Nerve roots are attached to the spine and grow out of each side of the spinal column at every spinal level.
They carry signals throughout the body from the skin to the muscles. When one of the nerve roots is irritated, patients may experience pain, numbness, tingling and sometimes weakness down an arm or a leg.
Blocks are diagnostic procedures that help to determine the source of patients’ back pain. They may also temporarily relieve pain. There are two main types of blocks – facet blocks and selective nerve root blocks. A test performed under anaesthetic intravenous sedation with x-ray screening whilst laying face down a 3.5" needle is positioned in the Foramen or nerve root exit hole, at the side of the spine. X-ray contrast medium is injected to outline the nerve root.
The use of nerve blocks has also been criticised because of the lack of appropriate double-blind, randomised controlled trials. However, it must be appreciated that these are hard to carry out for non drug treatments, and in such a disparate group of patients as for instance those with low back pain and neurogenic pain. However, it is clear that trials are now being carried out and can show the efficacy of various treatments. On the whole I would veer away from permanent lesions for patients with chronic non-malignant pain.
Facet joint denervations have been shown by Lord, Barnsley and Bogduk to be effective for both low back pain and neck pain resulting from whiplash injuries.
Efficacy and safety of epidural steroids have been investigated extensively and recent randomised controlled trials appear to show benefit for their use in limb pain and also in acute back pain or neck pain. It is essential for an appropriate dose to be used and for careful placement of the drug in the correct compartment. It is suggested that the use of epidurography at least and the new technique of epiduroscopy is interesting, although as yet completely unproven.
This injection into the sheath surrounding a nerve root is done to decrease your pain temporarily and to define it more precisely. The exam uses therapeutic steroid and local anesthetic to decrease pain and inflammation. Pain relief from the procedure varies from minimal to long-term, depending on the specific symptoms.
You must have symptoms present for this procedure to be effective. If you are not experiencing symptoms prior to your procedure, please cancel your appointment and reschedule the exam once your symptoms have returned.
You will remain awake throughout the test. A radiologist will use a thin needle to place anesthetic and steroid into the nerve sheath. (There may be some discomfort from the needle, but, for most people, this is minor.) The radiologist checks the needle position by means of a fluoroscope (x-ray) connected to a television monitor. Contrast material is placed into the nerve sheath to document the needle position and x-rays are taken. During the injection, you may feel pressure or pain. The radiologist will want to know how this discomfort compares to your usual pain symptoms.
It is understandable and tempting to think of a painful disc as the cause of a significant number of certain patients' symptoms, and the new technique of disc denervation is another therapy under review at present.
Pulsed radiofrequency has been recommended by Dutch authors, but as yet I fail to see the rationale or the scientific evidence which would lead me to embrace this technique. At least it appears to be side-effect free, although it is a potentially expensive treatment, especially if it is only a placebo!
The use of Botulinum Toxin for muscle spasm is also under investigation at the present time. Clearly the agent has a powerful muscle relaxant effect, which is present from two to six months. Also it appears a relatively safe drug. However a great deal of work needs to be done now to identify the appropriate patients for treatment with this fairly extensive compound.