2.1. Search strategy and selection criteria

A systematic search was conducted in PubMed, Web of Science, and Embase databases to retrieve studies published before April 2022 with the following search terms: “migraine” and (“neuroimaging” or “fMRI” or “functional magnetic resonance imaging” or “ALFF” or “amplitude of low‐frequency fluctuations” or “fALFF” or “fractional amplitude of low‐frequency fluctuations” or “ReHo” or “regional homogeneity” or “ASL” or “arterial spin labeling” or “PET” or “positron emission tomography” or “SPECT” or “single photon emission computed tomography”) and (“resting state” or “rest”). The reference lists of included studies and relevant scholarly reviews were also searched for additional studies. To be included, the studies needed to satisfy the following criteria: (1) the studies were original research and published in English‐language journals with peer review; (2) enrolled adult patients with migraine according to established diagnostic criteria; (3) conducted a whole‐brain voxel‐wise analysis to compare regional spontaneous brain activity of migraineurs with that of HCs; (4) provided three‐dimensional coordinates of significant clusters in Montreal Neurological Institute (MNI) or Talairach space, or reported null findings; (5) applied consistent statistical thresholds across the whole brain. The exclusion criteria were as follows: (1) the studies concerned other types of headache (e.g., cluster headache, medication overuse headache or tension headache) or a special subtype of migraine (e.g., vestibular migraine or pediatric migraine); (2) the studies only reported results obtained from the region of interest analysis or small volume correction; (3) the number of participants was less than seven in either the migraine group or control group (Tahmasian et al., 2019); (4) sufficient data for the meta‐analysis could not be obtained from original articles or after contacting the authors. If one patient group overlapped with another study, the study with larger sample size was retained. If an article reported multiple independent patient samples or neuroimaging metrics, they were treated as separate datasets. Moreover, in case of a longitudinal design, we only included the baseline comparison between patients and HCs. The preferred reporting items for systematic reviews and meta‐analyses guidelines were followed in our study (Moher et al., 2009), and the detailed research screening process is presented in Figure 1.

The flow diagram of the search strategy and retrieved studies according to the PRISMA guidelines. N, number; PRISMA, preferred reporting items for systematic reviews and meta‐analyses