The amount of neck pain and disability suffered by patients varies greatly from very low pain levels and virtually no disability to high pain levels which interfere significantly with activities of daily living. The underlying reasons for this are likely to be related to the pathological and neurological mechanisms at work in the differing neck pain syndromes. Initial focus was on identifying pathology in the cervical spine which could be responsible but this approach has not led to a complete understanding. Attention has moved towards the underlying pain mechanisms potentially responsible.
If the pain syndromes in the neck can be accurately identified then for instance whiplash treatment can be directed at the particular process thought to be at work. Neck injury can be an obvious event such as a whiplash accident or a longer term process related to poor posture and tissues changes over time. If this leads to a degree of inflammation it is known that this has significant effects on pain processing both in the outer regions of the body and within the central nervous system of the spinal cord and brain. Much research done on animals can at least be considered when thinking about human neck pain.
The central nervous system can be pushed into a state of heightened sensitivity and overreact to incoming stimuli as a result of the chain reaction caused by the injury in the locally injured part and in the spinal cord and brain. On investigation of patients with whiplash syndrome and also with more non-specific neck pain the presence of a reduced pain threshold and a reduced pain tolerance has been established. Hyperalgesia is the medical term for this increase in pain response to a normally painful stimulus.
Hyperalgesia in the neck occurs in all whiplash injuries to some degree, whatever the severity, but settles over two to three months in those who recover or only have mild symptoms. Hyperalgesia has been found to persist in those with ongoing and more severe pain symptoms. The nerves in the local areas of damage may be sensitised and patients with whiplash have been shown to have damaged structures in cases where pain and disability has continued. Another argument is that the nerves in the central nervous system become sensitised by the pain inputs and this is responsible for ongoing pain.
The internal nerve mechanisms of the central nervous system are very likely important in neck pain problems but there is evidence of ongoing pain sources in the shape of damaged neck structures. Investigation of the facet joints of the neck by injection blocks has indicated they are a pain source in some chronic whiplash pain patients. Referred pain is also a typical phenomenon, with pain being perceived away from the site of its generation. This may be because the nervous system interprets pain inputs from bodily structures such as joints and discs as related to other areas linked with the same sensory nerve pathways.
Head pain can be referred from the upper neck segments of the third cervical vertebra and above, with arm pain potentially referred from those segments below this level and down to the first thoracic vertebra. Even in parts of the body where the patient is not complaining of any symptoms there may be evidence of a heightened pain response on testing. Both patients with general neck pain and whiplash may exhibit a hyperalgesic response to incoming stimuli. There may be a more involved upset in neurological functioning in the whiplash groups with overreaction to heat, cold and pressure.
A more widely occurring sensitivity response to incoming signals is present in patients with higher pain reports and who have more widespread symptoms. These findings are typical of syndromes such as whiplash and cervical nerve root disorder (radiculopathy, where the nerve root which is on its way out of the spinal canal towards the body is compressed or otherwise compromised along its route), both perhaps triggering a complicated change in the excitatory responses of the central nervous system to arriving pain inputs. However, this central mechanism might be kept going and sensitised by pain coming in continually from altered tissues in the neck. - 14130
If the pain syndromes in the neck can be accurately identified then for instance whiplash treatment can be directed at the particular process thought to be at work. Neck injury can be an obvious event such as a whiplash accident or a longer term process related to poor posture and tissues changes over time. If this leads to a degree of inflammation it is known that this has significant effects on pain processing both in the outer regions of the body and within the central nervous system of the spinal cord and brain. Much research done on animals can at least be considered when thinking about human neck pain.
The central nervous system can be pushed into a state of heightened sensitivity and overreact to incoming stimuli as a result of the chain reaction caused by the injury in the locally injured part and in the spinal cord and brain. On investigation of patients with whiplash syndrome and also with more non-specific neck pain the presence of a reduced pain threshold and a reduced pain tolerance has been established. Hyperalgesia is the medical term for this increase in pain response to a normally painful stimulus.
Hyperalgesia in the neck occurs in all whiplash injuries to some degree, whatever the severity, but settles over two to three months in those who recover or only have mild symptoms. Hyperalgesia has been found to persist in those with ongoing and more severe pain symptoms. The nerves in the local areas of damage may be sensitised and patients with whiplash have been shown to have damaged structures in cases where pain and disability has continued. Another argument is that the nerves in the central nervous system become sensitised by the pain inputs and this is responsible for ongoing pain.
The internal nerve mechanisms of the central nervous system are very likely important in neck pain problems but there is evidence of ongoing pain sources in the shape of damaged neck structures. Investigation of the facet joints of the neck by injection blocks has indicated they are a pain source in some chronic whiplash pain patients. Referred pain is also a typical phenomenon, with pain being perceived away from the site of its generation. This may be because the nervous system interprets pain inputs from bodily structures such as joints and discs as related to other areas linked with the same sensory nerve pathways.
Head pain can be referred from the upper neck segments of the third cervical vertebra and above, with arm pain potentially referred from those segments below this level and down to the first thoracic vertebra. Even in parts of the body where the patient is not complaining of any symptoms there may be evidence of a heightened pain response on testing. Both patients with general neck pain and whiplash may exhibit a hyperalgesic response to incoming stimuli. There may be a more involved upset in neurological functioning in the whiplash groups with overreaction to heat, cold and pressure.
A more widely occurring sensitivity response to incoming signals is present in patients with higher pain reports and who have more widespread symptoms. These findings are typical of syndromes such as whiplash and cervical nerve root disorder (radiculopathy, where the nerve root which is on its way out of the spinal canal towards the body is compressed or otherwise compromised along its route), both perhaps triggering a complicated change in the excitatory responses of the central nervous system to arriving pain inputs. However, this central mechanism might be kept going and sensitised by pain coming in continually from altered tissues in the neck. - 14130
About the Author:
Jonathan Blood Smyth is the Superintendent of Physiotherapists 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 physiotherapists in Oxford visit his website.
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