Impairment in Proverb Interpretation as an Executive Function Deficit in Patients with Amnestic Mild Cognitive Impairment and Early Alzheimer's Disease

Background/Aims: Proverb interpretation is assumed to reflect executive functions. We hypothesized that proverb interpretation is impaired in patients with amnestic mild cognitive impairment (aMCI) diagnosed as single-domain impairment by common neuropsychological testing. Methods: We compared performance in a proverb interpretation test in single-domain aMCI patients and patients with early Alzheimer’s disease (EAD). Results: The groups with aMCI and EAD performed significantly worse than healthy controls. Both patient groups gave concrete answers with a similar frequency. However, patients with EAD tended to give senseless answers more frequently. Conclusions: Our data suggest that in patients diagnosed as single-domain aMCI, deterioration of executive functions is detectable with subtle and appropriate neuropsychological testing. Implementation of these procedures may improve the early prediction of AD

cKit Lineage Hemogenic Endothelium-Derived Cells Contribute to Mesenteric Lymphatic Vessels

Peer reviewe

Perisylvian white matter connectivity in the human right hemisphere

Background By using diffusion tensor magnetic resonance imaging (DTI) and subsequent tractography, a perisylvian language network in the human left hemisphere recently has been identified connecting Brocas's and Wernicke's areas directly (arcuate fasciculus) and indirectly by a pathway through the inferior parietal cortex. Results Applying DTI tractography in the present study, we found a similar three-way pathway in the right hemisphere of 12 healthy individuals: a direct connection between the superior temporal and lateral frontal cortex running in parallel with an indirect connection. The latter composed of a posterior segment connecting the superior temporal with the inferior parietal cortex and an anterior segment running from the inferior parietal to the lateral frontal cortex. Conclusion The present DTI findings suggest that the perisylvian inferior parietal, superior temporal, and lateral frontal corticies are tightly connected not only in the human left but also in the human right hemisphere

Changes in cortical activation during retrieval of clock time representations in patients with mild cognitive impairment and early Alzheimer's disease

OBJECTIVE: We investigated healthy controls (HCs), and patients with mild cognitive impairment (MCI) and early Alzheimer's disease (AD) to identify neuronal correlates of clock time representation and changes resulting from neurodegenerative processes using functional magnetic resonance imaging. METHODS: Two clock-specific tasks demanding conceptual knowledge of clock hands, i.e. a minute hand and an hour hand task, were compared with a semantic control task. RESULTS: We observed that the minute hand task provoked a stronger activation of areas in the parietal lobes known to be involved in spatial mental imagery, while the semantic task primarily activated regions of the superior temporal lobes associated with verbal conceptual knowledge. The performance of the MCI group did not differ from that of the HC group, but additional activation was found in several brain regions. Decreased activation was detected during the minute hand task in the right middle temporal gyrus. Patients with early AD showed deteriorated performance in both clock tasks along with reduced activation in the occipital lobes and the left fusiform gyrus. Additional activation was detected in the precuneus. CONCLUSIONS: The fusiform gyrus might be crucial for the visual-semantic retrieval of clock time representation. In patients with early AD, access to this visual-semantic knowledge appears to be reduced