AUDITORY HALLUCINATIONS IN SCHIZOPHRENIA: AN INVESTIGATION OF ABNORMAL CORTICAL DIFFUSIVITY

AUDITORY HALLUCINATIONS IN SCHIZOPHRENIA: AN INVESTIGATION OF ABNORMAL CORTICAL DIFFUSIVITY

76 Abstracts / Schizophrenia Research 102/1–3, Supplement 2 (2008) 1–279 58 – AUDITORY HALLUCINATIONS IN SCHIZOPHRENIA: AN INVESTIGATION OF ABNORMAL...

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76

Abstracts / Schizophrenia Research 102/1–3, Supplement 2 (2008) 1–279

58 – AUDITORY HALLUCINATIONS IN SCHIZOPHRENIA: AN INVESTIGATION OF ABNORMAL CORTICAL DIFFUSIVITY

Marc Seal, Po Yin Tang, Mark Walterfang, Murat Yücel, Stephen Wood, Christos Pantelis Melbourne Neuropsychiatry Centre, The University of Melbourne, Carlton South, Victoria, Australia [email protected] Introduction: Auditory hallucinations (AH) are a common, severe and debilitating symptom of schizophrenia. While it is believed that AHs may be caused by abnormal cortical connectivity recent neuroimaging studies of AHs have produced inconclusive findings. The aims of this investigation were to establish a protocol for assessing cortical connectivity in vivo using DTI and to determine if the experience of AH in schizophrenia is associated with abnormal diffusivity in the temporal lobes. Methods: DTI data was acquired from two clinical samples of different duration of illness: First Episode [n = 11 First Episode Psychosis (FEP) and n = 9 age-matched Healthy Control (HC FEP)] and Chronic [(n = 14 Chronic Schizophrenia (CHR) and n = 14 age-matched Healthy Control (HC CHR)]. All participants were male and righthanded. The groups were compared on four measures of diffusivity [Fractional Anisotropy (FA), Axial Diffusivity (AD), Radial Diffusivity (RD) and Intervoxel Coherence (IC)] to and from functional areas of the auditory cortex. Results: Age-related differences in diffusivity were identified between diagnostic groups in measures of temporal lobe diffusivity (FA, AD and RD). No significant age-related changes were found in IC. Furthermore, individuals with AH demonstrated substantial decreases in FA and increases in IC with increasing duration of illness. Conclusions: This investigation identified age-related changes in diffusivity in temporal lobe tracts bilaterally associated with experience of AHs in schizophrenia. References [1] Allen P et al. (2008) The hallucinating brain: A review of structural and functional neuroimaging studies of hallucinations. Neurosciences and Biobehavioural Reviews, 32(1), 175-91. [2] Seal ML et al. (In Press) Abnormal white matter microstructure in schizophrenia: A voxelwise analysis of axial and radial diffusivity. Schizophrenia Research.

59 – EFECTS OF CHRONICITY AND ANTIPSYCHOTIC MEDICATION ON BRAIN ANATOMY IN A LARGE SAMPLE OF PATIENTS WITH SCHIZOPHRENIA: A VOXEL-BASED MORPHOMETRY STUDY

Paolo Brambilla 1 , Luisa Tomelleri 2 , Jogia Jigar 3 , Cinzia Perlini 1 , Marcella Bellani 1 , Adele Ferro 1 , Michele Tansella 1 , Sophia Frangou 3 1 University of Udine, Udine, Italy; 2 University of Verona, Verona; 3 Institute of Psychiatry, London [email protected] Introduction: It is now generally recognized that schizophrenia is associated with structural cerebral abnormalities. It remains unclear when they arise, if there is a progressive worsening of these changes with illness chronicity and if they are modified by antipsychotic treatment. We investigated in a large sample of patients with schizophrenia the presence of brain abnormalities and their relationship with the duration of illness Methods: 71 schizophrenic patients and 79 matched healthy participants underwent brain magnetic resonance imaging (MRI) scans. All images were processed with voxel based morphometry, using SPM5. Results: Compared to healthy participants, patients showed decrements in gray matter volume in the middle and inferior frontal gyrus on the left side and in the superior frontal gyrus on the right side. In addition, duration of illness was negatively associated with gray matter volume in the frontopolar regions bilaterally, on the temporal pole (BA 38) on the left and the caudal superior temporal gyrus on

the right (BA 22). Cumulative exposure to antipsychotics showed a positive correlation with right temporal volume in men only Conclusions: These findings add to the weight of evidence for structural abnormalities in prefrontal and temporal cortex associated with the duration of illness. Antipsychotic medication could ameliorate brain abnormalities linked with schizophrenia disease References [1] Kyriakopoulos M, Vyas NS, Barker GJ, Chitnis XA, Frangou S. A Diffusion Tensor Imaging Study of White Matter in Early-Onset Schizophrenia. Biol Psychiatry. 2007 Jul 27 [Epub ahead of print] [2] Andreone N, Tansella M, Cerini R, Versace A, Rambaldelli G, Perlini C, Dusi N, Pelizza L, Balestrieri M, Barbui C, Nosè M, Gasparini A, Brambilla P. Cortical white-matter microstructure in schizophrenia. Diffusion imaging study. Br J Psychiatry. 2007 Aug;191:113-9.

60 – DURATION OF UNTREATED ILLNESS AND BRAIN STRUCTURE CHANGES AT 6-YEAR FOLLOW-UP: THE EFFECT OF GENDER

Julia Lappin 1 , Kevin Morgan 2 , Simone Reinders 1 , Craig Morgan 1 , Paul Fearon 1 , Jolanta Zanelli 1 , Peter Jones 3 , Robin Murray 1 , Philip McGuire 1 , Paola Dazzan 1 1 Kings College London Institute of Psychiatry, London; 2 University of Westminster, London; 3 University of Cambridge, Cambridge, UK [email protected] Introduction: Both duration of untreated psychosis (DUP) and the prodrome have structural brain correlates in first episode psychosis (FEP) subjects. Together, prodrome and DUP comprise the duration of untreated illness (DUI). We examined how brain volume changes over time relate to DUI. Methods: 48 subjects, from an original cohort of 90 FEP patients, were re-scanned using Magnetic Resonance Imaging. Whole-braincorrected grey (GM) and white (WM) matter volume changes over follow-up were calculated. Results: Mean follow-up interval [6.3 (±0.9) years] did not differ between male (n=32) and female (n=16) subjects. Mean follow-up age was significantly less for males than females (p=0.005). No gender differences existed in DUP, DUI or prodrome. Shorter DUP correlated significantly with longer prodrome (=0.02). GM and WM matter decreases were observed at follow-up, with no difference by gender. Longer DUP was significantly associated with WM decrease (p=0.02), but not GM. Neither DUI nor prodrome was associated with WM or GM change. In males, longer DUP was significantly correlated with WM decrease (p=0.03). In females, shorter prodrome was significantly associated with WM decrease (p=0.009). Conclusions: WM decrease over six-year follow-up is associated with longer DUP, an effect more prominent in males than females. In females only, WM decrease is associated with a shorter prodrome. Symptom severity during DUI - less marked in the prodrome than in DUP – rather than duration alone, is related to structural changes, particularly in females. References [1] Lappin JM et al, Duration of prodromal phase and severity of volumetric abnormalities in first-episode psychosis.Br J Psychiatry Suppl. 2007 Dec;51:s123-7. [2] Lappin JM et al, Gray matter abnormalities associated with duration of untreated psychosis.