Neuropathic pain in patients with upper-extremity nerve injury

Contemporary Approaches to Peripheral Nerve Surgery

"State of the Art" Learning Objectives: This manuscript serves to provide the reader with a general overview of the contemporary approaches to peripheral nerve reconstruction as the field has undergone considerable advancement over the last 3 decades. The learning objectives are as follows: To provide the reader with a brief history of peripheral nerve surgery and some of the landmark developments that allow for current peripheral nerve care practices.To outline the considerations and management options for the care of patients with brachial plexopathy, spinal cord injury, and lower extremity peripheral nerve injury.Highlight contemporary surgical techniques to address terminal neuroma and phantom limb pain.Review progressive and future procedures in peripheral nerve care, such as supercharge end-to-side nerve transfers.Discuss rehabilitation techniques for peripheral nerve care.

How should we define and assess painful sensitivity in the hand? An international e-Delphi study

BACKGROUND

Painful sensitivity in the hand is commonly seen with neuropathic pain, interfering with daily activities including rehabilitation. However, there are currently several terms used to describe the problem and a lack of guidance on what assessments should be used.

PURPOSE

To gather expert opinion a) identifying current and common terminology used in hand therapy, b) developing a consensus definition of hypersensitivity, and c) developing consensus guidance on how to best assess allodynia.

STUDY DESIGN

International e-Delphi survey study.

METHODS

We conducted an e-Delphi consensus study drawing on international experts in hand rehabilitation. We planned up to four rounds of consensus-seeking, defining consensus as 75% or more of participants agreeing with a definition or recommendation. Experts were identified from 21 countries, with the nomination of other experts encouraged for 'snowball sampling'. The first round included clinical vignettes describing 'painful sensitivity of the hand' and asked participants to describe how they would assess each case. Definitions for hypersensitivity, tactile hyperesthesia, and allodynia were also requested.

RESULTS

We invited 68 participants: 44 more were added through nominations. Sixty-three agreed to participate and were sent the round one survey; 54 participants from 19 countries completed this survey and were invited to participate in all subsequent rounds. No two definitions of hypersensitivity were the same, while 87% of the definitions for allodynia and 78% for tactile hyperesthesia were concordant with a published taxonomy. Over 700 assessment items were proposed in round one: ultimately 38 items representing eight distinct constructs reached a consensus for assessing allodynia.

CONCLUSIONS

Therapists definitions were consistent with an existing taxonomy for allodynia. Although hypersensitivity conceptualizations varied regarding the qualities of stimulus and response, a working definition was reached. Recommended assessments were relatively consistent internationally, holistic, and reflected a potential link between allodynia and central sensitization.

Rehabilitation Following a Triceps Branch to Axillary Motor Nerve Transfer-A Pragmatic Therapy Guide

Peripheral motor nerve transfer surgery is a technique that may be used to restore motor function to paralyzed muscles. Motor nerve transfer involves harvesting an expendable motor nerve branch, and transfer to the motor branch of the denervated target muscle, using microsurgical coaptation. To date, a standardized rehabilitation protocol does not exist. The 6 stages of rehabilitation after motor nerve transfer surgery were outlined by colleagues in the Birmingham Peripheral Nerve Injury service in 2019. This article aims to provide a practical therapy perspective on the rehabilitation stages of motor nerve transfer surgery outlined in that paper, focusing on the radial to axillary nerve transfer. Timeframes for each stage along with exercise prescription and rationale are provided.

Multiple Concurrent Decompressions for the Treatment of Upper Extremity Pain

Purpose

Neuropathic pain can be life altering and difficult to treat. Nerves can be compressed along their path in the upper extremities, resulting in chronic neuropathic pain. This study was performed to evaluate the effectiveness and safety of multiple concomitant distal nerve decompressions for the treatment of upper extremity nerve pain.

Methods

A retrospective review of patients from a single surgeon's academic practice was performed to identify those undergoing nerve decompressions for an indication of "pain" as the referring diagnosis between April 2020 and June 2021. The primary outcomes included patient-reported severity of pain using the Visual Analog Scale and quality-of-life measures, including level of frustration, depression, and impact on quality of life attributable to pain on a similar 0-10 Likert scale. Complications, if any, were also determined.

Results

Eleven patients were identified to have undergone multiple concurrent nerve decompressions for the indication of upper extremity pain. All sites chosen for decompression were found to be provocative, ie, elicited increased pain on examination with compression. The median number of decompressions performed was 5 (interquartile range, 4-6), ranging from 3 to 7. The mean follow-up time was 5 months (SD, 3.43 months). The average pain over the last month and the average pain over the past week had significant improvement at the final follow-up, and there was a statistically significant decrease in the patient-reported mean impact of pain on quality of life following decompressions (preoperative, 5.8; postoperative, 3.6; P = .017; 95% confidence interval, 0.2-4.3). No complications were identified.

Conclusions

Performing multiple concomitant nerve decompressions of the upper extremities is safe and effective in the treatment of chronic neuropathic pain following upper extremity trauma.

Type of study/level of evidence

Therapeutic IV.

The efficacy of wrapping the neurorrhaphy site utilizing dura substitute: A case series

BACKGROUND

Different procedures have been developed to improve the surgical outcome of peripheral nerve injuries. The purpose of this study was to evaluate the efficacy of wrapping the neurorrhaphy site utilizing dura substitute graft as an alternative conduit in the management of peripheral nerve injury.

METHODS

This retrospective clinical case series included 42 patients with a single peripheral nerve injury. The mean age was 26.8 ± 11 years, and the mean duration of symptoms was 3 ± 1.8 months. The visual analogue score (VAS) for pain and the Medical Research Council's (MRC) grading for motor power were used to evaluate the functional outcome among our patients. All patients were operated on for primary microscopic end-to-end repair, followed by wrapping the neurorrhaphy site with dura substitute graft as a conduit. Patients were followed in the outpatient clinic with regular visits for average of 6 months.

RESULTS

Thirty-seven patients (83%), showed functional improvement in all aspects, the VAS for pain and the MRC for motor power, as well as the functional state. One patient (2.3%) developed a postoperative hematoma collection, which needed immediate evacuation. Superficial wound infection, reported in two patients (4.7%), was treated conservatively. No postoperative neuroma was observed among our patients during the follow-up period.

CONCLUSION

Wrapping the neurorrhaphy site utilizing dura substitute as conduit appears to be safe and might prove effective in managing peripheral nerve injury.

Tactile stimulation programs in patients with hand dysesthesia after a peripheral nerve injury: A systematic review

STUDY DESIGN

This is a systematic review performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards.

INTRODUCTION

Diverse approaches based on tactile stimulation are used in hand rehabilitation settings to treat touch-evoked dysesthesias. However, there is a lack of literature synthesis on the description and the effectiveness of the various approaches based on tactile stimulation that can be used for treating hand dysesthesia after nerve injury.

PURPOSE OF THE STUDY

The purpose of the study was to summarize the current evidence on tactile stimulation programs for managing touch-evoked hand dysesthesia due to nerve injury.

METHODS

The search was carried out on Medline, Embase, CINAHL, and the Cochrane Library databases. The selected studies had to present patients with touch-evoked dysesthesia after nerve injury who were treated with tactile stimulation approaches to reduce pain. The methodological quality of the included studies was assessed using the methodological index for nonrandomized studies scale, as well as the risk of bias.

RESULTS

Eleven studies met the inclusion criteria. These studies present tactile stimulation interventions that are heterogeneous relative to the target populations and the intervention itself (desensitization versus somatosensory rehabilitation method). Painful symptoms appear to diminish in patients with touch-evoked hand dysesthesia, regardless of the tactile stimulation program used. However, the included studies present significant risks of bias that limit the confidence in these results.

DISCUSSION

The evidence does not unequivocally support the beneficial effects of tactile stimulation to treat touch-evoked hand dysesthesia.

CONCLUSION

Future studies with more rigorous methodological designs, such as randomized controlled trials, are required to verify the potential benefits of these approaches.

Chronic neuropathic pain after traumatic peripheral nerve injuries in the upper extremity: prevalence, demographic and surgical determinants, impact on health and on pain medication

Background and aims Aside from the long term side effects of a nerve injury in the upper extremity with devastating consequences there is often the problem of chronic neuropathic pain. The studies concerning the prevalence of persistent pain of neuropathic origin after peripheral nerve injuries are sparse. The prevalence and risk factors associated with chronic neuropathic pain after nerve injuries in the upper extremity were assessed. Methods A standardized data collection template was employed prospectively and retrospectively for all patients with traumatic nerve injuries accepted at the Hand Surgery Department, Uppsala, Sweden between 2010 and 2018. The template included demographic data, pain diagnosis, type of injured nerve, level of injury, date of the lesion and repair, type of procedure, reoperation, time since the procedure, S-LANSS questionnaire (Self report-Leeds Assessment of Neuropathic Symptoms and Signs), RAND-36 (Item short form health survey), QuickDASH (Disability of Shoulder, Arm and Hand) and additional questionnaires concerned medication, pain intensity were sent to 1,051 patients with nerve injuries. Partial proportional odds models were used to investigate the association between persistent pain and potential predictors. Results More than half of the patients undergoing a surgical procedure developed persistent pain. Prevalence of neuropathic pain was 73% of the patients with pain (S-LANSS ≥ 12 or more). Multivariate analysis indicated that injury of a major nerve OR 1.6 (p = 0.013), years from surgery OR 0.91 (p = 0.01), younger age OR 0.7 (p < 0.001), were the main factors for predicting pain after surgery. The type of the nerve injured was the strongest predictor for chronic pain with major nerves associated with more pain (p = 0.019). Conclusions A high prevalence of chronic pain and neuropathic pain with a negative impact on quality of life and disability were found in patients after traumatic nerve injury. Major nerve injury, younger age and less time from surgery were predictors for chronic pain.

Peripheral nerve injuries, pain, and neuroplasticity

INTRODUCTION

Peripheral nerve injuries (PNIs) cause both structural and functional brain changes that may be associated with significant sensorimotor abnormalities and pain.

PURPOSE OF THE STUDY

The aim of this narrative review is to provide hand therapists an overview of PNI-induced neuroplasticity and to explain how the brain changes following PNI, repair, and during rehabilitation.

METHODS

Toward this goal, we review key aspects of neuroplasticity and neuroimaging and discuss sensory testing techniques used to study neuroplasticity in PNI patients.

RESULTS

We describe the specific brain changes that occur during the repair and recovery process of both traumatic (eg, transection) and nontraumatic (eg, compression) nerve injuries. We also explain how these changes contribute to common symptoms including hypoesthesia, hyperalgesia, cold sensitivity, and chronic neurogenic pain. In addition, we describe how maladaptive neuroplasticity as well as psychological and personality characteristics impacts treatment outcome.

DISCUSSION AND CONCLUSION

Greater understanding of the brain's contribution to symptoms in recovering PNI patients could help guide rehabilitation strategies and inform the development of novel techniques to counteract these maladaptive brain changes and ultimately improve outcomes.

Neurologic complications of shoulder joint replacement

BACKGROUND

Little attention has been given to neurologic complications after shoulder joint replacement (SJR). Previously thought to occur infrequently, it is likely that many are not clinically recognized, and they can result in postoperative morbidity and impair the patient's recovery. The purpose of this study was to document the prevalence of nerve complications after SJR, to identify the nerves involved, and to define patient outcomes.

METHODS

This was a retrospective review of 211 SJRs in 202 patients during a 5-year period were included, with 89 male and 122 female patients at an average age of 70 years. All patients underwent a comprehensive analysis of any postoperative nerve complication, including onset, duration, investigation, treatment, and symptom resolution.

RESULTS

Of the 211 SJR procedures, 44 were identified as having sustained a nerve complication (20.9%), with 36 female (81.8%) and 8 male patients (18.2%). Reverse SJR was associated with the highest number of nerve complications. The median nerve (25 patients) and musculocutaneous nerve (8 patients) were most commonly involved. Most nerve complications were transient and resolved within 6 months. Permanent sequelae and injuries that required secondary surgical intervention were rare.

CONCLUSION

The occurrence of nerve complications after SJR is common, but almost all will fully recover. Most are transient neurapraxias involving the lateral cord of the brachial plexus. Women are more likely to be affected, as are patients who have undergone prior surgery to the affected shoulder. Most are likely to be the result of excessive traction or direct injury to the nerves during glenoid exposure.

A longitudinal study of pain, personality, and brain plasticity following peripheral nerve injury

We do not know precisely why pain develops and becomes chronic after peripheral nerve injury (PNI), but it is likely due to biological and psychological factors. Here, we tested the hypotheses that (1) high Pain Catastrophizing Scale (PCS) scores at the time of injury and repair are associated with pain and cold sensitivity after 1-year recovery and (2) insula gray matter changes reflect the course of injury and improvements over time. Ten patients with complete median and/or ulnar nerve transections and surgical repair were tested ∼3 weeks after surgical nerve repair (time 1) and ∼1 year later for 6 of the 10 patients (time 2). Patients and 10 age-/sex-matched healthy controls completed questionnaires that assessed pain (patients) and personality and underwent quantitative sensory testing and 3T MRI to assess cortical thickness. In patients, pain intensity and neuropathic pain correlated with pain catastrophizing. Time 1 pain catastrophizing trended toward predicting cold pain thresholds at time 2, and at time 1 cortical thickness of the right insula was reduced. At time 2, chronic pain was related to the time 1 pain-PCS relationship and cold sensitivity, pain catastrophizing correlated with cold pain threshold, and insula thickness reversed to control levels. This study highlights the interplay between personality, sensory function, and pain in patients following PNI and repair. The PCS-pain association suggests that a focus on affective or negative components of pain could render patients vulnerable to chronic pain. Cold sensitivity and structural insula changes may reflect altered thermosensory or sensorimotor awareness representations.

The clinical characteristics of neuropathic pain in patients with total brachial plexus avulsion: A 30-case study

Neuropathic pain in patients with total brachial plexus avulsion has always been a sophisticated problem in clinical practice.

OBJECTIVES

For further researches on objective diagnosis, alleviation or even cure of neuropathic pain, we need to conclude the basic clinical features including pain intensity, distribution, type and possible risk factors.

METHODS

Thirty cases of patients with total brachial plexus avulsion were included and their baseline information was collected. Pain was evaluated by Present Pain Index using a visual analog scale; Douleur Neuropathique 4 was used for screening neuropathic pain. For more detailed pain description, the Neuropathic Pain Symptoms Inventory questionnaire and a picture showing the exact pain district were both fulfilled by all the eligible participants. The relationship between neuropathic pain and basic information, injury conditions, accompanied conditions and quality of life was tested.

RESULTS

All the participants were male in both groups. The neuropathic pain group contained 22 patients (73.33%) with the mean age of 30.18±9.47; while 29.00±7.95 in the other group. Patients with neuropathic pain presented variously in pain degree, location, type and time phase, according to the results of the Neuropathic Pain Symptoms Inventory questionnaire. Nevertheless, most pain distributed on the region of hand. Among several related factors, alcohol abuse may be possible risk factors of neuropathic pain (p=0.03). Quality of life was significantly affected by pain (p<0.01).

CONCLUSION

Neuropathic pain in patients with total brachial avulsion was characterized with heterogeneity in pain distribution, intensity, type and also time phase. Bad life habits might be risk factors associated with neuropathic pain. Neuropathic pain might affect quality of life of the patients with total brachial plexus avulsion remarkably.

Relationship Between Botulinum Toxin, Spasticity, and Pain: a Survey of Patient Perception

Objective: To assess the prevalence of pain in adults with spasticity and to assess the association between the subjective experience of pain and spasticity. Design: Cross-sectional study. Setting: outpatient spasticity management clinic of a rehabilitation centre. Patients: Patients with upper motor neuron lesions and spasticity (n=131) were recruited. Methods: We assessed pain intensity and location, relationship between spasticity and pain perception, and perception of pain relief from botulinum toxin type-A (BoNTA) injections. Main outcome measures: Pain perception rated on a 10-point numerical rating scale and pain quality. Results: 65% of the patients with spasticity reported presence of pain and 60% described it as an aching pain. More patients reported pain with movement (34%) compared to rest (21%). There was a statistically poor correlation between the severity of pain and spasticity (r=0.16; p>0.05). Most patients (80%) believed that their pain was related to spasticity and 62% reported that BoNTA injections decreased their pain. Conclusions: The high incidence of pain noted within our sample suggests that physicians may have to consider pain management as part of spasticity treatment. Participants reported that their pain was related to their spasticity, and that it decreased after BoNTA treatment. Further study is needed to explore the relationships between objective measures of spasticity and pain.

Rehabilitation of the upper extremity following nerve and tendon reconstruction: when and how

Following upper extremity nerve and tendon reconstruction, rehabilitation is necessary to achieve optimal function and outcome. In this review, the authors present current evidence and literature regarding the strategies and techniques of rehabilitation following peripheral nerve and tendon reconstruction.

Advances in nerve transfer surgery

Peripheral nerve injuries are devastating injuries and can result in physical impairments, poor functional outcomes and high levels of disability. Advances in our understanding of peripheral nerve regeneration and nerve topography have lead to the development of nerve transfers to restore function. Over the past two decades, nerve transfers have been performed and modified. With the advancements in surgical management and recognition of importance of cortical plasticity, motor-reeducation and perioperative rehabilitation, nerve transfers are producing improved functional outcomes in patients with nerve injuries. This manuscript explores the recent literature as it relates to current nerve transfer techniques and advances in post-operative rehabilitation protocols, with a focus on indications, techniques and outcomes.

Disability following combat-sustained nerve injury of the upper limb

Injuries to the limb are the most frequent cause of permanent disability following combat wounds. We reviewed the medical records of 450 soldiers to determine the type of upper limb nerve injuries sustained, the rate of remaining motor and sensory deficits at final follow-up, and the type of Army disability ratings granted. Of 189 soldiers with an injury of the upper limb, 70 had nerve-related trauma. There were 62 men and eight women with a mean age of 25 years (18 to 49). Disabilities due to nerve injuries were associated with loss of function, neuropathic pain or both. The mean nerve-related disability was 26% (0% to 70%), accounting for over one-half of this cohort’s cumulative disability. Patients injured in an explosion had higher disability ratings than those injured by gunshot. The ulnar nerve was most commonly injured, but most disability was associated with radial nerve trauma. In terms of the final outcome, at military discharge 59 subjects (84%) experienced persistent weakness, 48 (69%) had a persistent sensory deficit and 17 (24%) experienced chronic pain from scar-related or neuropathic pain. Nerve injury was the cause of frequent and substantial disability in our cohort of wounded soldiers.

Cite this article: Bone Joint J 2014;96-B:254–8.

Behavioral pharmacology of pain

Behavioral methods are extensively used in pain research. Rodent modeling tends to rely on evoked responses but there is a growing interest in behavioral readouts that may capture elements of ongoing pain and disability, reflecting the major clinical signs and symptoms. Clinically, analgesics show greater efficacy in acute pain after standard surgery than in chronic conditions but are never completely effective on a population basis. In contrast, experimental pharmacological studies in rodents often demonstrate full efficacy, but there is variability in sensitivity between models and readouts. Full efficacy is rarely seen when more complex or multiple readouts are used to quantify behavior, especially after acute surgery or in studies of clinical pain in animals. Models with excellent sensitivity for a particular drug class exist and are suitable for screening mechanistically similar drugs. However, if used to compare drugs with different modes of action or to predict magnitude of clinical efficacy, these models will be misleading. Effective use of behavioral pharmacology in pain research is thus dependent on selection and validation of the best models for the purpose.

Evidence and techniques in rehabilitation following nerve injuries

Following upper extremity peripheral nerve injury and surgery, rehabilitation is essential to optimize sensorimotor function and outcome. This review presents the evidence and related literature regarding a few key topics related to rehabilitation following peripheral nerve injury and surgery.

Potential for Cell-Transplant Therapy with Human Neuronal Precursors to Treat Neuropathic Pain in Models of PNS and CNS Injury: Comparison of hNT2.17 and hNT2.19 Cell Lines

Effective treatment of sensory neuropathies in peripheral neuropathies and spinal cord injury (SCI) is one of the most difficult problems in modern clinical practice. Cell therapy to release antinociceptive agents near the injured spinal cord is a logical next step in the development of treatment modalities. But few clinical trials, especially for chronic pain, have tested the potential of transplant of cells to treat chronic pain. Cell lines derived from the human neuronal NT2 cell line parentage, the hNT2.17 and hNT2.19 lines, which synthesize and release the neurotransmitters gamma-aminobutyric acid (GABA) and serotonin (5HT), respectively, have been used to evaluate the potential of cell-based release of antinociceptive agents near the lumbar dorsal (horn) spinal sensory cell centers to relieve neuropathic pain after PNS (partial nerve and diabetes-related injury) and CNS (spinal cord injury) damage in rat models. Both cell lines transplants potently and permanently reverse behavioral hypersensitivity without inducing tumors or other complications after grafting. Functioning as cellular minipumps for antinociception, human neuronal precursors, like these NT2-derived cell lines, would likely provide a useful adjuvant or replacement for current pharmacological treatments for neuropathic pain.

Biomedical and psychosocial factors associated with disability after peripheral nerve injury

BACKGROUND

The purpose of this study was to evaluate the biomedical and psychosocial factors associated with disability at a minimum of six months following upper-extremity nerve injury.

METHODS

This cross-sectional study included patients who were assessed between six months and fifteen years following an upper-extremity nerve injury. Assessment measures included patient self-report questionnaires (the Disabilities of the Arm, Shoulder and Hand Questionnaire [DASH]; pain questionnaires; and general health and mental health questionnaires). DASH scores were compared by using unpaired t tests (sex, Workers' Compensation/litigation, affected limb, marital status, education, and geographic location), analysis of variance (nerve injured, work status, and income), or correlations (age and time since injury). Multivariable linear regression analysis was used to evaluate the predictors of the DASH scores.

RESULTS

The sample included 158 patients with a mean age (and standard deviation) of 41 ± 16 years. The median time from injury was fourteen months (range, six to 167 months). The DASH scores were significantly higher for patients receiving Workers' Compensation or involved in litigation (p = 0.02), had a brachial plexus injury (p = 0.001), or were unemployed (p < 0.001). There was a significant positive correlation between the DASH scores and pain intensity (r = 0.51, p < 0.001). In the multivariable regression analysis of the predictors of the DASH scores, the following predictors explained 52.7% of the variance in the final model: pain intensity (Beta = 0.230, p = 0.006), brachial plexus injury (Beta = -0.220, p = 0.000), time since injury (Beta = -0.198, p = 0.002), pain catastrophizing score (Beta = 0.192, p = 0.025), age (Beta = 0.187, p = 0.002), work status (Beta = 0.179, p = 0.008), cold sensitivity (Beta = 0.171, p = 0.015), depression score (Beta = 0.133, p = 0.066), Workers' Compensation/litigation (Beta = 0.116, p = 0.049), and female sex (Beta = -0.104, p = 0.090).

CONCLUSIONS

Patients with a peripheral nerve injury report substantial disability, pain, and cold sensitivity. Disability as measured with the DASH was predicted by brachial plexus injury, older age, pain intensity, work status, time since injury, cold sensitivity, and pain catastrophizing.