Efficacy and safety of sphenopalatine ganglion pulsed radiofrequency in episodic cluster headache: a randomized controlled trial

This multicenter, randomized, controlled, blinded-endpoint trial aimed to assess the efficacy of pulsed radiofrequency (PRF) targeting the sphenopalatine ganglion (SPG) as an add-on to verapamil for the treatment of episodic cluster headache (ECH). Eligible participants with a history of ECH who presented to a pain clinic within 5 days after the onset of a cluster period were enrolled. Participants were randomly assigned (1:1) to receive PRF (PRF group) or nerve block (NB group) targeting the SPG. All participants received oral verapamil (360 mg/day) after the procedure. The primary endpoint was cluster-period duration. Secondary endpoints included pain intensity during attacks, assessed using the numerical rating scale (NRS); attack frequency; attack duration; and rizatriptan use at day 1, day 3, week 1, week 2, month 1, month 3, month 6, and year 1 after treatment. Eighty participants were randomly assigned to the PRF group (n = 40) or the NB group (n = 40). Median cluster-period duration was 15.0 days (interquartile range [IQR], 6.2–30.0) in the PRF group and 61.0 days (IQR, 17.0–90.0) in the NB group. PRF was superior to NB in reducing cluster-period duration (median difference, -34.0 days; 95% confidence interval [CI], -56.0 to -17.0; P < 0.001). NRS scores during attacks, attack frequency, attack duration, and rizatriptan use at week 1, week 2, month 1, and month 3 were significantly lower in the PRF group than in the NB group (P < 0.05). The median between-group differences in NRS scores at day 3, week 1, week 2, and month 1 were -1.0, -2.0, -3.0, and -4.0 points, respectively. In patients with ECH resistant to oral medications, SPG-PRF plus verapamil provided greater pain relief than SPG-NB plus verapamil, with few adverse effects. ClinicalTrials.gov, NCT03567590