Peripheral nerve stimulation for the treatment of chronic intractable headaches: Long-term efficacy and safety study

Background: Despite the various modalities available for treating headaches, typical therapydoes not provide adequate pain relief for some patients.Objectives: This study explored the efficacy and safety of long-term peripheral nerve stimulation(PNS) for intractable chronic headaches.Study Design: Retrospective study of refractory headache patients at academic pain center.Methods: The medical records of all patients (N = 46) permanently implanted with PNSbetween January 2005 and January 2012 were reviewed retrospectively. Patient records andphone interviews were used to quantify the levels of pain intensity, headache days per month,and overall patient satisfaction with treatment. The correlation between headache duration andeffectiveness of PNS was also assessed.Results: Pain intensity on the 11-point Numeric Rating Scale decreased from 7.60 ± 1.73 beforeimplantation to 3.78 ± 2.41, 3.32 ± 2.67, 3.42 ± 2.74, and 2.04 ± 2.27 at one, 6, 12, and >12 (19 – 98) months after implantation, respectively (P < .001). The mean number of headachedays per month decreased by about 14 days from the base line. No correlation (r = -.33) wasfound between the number of years the patients had suffered from headaches and the efficacyof treatment.Limitations: Due to the limitation of a retrospective study, the data collected via chart reviewsand phone interviews are susceptible to selection and information biases.Conclusions: PNS is an effective modality in the long-term management of intractable chronicheadaches. Despite long histories of chronic headaches, the majority of patients had significantreductions in pain scores and the number of headache days per month. The outcomes werenot dependent on the number of years the patients had suffered from headaches before PNS treatment.