Chen Z, et al. – The physicians examined altered thalamic subnuclei volume in medication–overuse headache (MOH) compared with normal controls, and evaluated the relationship of each thalamic subnuclei volume with the clinical variables. In MOH, increased gray matter volume in the whole thalamus and all the thalamus subnuclei could reflect central sensitization and higher–order of pain alteration. In the thalamus, these structural changes could also be affected by mood disturbances associated with the MOH.

• The physicians obtained high resolution three-dimensional T1-weighted fast spoiled gradient recalled echo MR images from 27 patients with MOH and 27 normal controls (NC).
• They created thalamic subnuclei templates based on Talairach template with MNI space transformation.
• They generated the individual thalamic subnuclei templates by applying the deformation field from structural image segment to the thalamic subnuclei templates, and then individual thalamci subnuclei volume were calculated.

• Compared with NC, the whole thalamus and each thalamic subnuclei presented increased volume (P < 0.05).
• The correlation analysis indicated that the whole thalamus volume and each thalamic subnuclei volume demonstrated a negative association with HAMD scores(P < 0.05), and no any relationship with HAMA, VAS score, and disease duration (P > 0.05).