After neck injury or generalised pain problems, the disturbances in sensory aspects may occur in the arms and legs even though there are no symptoms in these areas. Local hyperalgesia in the neck, an increased pain response to normally painful stimuli, may be due to the local nerve systems being abnormally sensitised to incoming stimuli. But these more widespread reactions can be indicative of altered processing in the central nervous system. Locally increased pain reactions in the neck can be present in whiplash and general neck pain sufferers but the more widespread sensory upsets may help distinguish whiplash from less severe neck problems.

Higher levels of neck pain and disability and more extensive pain when examined clinically are typical of patients with whiplash syndrome. Patients who suffer from whiplash associated disorder and from cervical nerve root lesions show similarities of abnormal sensory function which gives a clue that similar nerve mechanisms underlie both clinical syndromes. Allodynia may also occur, an abnormal pain reaction which again points towards central systems being involved in pain generation. If pain is reported by a patient when stimulated with a stimulus which would not normally be painful, this is termed allodynia.

Chronic whiplash sufferers have been found to have the same abnormal mechanisms present in their sensory systems as at the time of the precipitating event. There is some mechanical hyperalgesia to local inputs present in all patients with whiplash injuries, however over 2 to 3 months this will settle down in mild cases. Patients who have more long term neck symptoms or higher pain levels will tend to suffer from ongoing hyperalgesia which may not settle down as in milder cases. Pain thresholds in patients with musculoskeletal pain can also be changed by the levels of psychological distress such as anxiety.

Psychological distress is commonly present in patients who have whiplash associated disorder and if a patient has higher levels of pain and disability they are also likely to have elevated amounts of mental distress. The increased pain sensitivity that patients exhibit is not thought to be the result of psychological distress but the underlying pain reaction mechanisms in the central nervous system might be responsible for both the hyperalgesia and the psychological distress. Along with these findings, cold hyperalgesia (an increased pain reaction to cold) and abnormalities of circulatory function can occur.

As an overreaction to cold is part of the typical symptoms of injury to the peripheral nerves of the body this may indicate that nerve injury is present in some cases of whiplash injury. This cold overreaction is also found in neck nerve root injury, reinforcing the idea that the same underlying nerve abnormalities are found in both this condition and whiplash. In investigations of acute whiplash patients a significant percentage of neuropathic pain symptoms such as cold overreaction, burning neck pain and sudden bursts of electric shock pains have been found.

Many of the sensory findings in the neck may not easily translate into ways of managing whiplash by physiotherapy. However, if there is only local hyperalgesia in response to mechanical inputs and no other sensory abnormalities, then the local neck structures may be oversensitive due to the injury to the neck tissues. This kind of local abnormality has been shown to react favourably to physiotherapy or other manual therapies. Exercise may also reduce this type of increased nerve reactions and also improves the ways the muscles coordinate, improving the management of neck pain.

The presence of the allodynia, the overreaction to cold and the wider spread sensitivity to mechanical inputs means that the treatment needs to be approached with much greater care. It is very easy to stir up the symptoms in this condition and this merely increases the abnormal nerve processing. Manual and manipulative techniques must be applied with care and if this is done then there is some expectation that physiotherapy can be of some use in the management of this kind of disorder.

However if the patients do exhibit neuropathic symptoms such as overreaction to cold stimuli then the therapeutic approach is much less clear, with much higher levels of pain and disability reported. With about 30 percent of patients being helped by drug therapy, the role of physiotherapy in these cases has not been established.

Jonathan Blood Smyth is the Superintendent of Physiotherapy at an NHS hospital in the South-West of the UK. He writes articles about back pain, neck pain, and injury management. If you are looking for physiotherapist in Blackpool visit his website.