A whole-brain morphometry study of misophonia: comparing voxel-based and surface-based approaches

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Abstract Submission 

Nimesha Gerlus¹, Kevin LaBar¹, Andrada Neacsiu²

¹Duke University, Durham, NC, ²Duke University School of Medicine, Durham, NC

Nimesha Gerlus  
Duke University
Durham, NC

Kevin LaBar, Ph.D.  
Duke University
Durham, NC

Andrada Neacsiu, Ph.D.  
Duke University School of Medicine
Durham, NC

Misophonia is a disorder of decreased tolerance to specific sounds and their associated stimuli, which often evoke negative emotional responses and distress. Research on misophonia's neural correlates is needed to inform the development of novel interventions. Previous MRI studies have used voxel-based morphometry (VBM) to compare individuals with misophonia to individuals with no psychiatric history. This study investigated whether individuals with misophonia display different morphometric characteristics compared to a group of clinical controls. We also examined whether the estimation of group differences in whole-brain morphometry varies based on the utilization of surface-based morphometry (SBM) versus voxel-based techniques.

Participants were 27 adults with misophonia, and 27 adults with transdiagnostic emotion dysregulation and at least one DSM-V psychiatric disorder. All participants completed a T1-weighted MRI in a 3T scanner as part of a clinical neurostimulation trial. fMRIPrep was used to correct the bias field of the images. Freesurfer and FSL were respectively used for SBM and VBM analyses. General linear models were implemented to compare group differences in morphometry and controlled for the effects of estimated total intracranial volume. Vertex-wise and voxel-wise cluster-forming thresholds (p = 0.05) were established using permutation testing. All models were corrected for multiple comparisons at a cluster-wise threshold of p_corr = 0.05.

Compared to clinical controls, individuals with misophonia display significantly increased volume of the right primary auditory cortex (5980 vertices, p_corr = 0.03) using SBM. The SBM method also revealed significantly larger surface area in the left paracentral lobule (11707 vertices, p_corr = 0.01) and the right rostral superior temporal gyrus (11304 vertices, p_corr = 0.04) in the misophonia group compared to the clinical control group. Individuals with misophonia displayed larger surface area in the right superior frontal gyrus (7482 vertices); however, this region did not survive the cluster-wise correction (p_corr = 0.08). No significant between-group differences in morphometry were observed using VBM.

Although emotional distress underlies the behavioral phenotype of both participant groups, only participants with misophonia experience emotional distress associated with misophonic trigger sounds. In these individuals, surface-based but not voxel-based morphometric techniques show perceptual regions with greater surface area and volume compared to clinical controls with transdiagnostic emotion dysregulation. Therefore, SBM may detect structural abnormalities in the misophonic brain with greater sensitivity than VBM. Specifically, increased right auditory cortex volume using SBM distinguishes misophonic participants from clinical control participants without auditory affective processing deficits. Future directions include using SBM to further characterize distinct structural features of misophonia by comparing morphometry to that of non-clinical controls, as well as examining whether identified morphometric features are associated with self-reported misophonic symptoms.

Psychiatric (eg. Depression, Anxiety, Schizophrenia) ¹

Emotional Perception

Image Registration and Computational Anatomy ²

Univariate Modeling

Perception: Auditory/ Vestibular

ADULTS

Cortex

Emotions

Hearing

Morphometrics

Perception

Psychiatric Disorders

Somatosensory

STRUCTURAL MRI

Univariate