A prospective study of early tactile stimulation after digital nerve repair

Similar 2-point discrimination and stereognosia but better locognosia at long term with an independent home-based sensory reeducation program vs no reeducation after low-median nerve transection and repair

STUDY DESIGN

Prospective controlled study.

INTRODUCTION

Previous studies evaluated the effectiveness of sensory reeducation (SR) after peripheral nerve injury and repair. However, evidence for long-term clinical usefulness of SR is inconclusive.

PURPOSE OF THE STUDY

The purpose of this study is to compare the sensory results of patients with low-median nerve complete transection and microsurgical repair, with and without SR at long term.

METHODS

We prospectively studied 52 consecutive patients (mean age, 36 years; range, 20-47 years) with low-median nerve complete transection and microsurgical repair. When reinnervation was considered complete with perception of vibration with a 256-cycles per second tuning fork (mean, 3.5 months after nerve injury and repair), the patients were sequentially allocated (into 2 groups [group SR, 26 patients, SR; group R, 26 patients, reassured on recovery without SR). SR was conducted in a standardized fashion, in 2 stages, as an independent home-based program: the first stage was initiated when reinnervation was considered complete, and included instruction in home exercises to identify familiar objects and papers of different roughness, and localization of light touch (eyes open and closed); the second stage was initiated when the patients experienced normal static and moving 2-point discrimination (2PD) at the index fingertip of injured hand, and included instruction in home exercises for stereognosia, supplementary exercises for localization of light touch, and identification of small objects (eyes open and closed). Exercises were prescribed for 5-10 minutes, 4 times per day. At 1.5, 3, and 6 years after nerve injury and repair, we evaluated the static and moving 2PD, stereognosia with the Moberg's pick-up test, and locognosia with the modified Marsh test. Comparison between groups and time points was done with the nonparametric analysis of variance (Kruskal-Wallis analysis of variance).

RESULTS

Static and moving 2PD and stereognosia were not significantly different between groups at any study period. Locognosia was significantly better at 1.5 and 3 years in group SR; locognosia was excellent in 17 patients of group SR vs 5 patients of group R at 1.5-year follow-up and in 14 patients of group SR vs 5 patients of group R at 3-year follow-up. Locognosia was not different between the study groups at 6-year follow-up.

CONCLUSION

A 2-stage home program of SR improved locognosia at 1.5 and 3 years after low-median nerve complete transection and repair without significant differences in other modalities or the 6-year follow-up of a small subsample.

Patients' views on early sensory relearning following nerve repair-a Q-methodology study

STUDY DESIGN

Descriptive study.

INTRODUCTION

Early sensory relearning where the dynamic capacity of the brain is used has been shown to improve sensory outcome after nerve repair. However, no previous studies have examined how patients experience early sensory relearning.

PURPOSE OF THE STUDY

To describe patient's views on early sensory relearning.

METHODS

Statements' scores were analyzed by factor analysis.

RESULTS

Thirty-seven consecutive adult patients with median and/or ulnar nerve repair who completed early sensory relearning were included. Three factors were identified, explaining 45% of the variance: (1) "Believe sensory relearning is meaningful, manage to get an illusion of touch and complete the sensory relearning"; (2) "Do not get an illusion of touch easily and need support in their sensory relearning" (3) "Are not motivated, manage to get an illusion of touch but do not complete sensory relearning".

DISCUSSION

Many patients succeed in implementing their sensory relearning. However, a substantial part of the patient population need more support, have difficulties to create illusion of touch, and lack motivation to complete the sensory relearning. To enhance motivation and meaningfulness by relating the training clearly to everyday occupations and to the patient's life situation is a suggested way to proceed.

CONCLUSION

The three unique factors indicate motivation and sense of meaningfulness as key components which should be taken into consideration in developing programs for person-centered early sensory relearning.

LEVEL OF EVIDENCE

3.

Outcomes of surgical repair of a single digital nerve in adults

Current standard management of a cut digital nerve is end-to-end microsurgical nerve coaptation where possible. A recent systematic review of adult digital nerve injuries that were either repaired or left unrepaired showed that the evidence for good nerve recovery or improved function following nerve repair is poor. In the 30 studies included, only 24% of repaired nerves regained sensory recovery close to or equivalent to estimated pre-injury levels. Neuroma rates were the same in those nerves repaired (4.6%) and those not repaired (5%). Questions under debate include proper assessment methods of outcomes, decision making for repair or no repair to different fingers or the thumb, levels of injury, age, and hand dominance. This review summarizes the major evidence available and debates the surgical dogma that surrounds this injury.

Outcome of surgical repair of adult digital nerve injury: a systematic review

OBJECTIVES

A systematic review to assess the evidence supporting surgical repair of digital nerve injury versus no repair in adults in terms of clinical outcomes.

DESIGN

A Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant systematic review with methodology based on the Cochrane Handbook of Systematic Reviews of Interventions.

DATA SOURCES

Databases included OvidMEDLINE, EMBASE, AMED, clinicaltrials.gov and the Cochrane Database of Systematic Reviews, searched from inception until 10 November 2018.

ELIGIBILITY CRITERIA

Adult digital nerve injury in which either direct repair or no repair was undertaken and an outcome measure was recorded.

DATA EXTRACTION AND SYNTHESIS

Study data extracted included demographics, injury type and extent, timing, treatment details, outcome data and time points, adverse outcomes, hand therapy and return to work. The National Institute of Health quality assessment tool for case series was used to assess risk of bias.

RESULTS

Thirty studies were included. One compared surgical repair with non-repair. All studies were case series of between 15 and 110 nerve injuries, with heterogeneous patient, injury and treatment characteristics. Two studies detailed nerve repair without magnification. Static 2-point discrimination (s2PD) was the most commonly reported outcome measure. Return of protective sensation was achieved in most cases in the nerve repair and no nerve repair groups. Repair resulted in better s2PD than no repair, but <25% repaired nerves achieved normal levels. Adverse outcomes were similar between repair and no repair groups.

CONCLUSIONS

Only level IV evidence is available to support surgical repair of digital nerves in adults. Return of normal sensibility is uncommon and almost all unrepaired nerves regained protective sensation by 6 months and all patients declined further surgery. There was no difference in adverse outcomes. There is currently a lack of high-quality evidence to support surgical repair of digital nerve injuries in adults and further research is needed.

PROSPERO REGISTRATION NUMBER

CRD42017065092.

The effect of early relearning on sensory recovery 4 to 9 years after nerve repair: a report of a randomized controlled study

Twenty patients randomized to early sensory relearning (nine patients) or traditional relearning (11 patients) were assessed regarding sensory recovery 4 to 9 years after median or ulnar nerve repair. Outcomes were assessed with the Rosen score, questionnaires, and self-reported single-item questions regarding function and activity. The patients with early sensory relearning had significantly better sensory recovery in the sensory domain of the Rosen score, specifically, discriminative touch or tactile gnosis and dexterity. They had significantly less self-reported problems in gripping, clumsiness, and fine motor skills. No differences were found in questionnaires between the two groups. We conclude that early sensory relearning improves long-term sensory recovery following nerve repair.

LEVEL OF EVIDENCE

I.

Sensory Re-education Today and Tomorrow: A Review of Evolving Concepts

Following surgical repair of major nerve trunks there is a rapid functional reorganisation in the brain, characterised by a changed cortical mapping of the hand secondary to incorrect reinnervation of peripheral targets. Sensory re-educational programmes are used in the rehabilitation phase to facilitate and positively influence the re-learning process, which is required to make possible an adaptation to the new synaptic organisation and to improve the recovery of functional sensibility - tactile gnosis. However, the outcome is often disappointing, especially in adults. The design of sensory re-education programmes has not changed for several decades. The purpose of this paper is to review evolving concepts in neuroscience and cognitive science, present a rationale for a modified approach to classic sensory re-education, and suggest new strategies for enhanced sensory re-learning following nerve repair.

Sensory re-education after nerve injury of the upper limb: a systematic review

Objective : To systematically review the available evidence for the effectiveness of sensory re-education to improve the sensibility of the hand in patients with a peripheral nerve injury of the upper limb.

Data sources : Studies were identified by an electronic search in the databases MEDLINE, Cumulative Index to Nursing & Allied Health Literature (CINAHL), EMBASE, the Cochrane Library, the Physiotherapy Evidence Database (PEDro), and the database of the Dutch National Institute of Allied Health Professions (Doconline) and by screening the reference lists of relevant articles.

Review methods : Two reviewers selected studies that met the following inclusion criteria: all designs except case reports, adults with impaired sensibility of the hand due to a peripheral nerve injury of the upper limb, and sensibility and functional sensibility as outcome measures. The methodological quality of the included studies was independently assessed by two reviewers. A best-evidence synthesis was performed, based on design, methodological quality and significant findings on outcome measures.

Results : Seven studies, with sample sizes ranging from 11 to 49, were included in the systematic review and appraised for content. Five of these studies were of poor methodological quality. One uncontrolled study (N = 1 3 ) was considered to be of sufficient methodological quality, and one randomized controlled trial ( N = 49) was of high methodological quality. Best-evidence synthesis showed that there is limited evidence for the effectiveness of sensory re-education, provided by a statistically significant improvement in sensibility found in one high-quality randomized controlled trial.

Conclusion : There is a need for further well-defined clinical trials to assess the effectiveness of sensory re-education of patients with impaired sensibility of the hand due to a peripheral nerve injury.

Influence of immobilization and sensory re-education on the sensory recovery after reconstruction of digital nerves with direct suture or muscle-in-vein conduits

The influence of duration of immobilization and postoperative sensory re-education on the final outcome after reconstruction of digital nerves with direct suture or muscle-in-vein conduits was investigated. The final sensory outcome of 35 patients with 41 digital nerve injuries, who either underwent a direct suture (DS) or a nerve reconstruction with muscle-in-vein conduits (MVC), was assessed the earliest 12 months postoperatively using static and moving two-point discrimination as well as Semmes-Weinstein monofilaments. There was no significant difference in sensory recovery in cases with an immobilization of 3-7 days versus 10 days in the DS or MVC group. Moreover, no statistically significant difference in sensory recovery was found in cases receiving postoperative sensory re-education versus those not receiving in the DS or MVC group. An early mobilization does not seem to have a negative impact on the final outcome after digital nerve reconstruction. The effect of sensory re-education after digital nerve reconstruction should be reconsidered.

Long-term clinical outcome after epineural coaptation of digital nerves

This study evaluates the long-term clinical outcome and complication rate after digital nerve repair in adults and aims to identify possible prognostic factors of sensory recovery. End-to-end epineural coaptation was performed under magnification. A total of 93 coapted digital nerves were clinically evaluated with a mean follow-up of 3.5 years (range 1-6 years). The mean two-point discrimination was 10.6 mm (versus 4.4 mm for the contralateral side). Cutaneous pressure threshold tested with Semmes-Weinstein monofilaments showed a mean value of 2.7 (versus 2.2 for the contralateral side). Only 2% of our patients developed painful neuromas. None of our patients recovered normal functional sensibility, however, recovery of protective sensation contributed to a high reported level of satisfaction. No correlation was observed between the sensory outcome and age, smoking, mechanism of injury, lesion to or anastomosis of a digital artery, or time of immobilization. The only identified predictor of the result was the surgeon's level of experience. This highlights the importance of adequate training and practice in the surgical repair of smaller peripheral nerves.

LEVEL OF EVIDENCE

IV.

Microsurgeons do better--tactile training might prevent the age-dependent decline of the sensibility of the hand

Recent data demonstrate that the normal sensibility of the hand seems to be age-dependent with the best values in the third decade and a consecutive deterioration afterwards. However, it is not clear if long-term tactile training might prevent this age-dependent decline. We evaluated sensibility of the hand in 125 surgeons aged between 26 and 75 years who perform microsurgical operations, thereby undergoing regular tactile training. We examined sensibility of the radial digital nerve of the index finger (N3) and the ulnar digital nerve of the small finger (N10) using static and moving two-point discrimination (2PD) tests and compared the results to 154 age-matched individuals without specific long-term tactile training. We found significantly lower static and moving 2PD values for the sixth, seventh, and eighth decade of life in the microsurgery group compared to the control group (p < 0.05). This study demonstrates that long-term tactile training might prevent the known age-dependent decline of the sensibility of the hand.

Enhanced early sensory outcome after nerve repair as a result of immediate post-operative re-learning: a randomized controlled trial

We assessed the use of guided plasticity training to improve the outcome in the first 6 months after nerve repair. In a multicentre randomized controlled trial, 37 adults with median or ulnar nerve repair at the distal forearm were randomized to intervention, starting the first week after surgery with sensory and motor re-learning using mirror visual feedback and observation of touch, or to a control group with re-learning starting when reinnervation could be detected. The primary outcome at 3 and 6 months post-operatively was discriminative touch (shape texture identification test, part of the Rosen score). At 6 months, discriminative touch was significantly better in the early intervention group. Improvement of discriminative touch between 3 and 6 months was also significantly greater in that group. There were no significant differences in motor function, pain or in the total score. We conclude that early re-learning using guided plasticity may have a potential to improve the outcomes after nerve repair. LEVEL OF EVIDENCE II.

Differential recovery of touch thresholds and discriminative touch following nerve repair with focus on time dynamics

Introduction

The purpose of this secondary analysis of pooled data from two randomised controlled trials was to explore the differential rate of recovery of sensory and motor functions over time following repair of median or ulnar nerve.

Methods

Recovery over two years following median or ulnar nerve repair at wrist level using the Rosen score was analysed in 67 patients.

Results

Within the sensory domain of the Rosen score, a substantial gap was observed between recovery of touch thresholds and discriminative touch. Within the motor domain, manual muscle strength and grip strength showed a closer and more parallel recovery rate.

Conclusion

The differential recovery rates in touch thresholds and discriminative touch after a peripheral nerve injury are likely due to neurobiological factors that cannot be influenced by surgical interventions. However, new knowledge about brain plasticity opens up the possibility that this differential recovery may diminish through the use of revised rehabilitation programs focused on the use of guided plasticity, and the timing of onset of sensory re-learning.

Sensory recovery 1 year after bridging digital nerve defects with collagen tubes

PURPOSE

To investigate digital nerve regeneration following implantation of collagen tubes in a prospective study.

METHODS

Forty-five digital nerve defects (≤ 2.6 cm) in the hand were reconstructed in 35 patients (6 female, 29 male; mean age, 47 y). Nerve regeneration was evaluated at 3, 6, and 12 months after surgery by applying a sum score comprising static 2-point discrimination, sensory threshold with Semmes-Weinstein monofilament mechanical stimuli, warm/cold sensation, vibration sense, sharp/dull recognition, recognition of numbers, and subjective estimation of the patient. Electroneurography and ultrasound were also performed.

RESULTS

In the distribution of 60% of the operated nerves, very good or good recovery was found. In contrast to basic sensory function, the more complex static 2-point discrimination was more frequently impaired after 1 year. After 6 months, the sum score correlated with electroneurography. The type of injury altered the final sensory nerve function. Circular saw and iatrogenic injuries showed a negative correlation with final sensory nerve function. Complications (infection) were observed in 2 patients.

CONCLUSIONS

Owing to the good functional outcome in the majority of cases, the use of collagen tubes is useful to span digital nerve defects up to 2.6 cm.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Digital nerve injuries: a review of predictors of sensory recovery after microsurgical digital nerve repair

BACKGROUND

Optimal surgical management of digital nerve lesions remains uncertain despite the publication of numerous studies. The purposes of this review were primarily to analyze whether there is a superior surgical technique for digital nerve repair and secondarily to statistically verify the variables to be predictors of sensory recovery.

METHODS

A literature search was performed using PubMed including citation from MEDLINE. Studies were included if they involved patients with digital nerve lacerations in whom end-to-end neurorrhaphy, nerve grafts, conduits, or end-to-side neurorrhaphy were performed. Further, the sensory outcome had to be assessed according to the modified American Society for Surgery of the Hand guidelines to stratify for two-point discrimination in millimeters. The variables age, follow-up, delay in repair, type of trauma, and gap length were extracted. The association between each predictor and response was assessed using a linear mixed model and corrected for heterogeneity between studies. Significance was considered present at p ≤ 0.05.

RESULTS

Of the 34 articles found, 14 articles were included giving appropriate individual data for 191 nerves. There was no statistically significant difference in outcome between operation techniques. Age and follow-up were verified predictors of sensory recovery.

CONCLUSION

In this review, the type of operation for digital nerve repair does not influence sensory outcome. However, we verified outcome to be influenced by the patient's age and the follow-up period. To add more scientific evidence to our results, larger cohort prospective studies need to be done with better detailed description of data.

Pathophysiology of nerve regeneration and nerve reconstruction in burned patients

In extensive burns peripheral nerves can be involved. The injury to the nerve can be direct by thermal or electrical burns, but nerves can also be indirectly affected by the systemic reaction that follows the burn. Mediators will be released causing a neuropathy to nerves remote from the involved area. Involved mediators and possible therapeutic options will be discussed. In burned patients nerves can be reconstructed using autologous nerve grafts or nerve conduits. A key factor is an adequate wound debridement and a well-vascularized bed to optimize the outgrowth of the axons. Early free tissue transfers have shown promising results.

Early clinical outcomes with the use of decellularized nerve allograft for repair of sensory defects within the hand

Nerve conduits have become an established option for repair of sensory deficits of up to 2 cm. More recently, decellularized nerve allograft has also been advocated as an option for nerve repair; however, no clinical studies have examined its efficacy for the treatment of sensory nerve defects. The aim of this study was to examine our early experience with the use of decellularized nerve allograft for repair of segmental nerve defects within the hand and fingers. From July 2007 to March 2008, seven patients who had ten nerve gaps were treated surgically using decellularized nerve allograft. Eight digital and two dorsal sensory nerves were repaired. The etiologies of the nerve defects were traumatic nerve transection in eight defects and neuroma resection and reconstruction in two defects. All of the affected nerves were pure sensory fibers. Functional recovery was evaluated by blinded hand therapist using moving and static two point discrimination tests. Implantation sites were also evaluated for any signs of infection, rejection, or graft extrusion. There were five men and two women with a mean age of 44 years (range 23-65). Mean nerve graft length was 2.23 cm with a range of 0.5-3 cm. Mean follow up time was 9 months (range 5-12). Average two point discrimination was 4.4 mm moving and 5.5 mm static at last recorded follow-up. There were no wound infections observed around the graft material and sensory improvement was observed in all of the patients despite this short-term follow-up. Re-exploration of two fingers was required for flexor tendon rupture in one and flexor tendon tenolysis in the other. In both cases, the nerve allograft was visualized and appeared well incorporated in the repair site. Decellularized nerve allografts were capable of returning adequate sensation in nerve defects ranging from 0.5 to 3 cm. There were no cases of infection or rejection. Decellularized nerve allograft may provide an option for segmental nerve gaps beyond 2 cm. Randomized comparative studies will be required to determine efficacy in comparison to collagen conduits or nerve autograft.

Efeitos de um protocolo de reeducação sensorial da mão: estudo de caso

Uma paciente em pós-operatório de reparo das lesões dos tendões flexores e nervo digital do 5o dedo da mão direita foi estudada com o objetivo de avaliar os efeitos da aplicação de um protocolo de reeducação sensorial da mão. A paciente foi avaliada antes e após três meses da aplicação do protocolo. Nessas avaliações foram aplicados: teste de limiar de sensibilidade com monofilamentos, teste de discriminação de dois pontos estático e dinâmico, o questionário Dash (sigla em inglês de incapacidades de ombro, braço e mão) e testes de força de preensão palmar e de pinça. Os exercícios propostos envolveram: discriminação de toque estático e dinâmico e de objetos de diferentes formas, tamanhos e texturas. A paciente também foi orientada a executar programa domiciliar. Foi realizada a análise descritiva dos dados. Ao final dos três meses, verificou-se redução do limiar sensitivo na região volar do 5º dedo, bem como desenvolvimento de discriminação estática de dois pontos nessa região. Além disso, verificou-se aumento das forças de preensão palmar e de pinça e menor pontuação no questionário Dash. Os resultados sugerem que a aplicação de programas de reeducação da sensibilidade pode contribuir para a recuperação da função sensorial da mão, trazendo benefícios reais ao paciente.

Postoperative splinting for isolated digital nerve injuries in the hand

Digital nerve injuries in the hand are common and can result in significant impairment and functional restriction. Despite this, there is relatively little literature, particularly with respect to postoperative rehabilitation. Splinting after repair, purported to protect the repaired nerve from excessive stretch is still commonly used. Recent cadaveric studies indicate postoperative rehabilitation is not necessary with resection up to 2.5mm. A randomized controlled trial was therefore undertaken to determine whether splinting after isolated 5th degree digital nerve transection is in fact necessary. Twenty-six subjects were recruited over a two-year period and randomized to either three weeks of hand-based splinting or free active motion. ANCOVA indicated no differences in sensibility at six months between the two groups. Subjects also reported their greatest functional limitations were because of hyperesthesia. Although this study is underpowered, these limited results suggest splinting may not be required postoperatively.