Occipital nerve stimulation for the treatment of chronic cluster headache - lessons learned from 18 months experience

Neuromodulation has been recognized as a valuable surgical treatment option for patients with refractory chronic cluster headache (CCH). Due to the small number of afflicted individuals, the knowledge about this specific therapy is limited. In this study, we present our experiences with bilateral occipital nerve stimulation (ONS) in patients with CCH focusing on patient selection, pre- and postoperative evaluation, surgical procedures, and outcome.

Since December 2008, 10 patients with CCH have been treated with ONS at our department. Patients were recruited and clinically followed by a neurologist and a neurosurgeon. Baseline data records on frequency, intensity, and duration of attacks as well as the use of medication were assessed with a 30-day diary. Standardized questionnaires were used pre- and postoperatively and during the follow-up on a regular basis. Surgical procedure and stimulation parameters were standardized for all patients. Lead implantation was followed by a test period of 30 days prior to implantation of the permanent generator. Mean follow-up time was 12 months (range 3-18).

All patients responded to the stimulation treatment. Frequency, duration, and severity of the cluster attacks were reduced in 90% of the patients. One patient had a significant reduction of his concomitant tension headache. 70 % of the patients needed less medication during the attacks. All patients reported an improvement in their quality of life. The SF-36 showed a tendency toward objective improvement in the field of psychological comfort. As a major adverse event, one generator had to be exchanged due to a local infection. Another patient had to be reoperated due to a scar tissue formation around the thoracic connector.

ONS is a valuable tool in the treatment of patients with refractory CCH. According to our data, the potential side effects and complication rates of the operation are small. With a meticulous selection of patients by an interdisciplinary team, CCH can bed improve in the majority of the patients. Yet, the optimal parameters for the stimulation regarding pulse width and frequency remain unclear. For this reason, we started a prospective single-center observational trial at our center in October 2009, including patients with ONS, to identify the best stimulation parameters.