Subcortical hyperexcitability in migraineurs: a high-frequency oscillation study

Area of Science:

• Neuroscience
• Clinical Neurology
• Neurophysiology

Background:

• Central nervous system (CNS) excitability is altered in migraine patients, but whether it is hyper- or hypo-excitable remains debated.
• Somatosensory high-frequency oscillations (HFOs) offer a method to investigate subcortical excitability (early phase) and intracortical inhibition (late phase).

Purpose of the Study:

• To compare subcortical and intracortical excitability using HFOs in migraine patients and control subjects.
• To determine if migraine is associated with hyper- or hypo-excitability in CNS pathways.

Main Methods:

• HFOs were recorded from C3'-Fz using a 500-1000 Hz filter after right median nerve stimulation.
• HFOs were analyzed in early (subcortical excitability) and late (intracortical inhibition) phases relative to the N20 peak.
• Fifty-nine untreated migraine patients (24 ictal, 35 interictal) and 22 controls participated.

Main Results:

• Patients with migraine, both ictal and interictal, demonstrated significantly higher maximal amplitudes and area-under-curve in early HFOs compared to controls (p=0.039 and p=0.029, respectively).
• No significant differences were observed in late HFOs among the patient and control groups.

Conclusions:

• The findings suggest a hyper-excitable state in the subcortical regions of patients with migraine.
• This hyper-excitability is present during both interictal and ictal periods, indicating a persistent physiological difference in migraineurs.