MRI Diffusion Tensor Tractography to Track and Monitor Peripheral Nerve Recovery after Severe Crush or Cut/Repair Nerve Injury
Abstract
Background: Nerve injuries to the upper and lower extremities are very common in the United States in trauma patients, occurring in over 17,500 people annually. In the military, there is a greater than 90% chance of survival from a battlefield injury. Unfortunately, the increasing rate of survival means that more Wounded Warriors are living the rest of their lives with injured arms and legs or amputations. Many of these injuries involve damage to nerve(s). Often, these nerve injuries heal poorly and amputations are sometimes required because of severe nerve, bone, and vascular injury. This study seeks to develop a magnetic resonance imaging (MRI)-based strategy called diffusion tensor tractography (DTI) to monitor nerve recovery after injury and surgical repair to intervene in situations where nerves are not recovering appropriately. MRI-based DTI is non-invasive, while current methods of following nerve injury, electromyography (EMG) and nerve conduction studies, are invasive and only offer limited information about the repairs. This project is unique in that is proposes a partnership between (i) a peripheral neurosurgeon with expertise in nerve repair and (ii) engineers with expertise in developing/translating advanced MRI approaches for peripheral nerves. Objective/Specific Aims/Hypothesis: The objective of these studies is to evaluate the ability of MRI to monitor and predict nerve regrowth following crush or cut with surgical repair. Animal studies will be performed with DTI results compared to measures of axonal recovery from electrophysiology and histology, and validated protocols derived from these animal studies will be translated into humans. We hypothesize that the additional information from DTI will improve our ability to monitor nerve regrowth following surgical repair or severe crush injury, guiding clinical management either toward or away from surgical intervention. To accomplish this objective, we have set forth the following aims: (1) Determine if DTI fiber tracking can predict recovery of peripheral nerve function after crush or cut/repair peripheral nerve injury in a rat sciatic nerve model. Varied severity of nerve injury will be separately evaluated. Nerve conduits and graft repairs will also be evaluated. (2) Determine if our DTI fiber tracking protocol can predict recovery of peripheral nerve function in human case studies (crush or cut with repair). Pure sensory, motor, and mixed nerve injuries will be evaluated. Study Design: We propose this study bringing together the benefits of a clinical team and laboratory scientists. Together, these laboratories will determine if MRI can be used to track nerve recovery. Our early data indicate that MRI will serve as a useful technique to diagnose nerve injury and monitor recovery. We will first evaluate MRI using an animal model of nerve injury. Both nerve crush injuries and partial to complete nerve transections will be evaluated. We will follow these animals through their recovery and correlate the MRI results to animal behavior and nerve histology. Next, we will perform noninvasive MRI analysis following human nerve injuries and correlate those findings with invasive EMG and nerve conduction studies. This information may help diagnose nerve injuries that need surgery and for cases where nerves have been repaired, the study may help determine if the repair has been successful, guiding potential reoperation. Project Timeline: Our technology applies techniques available for current use in medical practice today. The timeline for this project is 3 years. We would then perform multicenter clinical trials on trauma patients in the next 3-6 years. Overall, we anticipate that the therapy could be clinically applicable within 6 years. Benefits: A recent review of Service member injuries during Operation Enduring Freedom noted significant increases in brachial plexus, ulnar, and radial nerve injuries attributable to modern w
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 31, 2017
- Source ID
- W81XWH1610605
Entities
People
- Wesley P Thayer
Organizations
- United States Army
- Vanderbilt University