Enhanced sensory relearning after nerve repair by using repeated forearm anaesthesia: aspects on time dynamics of treatment

Sensory re-education after free neurovascular toe pulp flap for digital pulp reconstruction

PURPOSE

To evaluate the effectiveness of a sensory re-education (SR) program after free neurovascular toe pulp flap for finger or thumb pulp defect reconstruction.

METHODS

From January 2015 to January 2020, 49 patients with finger or thumb pulp defects treated with free fibular side flaps of the great toe or tibial side flaps of the second toe were recruited. The patients were randomly divided into two groups one month after surgery. The training group received the SR program, and the control group underwent the traditional rehabilitation program. Clinical evaluation included Semmes-Weinstein Monofilament (SWM) tests, static two-point discrimination (2-PD), and sensibility grading, measured at 1, 3, 6, 9, and 12 months postoperatively.

RESULTS

A total of 42 patients completed the follow-up, including 22 (16 males) patients in the training group and 20 patients (12 males) in the control group. Compared with 1 month after the operation, significant improvements in sensory recovery were observed at 3, 6, 9, and 12 months postoperatively in both groups. In addition, earlier sensory recovery was seen in the SR group compared to the control group, showing significant differences at 3 and 6 months but not at 9 and 12 months postoperatively.

CONCLUSION

Although SR seemed to accelerate preliminary sensory recovery after free neurovascular toe pulp flaps for digital defect reconstruction, the program should be reconsidered as it offers no significant improvement over the control group at later follow-up stages.

The effects of sensory re-education on hand function recovery after peripheral nerve repair: A systematic review

BACKGROUND

Peripheral nerve injury can result in both sensory and motor deficits, and these impairments can last for a long period after nerve repair.

OBJECTIVE

To systematically review the effects of sensory re-education (SR) on facilitating hand function recovery after peripheral nerve repair.

METHODS

This systematic review was limited to articles published from 1970 to 20 December 2020. Electronic searching was performed in CINAHL, Embase, PubMed, Web of Science, and Medline databases to include trials investigating the effects of SR training on hand function recovery after peripheral nerve repair and included only those studies with controlled comparisons.

RESULTS

Sixteen articles were included in final data synthesis. We found that only four studies could be rated as having good quality and noted obvious methodological limitations in the remaining studies. The current evidence showed that early SR with mirror visual feedback and the combinational use of classic SR and topical temporary anesthetic seemed to have long- and short-term effects, respectively on improving the sensibility and reducing the disabilities of the hand. The evidence to support the effects of conventional classical SR on improving hand functions was not strong.

CONCLUSIONS

Further well-designed trials are needed to evaluate the effects of different SR techniques on hand function after nerve repair over short- and long-term periods.

Sensory Restoration of the Facial Region

Normal sensitivity of the face is very important for preserving its integrity and function as an efferent source of information for the brain. The trigeminal nerve, which is the largest cranial nerve, conducts most of facial sensory function through its 3 branches: the ophthalmic nerve (V1), the maxillary nerve (V2), and the mandibular nerve (V3). The trigeminal nerve may be damaged by a variety of etiologies including inflammatory disorders, brain tumor resection, trauma, iatrogenic injury, or congenital anomalies. Temporary or permanent damage can lead to numbness, lip-biting injury, corneal anesthesia, and, in the worst scenario, even blindness. Different age groups, mechanisms of the injury, and the time between injury and repair can affect the final result of the nerve repair. Unlike the well-understood facial nerve palsy, so far there is no universal approach to restore the facial sensory function. This article serves to thoroughly review the basic anatomy of trigeminal nerve, diagnosis of sensory nerve dysfunction, and attempts to establish a protocol for treatment and rehabilitation of affected patients.

Changes in Expressions of Major Histocompatibility Complex Class I, Paired-Immunoglobulin-Like Receptor B, and Cluster of Differentiation 3ζ in Motor Cortical Representations of the Brachial Plexus After Avulsion in Rats

OBJECTIVE

Major histocompatibility complex class I (MHCI), paired-immunoglobulin-like receptor B (PirB), and cluster of differentiation 3ζ (CD3ζ) negatively regulate neuronal plasticity in developing and adult brains. The aim of this study was to evaluate expressive changes of these factors in motor cortical representations of the brachial plexus (MCRBP) after total brachial plexus root avulsion (tBPRA).

METHODS

A total of 45 rats were randomly and equally divided into 3 groups for evaluating mRNA and protein expression levels of MHCI, PirB, and CD3ζ: 7 days, 3 months, and control. In the 7-day and 3-month groups, expressions were examined at 7 days and 3 months, respectively, after left tBPRA. In the control group, the brachial plexus was uninjured. Three rats from each group were used for examining expressions of MHCI, PirB, and CD3ζ proteins by immunofluorescence labeling, 6 rats for quantification of MHCI, PirB, and CD3ζ mRNAs by real-time quantitative polymerase chain reaction, and the remaining 6 animals for quantification of MHCI, PirB, and CD3ζ proteins by Western blotting.

RESULTS

In the original MCRBP, mRNA and protein expression levels of MHCI, PirB, and CD3ζ were down-regulated 7 days postinjury compared with control (P < 0.01). Interestingly, mRNA and protein expression levels of these factors were up-regulated at 3 months compared with 7 days (P < 0.01), excepting PirB protein, whose expression was not increasing (P > 0.05). Recovery of protein expressions were initiated from near the border region of the original MCRBP.

CONCLUSIONS

MHCI, PirB, and CD3ζ may participate in motor cortical reorganization after tBPRA.

Occupation-based intervention versus rote exercise in modified constraint-induced movement therapy for patients with median and ulnar nerve injuries: a randomized controlled trial

Objective:

To investigate effect of practice type during modified constraint-induced movement therapy on hand function in patients with chronic median and ulnar nerve injuries.

Design:

A prospective, single-blinded, randomized controlled clinical trial.

Setting:

Participants’ private home.

Subjects:

A convenience sample of 36 outpatient participants allocated randomly to three equal groups.

Interventions:

Intervention groups underwent 3-hour intensive training of affected hand each day, 3-day a week, 4-week in association with immobilisation of healthy hand: occupation-based group practiced meaningful occupations while rote exercise-based group performed rote exercises during constraint-induced movement therapy. Control group performed different activities with affected hand for 1.5-hour each day during 4-week without restriction of healthy hand.

Main measures:

A blinded assessor tested Canadian occupational performance measure, box and block, Static two-point discrimination, disabilities of arm, shoulder, hand questionnaire, and self-assessment manikin in a random order across sessions 3-time as baseline (pre-test), after 4-week intervention (post-test), and 1-month after intervention period (follow up).

Results:

Scores significantly changed in intervention groups compared to control. Despite significantly more improvement in occupation-based than rote exercise-based group in subjective measures at post-test and follow up (Canadian occupational performance measure: mean change 4.7 vs. 2.1 for performance, P< 0.001 and mean change 5.3 vs. 2.6 for satisfaction, P< 0.001), it was significant just at follow up for box and block and static two-point discrimination.

Conclusions:

Practice content of constraint-induced movement therapy is a critical part of its effectiveness on improving outcomes following peripheral nerve repair in favour of occupation-based intervention in present study.

Feasibility of the modified constraint-induced movement therapy in patients with median and ulnar nerve injuries: a single-subject A-B-A design

OBJECTIVE

The present study aimed to determine feasibility and efficacy of the modified constraint-induced movement therapy on upper limb function in patients with median and ulnar nerve injuries.

DESIGN

Single subject, A1-B-A2 design.

SETTING

Occupational therapy outpatient clinic.

SUBJECTS

A convenience sample including three patients with median and ulnar nerve injuries.

INTERVENTIONS

Modified constraint-induced movement therapy as follows: an intensive practice with affected hand for one hour daily, five days per week, for four weeks while the healthy hand was immobilised using a splint during waking hours.

MAIN MEASURES

Semmes-Weinstein monofilaments, Box and block test, and Disabilities of the arm, shoulder, and hand questionnaire. A blinded assessor administered the assessments in a random order across sessions, six times for the baseline phase (A1), four times for the intervention phase (B), and four times for the withdrawal phase (A2).

RESULTS

Touch perception did not occur after the intervention phase at the pulp of the index and little fingers. Manual dexterity and motor ability significantly improved (Box and block change scores exceeded the minimal detectable change of 5.5 blocks), as well performance in activities of daily living during real life (Disabilities of the arm, shoulder, and hand questionnaire change scores exceeded the clinically important change value of 20.9 points). These improvements maintained and even enhanced during the withdrawal phase.

CONCLUSIONS

Modified constraint-induced movement therapy is a feasible and useful adjunct to rehabilitation of the patients with median and ulnar nerve injuries that warrants further research.

Sensorimotor cortical changes assessed with resting-state fMRI following total brachial plexus root avulsion

OBJECTIVE

Peripheral nerve injury can induce immediate and long-standing remodelling of the brain cortex, which may affect outcomes of nerve repair. This study examined changes of corresponding cortical representations in patients with brachial plexus injuries.

METHODS

Resting-state fMRI was acquired for 13 adult patients with total brachial plexus root avulsion, three of whom underwent second scans 7 or 8 months later. The time of examination ranged from 1 to 16 months after injuries. Nine healthy adults were enrolled as control. Seed-based functional connectivity was performed for all subjects.

RESULTS

For nine patients whose first fMRI was performed from 1 to 4 months after brachial plexus injuries, images showed that their cortical maps of sensorimotor areas corresponding to the hand and arm in the hemisphere contralateral to the injured side had much weaker correlation with the supplementary motor area (SMA) than those ipsilateral to the injured side. Symmetrical maps of bilateral cortical sensorimotor areas corresponding to the hand and arm were observed in other four cases with fMRI tested from 7 to 16 months after injuries. For three of the nine patients with asymmetrical cortical representations, second scans indicated symmetric results or even stronger correlation with SMA in the cerebral cortex contralateral to the injured side.

CONCLUSIONS

Total brachial plexus root avulsion causes cortical representations of the brachial plexus to undergo a change from an inactive to an active state. This implies that peripheral deafferentation after brachial plexus injuries will induce corresponding cortical representations to be occupied by adjacent non-deafferented cortical territories.

Cortical plasticity induced by different degrees of peripheral nerve injuries: a rat functional magnetic resonance imaging study under 9.4 Tesla

BACKGROUND

Major peripheral nerve injuries not only result in local deficits but may also cause distal atrophy of target muscles or permanent loss of sensation. Likewise, these injuries have been shown to instigate long-lasting central cortical reorganization.

METHODS

Cortical plasticity changes induced after various types of major peripheral nerve injury using an electrical stimulation technique to the rat upper extremity and functional magnetic resonance imaging (fMRI) were examined. Studies were completed out immediately after injury (acute stage) and at two weeks (subacute stage) to evaluate time affect on plasticity.

RESULTS

After right-side median nerve transection, cortical representation of activation of the right-side ulnar nerve expanded intra-hemispherically into the cortical region that had been occupied by the median nerve representation After unilateral transection of both median and ulnar nerves, cortical representation of activation of the radial nerve on the same side of the body also demonstrated intra-hemispheric expansion. However, simultaneous electrical stimulation of the contralateral uninjured median and ulnar nerves resulted in a representation that had expanded both intra- and inter-hemispherically into the cortical region previously occupied by the two transected nerve representations.

CONCLUSIONS

After major peripheral nerve injury, an adjacent nerve, with similar function to the injured nerve, may become significantly over-activated in the cortex when stimulated. This results in intra-hemispheric cortical expansion as the only component of cortical plasticity. When all nerves responsible for a certain function are injured, the same nerves on the contralateral side of the body are affected and become significantly over-activated during a task. Both intra- and inter-hemispheric cortical expansion exist, while the latter dominates cortical plasticity.

Effects of sensory reeducation programs on functional hand sensibility after median and ulnar repair: a systematic review

INTRODUCTION

This is the first systematic review looking at the effectiveness of sensory re-education programmes on functional sensibility which focuses purely on clinical trials of adult patients with median and ulnar nerve injuries.

METHODS

A literature search of AMED, CINAHL, Embase and OVID Medline (from inception to July 2011) was undertaken. Studies were selected if they met the following inclusion criteria: controlled trials (with or without randomization) of sensory re-education, including early and late phase, in adults with median and/or ulnar nerve repair. Two independent assessors rated study quality and risk of bias using the 24 point MacDermid Evaluation Tool.

RESULTS

A total of seven articles met the inclusion criteria representing five separate studies Study quality ranged from 13 to 33 out of 48 points on the Evaluation Tool. Due to heterogeneity of the interventions and outcomes assessed it was not possible to pool the results from all studies. There is limited evidence to support the use of early and late SR programmes.

CONCLUSION

Further trials are needed to evaluate the effect of early and late sensory re-education which are adequately powered, include validated and relevant outcomes and which are reported according to CONSORT (Consolidated Standards of Reporting Trials) guidelines.

LEVEL OF EVIDENCE

2b.

Interventions in the disturbances in the motor and sensory environment

Treatment of peripheral nervous system (PNS) pathology presents intervention challenges to every therapist. Many of the current and future interventions will be directed at restoring the normal anatomy, function, and biomechanical properties of the PNS, restoring normal neural physiology and ultimately patient function and quality of life. Present interventions use mechanical (movement) or electrical procedures to affect various properties of the peripheral nerve. The purpose of this article was to apply basic science to clinical practice. The pathology and accompanying structural and biomechanical changes in the PNS will be presented in three specific areas commonly encountered in the clinic: nerve injury and laceration; compression neuropathies; and neuropathic pain and neural tension dysfunction. The intent is to address possible interventions exploring the clinical reasoning process that combines basic science and evidence-based best practice. The current lack of literature to support any one intervention requires a strong foundation and understanding of the PNSs' structure and function to refine current and develop new intervention strategies. Current evidence will be presented and linked with future considerations for intervention and research. During this interlude of development and refinement, best practice will rely on sound clinical reasoning skills that incorporate basic science to achieve a successful outcome when treating these challenging patients.

Principles of brain plasticity in improving sensorimotor function of the knee and leg in patients with anterior cruciate ligament injury: a double-blind randomized exploratory trial

Background

Severe traumatic knee injury, including injury to the anterior cruciate ligament (ACL), leads to impaired sensorimotor function. Although improvements are achieved by training, impairment often persists. Because good sensorimotor function is associated with better patient-reported function and a potential lower risk of future joint problems, more effective treatment is warranted. Temporary cutaneous anesthesia of adjacent body parts was successfully used on the hand and foot to improve sensorimotor function. The aim of this study was to test whether this principle of brain plasticity could be used on the knee. The hypothesis was that temporary anesthesia of the skin area above and below the knee would improve sensorimotor function of the ipsilateral knee and leg in subjects with ACL injury.

Methods

In this double-blind exploratory study, 39 subjects with ACL injury (mean age 24 years, SD 5.2, 49% women, mean 52 weeks after injury or reconstruction) and self-reported functional limitations and lack of trust in the knee were randomized to temporary local cutaneous application of anesthetic (EMLA®) (n = 20) or placebo cream (n = 19). Fifty grams of EMLA®, or placebo, was applied on the leg 10 cm above and 10 cm below the center of patella, leaving the area around the knee without cream. Measures of sensory function (perception of touch, vibration sense, knee kinesthesia) and motor function (knee muscle strength, hop test) were assessed before and after 90 minutes of treatment with EMLA® or placebo. The paired t-test was used for comparisons within groups and analysis of variance between groups, except for ordinal data where the Wilcoxon signed rank test, or Mann–Whitney test, was used. The number of subjects needed was determined by an a priori sample size calculation.

Results

No statistically significant or clinically relevant differences were seen over time (before vs. after) in the measures of sensory or motor functions in the EMLA® group or in the placebo group. There were no differences between the groups due to treatment effect (EMLA® vs. placebo).

Conclusions

Temporary cutaneous anesthesia of adjacent body parts had no effect in improving sensorimotor function of the knee and leg in subjects with severe traumatic knee ligament injury.