In addition to having a lowered number of headache days, around 20% of patients transformed to low-frequency, episodic migraine on follow-up.
Results from a prospective cohort study demonstrated that repetitive multiple cranial nerve blocks (MCNBs) could provide effective prevention in patients with chronic migraine.
Among the 64 patients included in the study, the mean (+SD) reduction in headache days following MCNBs was 5.4 (+5.4) days, as well as a mean (+SD) reduction in Headache Impact Test 6 (HIT6) scores of 5.3 (+10.3). About 42 (66%) patients responded to the MCNBs with ≥30% reduction in headache days, with a mean (+SD) duration of effect of 5.7 (+5.4) weeks.
“The transformation into episodic migraine in a third of our responders is promising and may suggest that repetitive occipital and trigeminal nerve blocks could have a better role in the management of chronic migraine,” Linford Fernandes, MBBS, lead investigator, neurology registrar and clinical research fellow, Leeds Teaching Hospital, and colleagues concluded.
As MCNBs are frequently used for the acute and transitional treatment of migraine, this single-center, prospective cohort study was designed to evaluate their efficacy as a preventive therapy for chronic migraine. Investigators from the Leeds Teaching Hospital Trust, United Kingdom, collected demographic and outcome data on chronic migraine patients who had MCNBs in the headache service between June 2017 and March 2019.
Patients were followed for up to 20 months based on the number of MCNBs they received and underwent repetitive occipital nerve blocks or bilateral occipital and trigeminal nerve blocks. This was determined on the response to the treatment, location of maximal tenderness and/or area of sensitization.
Researchers used the proportion of patients with ≥30% reduction in their headache days at 4 weeks post-block, following the blocks as the primary outcome measure of the study. Secondary outcomes of the study included HIT6 scores by 12 weeks, with the questionnaires administered between 10 and 12 weeks after the last nerve block.
Of the 64 patients with a diagnosis of chronic migraine, 54 (84%) were female and 20 (31%) had a diagnosis of chronic migraine with aura (MWA). The mean age at the first nerve block procedure was 41 (+12.4) years, with an age range of 21—72 years.
About 10 (16%) and 6 (9%) patients had a concomitant diagnosis of medication overuse headache (MOH) or accompanying occipital neuralgia, respectively. Treatments documented at baseline showed 37 (58%) patients had only repetitive occipital nerve blocks and 27 (42%) had a combination of occipital and trigeminal nerve blocks.
While the overall headache days was reduced, there were no statistically significant differences between patients who had occipital nerve blocks and those who had occipital and trigeminal nerve blocks (P = .429). Researchers also noted that 13 (20%) patients transformed to low-frequency episodic migraine on follow-up. No reduction in headache scores or HIT6 scores were recorded in 22 (34%) patients.
As for safety, of 112 individual nerve block encounters during the study, 9 (8%) instances of minor post-block complications were documented with a total of 501 injections. Among them included 4 episodes of transient dizziness, 4 episodes of injection site pain, and 1 episode of localized hair thinning.
Fernandes L, Khan N, Dobson J, Randall M, Idrovo L. Multiple cranial nerve blocks as an alternative preventative therapy for chronic migraine. Headache. Published online March 30, 2020. doi: 10.1111/head.13792