Altered brain activity and functional connectivity in migraine without aura during and outside attack

ABSTRACT

Background

Migraine is commonly seen as a cyclic disorder with variable cortical excitability at different phases. Herein, we investigated the cortical excitability in migraine without aura patients during an attack (MWoA-DA) and interictal period (MWoA-DI) and further explored the functional connectivity (FC) in brain regions with cortical excitability abnormalities in patients.

Methods

Seven MWoA-DA patients, twenty-seven MWoA-DI patients, and twenty-nine healthy controls (HC) underwent resting-state functional magnetic resonance imaging (rs-fMRI) scan. The amplitude of low-frequency fluctuations (ALFF) was assessed to identify spontaneous brain activity. Then, brain regions showing significant differences across groups were identified as regions of interest (ROI) in FC analysis.

Results

Compared with MWoA-DI patients and HC, the ALFF in the trigeminocervical complex (TCC) was higher in the MWoA-DA patients. Decreased FC in MWoA-DA patients was found between TCC and left postcentral gyrus compared with MWoA-DI patients. Compared with HC, ALFF was lower in the right cuneus but higher in the right rolandic operculum of MWoA-DI patients. Additionally, the ALFF in the right cuneus was negatively correlated with the Migraine Disability Assessment Scale (MIDAS) in MWoA-DI patients.

Conclusions

The trigeminovascular system and impairments in descending pain modulatory pathways participate in the pathophysiology of migraine during the ictal period. The defense effect exists in the interictal phase, and the dysfunction in the cuneus may be related to the disease severity. This dynamic change in different brain regions could deepen our understanding of the physiopathology underlying migraine.

KEYWORDS:

• Resting-state functional magnetic resonance imaging
• trigeminocervical complex
• amplitude of low-frequency fluctuations
• functional connectivity
• migraine

Abbreviations

MWoA-DA	=	migraine without aura during the attack
MWoA-DI	=	migraine without aura during the interictal period
HC	=	healthy controls
ALFF	=	amplitude of low-frequency fluctuation
FC	=	functional connectivity
rs-fMRI	=	resting-state functional magnetic resonance imaging
ROI	=	regions of interest
TCC	=	trigeminocervical complex
VAS	=	visual analogue scale
MIDAS	=	Migraine Disability Assessment Scale
HIT-6	=	Headache Impact Test
SF-MPQ-2	=	Short-form McGill Pain Questionnaire-2 scores
S2	=	secondary somatosensory cortex.

Acknowledgments

We would like to thank the volunteers for their involvement in the study.

Disclosure statement

No potential conflict of interest was reported by the author(s).

CRediT authorship contribution statement

Luping Zhang: Conceptualization, Methodology, Investigation, Data curation, Validation, Formal analysis, Writing – original draft, Visualization. Wenjing Yu: Software, Methodology, Data curation, Formal analysis. Zhengxiang Zhang: Investigation, Writing – review & editing. Maosheng Xu: Resources, Writing – review & editing. Feng Cui: Resources, Writing – review & editing. Wenwen Song: Software, Methodology. Zhijian Cao: Conceptualization, Project administration, Writing – review & editing, Supervision, Resources, Funding acquisition.

Statement of ethics

The study was carried out in accordance with the Code of Ethics of the World Medical Association (Declaration of Helsinki) and was approved by the Ethics Committee of the first Affiliated Hospital of Zhejiang Chinese Medical University (2018-KL-081-02).

Additional information

Funding

This study was supported by Zhejiang Traditional Chinese Medicine Administration [grant number 2016ZB045] and Health Science and Technology Project of the Zhejiang Provincial Health Commission [grant number 2022KY222]