Medication overuse headache associated with decreased dopamine transporter availability in the medial but not in the lateral orbitofrontal cortex: a ¹¹CFT PET/MR study

Abstract

Backgrounds

Dysfunction of the mesocorticolimbic dopamine system in medication overuse headache (MOH) is unknown. This study aimed to determine dopamine transporter (DAT) availability, which is sensitive to dopamine levels, in the mesocorticolimbic dopamine system in MOH patients.

Methods

This case–control study investigated eligible MOH patients admitted to the International Headache Centre in the neurological department of Chinese PLA General Hospital between July 2018 and August 2019. All subjects underwent an integrated positron emission tomography (PET)/magnetic resonance (MR) brain scans with ¹¹CFT, a radioligand that binds to DAT. Standardised uptake value ratio (SUVr) images were compared voxelwise between MOH patients and healthy controls (HCs). SUVr values from significantly changed regions were extracted, and partial correlation analyses with clinical measures were conducted.

Results

We examined 17 MOH patients and 16 HCs. MOH patients had lower SUVr levels in the medial rather than lateral orbitofrontal cortex (OFC) than HCs (T = −5.0317, P^GRF < 0.01), which showed no correlation with clinical features.

Conclusions

MOH is characterised by decreased DAT availability in the medial OFC, which might reflect compensatory downregulation due to low dopamine signalling within the mesocorticolimbic dopamine system and provide a new perspective to understand the pathogenesis of MOH.

Keywords:

• medication overuse headache
• dopamine transporter
• orbitofrontal cortex
• PET/MR

Acknowledgements

The authors thank all patients and healthy volunteers who took part in the study.

Declarations of interest statement

The authors declare that there is no conflict of interest.

Data availability

All data generated and analysed during this study will be available from the corresponding authors on reasonable request.

Additional information

Funding

This work was supported by grants from the National Natural Science Foundation of China (grants 81771200, 82071226, 82171208), and the Beijing Natural Science Foundation Essential Research Project (Z170002).