Background: Chronic migraine (CM) and medication overuse headache (MOH) are disabling conditions that may be only partially managed with conservative treatments. Occipital nerve stimulation (ONS) is an innovative treatment for headache disorders.
Objectives: To investigate the safety and efficacy of ONS for CM and MOH patients and to evaluate changes in disability, quality of life, and drug intake in implanted patients.
Study design: Prospective, randomized cross-over study.
Methods: Eligible patients who responded to a stimulation trial underwent device implantation and were randomized to "Stimulation On" and "Stimulation Off" arms. Patients crossed over after one month, or when their headaches worsened. Stimulation was then switched On for all patients. Disability as measured by the Migraine Disability Assessment (MIDAS), quality of life (SF-36), and drug intake (patient's diary) were assessed over a one-year follow-up.
Results: Thirty-four patients (76% women, 34% men, mean age: 46 ± 11 years) were enrolled; 30 were randomized and 29 completed the study. Headache intensity and frequency were significantly lower in the On arm than in the Off arm (p < 0.05) and decreased from the baseline to each follow-up visit in all patients with Stimulation On (median MIDAS A and B scores: baseline = 70 and 8; one-year follow-up = 14 and 5, p < 0.001). Quality of life significantly improved (p < 0.05) during the study. Triptans and nonsteroidal anti-inflammatory drug use fell dramatically from the baseline (20 and 25.5 doses/month) to each follow-up visit (3 and 2 doses/month at one year, p < 0.001). A total of 5 adverse events occurred: 2 infections and 3 lead migrations.
Limitations: Single-centre study, relatively small number of patients, absence of a control group.
Conclusions: According to the results obtained, ONS appears to be a safe and effective treatment for carefully selected CM and MOH patients.