Imaging the recovery of muscles following nerve trauma: Improving musculoskeletal outcome measures for nerve injured patients

Nerve injuries are a common outcome of traumatic incidents, such as road traffic accidents and stab wounds. The effects can be devastating with patients often left with permanent loss of movement, chronic pain, and an inability to do the activities that they used to enjoy. Many of these severe nerve injuries -can be helped by surgery, but the results are often disappointing. Many treatments have been shown in laboratory research to speed up nerve recovery. However, healthcare professionals lack the tools needed to objectively monitor nerve regeneration in humans. The existing test is on an estimate of the strength of the patient’s muscle long after the nerve has recovered. This has limited translation of treatments identified in the laboratory into patient benefit.

Dr Matthew Wilcox from UCL Centre for Nerve Engineering is a recipient of our Early Career Research Fellowship for his research into regenerative treatments for nerve injury and disease. He has a personal interest in this topic: ‘During undergraduate medical training, I was caught up in the Borough Market terrorist attacks, where there were lots of stab wounds. During my clinical rotations, I encountered a patient who had suffered a severe nerve injury, leaving them with almost no arm function. To my amazement, the surgeons were able to repair the damaged nerves and restore a high level of functionality. In observing the patient’s recovery, I realised there was an unmet clinical need for objective, reproducible and image-based methods through which recovery could be tracked and visualised. This sparked my interest in the field of regenerative medicine.’

Dr Wilcox’s research project is supported by his supervisor Associate Professor Tom Quick (Consultant Peripheral Nerve Surgeon, Royal National Orthopaedic Hospital and Cleveland Clinic Hospital) and the wider clinical teams at the Peripheral Nerve Injury Unit, Royal National Orthopaedic Hospital, as well as the Queen Square Centre for Neuromuscular Diseases. The project involves the development of a novel approach to monitor human nerve recovery using MRI scans. He says, ‘We’ve identified a patient group which provides a good model for monitoring human nerve recovery. Injury can have different effects on the nerve in different patients and there are also differences in patients’ treatments. By focussing on a group of patients who undergo a specific surgical procedure which restores elbow movement by rewiring uninjured nerves into damaged nerves (a nerve transfer), we are able to clearly monitor how that nerve regrows into the muscle over time.’

‘We are using MRI tests to watch muscles as they change in size after their nerve supply has been damaged. We hope this will lead to many patient benefits; patients will be able to see images of their muscles as they get bigger over time and change in structure. This will help patients monitor their own recovery after their surgery.  As researchers and healthcare professionals, this method will also enable us to start testing new treatments in humans by comparing how muscle size and structure changes with different treatments; helping turn treatments developed in the laboratory in to patient benefit.

This MRI based approach towards imaging nerve injured muscles through was developed through a collaboration with surgeons, neurologists, and scientists. Our ultimate aim is to improve treatments for patients with nerve damage, whether this be caused by trauma, abnormalities in the body systems (e.g. diabetes) or inherited diseases. Robust and reliable measurements are needed in order to test these treatments in humans.  We already know that MRI of muscles is a highly reproducible and sensitive method for monitoring changes in muscle volume and structure. For the first time, this project brings together a group of experts to apply a more detailed set of imaging methods for use in our nerve injury population. We hope this approach will benefit all nerve injured patients in the future.

Acknowledgements

• Tom Quick – Consultant Peripheral Nerve Surgeon, Royal National Orthopaedic Hospital, London
• Jasper Morrow – Consultant Neurologist, National Hospital for Neurology and Neurosurgery, London
• Tarek Yousry – Professor of Neuroradiology, UCL Queen Square Insitute of Neurology, London
• Hazel Brown – Clinical Specialist Physiotherapist, Royal National Orthopaedic Hospital, London
• John Thornton – Professor of Clinical Magnetic Resonance Physics, UCL Queen Square Insitute of Neurology, London