Depressive Symptoms and Cerebral Glucose Metabolism in Presurgical Epilepsy Patients Undergoing Brain Fluorodeoxyglucose (FDG) Positron Emission Tomography (PET)
Abstract number :
2.16
Submission category :
5. Neuro Imaging / 5B. Functional Imaging
Year :
2021
Submission ID :
1826755
Source :
www.aesnet.org
Presentation date :
12/5/2021 12:00:00 PM
Published date :
Nov 22, 2021, 06:56 AM
Authors :
Zuzana Balazova, MD - Faculty of Medicine, Masaryk University Brno, Czech Republic; Siti Yaakub - King's College London; Colm McGinnity - King's College London & Guy's and St Thomas' PET Centre - King's College London; Alexander Hammers - Professor (Hon. Consultant) of Imaging and Neuroscience, King's College London & Guy's and St Thomas' PET Centre, King's College London
Rationale: In patients with epilepsy, depression is the most frequent psychiatric comorbidity with prevalence ranging from 20 to 55%. [18F]fluorodeoxyglucose positron emission tomography (FDG PET) imaging is routinely used in presurgical evaluation of epileptic patients. In patients with depression, decreases in FDG uptake have been described, mainly in the frontal lobes. However, there is a dearth of FDG studies of comorbid depression in epilepsy. It is not known whether the presence of depression might impact on clinical reporting of FDG PET.
Methods: As part of a larger ongoing study comparing FDG PET/CT with PET/MR, 14 patients (8 women; median age 32 years, IQR 25-51 years) underwent 15 minutes of FDG PET/CT scanning as part of their presurgical investigations on a GE Discovery 710 scanner, starting ~30 minutes after injection of a median of 223 MBq (IQR 214-236) of FDG. On the same day, they filled in a Beck Depression Inventory-II (BDI-II) questionnaire.
FDG PET was preprocessed with Statistical Parametric Mapping software (SPM12) and regressed against BDI-II scores with the non-parametric SnPM12, controlling for global uptake via ANCOVA and thresholding at p< 0.001.
We also created average images of patients with minimal/mild versus moderate/severe BDI-II ratings. Images were read clinically on a Hermes workstation using a custom 20-point colourscale, with two clinicians (ZB and AH) blinded to diagnosis and BDI-II score independently predicting depression status.
Results: Patients had median BDI-II scores at the upper end of the “minimal depression” range (12.5, IQR 2-23, range 0-50). Eight of the 14 patients scored in the range for “minimal” depressive scores (0-13), 1/14 “mild” (14-19), 2/14 “moderate”(20-28) and 3/14 “severe”(29-63).
Higher BDI-II scores correlated negatively with FDG uptake in bilateral dorsolateral frontal lobes, with maximal pseudo-T scores of 5.00 (not significant after correction for multiple comparisons). There was no positive correlation of FDG uptake with BDI-II scores anywhere in the brain.
Average images also showed bifrontal decreases in FDG uptake in both lateral and medial cortices in the moderate/severe group, with less marked decreases elsewhere (Figure).
Visual reading of the images, blinded to BDI-II score, and dichotomising into minimal/mild and moderate/severe depression showed moderate agreement between the two raters (rho 0.28, p 0.12) and no significant correlation with actual BDI-II scores.
Conclusions: 1) Moderate and severe depressive symptoms were detected in 5/14 (36%) of presurgical epilepsy patients, indicating need for further assessment.
2) Decreases of frontal uptake as a correlate of depressive symptoms were confirmed in presurgical epilepsy patients.
3) It is unlikely that the presence of depressive symptoms would influence clinical assessment of FDG PET.
Funding: Please list any funding that was received in support of this abstract.: Erasmus KA103.
Neuro Imaging