BRAIN VOLUME CHANGES AFTER WITHDRAWAL OF ATYPICAL ANTIPSYCHOTICS IN FIRST-EPISODE SCHIZOPHRENIA PATIENTS

Abstracts

samples t-tests were run to compare the number of intermediate and posterior sulci between groups. Results: Contrary to findings in chronic patients, there were no significant differences in the distribution of the three OFC Types between groups (FES patients: Type I = 46.4%, Type II = 26.6%, Type III = 27.1%; controls Type I = 56.3%, Type II = 16.7%, Type III = 27.1%). Similar percentages were found when left and right hemispheres were analyzed separately. However, significantly fewer intermediate rostral sulci were observed in the left hemisphere of patients compared to controls (t(117) = − 2.09, p < .05). Discussion: Our findings showed OFC Type III was not more common in FES patients in comparison to healthy controls, suggesting chronicity or stage of illness may be a dependent factor. However, given that OFC sulcogyral folding patterns are determined during early neurodevelopment, it is more likely that OFC Type III is a risk factor for poor social and functional outcome in general. The finding of fewer intermediate sulci in the left hemisphere may reflect underdevelopment of the neural system in that area, which is in line with findings of abnormal sulcal morphometry in the left cingulate of schizophrenia patients (Yücel et al., 2002). Further investigation into the relationship between social functioning and OFC pattern Type is needed and should encompass not only schizophrenia cohorts but other clinical populations as well.

doi:10.1016/j.schres.2010.02.320

Poster 93 BRAIN VOLUME CHANGES AFTER WITHDRAWAL OF ATYPICAL ANTIPSYCHOTICS IN FIRST-EPISODE SCHIZOPHRENIA PATIENTS Geartsje Boonstra1,3, Neeltje E.M. van Haren1, Hugo G. Schnack1, Wiepke Cahn1, Huibert Burger1,2,3, Maria Boersma1, Diederick E. Grobbee1,2, Hilleke E. Hulshoff Pol1, Rene S. Kahn1 1 UMCU Utrecht, Utrecht, Netherlands; 2UMCG Groningen, Groningen, Netherlands; 3Julius Centre Utrecht, Utrecht, Netherlands Background: The influence of antipsychotic medication on brain morphology in schizophrenia may confound interpretation of brain changes over time in patients. We aimed to assess the effect of discontinuation of atypical antipsychotic medication on change in brain volume in patients with a schizophrenic disorder. Methods: Sixteen remitted, stable first-episode patients with schizophrenia, schizoaffective or schizophreniform disorder and twenty healthy controls, group-matched for age and sex, were included. A Magnetic Resonance Imaging scan was obtained of all patients and controls at baseline and at one year follow-up. The patients either discontinued (n=8) their atypical antipsychotic medication (risperidone, olanzapine or quetiapine) or not (n=8) during the follow-up period. Intracranial volume and volumes of total brain, cerebral gray and white matter, cerebellum, third and lateral ventricle, nucleus caudatus, nucleus accumbens and putamen were obtained. Multiple linear regression analyses were used to assess the influence of discontinuation of atypical antipsychotics on brain volume (change), while correcting for age, gender and intracranial volume. Main effect of group (patientcontrol) and effect of discontinuation (yes-no) were investigated. Results: Decrease in cerebral gray matter and caudate nucleus volume over time was significantly more pronounced in patients relative to controls (p= 0.04 and p = 0.03, respectively). Additionally, nucleus accumbens volume increase over time was more pronounced in controls as compared to patients (p= 0.05). Furthermore, cerebral white matter volume in patients showed a larger increase over time as compared to controls (p= 0.02). Comparing patients on and off antipsychotic medication showed significant differences in change over time in volumes of the nucleus accumbens and putamen. The

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nucleus accumbens and putamen volumes decreased during the interval in medication-free patients while increases were found in patients that continued their antipsychotics (nucleus accumbens: p = 0.04; putamen: p = 0.001). Discussion: We confirmed earlier findings of gray matter volume decrements in patients with schizophrenia in comparison to normal controls. Importantly, discontinuation of atypical antipsychotics was related to volume decrease over time in the putamen and nucleus accumbens. This suggests that increases seen in the basal ganglia as a result of starting typical antipsychotic medication, also occur in atypical medication and are reversed by medication discontinuation.

doi:10.1016/j.schres.2010.02.321

Poster 94 CORTICAL THICKNESS IN PATIENTS WITH SCHIZOPHRENIA AND THEIR SIBLINGS Heleen B.M. Boos, Wiepke Cahn, Neeltje E.M. Van Haren, Eske M. Derks, Rachel M. Brouwer, Hugo G. Schnack, Hilleke E. Hulshoff Pol, Rene S. Kahn Rudolf Magnus Institute of Neuroscience, Dept. of Psychiatry, University Medical Center Utrecht Utrecht, Utrecht, Netherlands Background: Brain imaging studies have consistently demonstrated brain abnormalities in patients with schizophrenia. However, it is unknown whether these are caused by genetic and/or disease related factors¹. As the heritability to develop the illness is around 80%, with first-degree relatives to share approximately 50% of their genetic variants, brain abnormalities may also be present in (healthy) first-degree relatives of patients with schizophrenia. This large MRI study examined cortical thickness in patients with schizophrenia as well as their non-psychotic siblings and compared them to healthy control subjects. Methods: From 193 patients with schizophrenia [age (mean/sd) = 26.90/5.58; male % = 81], 208 non-psychotic siblings [age (mean/ sd) = 27.54/6.76; male % = 46] and 136 healthy control subjects [age (mean/sd) = 27.53/8.24; male % = 50] whole brain scans were obtained on a 1.5 T Achieva scanner. In-house software2 was used to segment total brain (TB), gray matter (GM) and white matter (WM) of the cerebrum, lateral and third ventricle and cerebellum volumes. For each subject, cortical thickness (CortT) was calculated for every vertex3. Group differences in volumes were analysed by applying a Mixed Models approach. Differences in CortT were calculated using regression analyses with age, gender and handedness as covariates. Analyses were implemented in Mx. Results: Brain volume reductions in TB, GM and WM and increments in lateral and third ventricle volumes were found in patients with schizophrenia but not in non-psychotic siblings as compared with healthy control subjects. Moreover, in patients decreases in CortT were found in the frontal and temporal cortices and to a lesser extent in the occipital and parietal cortices. Nonpsychotic siblings of patients with schizophrenia were no different from healthy control subjects. Discussion: This study shows differences in cortical thickness in patients with schizophrenia but not in their non-psychotic siblings. This suggests that in schizophrenia cortical changes are mainly caused by disease-related factors. References: 1Hulshoff Pol et al., 2002. Am J Psychiatry 159(2): 244-50 2Schnack et al., 2001. Neuroimage (13): 230-7 3Software: McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal. doi:10.1016/j.schres.2010.02.322