Sustained Efficacy, Safety and High Adherence Rate of Onabotulinum Toxin Type A in Chronic Migraine Patients: A Multicentric Prospective Real-Life Study

Resistant and refractory migraine: clinical presentation, pathophysiology, and management

Migraine is a leading cause of disability worldwide. A minority of individuals with migraine develop resistant or refractory conditions characterised by ≥ 8 monthly days of debilitating headaches and inadequate response, intolerance, or contraindication to ≥3 or all preventive drug classes, respectively. Resistant and refractory migraine are emerging clinical definitions stemming from better knowledge of the pathophysiology of migraine and from the advent of migraine-specific preventive treatments. Resistant migraine mostly results from drug failures, while refractory migraine has complex and still unknown mechanisms that impair the efficacy of preventive treatments. Individuals with resistant migraine can be treated with migraine-specific preventive drugs. The management of refractory migraine is challenging and often unsuccessful, being based on combinations of different drugs and non-pharmacological treatment. Future research should aim to identify individuals at risk of developing treatment failures, prevent the condition, investigate the mechanisms of refractoriness to treatments, and find effective treatment strategies.

Onabotulinumtoxin-A: Previous Prophylactic Treatment Might Improve Subsequent Anti-CGRP Monoclonal Antibodies Response in Patients with Chronic Migraine

The aim of the present study was to evaluate whether previous preventive treatment with onabotulinumtoxin-A might influence subsequent clinical response following a switch to anti-CGRP monoclonal antibodies (mAbs). The present retrospective study was conducted at the Headache Centre-Neurology Clinic at the Spedali Civili Hospital of Brescia between November 2018 and May 2023. The primary objective was to assess clinical outcome (monthly headache days (MHDs), monthly migraine days (MMDs), mean analgesics consumption, and clinical disability according to Migraine Disability Assessment (MIDAS)) following three months (T3) of preventive treatment with anti-CGRP mAbs comparing patients who did and those who did not previously receive treatment with Onabotulinumtoxin-A. Moreover, we aimed to evaluate whether the clinical response to anti-CGRP mAbs was affected by the number of previous Onabotulinumtoxin-A administrations. At T3, compared to Onabotulinumtoxin-A naïve patients, patients who previously received Onabotulinumtoxin-A documented fewer MMDs (3.3 ± 3.7 versus 5.2 ± 5.0; p = 0.017) and a lower MIDAS score (23.2 ± 20.9 versus 37.4 ± 39.6; p = 0.013). Patients who received at least 3 onabotulinumtoxin-A administrations documented, at T3, lower MMDs compared to those who received fewer cycles (respectively, 2.1 ± 2.7 vs. 6.5 ± 4.4; p = 0.024). In conclusion, according to our data, previous treatment with onabotulinumtoxin-A might improve subsequent response to anti-CGRP mAbs preventive treatment.

Quantitative and Qualitative Pain Evaluation in Response to OnabotulinumtoxinA for Chronic Migraine: An Observational Real-Life Study

(1) Background: Randomized controlled trials and real-life studies demonstrated the efficacy of OnabotulinumtoxinA (OBT-A) for CM prevention. However, no studies specifically addressed its effect on pain's quantitative intensity and qualitative characteristics. (2) Methods: This is an ambispective study: a post-hoc retrospective analysis of real-life prospectively collected data from two Italian headache centers on CM patients treated with OBT-A over one year (i.e., Cy1-4). The primary endpoint was the changes in pain intensity (Numeric Rating Scale, NRS; the Present Pain Intensity (PPI) scale, the 6-point Behavioral Rating Scale (BRS-6)) and quality scale (the short-form McGill Pain Questionnaire (SF-MPQ)) scores. We also assessed the relationship between changes in intensity and quality of pain and disability scale (MIDAS; HIT-6) scores, monthly headache days (MHDs), and monthly acute medication intake (MAMI) (3) Results: We retrieved 152 cases (51.5 years SD 11.3, 80.3% females). From baseline to Cy-4, MHDs, MAMI, NRS, PPI, and BRS-6 scores decreased (consistently p < 0.001). Only the throbbing (p = 0.004), splitting (p = 0.018), and sickening (p = 0.017) qualities of pain collected in the SF-MPQ were reduced. Score variations in MIDAS related to those in PPI scales (p = 0.035), in the BRS-6 (p = 0.001), and in the NRS (p = 0.003). Similarly, HIT-6 score changes related to PPI score modifications (p = 0.027), in BRS-6 (p = 0.001) and NRS (p = 0.006). Conversely, MAMI variation was not associated with qualitative or quantitative pain score modifications except BRS-6 (p = 0.018). (4) Conclusions: Our study shows that OBT-A alleviates migraine by reducing its impact on multiple aspects, such as frequency, disability, and pain intensity. The beneficial effect on pain intensity seems specific to pain characteristics related to C-fiber transmission and is associated with a reduction in migraine-related disability.