Trigeminal sensory modulatory effects of galcanezumab and clinical response prediction

Cut-Off Values Able to Identify Migraine Patients With Increased Pressure-Pain Sensitivity Independent of the Migraine Cycle Through a Single Assessment: A Secondary Analysis of a Multicentre, Cross-Sectional, Observational Study

AIM

Identify values that could predict the presence of increased pressure-pain sensitivity independent of the migraine cycle through a single assessment.

METHODS

This was a secondary analysis of a previous study in which 198 episodic and chronic migraine patients were assessed during all phases of the migraine cycle. Pressure pain threshold (PPT) was assessed over the temporalis, cervical spine, hand, and leg. Migraine patients were divided into two sub-groups: patients with increased pressure-pain sensitivity (IPS) and with No IPS (No-IPS). A Chi-squared Automatic Interaction Detection decision tree analysis was used to identify predictors to be included in the IPS or NoIPS group. To assess the internal validity of the model, a tenfold cross-validation was applied.

RESULTS

161 (81%) patients were included in the IPS group, while 37 (19%) in the NoIPS group. Migraine patients with: (1) Temporalis PPT ≤ 130 kPa; (2) Temporalis PPT > 130 kPa and ≤ 197.5 kPa and hand PPT ≤ 347.33 kPa; (3) Temporalis PPT > 197.5 kPa and hand PPT ≤ 315 kPa; were correctly included in the IPS group with a sensitivity of 96%, a specificity of 81%, a positive predictive value of 96%, and a negative predictive value of 81%. The accuracy of the model and the cross-validation analysis were respectively 93% and 92%.

CONCLUSION

The high internal validity suggests that our model could precisely predict the presence of IPS independently by the phase in which the assessment occurred. Trigeminal and hand PPT cut-off values could be used to identify patients with IPS.

Pharmacological differences and switching among anti-CGRP monoclonal antibodies: A narrative review

Antibodies targeting either the calcitonin gene-related peptide (CGRP), such as galcanezumab, fremanezumab, and eptinezumab, or the receptor (erenumab) have been approved for the prevention of episodic and chronic migraine. Although widely used and generally effective, a proportion of patients discontinue treatment due to lack of efficacy. In both randomized controlled trials and observational studies, all anti-CGRP monoclonal antibodies (mAbs) have consistently demonstrated comparable efficacy and tolerability, suggesting a pharmacological class effect. However, differences in therapeutic targets, structure, and pharmacokinetic characteristics may influence their efficacy and safety differently. Therefore, in patients not achieving a clinically meaningful response with one anti-CGRP antibody, switching to a different antibody may be a viable option. This review examines the pharmacological characteristics and distinctions among anti-CGRP mAbs, highlighting their mechanisms of action and pharmacokinetic profiles, along with the clinical observational data of switching. Finally, we summarize suggestions from international guidelines.

Pain profiling in migraine: a systematic review of Quantitative Sensory Testing (QST), Conditioned Pain Modulation (CPM), and Corneal Confocal Microscopy (CCM)

OBJECTIVE

The aim of this systematic review is to identify pain profiling parameters that are reliably different between patients with migraine and healthy controls, using Quantitative Sensory Testing (QST) including Temporal Summation (TS), Conditioned Pain Modulation (CPM), and Corneal Confocal Microscopy (CCM).

METHODS

A comprehensive literature search was conducted (up to 23 May 2024). The quality of the research was assessed using the Newcastle-Ottawa Scale (NOS) for non-randomized studies.

RESULTS

Twenty-eight studies were included after screening. The QST studies indicate that migraine patients exhibit lower pressure pain thresholds (PPT), particularly in the trigeminal region. A previous meta-analysis reported lower heat pain thresholds (HPT). CPM studies suggest a (mild) inhibitory or absent response in migraine patients, not different from controls. High-frequency and chronic migraine patients may exhibit a facilitatory CPM response. With repeated executions of CPM, migraine patients display a diminishing CPM response, a phenomenon not observed in control subjects. CCM investigations in migraine patients revealed conflicting outcomes, likely as a result of small sample sizes and limited characterization of migraine features.

CONCLUSION

Pain profiling migraine patients varies due to sensory modality, applied methods, anatomical sites, and migraine features. Understanding pain profiling offers insights into migraine pathophysiology, requiring careful selection of parameters and differentiation among migraine subtypes.

Potential Predictors of Response to CGRP Monoclonal Antibodies in Chronic Migraine: Real-World Data

PURPOSE OF REVIEW

Real-world data (RWD) has identified potential predictors of response to anti-CGRP therapies in patients with chronic migraine (CM). This review aims to synthesize the most remarkable findings published to date regarding this topic.

RECENT FINDINGS

Migraine features such as unilateral pain and positive triptan response and chronic features such as daily headache or medication overuse (MO) emerge as predictors of positive outcomes, potentially linked to elevated baseline serum anti-calcitonin gene-related peptide (anti-CGRP) levels. Demographic and baseline characteristics, encompassing obesity, psychiatric comorbidities, and prior refractoriness to prophylactic treatments, are associated with poor responses in both treatment-naïve patients and after-switch scenarios. Nevertheless, the consistency of these predictors across diverse populations requires further investigation. Recent RWD literature highlights emerging predictors of response of different sources among patients with CM receiving anti-CGRP therapies. Comprehending these predictors and identifying novel biomarkers of response hold the potential to refine treatment strategies for CM patients, enhancing their management and therapeutic outcomes.

Profiling migraine patients according to clinical and psychophysical characteristics: clinical validity of distinct migraine clusters

AIMS

Investigate if different clinical and psychophysical bedside tools can differentiate between district migraine phenotypes in ictal/perictal (cohort 1) and interictal (cohort 2) phases.

METHOD

This observational study included two independent samples in which patients were subgrouped into distinct clusters using standardized bedside assessment tools (headache frequency, disability, cervical active range of motion, pressure pain threshold in different areas): (A) cohort 1-ictal/perictal migraine patients were subgrouped, based on previous studies, into two clusters, i.e., Cluster-1.1 No Psychophysical Impairments (NPI) and Cluster-1.2 Increased Pain Sensitivity and Cervical Musculoskeletal Dysfunction (IPS-CMD); (B) cohort 2-interictal migraine patients were subgrouped into three clusters, i.e., Cluster-2.1 NPI, Cluster-2.2 IPS, and Cluster-2.3 IPS-CMD. Clinical characteristics (multiple questionnaires), somatosensory function (comprehensive quantitative sensory testing (QST)), and cervical musculoskeletal impairments (cervical musculoskeletal assessment) were assessed and compared across headache clusters and a group of 56 healthy controls matched for sex and age.

RESULTS

Cohort 1: A total of 156 subjects were included. Cluster-1.2 (IPS-CMD) had higher headache intensity (p = 0.048), worse headache-related (p = 0.003) and neck-related disability (p = 0.005), worse quality of life (p = 0.003), and higher symptoms related to sensitization (p = 0.001) and psychological burden (p = 0.005) vs. Cluster-1.1(NPI). Furthermore, Cluster-1.2 (IPS-CMD) had (1) reduced cervical active and passive range of motion (p < 0.023), reduced functionality of deep cervical flexors (p < 0.001), and reduced values in all QST(p < 0.001) vs. controls, and (2) reduced active mobility in flexion, left/right lateral flexion (p < 0.045), and reduced values in QST (p < 0.001) vs. Cluster-1.1 (NPI). Cohort 2: A total of 154 subjects were included. Cluster-2.3 (IPS-CMD) had (1) longer disease duration (p = 0.006), higher headache frequency (p = 0.006), disability (p < 0.001), and psychological burden (p = 0.027) vs. Cluster-2.2 (IPS) and (2) higher headache-related disability (p = 0.010), neck-related disability (p = 0.009), and higher symptoms of sensitization (p = 0.018) vs. Cluster-2.1 (NPI). Cluster-2.3(IPS-CMD) had reduced cervical active and passive range of motion (p < 0.034), and reduced functionality of deep cervical flexors (p < 0.001), vs. controls, Custer-2.1 (NPI), and Cluster-2.2 (IPS). Cluster-2.2 (IPS) and 2.3 (IPS-CMD) had reduced QST values vs. controls (p < 0.001) and Cluster-2.1 (p < 0.039).

CONCLUSION

A battery of patient-related outcome measures (PROMs) and quantitative bedside tools can separate migraine clusters with different clinical characteristics, somatosensory functions, and cervical musculoskeletal impairments. This confirms the existence of distinct migraine phenotypes and emphasizes the importance of migraine phases of which the characteristics are assessed. This may have implications for responders and non-responders to anti-migraine medications.

Targeting CGRP pathways and aura: A peripheral site with a central effect

Targeting CGRP-pathways has substantially expanded our options for treating individuals with migraine. Although the efficacy of these drugs on migraine aura is yet to be fully revealed, it seems from existing studies that CGRP antagonism reduces the number of migraine auras. The present perspective summarizes the evidence linking CGRP to the migraine aura and proposes a model by which targeting the CGRP-pathways and, thus, inhibition the interaction between C- and Aδ-trigeminal fibers might reverse a possible high cortical glutamate level leading to a reduced number of migraine auras.

Profiling migraine patients according to clinical and psychophysical characteristics: a cluster analysis approach

AIM

This study aims to profile migraine patients according clinical and psychophysical characteristics.

METHOD

In this observational study, two cohorts of migraine patients(episodic/chronic) were included. Cohort-1: ictal/perictal phase; Cohort-2: interictal phase.The following variables were assessed: headache frequency; disability; cervical active range of motion(AROM) in flexion, extension, right/left lateral flexion, right/left rotation; pressure-pain threshold(PPT) over: temporalis, two cervical areas(C1/C4 vertebral segments), and two distal pain-free areas(hand/leg). Cluster analysis was performed using the K-means algorithm. Differences across clusters were investigated.

RESULTS

Cohort-1: 100 patients were included, and two clusters were identified. Cluster-1.1 (19%), Cluster-1.2 (81%). Cluster 1.1 had a higher percentage of men (P = .037) and higher disability (P = .003) compared to Clusters 1.2. Cluster 1.2 had reduced AROM in flexion, extension, and left/right lateral flexion (P < .037), and lower PPT value in all areas (P < .001) compared to Cluster 1.1. Cohort-2: 98 patients were included and three clusters were identified. Cluster-2.1(18%), Cluster-2.2(45%), and Cluster-2.3(37%). Cluster-2.1 had a higher percentage of men compared to clusters-2.2 and 2.3 (P = .009). Cluster-2.3 had higher headache frequency, and disability compared to Cluster-2.2 (P < .006), and higher disability compared to Cluster-2.1 (P = .010). Cluster-2.3 had reduced AROM in all directions compared to Clusters-2.1 and 2.2 (P < .029). Clusters-2.2 and 2.3 have lower PPT values in all areas compared to Cluster-1.1 (P < .001).

CONCLUSION

In the Ictal/perictal phase, two clusters were identified according to clinical and psychophysical characteristics, with one group showing no psychophysical impairment and one with increased pain-sensitivity and cervical musculoskeletal-dysfunctions.In the interictal phase, three clusters could be identified, with one group showing no psychophysical impairment, one increased pain-sensitivity, and one increased pain sensitivity and cervical musculoskeletal-dysfunctions.

Cervical musculoskeletal impairments and pain sensitivity in migraine patients

INTRODUCTION

Currently, examination of migraine patients relies on a clinical interview investigating symptoms characteristics. Despite this, to help identify distinct migraine subtypes and allow a personalized treatment approach, biomarkers to profile distinct migraine subtypes should be utilized in clinical and research settings. Therefore, there is a need to include physical and psychophysical examinations aimed at assessing migraine features quantitatively.

PURPOSE

This paper aimed to discuss if increased pressure pain sensitivity and impaired cervical musculoskeletal function could be considered 1) as quantitative features of migraine and 2) if they could be used as biomarkers to profile migraine patients in distinct subtypes.

IMPLICATION

Increased pain sensitivity and cervical musculoskeletal impairments have been suggested as quantitative biomarkers to phenotype and subgroup migraine patients in clinical and research settings. This could provide the first step for a mechanistically-driven and personalized treatment approach according to migraine phenotypes.

Galcanezumab treatment changes visual related EEG connectivity patterns in migraine patients

BACKGROUND

Monoclonal antibodies against calcitonin gene-related peptides (CGRP) are innovative therapies for migraine treatment. Although they are clinically effective, how anti-CGRP treatment reduces migraine attacks still remains unclear.

OBJECTIVE

In this observational case-control study, we aimed to apply graph theory to EEG data from 20 migraine patients and 10 controls to investigate the effects of 3 months of galcanezumab on brain connectivity.

METHODS

We analyzed EEG rhythms during black-white pattern reversal stimulation with 0.5 cycle per degree spatial frequency before (T0) galcanezumab injection, as well as after 3 months (T2). EEG recordings made 1 hour after galcanezumab administration served as the control session (T1). Patients' connectivity patterns obtained at T0, T1 and T2 were compared with normal controls.

RESULTS

We found that galcanezumab increased network integration (with a 5% significance level corrected with the false discovery rate), changing the intensity of connections between the occipital through the frontal areas. At 3 months follow up, patients with persistent high headache intensity had a minor effect on the strength of connections (evaluated using Kendall's rank correlation test and p < 0.05).

CONCLUSIONS

The potent anti-nociceptive action that galcanezumab exerts at a peripheral level could restore cortical connections and possibly factors predisposing to attack onset.

A Scoping Review and Meta-Analysis of Anti-CGRP Monoclonal Antibodies: Predicting Response

Calcitonin gene-related peptide-targeted monoclonal antibodies (CGRP mAbs) are increasingly being used as preventive treatments for migraine. Their effectiveness and safety were established through numerous randomized placebo-controlled trials and real-world studies, yet a significant proportion of patients do not respond to this treatment, and currently, there is a lack of accepted predictors of response to guide expectations, as data from studies so far are lacking and inconsistent. We searched Embase and MEDLINE databases for studies reporting on predictors of response to CGRP and/or CGRP-receptor (CGRP-R) mAbs, defined as a 30% or 50% reduction in monthly headache or migraine days at varying durations of follow-up. Quantitative synthesis was performed where applicable. We found 38 real-world studies that investigated the association between various predictors and response rates. Based on these studies, good response to triptans and unilateral pain with or without unilateral autonomic symptoms are predictors of a good response to CGRP(-R) mAbs. Conversely, obesity, interictal allodynia, the presence of daily headaches, a higher number of non-successful previous prophylactic medications, and psychiatric comorbidities including depression are predictive of a poor response to CGRP(-R) mAbs. Future studies should confirm these results and help to generate more tailored treatment strategies in patients with migraine.

Pre-treatment non-ictal cephalic allodynia identifies responders to prophylactic treatment of chronic and episodic migraine patients with galcanezumab: A prospective quantitative sensory testing study (NCT04271202)

BACKGROUND

Migraine is a complex neurological disorder involving generalized abnormalities in processing sensory information. Adopting evidence that central sensitization imposes major hurdles in the treatment of migraine, we hypothesized that it is the non-ictal (rather than ictal) allodynia that may determine the outcome of migraine prevention with peripherally-acting drugs.

METHODS

To test this hypothesis, we used Quantitative Sensory Testing to determine whether it is possible to identify a patient's response to prophylactic treatment with galcanezumab based on presence/absence of cephalic and/or extracephalic allodynia during the pre-treatment non-ictal phase of migraine.

RESULTS

Using strict criteria for allodynia (heat 32-40°C, cold 32-20°C, mechanical <60 g), we report that (a) the incidence of pre-treatment non-ictal cephalic allodynia was 21% in the 24 responders (>50% decrease in monthly migraine days) and 85% in the 19 non-responders; (b) the incidence of non-ictal extracephalic allodynia distinguishes responders from non-responders less accurately; and that (c) the incidence of non-ictal cephalic allodynia was similar in the chronic migraine and high-frequency episodic migraine groups.

CONCLUSIONS

Clinically, the findings suggest that presence/absence of non-ictal allodynia can be used to identify galcanezumab responders with nearly 80% accuracy and galcanezumab non-responders with nearly 85% accuracy. Mechanistically, the presence of non-ictal allodynia (reflecting a state of activity-independent central sensitization) in both chronic migraine and high-frequency episodic migraine patients raises the possibility that the state of non-ictal allodynia may be attributed to physiological properties of central trigeminovascular neurons that are due to the genetic load of the individual patient rather than their migraine frequency.