Veränderte Hirnperfusion während einer Planungsaufgabe bei Patienten mit Schizophrenie: eine funktionelle transkranielle Dopplersonographie-Studie

Abstract

There is evidence that executive functions are impaired in schizophrenia. Planning may be considered as one form of such complex functions, and deficits in planning abilities have been described in this disorder. Despite the importance of planning impairments in schizophrenia, there have been, to the best of our knowledge, no studies that examined brain perfusion during separate phases of a planning task. This distinction is important, because planning and execution of a plan in normals provoke distinct perfusion changes in the basal cerebral arteries. This functional transcranial Doppler sonography (fTCD) study compared the impact of a planning paradigm on cerebral blood flow velocity (CBFV) of the middle (MCA) and anterior (ACA) cerebral arteries in 14 patients with chronic schizophrenia and 20 healthy volunteers with similar sociodemographic variables. We assessed performance and CBFV during mental planning and movement execution. The main results were: (1) patients were unimpaired in planning times, but they showed longer movement execution times (p <0.01); (2) during mental planning, CBFV in the MCA increased less in patients as compared to healthy volunteers (p <0.005). In conclusion we found evidence of lower CBFV in the MCA during mental planning in chronic schizophrenia, which may suggest that neuronal activation in fronto-lateral cortical regions is impaired in this disease.