Injections around the spine have a number of uses. In the main they are used to provide control of symptoms whilst the condition treated goes on to natural resolution or to get intrusive symptoms under control to allow physical therapy to progress. In other words they are creating a ‘window of opportunity’ for therapies which otherwise would create too much discomfort to proceed.
The other main use would be in turning off symptoms for a temporary time period allowing an understanding of the pain generator. These injections are done under x-ray control and therefore it is possible to identify the painful structure. The third use of injections is to deliberately stimulate a source of pain to again identify a pain generator.The injection technique used most frequently for nerve pain is an epidural.
This differs from the one given in pregnancy as it contains hydrocortisone as well as local anaesthetic. The hydrocortisone is there as a treating agent to reduce inflammation caused by mechanical irritation of a nerve as well as chemical and cellular irritation. It can be administered by the traditional injection in the back or by a lower injection in the sacrum, or tail bone. That route is called a caudal. Epidurals can be performed in the cervical or thoracic spine by appropriately trained specialists.
Further common injections for nerve pain consist of nerve root blocks. These are targeted injections for individual nerves and need to be directed under x-ray control.
They are more specific than epidurals and therefore can also be used to identify a pain source.
Injections for back pain tend to be non specific injections such as trigger point injections into painful knots of muscle and connective tissue or targeted injections into facet joints under x-ray control.