The aims are:

1. Investigate new magnetic resonance imaging (MRI) scans for diagnosing severe nerve injury in the arm.
2. Understand how the brain and spinal cord respond to severe nerve injury using MRI.

The nerves which control movement and feeling in the arm can be severely damaged in eg. motorbike crashes, sporting or work-related injuries. Every year 500 adults sustain life-changing major nerve injuries, causing 1) disability needing constant care, 2) life-long pain and 3) mental illness. In England, major nerve injuries cost £250million every year in hospital treatments, unemployment and social care. Injured nerves can be repaired with surgery.

To decide if nerves need repairing, exploratory surgery is needed. Instead, we have developed a new MRI scan which could diagnose nerve injuries, meaning that exploratory surgery could be avoided, nerve injuries could be diagnosed sooner and reconstructive surgery performed sooner.

Some people with nerve injuries develop lifelong pain - if we could understand how the brain adapts, we could learn how to prevent nerve pain. Also, some people don't recover movement in their hand - if we could understand how the brain reorganises nerves controlling movement, we could predict who would benefit from surgery.

Inclusion Criteria:

Adults with traumatic BPIs who require surgical exploration of the supraclavicular brachial plexus. A traumatic BPI is defined by the absence of any or all motor or sensory function in an upper limb, following trauma.

Exclusion Criteria:

• Patients with an acutely ischaemic limb as they require immediate surgical intervention
• Unable to get into the MRI scanner due to habitus or claustrophobia
• Unable to lie still due to any cause (eg. athetoid movements, dystonias, chorea, etc)
• Intraocular or intracranial metallic foreign bodies
• Active implants (eg. pacemakers, implantable cardiac defibrillators, nerve stimulators, etc) which are not MRI safe or conditional.
• Pregnancy - whilst there are no known adverse effects of MRI(129-131) to the mother or fetus, MRI is generally avoided in pregnancy due to the acoustic trauma(132) and inductive heating generated by alternating magnetic fields.
• Any pre-existing neurological disorder, injury or disease causing a functional impairment in the affected limb
• Patients lacking capacity to consent