Fig. 1

Pre-operative thalamus volume in healthy controls (HC) and TN patients sorted by side-of-pain. (A) The left thalamus is larger than the right thalamus (p < 0.001) in healthy controls (HC). The contralateral thalamus is larger in TN patients regardless of the side-of-pain (left TN = LTN, right TN = RTN). (B) The left vs. right thalamus inter-hemispheric volume % difference differs (p < 0.001) between LTN and left-side healthy controls (LHC—see text for definition), while there is no difference in left vs. right thalamus inter-hemispheric % volume percentage difference between RTN and right-side healthy controls (RHC). Mann–Whitney tests were used to perform between-group comparisons, while Wilcoxon sign-rank tests were used to compare thalamus volumes within-groups. Statistical significance (p < 0.05) is indicated with *. Medians with interquartile ranges are displayed