Occipital nerve stimulation for cluster headache: lessons to learn from the 'voltage tuners'.

Background: Cluster headache (CH) is a significant health concern due to its major socioeconomic consequences and most patients being refractory to conventional strategies. For treatment resistant CH, occipital nerve stimulation (ONS) is considered an effective treatment option. Whereas most patients do not adjust the amplitude of the ONS system, a subset changes the amplitude on a regular basis using their remote control, and are therefore referred to as 'voltage tuners'. Anxiety and self-control are thought to be central themes to this behavior. Research on this voltage tuning behavior could provide new insights in the use of ONS as acute attack treatment. To date, voltage tuning has not been assessed for CH. Hence this is a unique study aiming to investigate the occurrence and efficacy of voltage tuning in patients with CH and ONS.

Methods: For this analysis, patients with CH who received ONS from 2020-2024, at our university medical center, were included. All patients underwent bilateral ONS implantation. Data on attack frequency, intensity and duration were collected retrospectively. Outcomes on the response, frequency, moment during the day, duration, rationale, sensation, average increase in amplitude, and efficacy of voltage tuning were collected with prospective interviews.

Results: Thirty-three patients (M = 20) (42 ± 12.7 years) were included in the current analysis. At 1y follow-up, an overall response rate of 70% (23/33) was found for ONS. In total, 48% (18/33) of patients were defined as voltage tuners. Voltage tuning was performed with an average increase in amplitude of 92 (20-360)%, a frequency of 1-20 times/month and duration of 20 minutes-48 hours. Sensations of voltage tuning were described as "tingling" and/or "pinching". The rationale for voltage tuning in patients varied from prevention and ceasing to lowering the intensity and enhance control of CH attack.

Conclusions: Outcomes show that voltage tuning may cease and/or terminate CH attacks and therefore raise interests in the use of ONS as acute attack treatment for patients with resistant CH treated with ONS. Future research on the occurrence and potential of voltage tuning will provide valuable insights for achieving optimal efficacy of ONS and quality of life in patients with CH.