Occipital neuralgia, also known as Arnold’s neuralgia, is defined by the International Headache Society as a paroxysmal, shooting or stabbing pain in the greater, lesser, and/or third occipital nerve distributions. Pain intensity is often severe and debilitating, with an associated negative impact on quality of life and function. Most cases of occipital neuralgia are idiopathic, with no clearly identifiable structural etiology. Treatment of occipital neuralgia poses inherent challenges as no criterion standard exists. Initially, conservative treatment options such as physical therapy and pharmacotherapy are routinely trailed. When occipital neuralgia is refractory to conservative measures, a number of interventional treatment options exist, including local occipital nerve anesthetic and corticosteroid infiltration, botulinum toxin A injection, occipital nerve subcutaneous neurostimulation, and occipital nerve pulsed radiofrequency ablation. Of these, pulsed radiofrequency ablation has garnered significant interest as a potentially superior, safe, non-invasive treatment with long-term efficacy.
Occipital neuralgia and related headaches are often confused with cervical spine disease and tension and migraine headaches. Occipital neuragia is a stand-alone syndrome, which can respond to multimodal medical management, supplemented by occipital nerve blocks with local anesthetic and steroid. If the patient does respond to local anesthetic blocks, consideration should be given to pulsed radiofrequency ablation of the greater occipital nerve, ipsilaterally or bilaterally, as clinically indicated. Evidence in support of PRF as a safe and effective interventional treatment option for occipital neuralgia appears promising. Clinical studies to date have demonstrated sustained improvement in pain, quality of life, and adjuvant pain medication usage.
At Pain Spa Dr. Krishna is very experienced in interventional treatments. Dr. Krishna always performs occipital nerve block under ultrasound guidance for greater accuracy and improved safety.
The Greater occipital nerve (GON) arises from the dorsal primary ramus of the second cervical nerve with contribution from the third cervical nerve It supplies sensory innervation to the medial portion of the posterior scalp as far anterior as the vertex, while also supplying motor innervation to the semispinalis capitis. Although the course of the GON is described with much variability, the most common site for compression occurs where the nerve penetrates the aponeurosis of the trapezius.
The Lesser occipital nerve (LON) arises from the ventral primary ramus of the second cervical nerve with contribution from the third cervical nerve. The LON traverses superiorly along the posterior border of the sternocleidomastoid muscle, supplying cutaneous innervation to the lateral portion of the scalp and the cranial surface of the auricle.
Injections are generally avoided in patients with systemic infection or skin infection over puncture site, bleeding disorders or coagulopathy, allergy to local anaesthetics or any of the medications to be administered. Pulsed radiofrequency ablation is contraindicated in patients with cardiac pacemaker or any neuromodulation implants.
The clinical application of pulsed radiofrequency (PRF) by interventional pain physicians for a variety of chronic pain syndromes, including occipital neuralgia, is growing. As a minimally invasive percutaneous technique with none to minimal neurodestruction and a favourable side effect profile, use of PRF as an interventional neuromodulatory chronic pain treatment is appealing.
The mechanism of action underlying the utility of PRF in interventional pain medicine is uncertain. Un- like conventional continuous radiofrequency ablation, whose pain relief effects are mediated through non-selective, temperature-dependent, neurodestruction, PRF is widely believed to act through a temperature- independent, neuromodulatory process, altering synaptic transmission and pain signaling via the emission of electric fields, with none to minimal resultant tissue destruction. Given the nondestructive nature of PRF, deafferentation pain—a feared complication of continuous radiofrequency ablation—is not a potential risk.
Patients who get temporary pain relief from occipital nerve blocks may be suitable for occipital nerve ablation procedure (pulsed radiofrequency treatment). This is likely to provide longer-term pain relief.
The procedure is done on an outpatient basis. The procedure is performed under ultrasound guidance to ensure the accuracy of needle placement. Specialized equipment including radiofrequency machine, probe, and RF needle is utilized to heat the nerve up to a temperature of 42°C. Generally local anaesthetic is injected around the nerve following nerve ablation. The local anaesthetic is responsible for immediate pain relief, whereas pulsed radiofrequency takes 4 to 6 weeks to provided sustained pain relief. Pain relief from pulsed radiofrequency ablation of the occipital nerve can last between 6 months to 24 months.
Complications are rare, particularly if the injections are performed using a precise needle-positioning technique. Possible complications include bruising, infection, hematoma, nerve injury and reaction to the injectates. Infection can be avoided with appropriate aseptic precautions. Severe allergic reactions to local anaesthetics are uncommon. Steroid injections may produce local reactions, occurring most often immediately after injection. These local reactions last for 24 to 48 hours and are relieved by application of ice packs. Post-procedural pain flare-up may occasionally occur and may be treated with painkillers. Neurological complications including paraesthesias and numbness have been described but are rare.