title: Gyrification of Broca's region is anomalously lateralized at onset of schizophrenia in adolescence and regresses at 2 year follow-up.
abstract: Gyrification of the human cerebral cortex starts in the foetus and progresses in early infancy; the pattern of folding in later life provides a lead to early developmental aberration. By studying gyrification at illness onset in adolescence we hoped to clarify the pathophysiology of schizophrenia. Here we find 1) an area of hypergyria includes Broca's area and extends into the Sylvian fissure to encroach on the anterior insula in the left hemisphere, and 2) an area of hypogyria in the superior temporal lobe approximates to Wernicke's area but is located in the right hemisphere and encroaches on the posterior insula. In Broca's/anterior insula area, right lateralization was present in healthy controls but patients were left lateralized: at two year follow-up gyrification had decreased in patients while it increased in controls, and the reduction predicted impaired category fluency. Progressive change was unaccompanied by cortical thinning (investigated only in the brain regions showing baseline changes in gyrification) indicating that the disease process affecting these brain regions (insula, inferior frontal and superior temporal) is not primarily degenerative. A deviation in the lateralized development of peri-Sylvian areas for language production and comprehension appears critical to the pathophysiology of schizophrenia and may point to its species-specific origin.
authors.affiliation: Division of Psychiatry, Institute of Mental Health, University of Nottingham, Nottingham NG7 2TU, UK; Nottinghamshire Healthcare NHS Trust, Nottingham, UK. Electronic address: Lena.Palaniyappan@nottingham.ac.uk.
authors.forename: L
authors.initials: L
authors.lastname: Palaniyappan
authors.affiliation: SANE-POWIC, University Department of Psychiatry, Warneford Hospital, Oxford OX3 7JX, UK.
authors.forename: T J
authors.initials: TJ
authors.lastname: Crow
authors.affiliation: Smith-Kettlewell Eye Research Institute, San Francisco, CA 94114, United States.
authors.forename: M
authors.initials: M
authors.lastname: Hough
authors.affiliation: FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, OX3 9DU UK.
authors.forename: N L
authors.initials: NL
authors.lastname: Voets
authors.affiliation: Division of Psychiatry, Institute of Mental Health, University of Nottingham, Nottingham NG7 2TU, UK.
authors.forename: P F
authors.initials: PF
authors.lastname: Liddle
authors.affiliation: Highfield Adolescent Unit, Warneford Hospital, Oxford OX3 7JX, UK.
authors.forename: S
authors.initials: S
authors.lastname: James
authors.affiliation: Highfield Adolescent Unit, Warneford Hospital, Oxford OX3 7JX, UK.
authors.forename: L
authors.initials: L
authors.lastname: Winmill
authors.affiliation: Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford OX3 7JX, UK.
authors.forename: A C
authors.initials: AC
authors.lastname: James
mesh_terms: D000293:Adolescent; D001931:Brain Mapping; D018450:Disease Progression; D005260:Female; D005625:Frontal Lobe / Q000473:pathology* / Q000503:physiopathology*; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D021621:Imaging, Three-Dimensional; D016014:Linear Models; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D012559:Schizophrenia / Q000473:pathology* / Q000503:physiopathology; D055815:Young Adult