Sensory Neuropathy May Cause Central Neuronal Reorganization but Does Not Respecify Perceptual Quality or Localization of Sensation

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.

Electromyographic Biofeedback in Motor Function Recovery After Peripheral Nerve Injury: An Integrative Review of the Literature

Electromyographic biofeedback (EMG-BF) has been applied to treat different types of peripheral nerve injuries (PNI). However, despite the clinical practice widespread use its evidence is controversial. With the objective of summarize the available evidence on the electromyographic biofeedback effectiveness and efficacy to help motor function recovery after PNI an integrative review was performed. A secondary objective was to identify the conceptual framework and strategies of EMG-BF intervention, and the quality of technical description of EMG-BF procedures. To conduct this integrative review a systematic search of the literature was performed between October 2013 and July 2018, in PUBMED, ISI and COCHRANE databases for EMG-BF original studies in PNI patients of any etiology, in English, Portuguese, Spanish or French, published after 1990. Exclusion criteria were poor description of EMG-BF treatment, associated treatment that could impair EMG-BF effect, inclusion of non-PNI individuals and case studies design. The PEDro scale was used to evaluate study quality of randomized clinical trials (RCTs) included. This resulted in 71 potential articles enrolled to full reading, although only nine matched the inclusion criteria. PNI included facial paralysis, acute sciatic inflammation and carpal tunnel syndrome. The average quality score of the included RCTs was five, corresponding to low methodological quality. Due to the small number of included articles, low quality studies and heterogeneity of interventions, outcomes and population we concluded that there is limited evidence of EMG-BF effectiveness and efficacy for motor function recovery in PNI patients.