Occipital nerve blockade is a useful modality to diagnose cervicogenic headache. This case series study by Todd D Rozen revealed that high-volume anaesthetic suboccipital nerve blocks (HVSON) show consistent response over long-term use with pain relief.

The current study was aimed to determine the efficacy of HVSON for chronic cluster headache (CCH) and to define consistency of response over long‐term use. There are studies which show the efficacy of greater occipital and suboccipital nerve block injections for CCH and also their most likely use as a preventive treatment modality. But, the data about the long‐term efficacy of repetitive greater occipital and suboccipital nerve injections in CCH was scarce. HVSON has not been studied for CH.

This open-label, observational, case series study comprised of patients with CCH who were evaluated at a dedicated headache clinic over 7 years and injected on at least 2 different occasions used for analysis. HVSON consisted of 1% lidocaine 9mL and 1 mL triamcinolone 40 mg/mL injected on the side of CH.

Ten CCH patients were retrospectively studied. Mean average response to HVSON as all the patients had complete pain freedom for 1.5–31 weeks (longest: 44 weeks in 2 patients). Only one patient did not respond. Two patients had 1.5–2 weeks of response and the remainder had at least 4 weeks of intervention. The Mean average duration of pain free effect was 10.3 weeks in responders. Five patients were injected serially for 2–4 years (30x, 17x, 15x, 10x and 3x, respectively). They had a consistent response of 6 weeks, 4 weeks, 12 weeks, 4 weeks, and 31 weeks, after each injection. Response duration was very reliable as per individual patient. All 5 patients felt HVSON was useful as a preventive treatment. Smoking history did not appear to affect the treatment response (8/10 were chronic current smokers, and 7/8 responded to HVSON). One patient who received the most injections had avascular necrosis of the hip; the remaining subjects had no adverse events.

HVSON from this open-label study appears to be useful for the preventive treatment of medicinal refractory CCH. It also showed consistent response over long‐term use with high rates of pain freedom.