PSYCHIATRIC WANDERING BEHAVIOR IN DEMENTIA PATIENTS CORRELATED WITH INCREASED STRIATAL DOPAMINE D-2 RECEPTOR AS SHOWN BY [C-11] YM-09151-2 AND POSITRON EMISSION TOMOGRAPHY

It is known that some demented patients show psychiatric symptoms and behavioural abnormalities such as wandering, However, how such behavio ural abnormalities are correlated with brain function is unclear, In t his study, the relationship between the dopaminergic receptor and psyc hiatric wandering behaviour in dementia was examined, Nine probable Al zheimer's disease (AD) patients with the NINCDS-ADRDA criteria, nine v ascular dementia (VD) patients with the NINDS-AIREN criteria and six a ge-matched controls were studied, Four of each of the dementia group s howed psychiatric wandering behaviour, The dopamine D-2 receptor was a ssessed using the radiolabeled D-2 antagonist, [C-11]YM-09151-2, and p ositron emission tomography (PET), A three-compartment analysis using the metabolite-corrected (with HPLC) plasma radioactivity curve was pe rformed for the calculation of receptor kinetics, Time-activity curves of the striatum were obtained, Two-way analysis of variance showed th at there was a significant difference in the k(3)/k(4) value between t he groups (normal, VD and AD) considering the effect of wandering beha viour (wanderers or not), Post hoc test indicated that the values for AD and VD were greater than those of the controls. Since the k(3)/k(4) value was equal to the binding potential under the tracer condition, the result indicated that psychiatric wandering behaviour of dementia was correlated with increased dopamine D-2 receptors.