Welcome to the Alder Hey Nerve Service. This is an information page to help you understand why you have been referred to us and the wide variety of treatments that may be offered to you. Nerve Injuries are wide-ranging in symptoms and treatment options. We hope that the information here will help you and guide discussions with the team.
What are nerves?
Nerves form a network of living cables that spread through the body from the brain and spinal cord like the branches of a tree spreading out from its trunk. They carry electrical signals throughout our body to and from the brain.
Motor nerves allow signals to travel from our brain to our muscles which control our movement.
Sensory nerves allow signals to travel from our skin to our brains. These signals allow us to feel pain, cold, heat and touch.
Any given one of the nerves can be motor, sensory or a combination of both.
Nerves can be injured at any point during their path from the brain to the muscles or skin.
If a motor nerve is damaged the signals to the muscles that travel through the nerve will be affected. If there is no signal the muscle will not work and movement will be affected. We call this paralysis. The paralysis can be very minor, so minor you don’t even notice! Or very severe – where, for example, the whole arm doesn’t work, or anything in between.
If a sensory nerve is damaged the sensory information for the skin carried by the injured nerve will be affected. This may cause an altered sensation in a patch of skin (numbness or pins and needles).
How do Nerve Injuries happen?
Nerves can be cut, stretched or crushed. The treatment of a nerve injury depends on the type of injury. Sometimes nerves which are crushed or stretched may heal by themselves over time so that the signals can pass through them to the muscle or from the skin.
Sometimes, the healing leaves a large scar within the nerve (a neuroma) which affects acts like a wall stopping electrical the ability of signals to pass through. It is often not clear how bad the stretch or crush is. It is therefore important to monitor the recovery of the nerve over time to help us understand if the scar forming will allow the signals to pass through again.
If a nerve is cut and the two cut ends are not lined up, the healing will cause a scar which signals cannot pass through.
Nerve injury patterns
At Birth (Obstetric Brachial Plexus)
The nerves in the neck that branch out into the arm and make it move and feel are called the brachial plexus. Sometimes, particularly during a difficult delivery, these nerves can be stretched or even torn.
The stretching is between the neck and the shoulder. As a result, the nerves which carry the signals to the muscles of the arm can be damaged – that is to say there may be some degree of paralysis and they may stop moving properly. The nerves most damaged affect movement at the shoulder, elbow and sometimes the wrist and finger joints can be affected. Sometimes, the whole arm can be paralysed.
Traumatic Injury
Nerves can be cut in a sharp injury or crushed or pulled in any other type of accident. Sometimes they can also be injured because of fracture or its subsequent fixation. Such nerve injuries will again result in decreased movement or sensation depending on the nerve that is damaged.
Facial nerve injuries
There is a very special nerve called the facial nerve that moves your face, helping you to smile, frown, eat and move your eyebrows. Sometimes, it doesn’t work, and it can cause problems with making facial expressions and with eating. We have a very special service that deals with these problems.
Management of nerve injuries
How do we treat nerve injuries?
Nerves can sometimes heal themselves, however, this ability to recover depends on the type of injury.
While waiting to see if a nerve will recover enough and quickly enough to work, it is often important that patients undergo physiotherapy to stop joints and muscles from getting stiff.
If a motor nerve is injured, it is important to restore its input into to the affected muscle or muscles within 18 months. This sometimes requires surgical intervention.
Surgical Management
Exploration – All surgery starts with exploration and a visual assessment of the damaged nerve to see what the problem is.
Direct nerve repair – sometimes, after a recent nerve injury, the two cut ends of the nerve can be found and one stitched to the other. We call this neurorrhaphy.
Neurolysis, decompression– If there is a lot of scarring around the nerves sometimes just releasing that (neurolysis) or releasing any tight areas (decompression) can help.
Nerve Grafting – If there is too big a gap between the cut ends of an important nerve, we can find a nerve you don’t need from somewhere else and use it to bridge the gap. This is called grafting.
Nerve transfer – In this procedure, a nerve that is working well nearby (that you can do without) can be transferred onto the nerve that’s not working.
Neuroma excision – If there is scarring the signals will not pass through the scarring (neuroma). Sometimes, the scarring can be removed and the cut ends of the nerve repaired (a neurorrhaphy) to allow the flow of the signals once healed.
At other times, the gap between the non-injured, healthy nerve ends is too far apart. To allow the signals to flow between these ends a nerve taken from elsewhere can be used as a bridge (nerve graft). Sometimes, on the other hand, a nerve transfer can be used. It is not uncommon for both nerve grafting and nerve transfers to be performed at the same time in surgery.
After surgery
Following surgery, the patient will usually have to not move the limb that has been fixed. How long for depends on various factors – it can be for between 1 day and 4 weeks! Thereafter, very commonly, hand therapy is needed to prevent things from stiffening up. Usually, interestingly, pain is not very bad after surgery, and simple painkillers like paracetamol and ibuprofen will be enough for two or three days afterwards
When will we see the results of the surgery?
This can take a long time! We often say that nerves grow at about 1mm per day. So if a nerve is injured in the elbow that moves the hand is repaired, and the distance from the elbow to the hand is 20 cm that can mean it would be 200 days from the date of surgery, often longer! That’s a long time to wait. Whilst the recovery of nerves is not guaranteed and can take a long time, luckily, children in general seem to do better than grown-ups and for the same injury, often get better results!
Musculoskeletal Procedures
Sometimes, someone will have a significant nerve injury, but we can’t reconstruct the nerve usefully. For example, if the patient is seen too late to repair the nerve, or if the nerve is cut so far away from its target muscle by the time it got there it would be greater than 18 months from the injury. So what do we do…?
Well, it’s by no means the end of the road! Firstly, good therapy is critical and can make a massive difference. Sometimes it can work so well that even though the patient does not regain working muscle, they get such good movement they don’t need anything else! But if that is not the case, we then have to turn to using musculoskeletal procedures.
Musculoskeletal procedures are ones where rather than moving the nerves around to reconstruct a lost function, we move muscles and tendons or even reshape bones to help compensate for the lost function. Musculoskeletal procedures include muscle transfers, tendon transfers, and joint fusions.
Muscle and Tendon transfers – the principle of this is very like nerve transfers. If a muscle is not working, a neighbouring “musculotendinous unit” that is expendable can be transferred to the bone that the muscle that’s not working normally moves. Sometimes, if there are no nearby muscles that can be used, one from a different part of the body can be transferred – this is called a free muscle transfer.
Joint fusion – sometimes if the paralysed muscles normally stabilize a joint, the joint can become unstable and floppy. In order to make it more stable we may fuse the two bones either side of the joint. While this does make the joint more stable, it makes it less mobile.
Osteotomies – All of our muscles move bones in balance – one group of muscles move the bones in one direction, and another the opposite way.
Sometimes, after a long period of time where one group of muscles is working well and the other not, the muscles are pulling on the bones in can change their shape. And if that happens, even if we can get the muscles working again, we may have to do operations on the bones to put them back where they should be.