Dados do Trabalho

Título

INDEPENDENT EFFECTS OF MAJOR DEPRESSIVE DISORDER AND PHARMACORESPONSE ON AMYGDALAR T2 SIGNAL IN TEMPORAL LOBE EPILEPSY

Introdução

Temporal lobe epilepsy (TLE) is frequently associated with antiseizure medication (ASM) resistance, while major depressive disorder (MDD) is a frequent psychiatric comorbidity. The amygdala plays a role in both disorders and T2 signal changes might help to better understand the coexistence of these diseases.

Objetivo

To evaluate the effects of ASM-response and MDD on the T2 signal changes in TLE.

Método

We included 119 individuals: MDD*responsive (n=10), MDD*ASM-resistant (n=19), no-MDD*responsive (n=12), no-MDD*ASM-resistant (n=17), MDD-only (n=26) and controls (n=35). Using Aftervoxel software (http://www.bergo.eng.br/academic/aftervoxel/), we performed relaxometry in T2 coronal multi-echo images (two slices of 3-mm thick) acquired at a 3T MRI scanner. MDD diagnosis followed DSM-V criteria. We performed generalized linear model with log link function, including MDD and pharmacoresponse as main effects and MDD*pharmacoresponse interaction, with sex, amygdalar volume and total intracranial volume as covariates. Partial correlation was used to explore the relationship between ipsilateral T2 signal and Beck Depression Inventory (BDI) scores, controlling for scholarity, age and seizure frequency. We used Holm Sidak to adjust for multiple comparisons, with p<0.05 as significant.

Resultados

There was an independent effect of MDD and pharmacoresponse on the ipsilateral amygdalar T2-signal (both p<0.001), but no MDD*ASM-response interactions (p=0.3), meaning both effects follow similar trajectories. When compared to no-MDD, we found increased ipsilateral T2-signal in patients with MDD, as well as increased T2-signal in both ASM-responsive and ASM-resistant when compared to controls and in ASM-resistant when compared to ASM-responsive (all p<0.001). We found an effect of pharmacoresponse (p<0.001) on the contralateral T2-signal, but no effect of MDD (p=0.37) nor pharmacoresponse*MDD (p=0.49). We found increased T2-signal in responsive and ASM-resistant patients compared to controls (p<0.01), regardless presence of MDD. Neither amygdalar volume nor sex significantly adjusted ipsi- and contralateral amygdalar T2-signal models (all p>0.1). We found a positive correlation between the ipsilateral T2 signal and BDI scores (r=0.31 p=0.03).

Conclusões

Our data suggest a bilateral effect of pharmacoresponse and only an ipsilateral effect of MDD in increased T2 signal in the amygdala of TLE patients, regardless amygdalar volume or sex.