Thursday, May 15, 2008

Radiculopathy and Radicular Pain - its relevance to the Osteopath


There is a subtle difference between radiculopathy and radicular pain and understanding the pathophysiology of both can help improve the osteopath's diagnosis, prognosis and treatment.

Radiculopathy is the term that describes the neurological state of blocked axon conduction in a nerve or a nerve root. If a sensory axon is blocked then it results in numbness. If a motor axon is blocked then it results in muscle weakness. A blocked axon normally occurs as a result of compression or ischemia of the affected axon. The most common causes of radiculopathy are vertical subluxation of a vertebrae and osteophytes from a disc.

The osteopath must realise that radiculopathy is a STATE OF NEUROLOGICAL LOSS and it does NOT cause pain neither in the back nor in the limbs.

If the osteopath finds that the patient describes pain as well as radiculopathy (neurological loss) then the osteopath should be aware that the mechanism of radiculopathy may not necessarily be the same as the mechanism of pain.

Radicular pain on the other hand is pain that arises out of IRRITATION of a spinal nerve or a nerve root.
So, at the risk of sounding repetitive:

Radiculopathy – neurological state (weakness or numbness) caused by conduction of the axon being blocked.

Radicular Pain – Pain caused by nerve irritation.

Radicular pain may or may not occur with radiculopathy.

Radicular pain is sharp and shooting in quality and it travels down the limb along a band of no more than 2 inches. This is different from somatic referred pain which is more constant in nature, poorly localised and aching. It is important that the osteopath be aware of the differences.

A good example of radicular pain is sciatica. Sciatica is caused by the irritation of the sciatic nerve or one of its roots. However the term sciatica should only be used to describe a case when the pain is indeed sharp, shooting and is of 2 inches in width down the leg. The osteopath should clearly make a distinction between this and somatic referred pain which, as mentioned above is broad, achey and poorly localised.

The single most common cause of radicular pain is a disc herniation. The pathophysiology of this is still unclear - whether the nerve irritation is caused by an autoimmune inflammatory response from the nucleus pulposis or from ischemia.

Thus the osteopath should use the above information to make a diagnosis and treatment plan. The osteopath must be direct in questioning and in examination of the patient in order to be able to distinguish between a state of neurological loss and between pain. Once the osteopath has distinguished between these he should further examine the parameters and quality of the pain to distinguish between radicular and somatic pain. This way his diagnosis will lean more towards foraminal stenosis - vertical subluxation of the vertebrae or osteophytes if radiculopathy is suspected and towards a disc herniation if radicular pain is suspected.

2 comments:

Anonymous said...

So does this mean pins and needles are caused by radiculopathy, but a milder form as opposed to full numbness?

Anonymous said...

Numbness should be full loss of nerve conduction and pins and needles would have some nerve conduction going through the sensory fibres.