A Neural Block/Blockade is an anesthetic or anti-inflammatory injection targeted towards a certain nerve or group of nerves to treat pain.
The purpose of the injection is to temporarily stop a pain signal coming from a specific location in the body or to decrease inflammation in that area. Nerve Blocks are preferred in few cases to avoid surgery.
There are different kinds of neural/nerve blocks used for various purposes.
Therapeutic Nerve Blocks are used to treat painful conditions. Such nerve blocks contain local anesthetic that can be used to control acute pain.
Diagnostic Nerve Blocks are used to determine sources of pain. These blocks typically contain an anesthetic with a known duration of relief.
Prognostic Nerve Blocks predict the outcomes of given treatments. For example, a nerve block may be performed to determine if more permanent treatments (such as surgery) would be successful in treating pain.
Preemptive Nerve Blocks are meant to prevent subsequent pain from a procedure that causes problems including phantom limb pain.
What are the different types of Nerve Blocks?
Various areas of pain require different nerve block types. Below are a few of the available nerve blocks and some parts of the body where they are used.
Sympathetic nerve block
A sympathetic nerve block is one that is performed to determine if there is damage to the sympathetic nerve chain. This is a network of nerves extending the length of the spine. These nerves control some of the involuntary functions of the body, such as opening and narrowing blood vessels.
Stellate ganglion block
This is a type of sympathetic nerve block performed to determine if there is damage to the sympathetic nerve chain supplying the head, neck, chest, or arms and if it is the source of pain in those areas. Although used mainly as a diagnostic block, the stellate ganglion block may provide pain relief in excess of the time duration of the anesthetic.
Facet joint block
The facet joint block is performed to determine whether a facet joint is a source of pain. Facet joints are located on the back of the spine, where one vertebra slightly overlaps another. These joints guide and restrict the spines movement.
Few other nerve blocks are: 5>
- Trigeminal nerve blocks (face)
- Ophthalmic nerve block (eyelids and scalp)
- Supraorbital nerve block (forehead)
- Maxillary nerve block (upper jaw)
- Cervical epidural, thoracic epidural, and lumbar epidural block (neck and back)
- Cervical plexus block and cervical paravertebral block (shoulder and upper neck)
- Brachial plexus block, elbow block, and wrist block (shoulder/arm/hand, elbow, and wrist)
- Subarachnoid block and celiac plexus block (abdomen and pelvis)
A Neurolytic Block is a form of nerve block which involves deliberate injury of a nerve by the application of chemicals called neurolysis, or physical agents such as freezing or heating known as ‘neurotomy’. These interventions cause degeneration of the nerve fibers and impermanent interference (lasting for few months) with the transmission of nerve signals.
In this procedure, the thin protective layer around the nerve fiber (basal lamina), is preserved so that, as a damaged fiber, it travels within its basal lamina tube and connects with the correct loose end, and function is restored. There are various kinds of chemical neurolytic techniques available. Some of them are:
- Spinal neurolytic techniques
- Neurolytic saddle block
- Phenol epidural block
- Celiac plexus block
- Neurolytic lumbar sympathetic block
- Neurolytic peripheral nerve blocks
- Local neurolytic injection
What are the target areas of a Neurolytic Block?
The target areas of the neurolytic blocks are:
The Celiac Plexus, most commonly for cancer of the gastrointestinal tract up to the transverse colon, and pancreatic cancer, but also for stomach cancer, gall bladder cancer, common bile duct cancer and chronic pancreatitis.
The Hypogastric Plexus, for cancer affecting the descending colon, sigmoid colon and rectum, as well as cancers of the bladder, prostatic urethra, prostate, seminal vesicles, testicles, uterus, ovary and vaginal area.
The Ganglion Impar, for the perinium, vulva, anus, distal rectum, distal urethra, and distal third of the vagina
The Stellate Ganglion, usually for head and neck cancer, or sympathetically mediated arm and hand pain
The Intercostal Nerves, which serve the skin of the chest and abdomen
Should I opt these therapies? What if I am a diabetic?
Different people respond differently for the same treatment. For some people, a nerve block gives immediate relief. For others, it takes a series of injections before it helps the pain. For some a neurolytic bock might be a better choice. Thus it is unpredictable. This is because pain is a personal perception and everyone responds differently.
Based on your medical history and physician preferences, you can usually repeat this procedure. Medical conditions, such as diabetes, will mean that your doctor will need make injections less frequent. Your doctor will determine the exact number of injections that you can receive.