At first glance, it may seem reasonable to cut or destroy pain-sensing nerves in order to relieve pain. After all, pain sensation is transmitted from the tissue pain source to the central nervous system by peripheral nerves, and one might think that destroying these nerves should eliminate pain. In practice, however, cutting or destroying pain-sensing nerves has often led to an increase of pain rather than a decrease. This is because the nervous system has a powerful capacity to regenerate and re-route itself in pathological ways. “The nervous system hates to be cut” is a lesson that has been repeatedly learned by patients and surgeons alike as post-neurolysis pain syndromes—such as anesthesia dolorosa, denervation hypersensitivity, and painful neuroma formation—have become increasingly recognized as common consequences of nerve destruction.
Early Methods of Nerve Destruction
Part of the problem with nerve destruction has stemmed from the rather primitive techniques previously available. In times past, nerves were either cut with a scalpel or injected with caustic chemicals such as alcohol or phenol. Cutting nerves with a sharp instrument often leads to a pathological regeneration of the nerve at the cut ends termed “painful neuroma.” Injecting nervedestroying chemicals may cause a painful post-destruction neuritis and, in addition, is imprecise because tissue injury often extends beyond the intended target nerve.
The Development of Radiofrequency Techniques
Radiofrequency techniques for nerve destruction have been developed and refined within the past decade and are now considered an acceptable and safe method for nerve destruction. With radiofrequency techniques, electromagnetic energy is transmitted into the nerve tissue causing a coagulation of proteins within the nerve tissue. The nerve sheath itself is left intact so that painful post-procedure neuroma does not occur. The technique is very precise because the energy is delivered by means of a special needle placed directly onto the target nerve with x-ray guided accuracy.
Radiofrequency and Treatment of Chronic Pain
In modern medical practice, radiofrequency nerve destruction is a useful treatment option for certain types of chronic pain including head and neck pain from whiplash injury, chronic lumbar facet joint pain, and certain types of neuralgia. The outcome of the radiofrequency procedure can usually be predicted by the patient’s response to precise local anesthetic nerve blocks. Diagnostic nerve blocks are routinely performed as a screening test before nerve destruction is considered. Radiofrequency nerve destruction is now a well-established treatment option and is commonly used in the modern pain clinic. It is safe and effective and can be performed as an outpatient procedure under local anesthesia with IV-conscious sedation.