title: Occipital bending (Yakovlevian torque) in bipolar depression.
abstract: Differing levels of occipital lobe asymmetry and enlarged lateral ventricles have been reported within patients with bipolar disorder (BD) compared with healthy controls, suggesting different rates of occipital bending (OB). This may exert pressure on subcortical structures, such as the hippocampus, reduced among psychiatric patients. We investigated OB prevalence in 35 patients with BD and 36 healthy controls, and ventricular and occipital volumes. Prevalence was four times higher among BD patients (12/35 [34.3%]) than in control subjects (3/36 [8.3%]), as well as larger lateral ventricular volumes (LVVs). Furthermore, we found OB to relate to left-to-right ventricular and occipital lobe volume (OLV) ratios. Those with OB also had reduced left-to-right hippocampal volume ratios. The results suggest that OB is more common among BD patients than healthy subjects, and prevalent in both BD Type I and Type II patients. We posit that anomalies in neural pruning or ventricular enlargement may precipitate OB, consequently resulting in one occipital lobe twisting around the other. Although the clinical implications of these results are unclear, the study suggests that asymmetrical ventricular volume matched with a pattern of oppositely asymmetrical occipital volume is related to OB and may be a marker of psychiatric illness.
authors.affiliation: Monash Alfred Psychiatry Research Centre, The Alfred & Monash University Central Clinical School, Melbourne, Victoria, Australia. Electronic address: jerome.maller@monash.edu.
authors.forename: Jerome J
authors.initials: JJ
authors.lastname: Maller
authors.affiliation: Monash Alfred Psychiatry Research Centre, The Alfred & Monash University Central Clinical School, Melbourne, Victoria, Australia.
authors.forename: Rodney
authors.initials: R
authors.lastname: Anderson
authors.affiliation: Monash Alfred Psychiatry Research Centre, The Alfred & Monash University Central Clinical School, Melbourne, Victoria, Australia.
authors.forename: Richard H
authors.initials: RH
authors.lastname: Thomson
authors.affiliation: Division of Clinical Sciences and Department of Surgery, Central Clinical School, Monash University, and Department of Neurosurgery, Alfred Hospital, Melbourne, Victoria, Australia.
authors.forename: Jeffrey V
authors.initials: JV
authors.lastname: Rosenfeld
authors.affiliation: Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, and Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Zafiris J
authors.initials: ZJ
authors.lastname: Daskalakis
authors.affiliation: Monash Alfred Psychiatry Research Centre, The Alfred & Monash University Central Clinical School, Melbourne, Victoria, Australia.
authors.forename: Paul B
authors.initials: PB
authors.lastname: Fitzgerald
mesh_terms: D000328:Adult; D000368:Aged; D001714:Bipolar Disorder / Q000175:diagnosis / Q000473:pathology* / Q000503:physiopathology; D016022:Case-Control Studies; D002552:Cerebral Ventricles / Q000473:pathology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009778:Occipital Lobe / Q000473:pathology* / Q000503:physiopathology; D009929:Organ Size; D019415:Torque
keywords: Bending; Bipolar disorder; Magnetic resonance imaging; Occipital; Torque