What are Nerve Blocks?
The spine is made up of 24 bones stacked into a column. These bones are called vertebrae. Between each vertebra is a cushion — the disk — that acts as a shock absorber between the bones. Every vertebra has two sets of bony knobs that meet each other. The point where they meet is called the facet joint. (In the neck, these are sometimes called the zygapophyseal or apophyseal joints.) The facet joints allow the spine to ﬂex forward or extend backward. They also allow the spine to twist from side to side. A capsule of soft tissue protects these joints.
A substance called synovial ﬂuid is made in this capsule to lubricate the joints so they move smoothly. A layer of slick white cartilage covers the joint, also helping it to glide smoothly when the body moves. Over time, the cartilage can get damaged or wear thin. The joints can become enlarged. Spurs of bone may grow on or near the joint. This causes arthritis, pain, and swelling in the joints. Nerves that branch off from the spinal cord pass through the facet joints. They extend nerves into the body to control its activities and movements as well as receive sensation.
These are called nerve roots. The nerves that serve the facet joints are called the medial branches. They carry pain signals to the spinal cord and on to the brain. The pain is a warning sign that a joint is irritated. The bones of the spine are grouped into three sections. The top part which connects the skull to the torso is the cervical spine. The middle portion is the thoracic spine where the ribs attach. The lowest part of the spine is the lumbar spine where the spine connects to the pelvis.
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.
- Trigeminal nerve blocks (face)
- Ophthalmic nerve block (eyelids and scalp)
- Supraorbital nerve block (forehead)
- Maxillary nerve block (upper jaw)
- Sphenopalatine nerve block (nose and palate)
- 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)
Side Effects and Risks of Nerve Blocks
Nerve blocks do have risks and side effects. They include:
- Elevated blood sugars
- Weight gain
- Extra energy
- Soreness at the site of injection
Although many kinds of nerve blocks exist, this treatment cannot always be used. If your pain isn’t related to pain in a single or small group of nerves, nerve blocks may not be right for you. Your doctor can advise you as to whether this treatment is appropriate for you.