Treatment Outcome After Switching From Galcanezumab to Fremanezumab in Patients With Migraine.

BACKGROUND AND PURPOSE: Monoclonal antibodies (mAbs) targeting calcitonin-gene-related peptide (CGRP) or its receptor (anti-CGRP-R) have been widely administered to patients with migraine who show inadequate responses to preventive medications. Among patients in whom a particular anti-CGRP-R mAb is ineffective, switching between different anti-CGRP-R mAbs can be the next option. Few studies have investigated treatment outcomes for antibody switching, especially between mAbs with the same target of the CGRP ligand. We aimed to determine the treatment outcome after switching between two anti-CGRP mAbs (galcanezumab to fremanezumab). METHODS: We identified migraine patients in a prospective headache clinic registry who received galcanezumab for ≥3 months and were switched to fremanezumab for a further ≥3 months at a single university hospital. We defined a treatment response as a ≥50% reduction in the number of days with a moderate or severe headache at the third month of treatment relative to baseline. The treatment response after switching to fremanezumab was compared with the initial treatment response to galcanezumab. RESULTS: Among 21 patients identified in the registry, 7 (33.3%) were initial responders to galcanezumab. After switching to fremanezumab, 7 (33.3%) showed a treatment response. The treatment response rate was 28.6% in the initial responders and 71.4% in the nonresponders to galcanezumab (p>0.999). CONCLUSIONS: Switching between anti-CGRP mAbs (galcanezumab to fremanezumab) yielded a treatment outcome comparable to that reported previously when switching from an anti-CGRP-R mAb (erenumab) to an anti-CGRP mAb (galcanezumab or fremanezumab). The treatment response to fremanezumab seems to be independent of the prior treatment response to galcanezumab. Our findings suggest that switching to another anti-CGRP mAb can be considered when a particular anti-CGRP mAb is ineffective or intolerable.

Epidemiology, burden and clinical spectrum of cluster headache: a global update.

BACKGROUND: This narrative review aims to broaden our understanding of the epidemiology, burden and clinical spectrum of cluster headache based on updated findings with a global perspective. METHODS: We conducted a literature search on the following topics: (a) epidemiology; (b) burden: quality of life, disability, economic burden, job-related burden and suicidality; and (c) clinical spectrum: male predominance and its changes, age, pre-cluster and pre-attack symptoms, aura, post-drome, attack characteristics (location, severity, duration and associated symptoms), bout characteristics (attack frequency, bout duration and bout frequency), circadian and seasonal rhythmicity and disease course. RESULTS: New large-scale population-based reports have suggested a lower prevalence than previous estimations. The impact of cluster headache creates a significant burden in terms of the quality of life, disability, economic and job-related burdens and suicidality. Several studies have reported decreasing male-to-female ratios and a wide age range at disease onset. The non-headache phases of cluster headache, including pre-cluster, pre-attack and postictal symptoms, have recently been revisited. The latest data regarding attack characteristics, bout characteristics, and circadian and seasonal rhythmicity from different countries have shown variability among bouts, attacks, individuals and ethnicities. Studies on the disease course of cluster headache have shown typical characteristics of attacks or bouts that decrease with time. CONCLUSIONS: Cluster headache may be more than a "trigeminal autonomic headache" because it involves complex central nervous system phenomena. The spectrum of attacks and bouts is wider than previously recognised. Cluster headache is a dynamic disorder that evolves or regresses over time.

Outcome of epidural blood patch for imaging-negative spontaneous intracranial hypotension.

BACKGROUND: Spontaneous intracranial hypotension is diagnosed by an abnormal finding in brain MRI, spinal imaging, or lumbar puncture. However, the sensitivity of each test is low. We investigated whether patients with suspected spontaneous intracranial hypotension and negative imaging findings would respond to epidural blood patch. METHODS: We prospectively recruited patients with new-onset orthostatic headache admitted at the Samsung Medical Center from January 2017 to July 2021. In patients without abnormal imaging findings and no history of prior epidural blood patch, treatment outcome-defined as both 50% response in maximal headache intensity and improvement of orthostatic component-was collected at discharge and three months after epidural blood patch. RESULTS: We included 21 treatment-naïve patients with orthostatic headache and negative brain and spinal imaging results who received epidural blood patch. After epidural blood patch (mean 1.3 times, range 1-3), 14 (66.7%) and 19 (90.5%) patients achieved both 50% response and improvement of orthostatic component at discharge and three months post-treatment, respectively. Additionally, complete remission was reported in 11 (52.4%) patients at three-month follow-up, while most of the remaining patients had only mild headaches. Among nine (42.9%) patients who underwent lumbar puncture, none had an abnormally low opening pressure (median 13.8 cm H2O, range 9.2-21.5). CONCLUSION: Given the high responder rates of epidural blood patch in our study, empirical epidural blood patch should be considered to treat new-onset orthostatic headache, even when brain and spinal imaging are negative. The necessity of lumbar puncture is questionable considering the high response rate of epidural blood patch and low rate of "low pressure."