NUMBNESS AND TINGLING
What is numbness and tingling?
Numbness means reduced or rarely absent feeling. It is a nuisance but not in itself painful. The nerve injury can however give pain which can be severe.
Tingling is a funny feeling often described as the feeling following being stung be nettles. It is usually not painful but rather uncomfortable.
These are symptoms typically found in patients with nerve problems. Usually the symptoms are in one region of the arm or hand and represent a local problem with nerve function and NOT a body wide nerve problem.
Why does it occur?
Normally the nerves of the body send signals to the brain the whole time. Hence we instinctively know where are hands are without looking. When a nerve is injured thus transmissions of signals is affected. If the nerve is cut or severely squashed no signals may pass. Thus there will be no feeling in the area of skin normally supplied by that nerve. If there is a partial injury to the nerve there may be tingling with or without some numbness. Depending upon the severity of the problem the tingling and numbness may be intermittent (come and go) or may be permanent. Intermittent tingling/numbness is usually curable. Permanent tingling/numbness may only resolve partially and sometimes not at all.
The commonest causes in the hand are carpal tunnel syndrome and ulnar neuritis (cubital tunnel syndrome) which are entrapment neuropathies i.e. the nerves are trapped (see information sheets). Other causes include nerve root entrapment in the neck, direct nerve injury such as a crush or cut and various other rarer injuries such as radial nerve entrapment (trapping of the radial nerve in the arm) and thoracic outlet syndrome (trapping of the nerves that have come out of the neck but not yet reached the arm). Some patients with pain will often describe numbness and tingling generally at the site of the problem. This probably represents a general response to pain/swelling rather than a specific nerve injury. Following surgery local numbness around the scar is quite common and usually settles without problem.Occasionally following surgery or an injury nerves will generally overreact giving rise to Chronic Regional Pain Syndrome (CRPS - see information sheet).
What happens if nothing is done?
(This is referred to as the natural history i.e. what happens if Nature runs its own course.) This depends upon the diagnosis. Some symptoms will simply settle. Others will progress. If so medical advice should be sought.
Making the diagnosis
The Hand specialist who sees the patient will ask questions about their symptoms, when they started, how they progressed, what treatment (if any) they have had and other questions relevant to the problems. They will then examine the patient looking at some or all of the neck, elbow, wrists and hands. Particular test such as tapping over the nerve will be performed. This may be a little uncomfortable but should not be painful.
What test(s) might be performed?
Tests (also known medically as Investigations) include X-rays, scans, blood tests and particularly in the hand electrical tests (known as EMGs or Neurophysiology). These may be used to help make or confirm a diagnosis after a patient has described their symptoms and been examined.
In many cases the diagnosis is usually obvious after listening to and examining a patient. If not the commonest tests are X-rays if there may be concerns about neck arthritis, and neurophysiological assessment (electrical test). This X-ray is usually performed on the same day. The neurophysiological assessment (electrical test). Is usually performed at a later date.
Neurophysiological assessment (electrical test): In this test mild electric shocks are sent up and down the arm and the strength and speed of their conduction is measured. This gives a measure of nerve function. Like all tests it is not completely reliable so it can be normal although the patient has a nerve problem and it can be abnormal when the patient does not have a nerve problem. Your Hand specialist will interpret the results in the light of the previous description of symptoms and examination and advise you accordingly.
If there were concerns about a significant nerve entrapment in the neck or the diagnosis was unclear then the Hand specialist may order an MRI scan: An MRI scanner is usually a short tunnel which the patient's arms and top half of the body go into. Once in the tunnel a loud magnet is spun around and images of the bones and soft tissues created. Some people find the tunnel rather claustrophobic. If any patient doubts whether they would tolerate the scan they are best advised to visit the scanner department in advance. The films will be reported by a radiologist but also reviewed by the Hand specialist who will advise the patient accordingly.
What are the non-operative and operative treatments?
Treatment should start with non-operative options. These include activity modification (which usually does not give much benefit or has already been tried by the patient), physiotherapy, splints and a steroid injection. These will depend upon the specific diagnoses. In general nerve entrapment in the neck usually settles with physiotherapy. Nerve entrapment in the hands e.g. carpal tunnel syndrome/ulnar nerve entrapment may settle initially with splints but often go to surgery. (For specific details see information sheets on each condition).
What are the results of the operation?
For the commonc nerve entrapments 90% of of our patients have good or excellent result following a carpal tunnel release and about 85% following ulnar nerve release, with relief of the pain and tingling. Incomplete recovery is more common in patients presenting with more severe symptoms particularly continuous numbness or tingling.
Are there any risks?
All interventions in medicine have risks. In general the larger the operation the greater the risks. For the common nerve releases the risks include:
- The scar may be tender, in about 20% of patients. This usually improves with scar massage, over 3 months.
- Aching for several moths particularly for carpal tunnel releases. Grip strength can also take some months to return to normal.
- Stiffness may occur in particular in the fingers. This is usually short-term and only infrequently requires physiotherapy. But it is very important that it is resolved quickly to avoid permanent stiffness. This occurs rarely but can do associated with CRPS (see below)
- Numbness can occur around the scar but this rarely causes any functional problems.
- Wound infections occur in about 1% of cases. These usually quickly resolve with antibiotics.
- Chronic Regional Pain Syndrome "CRPS". This is a rare but serious complication, with no known cause or proven treatment. The nerves in the hand "over-react", causing swelling, pain, discolouration and stiffness, which very slowly improve.
- Any operation can have unforeseen consequences and leave a patient worse than before surgery.