S100B and migraine disorder: We applied standardized mean differences (SMDs) with 95% confidence intervals (95%CIs) to appraise the association between S100B and migraine.<h4>Results</h4>The combined results of nine case-control studies indicated that compared with healthy controls, overall migraine patients had significantly increased S100B levels in peripheral blood (SMD = 0.688, 95%CI: 0.341-1.036, <i>P</i> < 0.001).