title: Source-based morphometry reveals distinct patterns of aberrant brain volume in delusional infestation.
abstract: Little is known about the neural correlates of delusional infestation (DI), the delusional belief to be infested with pathogens. So far, evidence comes mainly from case reports and case series. We investigated brain morphology in 16 DI patients and 16 healthy controls using structural magnetic resonance imaging and a multivariate data analysis technique, i.e. source-based morphometry (SBM). In addition, we explored differences in brain structure in patient subgroups based on disease aetiology. SBM revealed two patterns exhibiting significantly (p<0.05, Bonferroni-corrected) lower grey and higher white matter volume in DI patients compared to controls. Lower grey matter volume was found in medial prefrontal cortex, anterior cingulate cortex, medial temporal lobe structures (parahippocampus and hippocampus), sensorimotor cortices, bilateral insula and thalamus and inferior parietal regions. Higher white matter volume was found in medial and middle frontal and temporal cortices, left insula and lentiform nucleus. Grey matter volume was abnormal in both "psychiatric" (primary DI and DI associated with an affective disorder) and "organic" DI (DI due to a medical condition). In contrast, aberrant white matter volume was only confirmed for the "organic" DI patient subgroup. These results suggest prefrontal, temporal, parietal, insular, thalamic and striatal dysfunction underlying DI. Moreover, the data suggest that aetiologically distinct presentations of DI share similar patterns of abnormal grey matter volume, whereas aberrant white matter volume appears to be restricted to organic cases.
authors.affiliation: Center for Psychosocial Medicine, Department of General Psychiatry, University of Heidelberg, Germany. Electronic address: christian.wolf@med.uni-heidelberg.de.
authors.forename: Robert Ch
authors.initials: RCh
authors.lastname: Wolf
authors.forename: Markus
authors.initials: M
authors.lastname: Huber
authors.forename: Peter
authors.initials: P
authors.lastname: Lepping
authors.forename: Fabio
authors.initials: F
authors.lastname: Sambataro
authors.forename: Malte S
authors.initials: MS
authors.lastname: Depping
authors.forename: Martin
authors.initials: M
authors.lastname: Karner
authors.forename: Roland W
authors.initials: RW
authors.lastname: Freudenmann
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000473:pathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D010100:Oxygen / Q000097:blood; D012563:Schizophrenia, Paranoid / Q000209:etiology / Q000473:pathology* / Q000523:psychology
chemical_list: D010100:Oxygen
keywords: ANOVA; AP; DARTEL; DI; DSM-IV-TR; Delusional infestation; Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision; FOV; GIFT; GMV; Group ICA for fMRI Toolbox; ICA; Independent Component Analysis; Independent component analysis; MAP; MRI; Magnetic resonance imaging; PVE; SBM; Source-based morphometry; TD; TE; TIV; TR; Talairach Daemon; VBM; WMV; analysis of variance; anterior/posterior; delusional infestation; diffeomorphic anatomic registration through exponentiated lie algebra; echo time; field of view; grey matter volume; magnetic resonance imaging; maximum a posterior; partial volume estimation; repetition time; source-based morphometry; total intracranial volume; voxel-based morphometry; white matter volume