Occipital nerve stimulation (ONS) is associated with a substantial reduction in the frequency of headache attacks in patients with refractory chronic cluster headache (rCCH), and this efficacy appears to be maintained over 3 years, according to a study in Neurosurgery.
The study included 105 patients with rCCH (mean age, 45 years old) who were treated with ONS within a multicentric ONS registry. Investigators evaluated the efficacy of therapy, which included an assessment on the reductions in headache frequency and intensity of pain attacks. Efficacy was also evaluated by changes in quality of life (QoL) on the EuroQol 5 dimensions (EQ-5D) scale, functional impacts as assessed by the Headache Impact Test-6 and Migraine Disability Assessment, emotional impacts as assessed by the Hospital Anxiety Depression Scale (HAD), and medication consumption.
In the overall cohort, the mean period between disease onset to implantation was 11 years. The majority of attacks (74.2%) were unilateral, and approximately 52.4% of attacks were localized on the right side.
Over a mean follow-up period of 43.8 months (range, 19.2-105.6 months), the frequency of headache attacks was reduced by more than 50% in 68.8% of the 93 evaluable patients with rCCH. Additionally, ONS was associated with a reduction of greater than 30% in 73% (n=68) of patients.
The mean weekly attack frequency declined significantly from 22.5 at baseline to 9.9 at follow up (P <.001). Use of abortive therapies reduced from a mean of 15 sumatriptan weekly injections to 3 weekly injections. In addition, patients had a reduction in oxygen consumption from 10 uses per week to 3.5 uses per week following ONS.
From baseline to last follow up, there were also improvements in mean scores on the EQ-5D utility (0.40 vs 0.7; P <.0001), EQ-5D visual analogue scale (35.85 vs 62.43; P <.0001), short version of the Headache Impact Test score (67.75 vs 56.58; P <.0001), HAD anxiety subscale (11.30 vs 6.58; P <.0001), and HAD depression subscale (10.67 vs 6.53; P <.0001). In a subgroup of 44 patients who were evaluated after 1 year of continuous ONS stimulation, efficacy associated with the initial ONS was sustained over time.
According to a multivariable analysis, a predictive variable of the long-term reduction in attack frequency of greater than 50% and good ONS response was having a low preoperative HAD depression score (odds ratio, 1.35; 95% CI, 1.03-1.77; P =.0290). Complications during follow up occurred in 67 patients and included infection (6%), lead migration (12%) or fracture (4.5%), hardware dysfunction (8.2%), and local pain (20%).
Limitations of the study, according to the researchers, included several missing data for secondary endpoints and predictive factors of ONS outcomes.
The researchers wrote that the significant improvements of rCCH “potentially induced by ONS justifies, in our opinion, the risks, and cost of this therapeutic approach.”
Leplus A, Fontaine D, Donnet A, et al. Long-term efficacy of occipital nerve stimulation for medically intractable cluster headache. Published online September 28, 2020. Neurosurgery. doi: 10.1093/neuros/nyaa373