PATIENT INFORMATION
Nerve injuries
Injuries to the peripheral nerves, and how electrodiagnostic testing helps localise, grade and monitor them.
What is a nerve injury?
Peripheral nerves can be injured by cuts, fractures, dislocations, crush or traction injuries, or compression — for example following trauma, surgery, or a tight plaster or splint. Depending on the nerve involved and the severity, symptoms may include:
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Numbness, tingling or altered sensation in the area supplied by the nerve
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Weakness or paralysis of specific muscles
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Pain, which may be sharp, burning or electric shock-like
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Muscle wasting in longer-standing injuries
Nerve injuries vary widely in severity, from temporary conduction block, which often recovers well, through to complete division of the nerve, which may require surgical repair. Establishing which of these has occurred is central to planning treatment.
Why have I been referred for NCS and EMG?
Nerve conduction studies and EMG are particularly valuable in nerve injury. They help to localise the site of the injury, grade its severity, and distinguish an injury that is likely to recover on its own from one that may need surgical intervention. Repeated over time, they can also demonstrate early signs of nerve recovery (reinnervation) before these are apparent clinically, which helps to guide the timing of any surgery.
The findings are always interpreted alongside the mechanism of injury and your clinical examination, and are correlated with imaging where relevant. Read more about NCS/EMG.
What to Expect During the Test
Nerve conduction studies assess how well the injured nerve is conducting signals across and beyond the site of injury. EMG, using a fine needle electrode, samples the muscles supplied by the nerve for signs of denervation and, importantly, for early evidence of recovery.
The timing of the study matters in nerve injury — some changes take a few weeks to develop — and your referring clinician will usually have advised on when the study is best performed.
A specialist interest
Dr Foo contributes to a tertiary complex nerve injury diagnostic service within the NHS, working closely with orthopaedic, plastic, and spinal surgeons in the assessment of complex and traumatic peripheral nerve injuries. This multidisciplinary experience informs the electrodiagnostic assessment of nerve injury in his private practice, particularly where the findings need to be related directly to surgical decision-making.
Summary
Nerve injuries range from mild, self-limiting problems to complete nerve division requiring surgery. NCS and EMG localise and grade the injury, help distinguish injuries likely to recover from those that may need surgical repair, and can track early nerve recovery over time — information that is often central to deciding whether, and when, to operate.