Anticipating Efficacy of Nerve Transfers in SCI Using Quantitative Neurophysiology
Abstract
Objective and Rationale: The goal of this project is to (1) assess the diagnostic efficacy of quantitative neurophysiological methods for pre-operatively determining the innervation status of nerve branches being considered for nerve transfer, and (2) assess the efficacy of these quantitative neurophysiological methods for anticipating the results of nerve transfer procedures in patients with spinal cord injury (SCI). Applicability and Impact of the Research: SCI is debilitating and results in significant physical impairment. More than half of SCIs occur within the cervical spine, which results in the loss of hand and/or arm function. The goal of surgical intervention is to restore sufficient function such that affected individuals can regain a degree of independence and improve their quality of life. Although tendon transfers have been the traditional surgical approach, nerve transfers have gained traction as a comparable or potentially superior approach to restoring function in many cases. Nerve transfers involve providing new innervation sources to the original muscles that have lost function because of the injury. Healthy donor nerves that serve less important or redundant roles are redirected and transferred into a more important target or recipient nerve. The axons that it has donated then grow to the new target muscle and recover its function. The extent of functional recovery in the target muscles depends on the quality of both the donor and recipient nerves and receptivity of the target muscle. Unfortunately, variable outcomes have been published, and a detailed pre-operative assessment has not been outlined to determine which patients (or which nerves in a given patient) are the best candidates for these procedures. This project will develop and test quantitative neurophysiology (QNP) as a promising method to determine surgical candidacy and which procedures are most likely to succeed. QNP may help reduce failed attempts at reconstruction in this vulnerable population. Target Population(s): Patients with cervical SCIs with resulting arm and hand dysfunction will benefit from these assessments, regardless of the time interval since their injury. We will recruit patients from Massachusetts General Hospital and Spaulding Rehabilitation Hospital who present for arm and hand reconstruction. They will each undergo standard pre-op testing as well as the novel QNP assessments. QNP test results will be correlated with surgical outcomes achieved such as strength, function, and quality of life improvements for each nerve transfer performed. We will determine whether QNP testing provided additional predictive value. Potential Clinical Applications and Benefits: The efficacy of QNP testing will be assessed for each nerve transfer undertaken. Thresholds for QNP results below which inadequate function is achieved will be determined, and prediction models will be developed based upon results for both donor and recipient nerves, given the time interval from injury to surgery. This will allow surgeons and patients to make better decisions about which nerve transfer operations are likely to produce a satisfactory result, or whether an alternative procedure should be considered. Time to Achieve Person-Related Outcome: Typically, it takes 1 year after nerve transfer surgery to regain full strength, and additional months until new arm motion is incorporated into normal activities. Recovery time may be related to the retraining effort applied. Within 3 years from the initiation of this project, sufficient outcome measures will be available to test the hypothesis that QNP methods meaningfully predict clinical outcomes. Interim Outcomes: The first aim of correlating the QNP technique with the actual number of axons within the nerve branches being transferred will be available within weeks of the operation. This aim will be completed within 18 months of the initiation of this project. Contributions to Advancing t
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Dec 05, 2021
- Source ID
- W81XWH2110986
Entities
People
- Justin M. Brown
Organizations
- Massachusetts General Hospital
- United States Army