Authors :
Presenting Author: Mina Oates, BA – University of Alabama at Birmingham
Ayushe Sharma, PhD – Yale University School of Medicine
Yun Lien, MS – University of Alabama at Birmingham
Jane Allendorfer, PhD – University of Alabama at Birmingham
Jerzy Szaflarski, MD, PhD – University of Alabama at Birmingham
Rationale:
The mechanisms underlying the bidirectional relationship between epilepsy and mental health are not well understood. Arterial spin labelling (ASL) is a non-invasive MRI technique for mapping cerebral perfusion. Atypical perfusion patterns have been implicated in both epilepsy and depressive disorders. To date, studies investigating perfusion using ASL in patients with epilepsy and comorbid mood disorders have not been conducted. The goal of this study was to investigate the link between cerebral perfusion and mood disturbances in patients with temporal lobe epilepsy (TLE).
Methods:
33 patients with TLE and 27 healthy controls (HCs) completed the Profile of Mood States (POMS) questionnaire and underwent 3T MRI. 2D pASL scans were acquired using a Proximal Inversion with Control of Off-Resonance Effects (PICORE) labeling scheme. 60 pairs of label/control images were collected in the axial direction at a single inversion time of 1800ms, TR=2500ms, TE=16.18ms. Images were processed using the Bayesian Inference for Arterial Spin Labeling (BASIL) toolset in FMRIB Software Library (FSL). The majority of TLE patients had left ictal onset, and those with right ictal onset were flipped (affected vs. unaffected TL). Voxelwise general linear models were constructed in FSL with total mood disturbance (POMS-TMD) or depression-dejection subscale scores (POMS-D), age, and seizure-free status as covariates. P-values were uncorrected for multiple comparisons. A bilateral mesial temporal lobe mask was used for all tests.
Results:
After controlling for seizure control status and age, TLE patients showed significantly lower perfusion than HCs in the affected temporal pole and fusiform gyrus. TLE patients had higher POMS-D scores (t(58)=-3.65, p< 0.001) and POMS-TMD scores (t(58)=-4.13, p< 0.001) than HCs. There were positive main effects of POMS-D and POMS-TMD on perfusion throughout the bilateral medial temporal lobe, and negative main effects in the bilateral temporal poles. The correlation between perfusion and both POMS-D and POMS-TMD was stronger for TLE than for HCs in unaffected temporal regions. Conversely, the correlation of perfusion and both POMS-D and POMS-TMD was stronger for HCs than for TLE in affected temporal regions.