title: A meta-analysis of voxel-based morphometric studies on migraine.
abstract: OBJECTIVE
  To identify consistent results of voxel-based morphometry (VBM) studies in migraine.
  
  
  METHODS
  Whole-brain VBM studies comparing migraine patients with healthy controls (HC) were systematically searched in PubMed, ISI Web of Science, Embase, and Medline databases from January 1990 to Dec 2014. Coordinates were extracted from clusters with significant difference in gray matter volume (GMV) between migraine patients with healthy controls (HC). Meta-analysis was performed using activation likelihood estimation (ALE).
  
  
  RESULTS
  A total of 5 studies, comprising 126 migraineurs, including 23 migraine with aura, 41migraine without aura, 11 epidemic migraine and 16 chronic migraine as well as 19 Mm and 16 nmM, and 134 HC, were enrolled. The included studies report GMV reduction at 84 coordinates in migraine, as well as GMV increase at 2 coordinate in migraine. However, due to only two included studies have classified patients into these two phenotypes and one stated they included only migraine with aura patients , we were not able to perform a subgroup analysis and separate meta-analyses on each phenotype.
  
  
  CONCLUSIONS
  There were significant reductions in Middle frontal cortex (BA6, 9) structures and the Inferior frontal cortex (BA44) in migraine. These changes of GMV may indicate the mechanisms of the associated symptoms such as cognitive dysfunction, emotion problems and autonomic dysfunction. But whether this is the characteristics of the subtypes of migraine or can distinguish the types of migraine or primary headache, further studies examining larger samples may better elucidate the changes related to the illness and highlight its pathological mechanism.
authors.affiliation: Department of Neurology, West China Hospital, Sichuan University Chengdu 610041, Sichuan, China.
authors.forename: Wenting
authors.initials: W
authors.lastname: Hu
authors.affiliation: Department of Neurology, West China Hospital, Sichuan University Chengdu 610041, Sichuan, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Neurology, West China Hospital, Sichuan University Chengdu 610041, Sichuan, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Chen
authors.affiliation: Department of Neurology, West China Hospital, Sichuan University Chengdu 610041, Sichuan, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Neurology, West China Hospital, Sichuan University Chengdu 610041, Sichuan, China.
authors.forename: Li
authors.initials: L
authors.lastname: He
keywords: Migraine; meta-analysis; voxel; voxel-based morphometry (VBM); voxel-based or morphometry; voxel-wise