Artikel
Occipital nerve stimulation for primary chronic headache disorders – A randomized trial on treatment efficacy
Suche in Medline nach
Autoren
Veröffentlicht: | 13. Mai 2014 |
---|
Gliederung
Text
Objective: Migraine and other primary headache disorders are highly prevalent. A significant percentage of sufferers are refractory to conservative treatment. Occipital nerve stimulation (ONS) may provide pain relief in these patients. During ONS treatment, paraesthesia is generally experienced by the patient. The significance of paraesthesia on treatment effect, the possible role of placebo effect, and the importance of electrode placement are not well understood. In addition, previous studies examining ONS in primary headache syndromes have been unable to provide predictors of patient response and successful outcomes. To elucidate these issues, we conducted a double-blind sham-controlled trial in patients treated with ONS.
Method: Patients who were already being treated with ONS for different primary headache disorders, and were classified as stable for at least 3 months, were included. The study design comprised treatment groups: “effective Stimulation” (Group 1), “subthreshold Stimulation” (Group 2) with the implantable pulse generator (IPG) amplitude set just below perception level, and “no Stimulation” (Group 3) with the IPG set to the lowest possible amplitude. Both patient and physician examiner were blinded to the treatment group. Each patient cycled all treatment groups. Pain severity was measured using a visual analogue scale (VAS). Quality of life was measured using the validated SF-36 questionnaire.
Results: Twelve consecutive patients were recruited between March and December 2012. Median chronic headache duration was 5.3 years prior to surgery. Mean preoperative VAS score (± SD) for the cohort was 8.2 ± 1.5. This reduced to 1.6 ± 0.8 under ONS with optimal stimulation parameters prior to the start of the study. The mean preoperative VAS (± SD) score of 8.2 ± 1.5 improved highly significantly (p < 0.01) under effective stimulation to 1.5 ± 1.4. Pain also highly significantly improved under subthreshold stimulation compared with no stimulation, with a VAS score (± SD) of 7.9 ± 1.8 and 4.9 ± 2.0, respectively (p < 0.01). No changes in SF-36 were observed between the study groups.
Conclusions: ONS was efficacious in the treatment of medically intractable headache in this double-blind study. Paraesthesia is not required to achieve pain reduction, but suprathreshold stimulation yields better results underlining the significance of stimulation parameter customization.