P107. Disturbed fine motor performance is associated with altered structure and perfusion of the motor system in schizophrenia.

Introduction Motor symptoms are an integral part of the clinical presentation of schizophrenia and disturbances of fine motor function are frequent. However, only limited knowledge exists on the neural correlates of fine motor skills in schizophrenia. We implemented a complex fine motor task to test associations with whole brain gray matter (GM) volume as well as cerebral blood flow (CBF). We aimed to investigate whether patients with difficulties of fine motor performance would show structural and cerebral blood flow alterations in the motor loop. Methods In total 42 schizophrenia patients (59.5% men, mean age = 38.6 ± 11.4) diagnosed according to DSM-V underwent MR-neuroimaging. All patients but four received antipsychotic treatment. Parkinsonism was assessed using the motor part of the Unified Parkinson Disease Rating Scale (UPDRS). Fine motor skills were assessed using the coin rotation task. The task is to rotate a coin (.5 swiss francs) using three fingers of the left hand (thumb, index, middle) through serial 180-degree turns as rapidly as possible. Deficits are indicated by the reduced number of half turns and coin drops. We processed structural images using standard SPM8 procedures, in particular voxel-based morphometry (VBM) toolbox. Resting state CBF was measured by arterial spin labeling (ASL). ASL data was analyzed with our custom written MATLAB programs ( Federspiel et al., 2006; Walther et al., 2011 ). The main emphasis was to explore the effect of task performance on GM volume and CBF. Correlations of task performance (mean = 10.7 ± 4.1) and GM volume (covariates total intracranial volume and UPDRS) as well as CBF (covariate UPDRS) were calculated. A threshold of p - uncorr < 0.001 (min. cluster size = 17: equivalent to a map-wise false positive rate of alpha < 0.0001 using a Monte Carlo procedure) was applied. Results We found significant correlations of coin rotation scores and GM volume in the bilateral pre-supplementary motor area (pre-SMA) extending to the SMA, in the left primary motor cortex, the right superior frontal gyrus, bilateral the cerebellum and the left putamen. The pre-SMA cluster survived family wise error correction at cluster level. Significant correlations of CBF and the coin rotation scores were detected in the right SMA, the left primary motor cortex and in the right superior frontal gyrus (Area Fp1), the left inferior frontal gyrus and the right precuneus. Two clusters survived family wise error correction: right superior frontal gyrus and the left inferior frontal gyrus. Discussion Difficulties of fine motor task performance were associated with structural gray matter volume reduction in the motor loop, particularly in cortical motor control areas. In addition fine motor function in schizophrenia patients was linked with cerebral blood flow. These findings were corrected for parkinsonism. In sum, the results argue for specific alterations of the motor system in schizophrenia as source of impaired fine motor function beyond parkinsonism. [ABSTRACT FROM AUTHOR]