Background: Millions of patients suffer from medically refractory and disabling
primary headache disorders. This problem has led to a search for new and innovative
treatment modalities, including neuromodulation of the occipital nerves.
Objectives: The primary aim of this study is to describe an implantation technique
for the Bion® microstimulator and document stimulation parameters and stimulation
maps after Bion placement adjacent to the greater occipital nerve. The secondary aim
is to document outcome measures one year post-implant.
Design: Prospective, observational feasibility study.
Methods: Nine patients with medically refractory primary headache disorders
participated in this study. Approximately 6 months after Bion insertion, stimulation
parameters and maps were documented for all patients. At one year, outcome
measures were collected including the Migraine Disability Assessment Score.
Results: At 6 months, the mean perception threshold was 0.47 mA, while the
mean discomfort threshold was 6.8 mA (stimulation range 0.47 – 6.8 mA). The mean
paresthesia threshold was 1.64 mA and the mean usage range was 16.0. There were
no major complications reported such as device migration, infection, or erosion. One
patient stopped using her Bion before the 12-month follow-up visit. At one year, 7
of the 8 patients were judged as having obtained fair or better results in terms of
reduction of disability; 5 patients had greater than a 90% reduction in disability.
Limitations: Small, heterogeneous patient population without control group. Not
blinded or randomized.
Conclusion: The Bion can be successfully inserted adjacent to the greater occipital
nerve in an effort to treat refractory primary headache disorders. This microstimulator
may provide effective occipital stimulation and headache control while minimizing the
risks associated with percutaneous or paddle leads implanted subcutaneously in the
occipital region.
Key words: Chronic headache, migraine, cluster headache, peripheral nerve
stimulation