LEAD

Functional Amnesia - Neuropsychological and Neurobiological Findings

Hans J. Markowitsch

Physiological Psychology, University of Bielefeld, Bielefeld, Germany

There is a multitude of causes which can lead to severe and lasting forms of amnesia. Aside from those triggered by direct infarct-, tumor-, or degeneration-based tissue damage, there are also congenital or perinatal forms as in developmental amnesias. Furthermore, amnesic conditions may occur in psychiatric patients as well. While most of the more traditionally recognized neurological disease conditions lead to anterograde memory, there are more rare examples of patients with selective retrograde amnesia. I will give examples of case descriptions of these patient groups, stressing the outcomes in a number of patients with dissociative or functional amnesia and emphasizing that even in these anterograde amnesia may occur (together with some other cognitive deficits). Recent advances in both static and functional brain imaging revealed that also in these patients significant changes may occur in their nervous tissue (compared to normal individuals). During the last years we studied about 50 patients with functional amnesia and documented their intellectual deficits as well as alterations in nervous tissue, obtained with functional (positron emission tomography, dynamic magnetic resonance imaging) and static imaging methods (static magnetic resonance imaging, diffusion tensor imaging).