Work

Assessing Cortical Excitability across the Migraine Cycle – A TMS Approach

Year: 2025

Type: article

Abstract: Background: Migraine is a primary headache and a major cause of global disability.In migraine pathophysiology, cortical excitability changes across the migraine cycle.An improved understanding of these dynamics could translate to therapeutic advances.We conducted a longitudinal assessment of motor cortex excitability via transcranial magnetic stimulation (TMS) based Input/Output-Curves (IOC) in migraine patients (MIG) across the cycle and in healthy controls (HC).Methods: 11 MIG (11 F; 26.1 ± 2.7) and 10 HC (4 F/6 M; 24.6 ± 0.8 y) underwent navigated TMS.Each MIG underwent three appointments, >3d before, during and >3d after a migraine attack.For HC, appointments were separated by at least 5 days.Resting motor threshold (rMT) was determined on the abductor pollicis brevis hotspot.8 intensity levels (rMT -10 % maximum stimulator output (MSO) to rMT + 25 % MSO; 5 % MSO intervals) were tested in random sequence.For each level, 15 motor evoked potentials (MEPs) were recorded.rMTs were analyzed via ANCOVA.IOC MEP amplitudes were analyzed in a multivariate linear mixed-effects regression model with bootstrapping.Results: rMTs did not significantly differ between appointments for either group.Main results of the regression analysis included lower overall MEP amplitudes for MIG compared to HC (factorial decrease of e -0.35 z 0.71; p ¼ 0.038) and a separate significant interaction of patient status and appointment with higher MEPs for HC specific to session 2, the attack session for MIG (factorial increase of e 0.39 z 1.48; p < 0.001).Conclusion: Our findings demonstrate the potential for usage of TMS in the tracking of cortical excitability dynamics in the migraine cycle, especially when longitudinal study designs are employed.Additionally, our findings support pathophysiological models in which cortical excitability drops during the migraine attack with a subsequent return to baseline.

Source: Brain stimulation

DOI: 10.1016/j.brs.2024.12.889