Psychische Erkrankungen in der Lebensspanne ... - DGPPN

Topic 12 G Bildgebung, Neurophysiologie, Neuropsychologie // Brain Imaging, neurophysiology, neuropsychology
± 13.7) completed over one year seven testing timepoints (baseline,
week 3, 6, 9, months 3, 6, 12). The neuropsychological test battery
covered all important cognitive domains (attention, executive functions,
memory, motor functions, language, and visuospatial functions)
by several well-established tests per domain. Additionally,
the impact of potential confounding variables – age, IQ, personality
– on the course of cognitive performance was explored.
Discussion / Results: The majority of tests exhibit a similar pattern:
(1) Significant and clinically relevant practice effects until month 3
(Cohen’s d 0.30-1.19) – with most pronounced effects towards the
second testing timepoint – and (2) a plateau after month 3. Exceptions
from these results uncovered either tests non-susceptible to
practice or hampered by ceiling effects. None of the ex plored covariates
showed consistent influence on the course of cognitive performance.
Conclusions: Practice effects play a major role in repetitive
cognitive testing. Using an optimal combination and timing of
tests will minimize their impact. On the other hand, rather than
interpreting measurable practice as disturbing factor, its course
should be employed for estimation of normal learning processes.
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EEG-based vigilance and cerebral glucose metabolism – a parallel
EEG and FDG PET study
Thomas Günther (Klinik für Psychiatrie, Neurobiologische Forschung,
Leipzig)
S. Hesse, K. Kendziorra, H. Barthel, C. Sander, S. Olbrich, M. Adamaszek,
G. Becker, O. Sabri, U. Hegerl, P. Schönknecht
Introduction: Patients with Alzheimer’s disease (AD) compared to
controls can be characterized by a pattern of reduced glucose metabolism
in temporoparietal, posterior cingulate, and frontal cortices
using 2-[18F]fluoro-2-deoxy-D-glucose (FDG) positron emission
tomography (PET). Sleep studies demonstrated an altered glucose
metabolism in some of the respective cortices during the transition
from wake to sleep. While sleep can be excluded during the examination,
drowsiness may still bias the glucose metabolism of these
patients during the FDG PET.
Method: In the present study, a preliminary sample of 10 patients
with probable AD (53-76 years, 3 women) was investigated with
simultaneous EEG PET (FDG). According to the drowsiness level
the sample was median split into a group with stable and unstable
EEG-vigilance, respectively. Imaging analyses were performed in
SPM5.
Discussion / Results: Patients with stable compared to unstable
EEG-vigilance showed an increased glucose metabolism in the lateral
superior temporal gyrus (p