Nerve Blocks for Treatment of Pain
What is nerve pain?
Many people suffer from nerve-related pain in their body. It’s a deep burning, aching, and at times knifelike pain that just won’t go away and is hard to describe. Most physicians prescribe pain medications for this type of pain with limited success and few have knowledge of newer treatment strategies. What causes nerve pain? Parts of the nerve are sensitive to stretching and compression and can lead to the release of inflammatory cytokines that signal to the surrounding area that injury has occurred. These injured nerves tend to be swollen, tender, and leak substances that can cause further abnormal nerve firing, breakdown to surrounding joints and soft tissue, and even insomnia, depression and anxiety. With the repetitive injury to a nerve, a vicious cycle develops. When nerves are not healthy they can lead to “sick” fascia and vice versa. Poor movement of nerves through fascia can lead to nerve entrapments, thus causing more pain. There are many different types of nerve entrapments in the body. Carpal tunnel is probably the most familiar nerve entrapment, but essentially any nerve can get entrapped due to poorly moving or injured fascia or muscles, crossing over bony edges, going through tunnels, and/or being compressed or stretched beyond its tolerance level. When a nerve gets entrapped, it can become inflamed or “sick”. This leads to the nerve becoming larger in some cases and the release of chemicals, both of which can cause further pain and poor movement. The vicious cycle continues until we treat the area of entrapment and determine why the nerve became sick in the first place.
How is nerve pain treated?
Nerve pain can be treated several ways, either by superficial injections or deeper injections called nerve hydrodissections, performed with ultrasound guidance. Hydrodissections use large volumes of fluid to help break up tissue restrictions causing the entrapment of the nerve and to stop the release of the inflammatory proteins.
Dr. John Lyftogt introduced superficial nerve block treatments by expanding on treatments that were introduced in 1989. Dr. Lyftogt found that an irritated nerve that supplies sensation to the skin over a joint may also cause dysfunction and pain to the muscles and tissue around that joint. He theorized that restoring peripheral nerve function would lead to healing in deeper structures and a reduction in pain. He has been using this technique to treat various pain and musculocutaneous conditions with outstanding results, and now these treatments are being taught around the world. The theory is based on Hilton’s Law named after Dr. John Hilton, a British surgeon. He stated that the nerve that provides sensation to a joint also provides sensation to the skin overlying that joint as well as the muscles that move the joint.
Others have continued to expand on these theories by adding hydrodissections. These injections use a mixture of 5% dextrose solution. Dextrose is a sugar analogue and it connects to a specific receptor on the nerve and “resets” the nerve. The nerves being treated have been firing incorrectly for some time and want to go back to firing incorrectly as it is a habit. This is why a series of injections is recommended so that we can help those nerves break that bad firing pattern.
What to expect with superficial nerve blocks?
With superficial injections, most patients get immediate relief of pain after the injections. A few hours to few days of relief is expected after the first set, with a 15-20% improvement each time- lasting longer and a return to a new baseline with less pain. It is usually planned to do a series of 3 to start, each 1-2 weeks apart, and reassess to see if you are responding as would be expected. The superficial injections are done along the course of the tender nerve with a small gauge short needle. The number of injections may vary at each visit. This is determined by palpating along the nerve. The injections can be uncomfortable but are like a mosquito-bite or bee-sting. Again, most patients have a significant decrease in pain right after the injections. There may be some soreness or bruising at the injection site. There are no specific activity restrictions after the injections; recommend that pain and symptoms be your guide.
What should I expect with a US guided hydrodissection procedure?
If an ultrasound guided injection hydrodissection is done, there may be immediate relief of symptoms, but results can also take a few weeks to show full effect. Nerve hydrodissections can be done as a one-time injection, but depending on nerve location and issue may be done in a series but spaced out further, usually every 3-4 weeks. Care instructions afterward are same as with superficial injections. There may be activity restrictions given based on the area treated.
What if these do not help my pain?
If you are not making progress, it may be recommended to use a different product, target a different area, or add other modalities/treatments. If you are taking opioids, you may not respond as well to this type of treatment based on how both work and interact with each other. These treatments can still be tried and used to help wean off pain medications. Many patients also have other medical problems, degenerative conditions, and are on medications that can interfere, that need to be treated in conjunction. In these cases the nerve blocks can be helpful in improving pain in the short term, but ultimately another procedure like prolotherapy or PRP may need to be done to help keep the pain from returning. We have found this combination, in conjunction with utilizing lifestyle factors can improve outcomes.
