with persistent LBP versus pain-free controls; and investigated associations between pain sensitivity and 3 clinical pain measures: recalled, resting, and movement-evoked pain (MEP).

MATERIALS AND METHODS

A lifespan sample of 60 adults with persistent LBP and 30 age-matched/sex-matched controls completed 4 laboratory sessions. Static pain sensitivity (pressure pain threshold [PPT], heat pain threshold) and dynamic pain sensitivity (heat pain aftersensations [AS], temporal summation [TS] of second heat pain) were measured. Demographic and clinical factors collected were education, global cognition, and perceived health. Resting and recalled pain were measured via questionnaire, and MEP via the Back Performance Scale.

RESULTS

LBP participants demonstrated lower PPT remotely (hand; F1,84=5.34, P=0.024) and locally (low back; F1,84=9.55, P=0.003) and also had higher AS (F1,84=6.01, P=0.016). Neither static nor dynamic pain sensitivity were associated with recalled pain (P>0.05). However, static pain sensitivity (local PPT) explained an additional 9% variance in resting pain, while dynamic pain sensitivity (AS, TS) explained an additional 10% to 12% variance in MEP.

DISCUSSION

This study characterized pain sensitivity measures among individuals with persistent LBP and suggests static pain sensitivity plays a larger role in resting pain while dynamic pain sensitivity plays a larger role in MEP. Future studies will confirm these relationships and elucidate the extent to which changes in static or dynamic pain sensitivity predict or mediate clinical pain among adults with persistent LBP.

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.

Contralateral Sensory and Pain Perception Changes in Patients With Unilateral Neuropathy

OBJECTIVE

To test whether contralateral sensory abnormalities in the clinically unaffected area of patients with unilateral neuropathic pain are due to the neuropathy or pain mechanisms.

METHODS

We analyzed the contralateral clinically unaffected side of patients with unilateral painful or painless neuropathy (peripheral nerve injury [PNI], postherpetic neuropathy [PHN], radiculopathy) by standardized quantitative sensory testing following a validated protocol. Primary outcome was the independent contribution of the following variables on the contralateral sensory function using generalized linear regression models: pain intensity, disease duration, etiology, body area, and sensory patterns in the most painful area.

RESULTS

Among 424 patients (PNI n = 256, PHN n = 78, radiculopathy n = 90), contralateral sensory abnormalities were frequent in both painful (n = 383) and painless (n = 41) unilateral neuropathy, demonstrating sensory loss for thermal and mechanical nonpainful stimuli and both sensory loss and gain for painful test stimuli. Analysis by etiology revealed contralateral pinprick hyperalgesia in PHN and PNI. Analysis by ipsilateral sensory phenotype demonstrated mirror-image pinprick hyperalgesia in both mechanical and thermal hyperalgesia phenotypes. Pain intensity, etiology, and affected body region predicted changes in only single contralateral somatosensory parameters. Disease duration had no impact on the contralateral sensory function.

CONCLUSION

Mechanisms of sensory loss seem to spread to the contralateral side in both painful and painless neuropathies. Contralateral spread of pinprick hyperalgesia was restricted to the 2 ipsilateral phenotypes that suggest sensitization; this suggest a contribution of descending net facilitation from supraspinal areas, which was reported in rodent models of neuropathic pain but not yet in human patients.

Abnormal Brain Connectivity in Carpal Tunnel Syndrome Assessed by Graph Theory

Introduction

Numerous resting-state functional magnetic resonance imaging (fMRI) researches have indicated that large-scale functional and structural remodeling occurs in the whole brain despite an intact sensorimotor network after carpal tunnel syndrome (CTS). Investigators aimed to explore alterations of the global and nodal properties that occur in the whole brain network of patients with CTS based on topographic theory.

Methods

Standard-compliant fMRI data were collected from 27 patients with CTS in bilateral hands and 19 healthy control subjects in this cross-sectional study. The statistics based on brain networks were calculated the differences between the patients and the healthy. Several topological properties were computed, such as the small-worldness, nodal clustering coefficient, characteristic path length, and degree centrality.

Results

Compared to those of the healthy controls, the global properties of the CTS group exhibited a decreased characteristic path length. Changes in the local-level properties included a decreased nodal clustering coefficient in 6 separate brain regions and significantly different degree centrality in several brain regions that were related to sensorimotor function and pain.

Discussion

The study suggested that CTS reinforces global connections and makes their networks more random. The changed nodal properties were affiliated with basal ganglia-thalamo-cortical circuits and the pain matrix. These results provided new insights for improving our understanding of abnormal topological theory in relation to the functional brain networks of CTS patients.

Perspective

This article presents that the CTS patients’ brain with a higher global efficiency. And the significant alterations in several brain regions which are more related to pain and motor processes. The results provided effective complements to the neural mechanisms underlying CTS.

Manual Therapy Versus Surgery for Carpal Tunnel Syndrome: 4-Year Follow-Up From a Randomized Controlled Trial

OBJECTIVE

No study to our knowledge has investigated the effects longer than 1 year of manual therapy in carpal tunnel syndrome (CTS). The purpose of this study was to investigate the effects of manual therapy versus surgery at 4-year follow-up and to compare the post-study surgery rate in CTS.

METHODS

This randomized controlled trial was conducted in a tertiary public hospital and included 120 women with CTS who were randomly allocated to manual therapy or surgery. The participants received 3 sessions of physical therapy, including desensitization maneuvers of the central nervous system or carpal tunnel release combined with a tendon/nerve gliding exercise program at home. Primary outcome was pain intensity (mean and the worst pain). Secondary outcomes included functional status, symptom severity, and self-perceived improvement measured using a global rating of change scale. Outcomes for this analysis were assessed at baseline, 1 year, and 4 years. The rate of surgical intervention received by each group was assessed throughout the study.

RESULTS

At 4 years, 97 (81%) women completed the study. Between-group changes for all outcomes were not significantly different at 1 year (mean pain: mean difference [MD] = -0.3, 95% CI = -0.9 to 0.3; worst pain: MD = -1.2, 95% CI = -3.6 to 1.2; function: MD = -0.1, 95% CI = -0.4 to 0.2; symptom severity: MD = -0.1, 95% CI = -0.3 to 0.1) and 4 years (mean pain: MD = 0.1, 95% CI = -0.2 to 0.4; worst pain: MD = 0.2, 95% CI = -0.8 to 1.2; function: MD = 0.1, 95% CI = -0.1 to 0.3; symptom severity: MD = 0.2, 95% CI = -0.2 to 0.6). Self-perceived improvement was also similar in both groups. No between-group differences (15% physical therapy vs 13% surgery) in surgery rate were observed during the 4 years.

CONCLUSIONS

In the long term, manual therapy, including desensitization maneuvers of the central nervous system, resulted in similar outcomes and similar surgery rates compared with surgery in women with CTS. Both interventions were combined with a tendon/nerve gliding exercise program at home.

IMPACT

This is the first study to our knowledge to report clinical outcomes and surgical rates during a 4-year follow-up and will inform decisions regarding surgical versus conservative management of CTS.

LAY SUMMARY

Women with CTS may receive similar benefit from a more conservative treatment-manual therapy-as they would from surgery.

Mathematical Modeling for Neuropathic Pain: Bayesian Linear Regression and Self-Organizing Maps Applied to Carpal Tunnel Syndrome

A better understanding of the connection between risk factors associated with pain and function may assist therapists in optimizing therapeutic programs. This study applied mathematical modeling to analyze the relationship of psychological, psychophysical, and motor variables with pain, function, and symptom severity using Bayesian linear regressions (BLR) and self-organizing maps (SOMs) in carpal tunnel syndrome (CTS). The novelty of this work was a transfer of the symmetry mathematical background to a neuropathic pain condition, whose symptoms can be either unilateral or bilateral. Duration of symptoms, pain intensity, function, symptom severity, depressive levels, pinch tip grip force, and pressure pain thresholds (PPTs) over the ulnar, radial, and median nerve trunks, the cervical spine, the carpal tunnel, and the tibialis anterior were collected in 208 women suffering from CTS. The first BLR model revealed that symptom severity, PPTs over the radial nerve, and function had significant correlations with pain intensity. The second BLR showed that symptom severity, depressive levels, pain intensity, and years with pain were associated with function. The third model demonstrated that pain intensity and function were associated with symptom severity. The SOMs visualized these correlations among variables, i.e., clinical, psychophysical, and physical, and identified a subgroup of women with CTS exhibiting worse clinical features, higher pressure sensitivity, and lower pinch tip grip force. Therefore, the application of mathematical modeling identified some interactions among the intensity of pain, function, and symptom severity in women with CTS.

The Utilization of Joint Mobilization As Part of a Comprehensive Program to Manage Carpal Tunnel Syndrome: A Systematic Review

OBJECTIVE

The purpose of this review is to identify the role of joint mobilization for individuals with Carpal tunnel syndrome (CTS).

METHODS

A systematic search of 5 electronic databases (PubMed, CINAHL, Scopus, Cochrane Central Register of Controlled Trials, and SPORTDiscus) was performed to identify eligible full-text randomized clinical trials related to the clinical question. Joint mobilization had to be included in one arm of the randomized clinical trials to be included. Two reviewers independently participated in each step of the screening process. A blinded third reviewer assisted in cases of discrepancy. The PEDro scale was used to assess quality.

RESULTS

Ten articles were included after screening 2068 titles. In each article where joint mobilization was used, positive effects in pain, function, or additional outcomes were noted. In most cases, the intervention group integrating joint mobilization performed better than the comparison group not receiving joint techniques.

CONCLUSION

In the articles reviewed, joint mobilization was associated with positive clinical effects for persons with CTS. No studies used joint mobilization in isolation; therefore, results must be interpreted cautiously. This review indicates that joint mobilization might be a useful adjunctive intervention in the management of CTS.

Can self-reported pain characteristics and bedside test be used for the assessment of pain mechanisms? An analysis of results of neuropathic pain questionnaires and quantitative sensory testing

Hyperalgesia and allodynia are frequent in neuropathic pain. Some pain questionnaires such as the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) and the Neuropathic Pain Scale (NPS) include self-assessment or bedside testing of hyperalgesia/allodynia. The aim of this study was to determine to what extent LANSS and NPS data are congruent with findings on quantitative sensory testing (QST). Self-reported presence of dynamic mechanical allodynia (DMA) and descriptors of hot, cold, or deep ongoing pain (the NPS and LANSS) as well as bedside findings of mechanical allodynia (LANSS) were compared with signs of DMA and thermal hyperalgesia on QST in 617 patients with neuropathic pain. Self-reported abnormal skin sensitivity (LANSS) showed a moderate concordance with DMA during bedside test (67.9%, κ = 0.391) or QST (52.8%, κ = 0.165). Receiver operating curve analysis for self-reported DMA yielded similar area-under-the-curve values for the LANSS (0.65, confidence interval: 0.59%-0.97%) and NPS (0.71, confidence interval: 0.66%-0.75%) with high sensitivity but low specificity. Self-reported deep pain intensity was higher in patients with blunt pressure hyperalgesia, but not in patients with DMA or thermal hyperalgesia. No correlations were observed between self-reported hot or cold pain quality and thermal hyperalgesia on QST. Self-reported abnormal skin sensitivity has a high sensitivity to identify patients with DMA, but its low specificity indicates that many patients mean something other than DMA when reporting this symptom. Self-reported deep pain is related to deep-tissue hypersensitivity, but thermal qualities of ongoing pain are not related to thermal hyperalgesia. Questionnaires mostly evaluate the ongoing pain experience, whereas QST mirrors sensory functions. Therefore, both methods are complementary for pain assessment.

Central sensitization and its relationship with health profile in Behçet's disease

OBJECTIVES

In this study, we aimed to evaluate the level of central sensitization (CS) and its relationship with health profile, including neuropathic pain and sleep quality in Behçet's disease (BD).

METHOD

Eighty-eight patients with BD and 60 healthy controls (HCs) were included in the study between May 2018 and February 2019. Nottingham health profile (NHP), pain DETECT, Pittsburgh sleep quality index (PSQI) questionnaires and the central sensitization inventory (CSI) were administered to all participants. To evaluate the correlations of the NHP, PSQI, and PDQ scores with the CSI score, the CSI was modified for each questionnaire. The activity of BD was determined by the Behçet's disease current activity form (BDCAF).

RESULTS

CSI scores were significantly higher in patients with BD than HCs (BD: 41.2 ± 21.1 vs HCs: 20.4 ± 16.9, p < .001). Clinical CS was detected in 69.3% of patients with BD and 28.3% of HCs (p < .001). Severe or extreme CS (CSI score ≥ 50) was present in 37.5% of patients with BD and 5.0% of HCs (p < .001). There were high correlations between the modified CSI scores and the NHP, PDQ and PSQI scores in patients with BD (R = 0.804; p < .001, Rho = 0.698; p < .001, and Rho = 0.734; p < .001, respectively). There was significant correlation between CSI and BDCAF scores (Rho= 0.470, p < .001).

CONCLUSION

CS is more frequent and more severe in patients with BD than in HCs. There is a strong correlation between the severity of CS and poor health profile in patients with BD.

Entrapment neuropathies: a contemporary approach to pathophysiology, clinical assessment, and management

Entrapment neuropathies such as carpal tunnel syndrome, radiculopathies, or radicular pain are the most common peripheral neuropathies and also the most common cause for neuropathic pain. Despite their high prevalence, they often remain challenging to diagnose and manage in a clinical setting. Summarising the evidence from both preclinical and clinical studies, this review provides an update on the aetiology and pathophysiology of entrapment neuropathies. Potential mechanisms are put in perspective with clinical findings. The contemporary assessment is discussed and diagnostic pitfalls highlighted. The evidence for the noninvasive and surgical management of common entrapment neuropathies is summarised and future areas of research are identified.

Understanding central sensitization for advances in management of carpal tunnel syndrome

Carpal tunnel syndrome is the most common nerve compression disorder of the upper extremity, and it is traditionally considered a peripheral neuropathy associated with a localized compression of the median nerve just at the level of the carpal tunnel. Surgery and physiotherapy are treatment approaches commonly used for this condition; however, conflicting clinical outcomes suggest that carpal tunnel syndrome may be more complex. There is evidence supporting the role of peripheral nociception from the median nerve in carpal tunnel syndrome; however, emerging evidence also suggests a potential role of central sensitization. The presence of spreading pain symptoms (e.g. proximal pain), widespread sensory changes, or bilateral motor control impairments in people presenting with strictly unilateral sensory symptoms supports the presence of spinal cord changes. Interestingly, bilateral sensory and motor changes are not directly associated with electrodiagnostic findings. Other studies have also reported that patients presenting with carpal tunnel syndrome exhibit neuroplastic brainstem change supporting central sensitization. Current data would support the presence of a central sensitization process, mediated by the peripheral drive originating in the compression of the median nerve, in people with carpal tunnel syndrome. The presence of altered nociceptive gain processing should be considered in the treatment of carpal tunnel syndrome by integrating therapeutic approaches aiming to modulate long-lasting nociceptive barrage into the central nervous system (peripheral drive) and strategies aiming to activate endogenous pain networks (central drive).

Evaluation of axonal loss in ulnar sensory nerve fibers recorded from ring and little fingers secondary to idiopathic carpal tunnel syndrome in Egyptian patients

Background

The association between carpal tunnel syndrome (CTS) and ulnar nerve entrapment is unclear, and the extra-median paresthesia in the ulnar nerve territory innervation in CTS is unexplained. Our purpose is to evaluate the neurophysiologic changes in ulnar nerve sensory fibers secondary to idiopathic CTS in comparison to normal subjects, and their relation to the severity of CTS.

Results

The difference between CTS and control hands regarding all parameters of ulnar motor nerve conduction studies (MNCS) was not statistically significant (p > 0.05). There was a statistically significant difference in all parameters of median sensory conduction study (SCS) and MNCS between CTS and control hands (p < 0.0001) except for conduction velocity and in all parameters of median and ulnar SCS recording digit 4 (D4) (p < 0.05). The mean value of abnormalities of ulnar SCS recording D4 and digit 5 (D5) was significantly higher in moderate and severe CTS hands (p < 0.05). There were significant negative correlations between median motor and sensory latency and ulnar sensory amplitude recording D4 and D5.

Conclusion

Ulnar sensory nerve abnormalities exist among CTS patients, which were more in moderate and severe grades. The drop in amplitude of ulnar nerve sensory response argues in favor of the possible impact of CTS on the ulnar nerve and did not indicate axonal deterioration of the ulnar nerve.

Characterizing the Mechanical Properties of Ectopic Axonal Receptive Fields in Inflamed Nerves and Following Axonal Transport Disruption

Radiating pain is a significant feature of chronic musculoskeletal pain conditions such as radiculopathies, repetitive motion disorders and whiplash associated disorders. It is reported to be caused by the development of mechanically-sensitive ectopic receptive fields along intact nociceptor axons at sites of peripheral neuroinflammation (neuritis). Since inflammation disrupts axonal transport, we have hypothesised that anterogradely-transported mechanically sensitive ion channels accumulate at the site of disruption, which leads to axonal mechanical sensitivity (AMS). In this study, we have characterised the mechanical properties of the ectopic axonal receptive fields in the rat and have examined the contribution of mechanically sensitive ion channels to the development of AMS following neuritis and vinblastine-induced axonal transport disruption. In both models, there was a positive force-discharge relationship and mechanical thresholds were low (∼9 mN/mm²). All responses were attenuated by Ruthenium Red and FM1-43, which block mechanically sensitive ion channels. In both models, the transport of TRPV1 and TRPA1 was disrupted, and intraneural injection of agonists of these channels caused responses in neurons with AMS following neuritis but not vinblastine treatment. In summary, these data support a role for mechanically sensitive ion channels in the development of AMS.

Comparison of the effectiveness of orthotic intervention, kinesiotaping, and paraffin treatments in patients with carpal tunnel syndrome: A single-blind and randomized controlled study

PURPOSE

The aim of the study was to compare different conservative treatments in patients with carpal tunnel syndrome (CTS).

STUDY DESIGN

A single-blind randomized controlled study.

METHODS

Patients (n = 169) diagnosed with mild or moderate CTS were screened; 110 met study requirements. The patients were randomized into 3 groups. The control (CON) comparison provided to all patients was a fabricated night orthotic which held the wrist in a neutral position. The second group received adjunctive kinesiotaping (KIN) and the third group received paraffin (PARA). All patients were evaluated clinically, electrophysiologically, and ultrasonographically before treatment and at 3 weeks, 3 months, and 6 months.

RESULTS

There were 36 patients in CON, 37 in KIN, and 37 in PARA. Pain reduction in KIN was better than the other groups at 3 weeks (mean difference [MD] in CON 2.4 ± 2.5, KIN 3.7 ± 2.0, PARA 2.7 ± 2.3; P < .01) and 6 months (MD in CON 3.4 ± 3.0, KIN 4.9 ± 3.1, PARA 3.7 ± 2.9; P < .05). KIN pain reduction was better than CON at 3 months (MD in CON 3.8 ± 2.8, KIN 5.0 ± 2.5; P < .05). Reduction of the cross-sectional area of median nerve at the level of radioulnar joint was greater for KIN than CON at 3 weeks (MD in CON 0.0 ± 0.5, KIN 0.3 ± 0.7; P < .01) than PARA at 3 months (MD in KIN 0.3 ± 0.8, PARA 0.0 ± 0.8; P < .05) and both groups at 6 months (MD in CON 0.1 ± 0.8, KIN 0.5 ± 0.9, PARA 0.0 ± 1.0 P < .05).

CONCLUSION

Adding KIN to night use of an orthotic was more effective in achieving symptomatic and structural improvements than either the orthotic alone or adjunctive use of paraffin in patients with mild and moderate CTS.

Bilateral sensory and motor as well as cognitive differences between persons with and without musculoskeletal disorders of the wrist and hand

BACKGROUND

Sensory and motor disturbances are characteristic of musculoskeletal injuries and conditions. Rehabilitation interventions aimed at remediating these disturbances are traditionally exclusively targeted to the affected area. However, there is some evidence of bilateral changes in sensory and motor function associated with unilateral injuries and conditions suggesting central changes. Deficits on specific cognitive tasks have also been documented in persons with chronic pain.

PURPOSE

The purpose of the present study was to determine if participants with unilateral pain arising from heterogeneous wrist/hand injuries and conditions demonstrate bilateral changes in sensory and motor functions as well as cognitive deficits.

DESIGN/METHODS

Sensory (Pressure Pain Thresholds, Two Point Orientation Discrimination), Motor (grip strength and Purdue Pegboard), and Cognitive function (Stroop test and mental rotation task) were measured in 30 participants with wrist/hand pain and 30 healthy control participants in an observational cross-sectional study.

RESULTS

Participants with unilateral wrist/hand pain demonstrated differences in cognitive function measured with the Stroop test (p = 0.03). They also demonstrated bilateral sensorimotor differences in pressure pain thresholds (p = 0.03), grip strength (p = 0.00) and Purdue pegboard test (p = 0.03) results compared to healthy control participants.

CONCLUSION

Cognitive as well as bilateral alterations in sensory and motor function in participants with musculoskeletal injuries and conditions suggest central changes are involved in their pathophysiology. These findings in persons with heterogeneous injuries/conditions suggest that these changes are not specific to an injury/condition. Bilateral sensorimotor changes have important implications with regards to the pathophysiology of musculoskeletal disorders of the wrist/hand, for rehabilitative interventions and research.

Local and Widespread Pressure Pain Hyperalgesia Is Not Side Specific in Females with Unilateral Neck Pain that Can Be Reproduced during Passive Neck Rotation

Current evidence for widespread hyperalgesia in non-specific neck pain (NSNP) is unclear. It is currently recommended to group NSNP patients according to pain-provoking movements. The aim of this study was to investigate local and widespread pain sensitivity in females with unilateral NSNP that is reproducible during passive neck rotation compared with matched controls, and to compare the side specific effect of pain location on pressure pain sensitivity among females with unilateral NSNP. Thirty-six females with unilateral NSNP evoked during passive ipsilateral (n = 20) or contralateral (n = 16) rotation toward the painful side were compared with 20 controls. Participants reported their pain intensity at rest and during passive neck rotation and completed the Neck Disability Index. Pressure pain thresholds (PPTs) were assessed bilaterally over the anterior scalene; the sternocleidomastoid; the levator scapulae; lateral to the spinous process of C6; the median, ulnar, and radial nerves; and the tibialis anterior. The ANOVA revealed lower PPTs in females with unilateral NSNP compared with the controls (all at p < 0.001), but no differences were found between the sides, nor was there any Group × side interaction. Among females with NSNP, those with higher pain intensity during ipsilateral rotation toward the painful side showed lower PPTs over the anterior scalene, median nerve, ulnar nerve, and tibialis anterior (all, p < 0.05) than females with higher pain intensity during contralateral rotation toward the painful side. These findings demonstrated bilateral local and widespread pressure pain hyperalgesia in females with unilateral NSNP that was reproducible during passive neck rotation compared with controls. There was no side specific effect of pain location on PPTs among females with unilateral NSNP.

Association between Physiological and Subjective Aspects of Pain and Disability in Post-Stroke Patients with Shoulder Pain: A Cross-Sectional Study

Background: Patients often experience pain as a result of a stroke. However, the mechanism of this pain remains uncertain. Our aim was to investigate the relationship between pressure pain thresholds (PPTs) and disability pain in patients with hemiplegic shoulder pain (HSP). Methods: Twenty-six post-stroke patients (age 53.35 ± 13.09 years) and healthy controls (54.35 ± 12.37 years) participated. We investigated spontaneous shoulder pain, disability pain perception through the shoulder pain and disability index (SPADI), and the PPTs over joint C5–C6, upper trapezius, deltoid, epicondyle, second metacarpal, and tibialis anterior, bilaterally. Results: The analysis of variance (ANOVA) showed significant differences in pain between groups (p < 0.001) and differences in the SPADI (p < 0.001) between groups but not between sides for PPTs over deltoid (group: p = 0.007; side: p = 0.750), epicondyle (group: p = 0.001; side: p = 0.848), and tibialis anterior (group: p < 0.001; side: p = 0.932). Pain in the affected arm was negatively associated with PPTs over the affected epicondyle (p = 0.003) and affected tibialis anterior (p = 0.009). Pain (SPADI) appeared negatively correlated with PPTs over the affected epicondyle (p = 0.047), and disability (SPADI) was negatively associated with PPTs over the affected tibialis anterior (p = 0.041). Conclusions: Post-stroke patients showed a relationship between widespread pressure pain hypersensitivity with lower PPT levels and pain disability perception, suggesting a central sensitization mediated by bilateral and symmetric pain patterns.

Widespread Pressure Pain Sensitivity over Nerve Trunk Areas in Women with Frequent Episodic Tension-Type Headache as a Sign of Central Sensitization

Objective

Previous studies reported the presence of widespread pressure pain sensitivity in patients with tension-type headache. However, most of the studies assessed pressure pain sensitivity over muscle tissue. Our aim was to investigate the difference in pressure pain sensitivity over musculoskeletal and nerve symptomatic and distant areas between women with frequent episodic tension-type headache (FETTH) and healthy subjects.

Methods

Thirty-two women with FETTH and 32 matched healthy women participated. Pressure pain threshold (PPT) was bilaterally assessed over several nerve trunks (greater occipital, median, radial, ulnar, common peroneal, tibialis posterior) and musculoskeletal structures (temporalis muscle, C5/C6 joint, tibialis anterior) by an assessor blinded to the subject’s condition. A four-week headache diary was used to collect the intensity, frequency, and duration of headache. The Hospital Anxiety and Depression Scale was used to determine anxiety and depressive levels.

Results

Analysis of covariance found lower widespread and bilateral PPTs over all nerve trunks and musculoskeletal structures in women with FETTH pain (P &lt; 0.001). No significant effect of anxiety and depressive levels on PPTs was found (all P &gt; 0.222). PPT over the temporalis muscle was significantly negatively correlated with headache intensity.

Conclusions

This study found widespread pressure pain hypersensitivity over both nerve trunks and musculoskeletal structures in women with FETTH, suggesting that the presence of central altered nociceptive processing is not just restricted to musculoskeletal areas, for example, muscles, but also pain evoked from directly provoking the nerve trunks by pressure. It is also possible that nerve tissue treatment could lead to a decrease in central sensitization and headache features.

Widespread Pressure Pain Hypersensitivity, Health History, and Trigger Points in Patients with Chronic Neck Pain: A Preliminary Study

Background

Pain sensitivity in chronic neck pain patients may be influenced by health conditions related to higher levels of widespread pressure pain hypersensitivity (sensitization). Trigger points have also been reported to play a role in the sensitization process.

Objectives

To investigate the association between pressure pain thresholds, trigger points, and health conditions in patients with chronic neck pain.

Design

Original research, preliminary study.

Setting

A private clinic.

Subjects

Thirty-four chronic mechanical neck pain patients and 34 chronic whiplash-associated neck pain patients, giving a final sample of 68 chronic neck pain patients.

Methods

Patients underwent an assessment of pressure pain thresholds over the upper trapezius, extensor carpi radialis longus, and tibialis anterior muscles and were screened for the presence of trigger points in the upper trapezius muscle. Further, information about health history conditions was obtained and collected in a form.

Results

Significantly negative correlations between all pressure pain thresholds and duration of health history conditions were found (all P &lt; 0.02). Significantly lower pressure pain thresholds (all P &lt; 0.01) were found in patients with active trigger points as compared with those with latent trigger points.

Conclusion

Widespread pressure pain hypersensitivity was associated with duration of health history conditions, suggesting that long-lasting health complaints may act as a triggering/perpetuating factor, driving sensitization in individuals with chronic neck pain. Active trigger points may be associated with higher widespread pressure hypersensitivity.

Central sensitization in chronic pain and medically unexplained symptom research: A systematic review of definitions, operationalizations and measurement instruments

OBJECTIVE

Central sensitization (CS), a mechanism explaining the persistence of symptoms, has been the focus of many research projects. Explanations given to patients with chronic pain are often based on this mechanism. It is hypothesized that CS also plays an important role in the persistence of medically unexplained symptoms (MUS). However, definitions and operationalizations of CS vary. We conducted a systematic review of definitions, operationalizations and measurement instruments of CS.

METHODS

We searched in PubMed, EMBASE, PsycINFO, Cinahl and The Cochrane Library till September 2017 and included papers that addressed CS in relation to chronic pain and/or MUS. Two reviewers independently selected, analysed and classified information from the selected publications. We performed a thematic analysis of definitions and operationalizations. We listed the measurement instruments.

RESULTS

We included 126 publications, 79 publications concerned chronic pain, 47 publications concerned MUS. Definitions of CS consistently encompass the theme hyperexcitability of the central nervous system (CNS). Additional themes are variably present: CNS locations, nature of sensory input, reduced inhibition and activation and modulation of the NDMA receptor. Hyperalgesia and allodynia are widely mentioned as operationalizations of CS. Quantitative sensory testing (QST) and (f)MRI are the most reported measurement instruments.

CONCLUSIONS

There is consensus that hyperexcitability is the central mechanism of CS. Operationalizations are based on this mechanism and additional components. There are many measurement instruments available, whose clinical value has still to be determined. There were no systematic differences in definitions and operationalizations between the publications addressing MUS and those addressing chronic pain.

Cost-Effectiveness Evaluation of Manual Physical Therapy Versus Surgery for Carpal Tunnel Syndrome: Evidence From a Randomized Clinical Trial

BACKGROUND

Carpal tunnel syndrome (CTS) results in substantial societal costs and can be treated either by nonsurgical or surgical approaches.

OBJECTIVE

To evaluate differences in cost-effectiveness of manual physical therapy versus surgery in women with CTS.

METHODS

In this randomized clinical trial, 120 women with a clinical and an electromyographic diagnosis of CTS were randomized through concealed allocation to either manual physical therapy or surgery. Interventions consisted of 3 sessions of manual physical therapy, including desensitization maneuvers of the central nervous system, or decompression/release of the carpal tunnel. Societal costs and health-related quality of life (estimated by the European Quality of Life-5 Dimensions [EQ-5D] scale) over 1 year were used to generate incremental cost per quality-adjusted life year ratios for each treatment.

RESULTS

The analysis was possible for 118 patients (98%). Incremental quality-adjusted life years showed greater cost-effectiveness in favor of manual physical therapy (difference, 0.135; 95% confidence interval: 0.134, 0.136). Manual therapy was significantly less costly than surgery (mean difference in cost per patient, €2576; P<.001). Patients in the surgical group received a greater number of other treatments and made more visits to medical doctors than those receiving manual physical therapy (P = .02). Absenteeism from paid work was significantly higher in the surgery group (P<.001). The major contributors to societal costs were the treatment protocol (surgery versus manual therapy mean difference, €106 980) and absenteeism from paid work (surgery versus manual physical therapy mean difference, €42 224).

CONCLUSION

Manual physical therapy, including desensitization maneuvers of the central nervous system, has been found to be equally effective but less costly (ie, more cost-effective) than surgery for women with CTS. From a cost-benefit perspective, the proposed CTS manual physical therapy intervention can be considered.

LEVEL OF EVIDENCE

Economic and decision analyses, level 1b. J Orthop Sports Phys Ther 2019;49(2):55-63. Epub 30 Nov 2018. doi:10.2519/jospt.2019.8483.

The treatment of central sensitization in an adolescent using pain neuroscience education and graded exposure to activity: A case report

Chronic pain affects 1.7 million children in the United States, and its effects often linger into adulthood. Unfortunately, chronic pediatric pain is often undertreated. The current case report discusses the use of pain neuroscience education (PNE) combined with progressive exposure to activity to treat persistent pain in a 13-year-old female diagnosed with central sensitization syndrome. Prior to the diagnosis, the patient underwent two unsuccessful episodes of physical therapy that focused on musculoskeletal sources of pain. The patient was then referred to a physical therapist specializing in pain management. Following a detailed evaluation, PNE and graded exposure were used over a 4-week period to address the patient's condition and her behavioral responses to it. Significant decreases were observed in lowest (67%) and usual (50%) pain ratings and the portion of the day her worst pain was felt (67%), while the portion of the day with bearable pain (80%). Significant improvements in her ability to dance (168%), hike (50%), and run (200%) were observed. Reconceptualizing pain and its meaning changed perceptions and behaviors, allowing improvement when other approaches failed. Although effective for this patient, more research is needed into the use of this approach in the treatment of chronic pediatric pain.

The Val158Met polymorphism of the catechol-O-methyltransference gene is not associated with long-term treatment outcomes in carpal tunnel syndrome: A randomized clinical trial

DESIGN

Randomized clinical trial.

OBJECTIVE

To investigate the association of the Val158Met polymorphism with pain and function outcomes in women with carpal tunnel syndrome (CTS) who received surgery or manual therapy including desensitization manoeuvres of the central nervous system.

METHODS

A pre-planned secondary analysis of a randomized controlled trial investigating the efficacy of manual therapy including desensitization manoeuvres of the central nervous system vs. surgery in 120 women with CTS was conducted. Women were randomized to receive 3 sessions of manual therapy (n = 60) or decompression of the carpal tunnel (n = 60). The primary outcome was intensity of pain (mean pain and the worst pain), and secondary outcomes included function and symptoms severity subscales of the Boston Carpal Tunnel Questionnaire. Outcomes were assessed at baseline, and 1, 3, 6, and 12 months after the intervention. Rs4680 genotypes were determined after amplifying the Val158Met polymorphism by polymerase chain reactions. We classified subjects according to their Val158Met polymorphism: Val/Val, Val/Met, or Met/Met. The primary aim (treatment group*Val158Met*time) was examined with repeated measures ANCOVA with intention-to-treat analysis.

RESULTS

At 12 months, 111 (92%) women completed the follow-up. No interaction was observed between the Val158Met genotype and any outcome: mean pain intensity (F = 0.60; P = 0.69), worst pain intensity (F = 0.49; P = 0.61), function (F = 0.12; P = 0.88) or symptom severity (F = 0.01; P = 0.98).

CONCLUSION

The current clinical trial did not show an association between the Val158Met polymorphism and changes in pain and function outcomes after either surgery or physical therapy in women with CTS.

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

Patients with carpal tunnel syndrome (CTS) often show bilaterally increased pain sensitivity and widespread symptoms. We evaluated the influence of centrally mediated symptoms on functional outcomes of carpal tunnel release (CTR). A total of 120 patients with surgically treated CTS were enrolled. Centrally mediated symptoms were preoperatively measured by administering a self-reported central sensitization inventory (CSI) questionnaire and peripheral sensitization was measured by assessing patient's pressure pain thresholds (PPT) in the forearm. Boston Carpal Tunnel Questionnaires (BCTQ) were assessed preoperatively and postoperatively at 3 and 12 months. CSI scores slightly correlated with symptom duration and moderately correlated with preoperative BCTQ scores, while PPT slightly correlated with the BCTQ scores. At 3 months, BCTQ symptom and function scores moderately correlated with lower PPTs and higher CSI scores. At 12 months, only severe electrophysiological grade was associated with BCTQ function scores. Multivariable analysis revealed that preoperative PPT, CSI, and female gender were associated with BCTQ scores at 3 months; these factors failed to be associated for 12-month outcomes. Centrally mediated symptoms measured by CSI and peripheral sensitization measured by PPTs correlated with symptom severity and duration. They were associated with poorer functional outcomes after CTR up to 3 months. However, they did not show persistent effects in the long term.

Are the Sensory Fibers of the Ulnar Nerve Affected in Carpal Tunnel Syndrome?

PURPOSE

Distribution of paresthesia throughout the skin area without median nerve innervation is frequently seen in carpal tunnel syndrome (CTS). However, its pathophysiologic mechanisms are still unclear. We aimed to research whether a dysfunction in sensory fibers of the ulnar nerve (UN) was present or not in hands with CTS.

METHODS

Totally, upper extremity nerve conduction study recordings of 508 patients were considered. After exclusions, 331 upper extremity recordings of 277 patients were included. We compared the results of sensory conduction studies of median nerve and UN between normal hands and hands with CTS.

RESULTS

The mean distal sensory latency of the median nerve was longer, the mean conduction velocity was slower, and mean nerve action potential amplitude was higher in the hands with CTS than in normal hands (P < 0.001 for all comparisons). There was no statistically significant difference on any sensory conduction parameters of UN recorded on digit IV or digit V between the disease and control groups (P > 0.05 for all comparisons). The rates of conduction abnormalities of the UN sensory fibers were also similar in hands with CTS and in normal hands (P > 0.05 for all comparisons).

CONCLUSIONS

The hands with CTS do not have an increased rate of conduction abnormalities of UN sensory fibers compared with the normal hands in our study population. Therefore, our study did not confirm the distortion of UN sensory fibers as a mechanism underlying the spread of paresthesia throughout the skin area without median nerve innervation in CTS.

Carpal tunnel syndrome: just a peripheral neuropathy?

Carpal tunnel syndrome (CTS) is considered just a peripheral neuropathy of the upper extremity associated to the compression of the median nerve. There is evidence suggesting the presence of complex sensitization mechanisms in CTS. These processes are manifested by symptoms in extra-median regions and the presence of bilateral sensory and motor impairments. These sensory and motor changes are not associated to electrodiagnostic findings. The presence of sensitization mechanisms suggests that CTS should not be considered just as a peripheral neuropathy. The presence of altered nociceptive gain processing should be considered for therapeutic management of CTS by considering the application of therapeutic interventions that modulate nociceptive barrage into the CNS.

Laterality recognition of images, motor performance, and aspects related to pain in participants with and without wrist/hand disorders: An observational cross-sectional study

OBJECTIVE

Musculoskeletal disorders are associated with altered sensory, proprioceptive and cognitive processes. Sensory processes affect the internal cortical representation of the body in space, the body schema, which in turn influences motor control. The purpose of this study was to determine if participants with wrist/hand disorders had impaired performance on a task associated with the body schema, the Left/Right Judgement Task (LRJT) and secondly how LRJT performance, motor performance, disability, pain and related aspects are associated.

METHODS

Fifteen healthy control participants and 15 participants with hand/wrist pain were asked to determine the laterality of images of hands. Measures of motor performance (Purdue Pegboard test), self-reported disability (Australian Canadian Hand Index), and pain related aspects (pain intensity, symptom duration, pain interference and affective distress) were recorded.

RESULTS

Participants with wrist/hand pain scored lower on all segments of the Purdue Pegboard test. There were differences in LRJT performance between groups for both Accuracy (p = 0.03) and Reaction Time (RT) (p < 0.01). There was no correlation between RT and Accuracy with pain intensity, pain duration, and disability. Both motor performance (r = 0.58-0.64) and LRJT performance Accuracy (r = 0.59) and RT (r = -0.56) were correlated with affective distress. A significant correlation was observed between RT and motor performance in healthy control participants (r = -0.56, p = 0.03) but not in participants with wrist/hand pain (r = -0.26, p = 0.44).

CONCLUSIONS

LRJT and motor performance was correlated with affective distress in participants with wrist/hand pain suggestive of complex interactions between cognitive-affective processes and sensorimotor integration.

Selective cold pain inhibition by targeted block of TRPM8-expressing neurons with quaternary lidocaine derivative QX-314

Treatment of pain with local anesthetics leads to an unfavorable decrease in general sensory acuity due to their indiscriminate block of both pain sensing (nociceptors) and non-pain sensing nerves. However, the cell impermeant lidocaine derivative QX-314 can be selectively targeted to only nociceptors by permeation through ligand-gated cation channels. Here we show that localized injection of QX-314 with agonists for the menthol receptor TRPM8 specifically blocks cold-evoked behaviors in mice, including cold allodynia and hyperalgesia. Remarkably, cooling stimuli also promotes QX-314-mediated inhibition of cold behaviors, and can be used to block cold allodynia, while retaining relatively normal cold sensation. The effects of both agonist and thermally evoked uptake of QX-314 are TRPM8-dependent, results demonstrating an effective approach to treat localized cold pain without altering general somatosensation.

Serra Ongun, Angela Sarkisian and David McKemy show that localized co-injection of lidocaine derivative QX-314 and receptor agonists is able to block cold sensitivity in mice in a targeted way, with implications for treating cold pain associated with injury and disease.

Effectiveness of an Osteopathic Abdominal Manual Intervention in Pain Thresholds, Lumbopelvic Mobility, and Posture in Women with Chronic Functional Constipation

OBJECTIVES

To assess the effect of an osteopathic abdominal manual intervention (AMI) on pressure pain thresholds (PPTs), mobility, hip flexibility, and posture in women with chronic functional constipation.

DESIGN

Randomized, double-blind placebo-controlled trial.

SETTING/LOCATION

Subjects were recruited for the study by referral from different gastroenterology outpatient clinics in the city of Madrid (Spain).

SUBJECTS

Sixty-two patients suffering from chronic functional constipation according to the guidelines of the Congress of Rome III.

INTERVENTIONS

The experimental group (n = 31) received an osteopathic AMI, and the control group (n = 31) received a sham procedure.

OUTCOME MEASURES

PPTs at different levels, including vertebral levels C7, T3, T10, T11, and T12, trunk flexion range of motion (ROM), hip flexibility, and posture, were measured before and immediately after the intervention. A comparison between the difference between the pre- and postintervention values using the Student's t test for independent samples or nonparametric U-Mann-Whitney test depending on the distribution normality of the analyzed variables was perfomed.

RESULTS

In the intergroup comparison, statistically significant differences were found in PPT at T11 (p = 0.011) and T12 (p = 0.001) and also in the trunk flexion ROM (p < 0.05). Moreover, women showed no adverse effects with acceptable pain tolerance to the intervention.

CONCLUSION

The application of an osteopathic AMI is well tolerated and improves pain sensitivity in areas related to intestinal innervation, as well as lumbar flexion.

Preoperative Pain Sensitization Is Associated With Postoperative Pillar Pain After Open Carpal Tunnel Release

BACKGROUND

Postoperative pillar pain (deep-seated wrist pain worsened by leaning on the heel of the hand) sometimes occurs after carpal tunnel release (CTR), leading to weakness in the hand and delayed return to work. Increased pain sensitivity has been found to be associated with worse symptoms and poorer treatment response in a number of chronic musculoskeletal conditions, but few studies have investigated the association of pain sensitization with pillar pain after CTR.

QUESTIONS/PURPOSES

(1) Is preoperative pain sensitization in patients with carpal tunnel syndrome (CTS) associated with increased severity of pillar pain after open CTR? (2) What other demographic, electrophysiological, or preoperative clinical characteristics are associated with pillar pain after CTR?

METHODS

Over a 35-month period, one surgeon performed 162 open carpal tunnel releases. Patients were eligible if they had sufficient cognitive and language function to provide informed consent and completed a self-reported questionnaire; they were not eligible if they had nerve entrapment other than CTR or if the surgery was covered by workers compensation insurance. Based on these criteria, 148 (91%) were approached for this study. Of those, 17 (9%) were lost to followup before 12 months, leaving 131 for analysis. Their mean age was 54 years (range, 32-78 years), and 81% (106 of 131) were women; 34% (45 of 131) had less than a high school education. We preoperatively measured pain sensitization by assessing the patients' pressure pain thresholds by stimulating pressure-induced pain in the pain-free volar forearm and administering a self-reported Pain Sensitivity Questionnaire minor subscale, an instrument that assesses pain intensity in daily life situations. We evaluated postoperative pillar pain using the "table test" (having the patient lean on a table with their weight on their hands placed on the table's edge with elbows straight) with an 11-point ordinal scale at 3, 6, and 12 months after their surgical procedures. We conducted bivariate and multivariable analyses to determine whether the patients' clinical, demographic, and pain sensitization factors were associated with their postoperative pillar pain severity after CTR.

RESULTS

After controlling for relevant confounding variables such as age, education level, and functional states, we found that increased pillar pain severity was associated with the pressure pain threshold (β = -1.02 [-1.43 to -0.61], partial R = 11%, p = 0.021) and Pain Sensitivity Questionnaire minor (β = 1.22 [0.73-1.71], partial R = 17%, p = 0.013) at 3 months, but by 6 months, only Pain Sensitivity Questionnaire minor (β = 0.92 [0.63-1.21], partial R = 13%, p = 0.018) remained an associated variable for pillar pain. Additionally, gender (women) was associated with increased pain severity at 3 (β = 0.78 [0.52-1.04], partial R = 9%, p = 0.023) and 6 months (β = 0.72 [0.41-1.01], partial R = 8%, p = 0.027). At 3 months, pressure pain threshold, Pain Sensitivity Questionnaire minor, and gender (women) collectively accounted for 37% of the variance in pillar pain severity; at 6 months, Pain Sensitivity Questionnaire minor and gender (women) accounted for 21% of the variance, but no relationship between those factors and pillar pain was observed at 12 months.

CONCLUSIONS

Gender (women) and preoperative pain sensitization measured by pressure pain threshold and self-reported Pain Sensitivity Questionnaire were associated with pillar pain severity up to 3 and 6 months after CTR, respectively. However, the influence of pain sensitization on pillar pain was diminished at 6 months and it did not show persistent effects beyond 12 months. Pain sensitization seems to be more important in the context of recovery from surgical intervention (in the presence of a pain condition) than in healthy states, and clinicians should understand the role of pain sensitization in the postoperative management of CTS. Future research may be needed to determine if therapeutic interventions to reduce sensitization will decrease the risk of pillar pain.

LEVEL OF EVIDENCE

Level III, prognostic study.

Immediate preoperative outcomes of pain neuroscience education for patients undergoing total knee arthroplasty: A case series

BACKGROUND

Standard preoperative education for total knee arthroplasty (TKA) has been shown to have no effect on postoperative outcomes. This may be because such education programs fail to educate patients about pain. Pain neuroscience education (PNE) focuses on teaching people more about pain from a neurobiological and neurophysiological perspective.

DESIGN AND SETTING

Case Series.

AIM

To determine the immediate effects, if any, of providing PNE before TKA surgery on patient self-report measures.

PARTICIPANTS

Twelve patients (female = 10) prior to TKA for knee osteoarthritis (OA).

INTERVENTION

Preoperative educational session by a physical therapist on the neuroscience of pain, accompanied by an evidence-based booklet.

MAIN OUTCOME MEASURES

Comparison of pre- and post-PNE self-report measures on knee pain (NPRS), Pain Catastrophization Scale (PCS), fear of movement (TSK), and beliefs about TKA; as well as three physical performance measures - knee flexion active range of motion, 40 m self-paced walk, and pressure pain threshold (PPT).

RESULTS

Immediately following the PNE, patients had statistically significant lower TSK scores, increased PPT, and improved beliefs about their upcoming surgery. There were no significant changes in knee pain, function, or flexion active range of motion.

CONCLUSIONS

Results appear to suggest that immediately after PNE, patients scheduled for TKA had statistically significant changes in fear of movement, decreased sensitivity to pain and positive shifts in their beliefs about their future knee surgery. Larger trials with control/comparison groups are warranted to determine the true effects of preoperative PNE for patients about to undergo TKA.