Pulsed Radiofrequency vs. Steroid Injections for Occipital Neuralgia

Up to 76 patients referred to one of the participating pain clinic with occipital neuralgia, or migraines with occipital nerve tenderness (dual diagnoses) will be randomized in a 1:1 ratio by a computer generated randomization table to receive one of two treatments. Treatments will be randomized at each institution. Within each group, those patients with plain occipital neuralgia, and those with occipital neuralgia with migraines, will be sub-randomized in the same 1:1 ratio. Diagnosis of ON will be made by low-volume (\< 3 mL bupivacaine per nerve). Our criterion for a positive response will be \> 50% pain relief lasting at least 3 hours. Those individuals who have symptoms in the distribution of both the greater and lesser occipital nerves will receive treatment of both nerves. The greater occipital nerve is more frequently affected than the lesser nerve. Half (n=38) of the patients will be allocated to receive local anesthetic \& corticosteroid injections at each nerve (group I), with an equal number allocated to receive local anesthetic \& PRF at each (group II). In those patients who request sedation, an intravenous will be inserted and light sedation administered with low doses of midazolam and fentanyl, in accordance with our standard clinic practice. Treatment in all patients will be accomplished using 20-gauge radiofrequency needles with 10 mm active tips. Prior to treating, electrical stimulation will be performed to ensure ample proximity to the targeted nerve(s), with our target threshold being concordant stimulation at \< 0.3 volts at each site. Once proper needle position is ensured, those in group I will receive an injection at each nerve containing 30 mg of depomethylprednisolone mixed with 2 mL of a 50:50 mixture of 2% lidocaine and 0.5% bupivacaine (2.75 mL). Anywhere between 1 and 4 nerves can be injected, with 4 nerves being targeted if a patient had bilateral lesser and greater occipital nerve involvement. This will be followed by 3 cycles of sham PRF at 120 s per cycle, with slight (approximately 30o electrode adjustments between cycles. For sham PRF, no electrical field or heat is generated (i.e. the machine is not set to any radiofrequency cycle after stimulation), but the cycle times (120 s per cycle) are adhered to (i.e. we will wait a total of 6", 2" per cycle). Those patients in group II will receive injections at each nerve containing 2.75 mL of a solution with 2 mL of 50:50 2% lidocaine and 0.5% bupivacaine + 0.75 mL saline (2.75 mL), followed by 3 cycles of PRF using the following standard settings: voltage output 40-60 V; 2 Hz frequency; 20 ms pulses in a 1-second cycle, 120 second duration per cycle; impedance range between 150 and 400 Ohms; and 42o C plateau temperature. No patient will be prescribed additional medications or therapy between their procedure and first follow-up. However, they will be allowed to remain on their current, stable analgesic regimen. Rescue medications will consist of tramadol 50 mg 1 to 2 tablets every 6 hours PRN (up to 8/d) and/or acetaminophen or a non-steroidal anti-inflammatory drug such as ibuprofen, diclofenac or ketorolac on an "as needed" basis. Follow-ups will be performed by a physician blinded to treatment allocation. A preliminary follow-up will be performed at weeks. The first full follow-up visit will be scheduled 6-weeks from the start of treatment. A positive outcome will be defined as a \> 50% decrease in headache coupled with a positive satisfaction rating (\> 3 on a 0-5 scale). Subjects who obtain a positive outcome at their initial 6-week follow-up visit will remain in the study and return for their 3-month follow-up visit. Those with a negative outcome will exit the study "per protocol" to receive standard care. Subjects who obtain a positive outcome at 1-month but experience a recurrence before their 3-month follow-up visit will also exit the study per protocol, with their final outcome measures recorded before they receive standard care. Those who obtain a positive outcome at 3-months will remain in the study for their final 6-month follow-up, while those who obtain a negative outcome will exit the study. Unblinding for both patients and the treating physician will be after the patient exits the study or after their final follow-up visit for those with continued benefit.