Migraine is associated with altered sensory processing, that may be evident as changes in cortical responsivity due to altered excitability, especially in migraine with aura. Cortical excitability... Show moreMigraine is associated with altered sensory processing, that may be evident as changes in cortical responsivity due to altered excitability, especially in migraine with aura. Cortical excitability can be directly assessed by combining transcranial magnetic stimulation with electroencephalography (TMS-EEG). We measured TMS evoked potential (TEP) amplitude and response consistency as these measures have been linked to cortical excitability but were not yet reported in migraine.We recorded 64-channel EEG during single-pulse TMS on the vertex interictally in 10 people with migraine with aura and 10 healthy controls matched for age, sex and resting motor threshold. On average 160 pulses around resting motor threshold were delivered through a circular coil in clockwise and counterclockwise direction. Trial-averaged TEP responses, frequency spectra and phase clustering (over the entire scalp as well as in frontal, central and occipital midline electrode clusters) were compared between groups, including comparison to sham-stimulation evoked responses.Migraine and control groups had a similar distribution of TEP waveforms over the scalp. In migraine with aura, TEP responses showed reduced amplitude around the frontal and occipital N100 peaks. For the migraine and control groups, responses over the scalp were affected by current direction for the primary motor cortex, somatosensory cortex and sensory association areas, but not for frontal, central or occipital midline clusters.This study provides evidence of altered TEP responses in-between attacks in migraine with aura. Decreased TEP responses around the N100 peak may be indicative of reduced cortical GABA-mediated inhibition and expand observations on enhanced cortical excitability from earlier migraine studies using more indirect measurements. Show less
Background and Objectives Increased sensitivity to light and patterns is typically associated with migraine, but has also been anecdotally reported in cluster headache, leading to diagnostic... Show moreBackground and Objectives Increased sensitivity to light and patterns is typically associated with migraine, but has also been anecdotally reported in cluster headache, leading to diagnostic confusion. We wanted to assess whether visual sensitivity is increased ictally and interictally in cluster headache.Methods We used the validated Leiden Visual Sensitivity Scale (L-VISS) questionnaire (range 0-36 points) to measure visual sensitivity in people with episodic or chronic cluster headache: (i) during attacks; (ii) in-between attacks; and in episodic cluster headache (iii) in-between bouts. The L-VISS scores were compared with the L-VISS scores obtained in a previous study in healthy controls and participants with migraine.Results Mean L-VISS scores were higher for: (i) ictal vs interictal cluster headache (episodic cluster headache: 11.9 +/- 8.0 vs. 5.2 +/- 5.5, chronic cluster headache: 13.7 +/- 8.4 vs 5.6 +/- 4.8; p < 0.001); (ii) interictal cluster headache vs controls (5.3 +/- 5.2 vs 3.6 +/- 2.8, p < 0.001); (iii) interictal chronic cluster headache vs interictal ECH in bout (5.9 +/- 0.5 vs 3.8 +/- 0.5, p = 0.009), and (iv) interictal episodic cluster headache in bout vs episodic cluster headache out-of-bout (5.2 +/- 5.5 vs. 3.7 +/- 4.3, p < 0.001). Subjective visual hypersensitivity was reported by 110/121 (91%; 9 missing) participants with cluster headache and was mostly unilateral in 70/110 (64%) and ipsilateral to the ictal pain in 69/70 (99%) participants.Conclusion Cluster headache is associated with increased ictal and interictal visual sensitivity. In contrast to migraine, this is mostly unilateral and ipsilateral on the side of the ictal pain. Show less
Perenboom, M.J.L.; Schenke, M.; Ferrari, M.D.; Terwindt, G.M.; Maagdenberg, A.M.J.M. van den; Tolner, E.A. 2020
Migraine patients often report (inter)ictal hypersensitivity to light, but the underlying mechanisms remain an enigma. Both hypo- and hyperresponsivity of the visual network have been reported,... Show moreMigraine patients often report (inter)ictal hypersensitivity to light, but the underlying mechanisms remain an enigma. Both hypo- and hyperresponsivity of the visual network have been reported, which may reflect either intra-individual dynamics of the network or large inter-individual variation in the measurement of human visual evoked potential data. Therefore, we studied visual system responsivity in freely behaving mice using combined epidural electroencephalography and intracortical multi-unit activity to reduce variation in recordings and gain insight into visual cortex dynamics. For better clinical translation, we investigated transgenic mice that carry the human pathogenic R192Q missense mutation in the alpha(1A) subunit of voltage-gated Ca(V)2.1 Ca2+ channels leading to enhanced neurotransmission and familial hemiplegic migraine type 1 in patients. Visual evoked potentials were studied in response to visual stimulation paradigms with flashes of light. Following intensity-dependent visual stimulation, FHM1 mutant mice displayed faster visual evoked potential responses, with lower initial amplitude, followed by less pronounced neuronal suppression compared to wild-type mice. Similar to what was reported for migraine patients, frequency-dependent stimulation in mutant mice revealed enhanced photic drive in the EEG beta-gamma band. The frequency-dependent increases in visual network responses in mutant mice may reflect the context-dependent enhancement of visual cortex excitability, which could contribute to our understanding of sensory hypersensitivity in migraine. Show less
Perenboom, M.J.L.; Ruit, M. van de; Zielman, R.; Maagdenberg, A.M.J.M. van den; Ferrari, M.D.; Carpay, J.A.; Tolner, E.A. 2020
BackgroundMigraine is associated with altered sensory processing and cortical responsivity that may contribute to susceptibility to attacks by changing brain network excitability dynamics. To gain... Show moreBackgroundMigraine is associated with altered sensory processing and cortical responsivity that may contribute to susceptibility to attacks by changing brain network excitability dynamics. To gain better insight into cortical responsivity changes in migraine we subjected patients to a short series of light inputs over a broad frequency range ("chirp" stimulation), designed to uncover dynamic features of visual cortex responsivity.MethodsEEG responses to visual chirp stimulation (10-40 Hz) were measured in controls (n = 24) and patients with migraine with aura (n = 19) or migraine without aura (n = 20). Average EEG responses were assessed at (i) all EEG frequencies between 5 and 125 Hz, (ii) stimulation frequencies, and (iii) harmonic frequencies. We compared average responses in a low (10-18 Hz), medium (19-26 Hz) and high (27-40 Hz) frequency band.ResultsResponses to chirp stimulation were similar in controls and migraine subtypes. Eight measurements (n = 3 migraine with aura; n = 5 without aura) were assigned as "pre-ictal", based on reported headache within 48 hours after investigation. Pre-ictally, an increased harmonic response to 22-32 Hz stimulation (beta band) was observed (p = 0.001), compared to interictal state measurements.ConclusionsWe found chirp responses to be enhanced in the 48 hours prior to migraine headache onset. Visual chirp stimulation proved a simple and reliable technique with potential to detect changes in cortical responsivity associated with the onset of migraine attacks. Show less
