Brain SPECT perfusion and PET metabolism as discordant biomarkers in major depressive disorder

Maud Tastevin,Laurent Boyer,Theo Korchia,Eric Guedj,Raphaëlle Richieri,Christophe Lançon,Guillaume Fond

doi:10.1186/s13550-020-00713-2

Abstract

BackgroundBrain SPECT perfusion and PET metabolism have been, most often interchangeably, proposed to study the underlying pathological process in major depressive disorder (MDD). The objective of this study was to specify similarities and inconsistencies between these two biomarkers according to global characteristics of the disease. We conducted a retrospective study in 16 patients suffering from treatment-resistant MDD who underwent, during the same current episode, a cerebral perfusion SPECT with 99mTc-HMPAO and a metabolic PET with 18F-FDG. Whole-brain voxel-based SPM(T) maps were generated in correlation with the number of depressive episodes and in correlation with the depression duration, separately for the two exams (p-voxel < 0.001 uncorrected, k > 20).ResultsNo significant correlations were found between brain metabolism and either the number of depressive episodes or the duration of the disease, even at an uncorrected p-voxel < 0.005. On the other hand, the increased number of depressive episodes was correlated with decreased perfusion of the right middle frontal cortex, the right anterior cingulum cortex, the right insula, the right medial temporal cortex and the left precuneus. The increased depression duration was correlated with decreased perfusion of the right anterior cingulum cortex.ConclusionsThis preliminary study demonstrates more significant results with brain perfusion compared with glucose metabolism in treatment-resistant MDD, highlighting the value of brain SPECT despite less favourable instrumentation detection compared to PET.

Highlights

Brain SPECT perfusion and PET metabolism have been, most often interchangeably, proposed to study the underlying pathological process in major depressive disorder (MDD)
Whole-brain voxelbased SPM(T) maps were generated in correlation with the number of depressive episodes and in correlation with the depression duration, separately for the two exams (p-voxel < 0.001 uncorrected, k > 20), using proportional scaling with a grand mean scaled value fixed at 50
Our sample included 4 men and 12 women; 13 patients were single, and 10 had less than 12 years of education. They all presented with treatment-resistant depression (TRD) with a mean number of depressive episodes estimated at 2.31 ± 1.9

Summary

Introduction

Brain SPECT perfusion and PET metabolism have been, most often interchangeably, proposed to study the underlying pathological process in major depressive disorder (MDD). We conducted a retrospective study in 16 patients suffering from treatment-resistant MDD who underwent, during the same current episode, a cerebral perfusion SPECT with 99mTc-HMPAO and a metabolic PET with 18F-FDG. The pathophysiology of depression and the neural and biological mechanisms of treatment efficacy are still not fully understood. In this context, neuroimaging biomarkers are needed for diagnosing, Tastevin et al EJNMMI Res (2020) 10:121 predicting the course of the disorder and guiding the choice of therapy, as well as monitoring the response to these therapies

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