Brain alterations in low-frequency fluctuations across multiple bands in obsessive compulsive disorder
Mònica Giménez1,2, Andrés Guinea-Izquierdo1,2,3, Victoria Villalta-Gil4,5
1Department of Psychiatry, Bellvitge University Hospital, Bellvitge Biomedical Research Institute (IDIBELL), Feixa Llarga s/n, 08907, L'Hospitalet de Llobregat, Barcelona, Spain.
Brain Imaging and Behavior
|October 25, 2016
Summary
This study reveals distinct patterns of brain activity in obsessive-compulsive disorder (OCD) by analyzing local low-frequency fluctuations. Findings highlight altered functional connectivity in frontal-subcortical circuits across different brain signal frequencies in OCD patients.
Area of Science:
- Neuroscience
- Psychiatry
- Medical Imaging
Background:
- Functional abnormalities in frontal-subcortical circuits are implicated in obsessive-compulsive disorder (OCD).
- Previous resting-state functional Magnetic Resonance Imaging (rs-fMRI) studies primarily focused on low-frequency (<0.08 Hz) between-region connectivity.
- The local attributes of the Blood Oxygen Level Dependent (BOLD) signal across various frequency bands in OCD remain underexplored.
Purpose of the Study:
- To investigate local alterations in low-frequency fluctuations across different oscillation bands in the brains of individuals with OCD.
- To examine the relationship between these local functional alterations and clinical variables in OCD.
Main Methods:
- Sixty-five patients with OCD and 50 healthy controls underwent resting-state functional Magnetic Resonance Imaging (rs-fMRI).
- Voxel-wise analysis of the fractional amplitude of low-frequency fluctuations (fALFF) was performed across four frequency bands (0.01 Hz to 0.25 Hz).
- Associations between fALFF values and clinical symptom severities were assessed.
Main Results:
- OCD patients exhibited decreased fALFF in medial orbitofrontal regions and increased fALFF in the dorsal-medial prefrontal cortex (DMPFC) at frequencies <0.08 Hz.
- At higher frequencies, this pattern reversed, with increased fALFF observed in medial temporal lobe structures and the medial thalamus.
- Clinical variables, specifically symptom severities, were significantly associated with fALFF values across different frequency bands.
Conclusions:
- The study provides novel insights into the regional distribution and nature of functional brain alterations in OCD across multiple frequency bands.
- Altered local BOLD signal attributes across different frequency bands may serve as a sensitive marker for characterizing brain dysfunction in OCD.
- Findings contribute to refining neurobiological models of OCD and suggest a promising avenue for future research in psychiatric disorders.
