title: Hippocampal volume reduction in chromosome 22q11.2 deletion syndrome (22q11.2DS): a longitudinal study of morphometry and symptomatology.
abstract: Recent studies observed an association between the structural integrity of the hippocampal structure and the manifestations of clinically significant psychotic symptoms in participants at high risk for psychosis. The present study sought to investigate the longitudinal trajectory of the hippocampal volume and its subregions among a sample of participants affected by 22q11.2 deletion syndrome (22q11.2DS), a neurogenetic disorder associated with elevated risk for psychosis. We specifically investigated possible correlations between hippocampal volumes, as measured by magnetic resonance imaging (MRI), and the manifestation of positive psychotic symptoms (hallucinations and delusions). Regional hippocampal volumes were measured twice with cerebral MRI obtained at 3-year intervals in 30 healthy participants and 31 gender-matched 22q11.2 microdeletion carriers aged 6 to 22. We examined potential associations between psychotic symptom manifestations and volumetric parameters at both time points. We found a hippocampal body-driven significant reduction in hippocampal volume among patients with 22q11DS compared to controls. No significant group by time interaction for the total or the subregional volumes were observed. In patients, larger hippocampal head at baseline was associated with the presence of hallucinations at follow-up. We first discuss the reduced hippocampal body finding in light of potentially abnormal mesiocortical circuits. We further discuss the association between baseline hippocampal head volume in participants with 22q11DS as a possible marker related to the later unfolding of psychotic symptoms.
authors.affiliation: Department of Psychiatry, University of Geneva School of Medicine, 1 rue David Dufour, P.O. Box 50, CH-1211 Geneva 8, Switzerland.
authors.forename: Astrid
authors.initials: A
authors.lastname: Flahault
authors.forename: Marie
authors.initials: M
authors.lastname: Schaer
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Ottet
authors.forename: Martin
authors.initials: M
authors.lastname: Debbané
authors.forename: Stephan
authors.initials: S
authors.lastname: Eliez
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002394:Catechol O-Methyltransferase / Q000235:genetics; D002648:Child; D003702:Delusions / Q000209:etiology / Q000473:pathology; D004062:DiGeorge Syndrome / Q000150:complications / Q000473:pathology* / Q000523:psychology; D005260:Female; D006212:Hallucinations / Q000209:etiology / Q000473:pathology; D006624:Hippocampus / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D059906:Neuroimaging; D009929:Organ Size; D011618:Psychotic Disorders / Q000209:etiology / Q000473:pathology*
chemical_list: D002394:Catechol O-Methyltransferase