Mild cognitive impairment (MCI) and actual retrieval performance affect cerebral activation in the elderly

Heun, Reinhard; Freymann, Katrin; Erb, Michael; Leube, Dirk T.; Jessen, Frank; Kircher, Tilo T.; Grodd, Wolfgang

doi:10.1016/j.neurobiolaging.2006.01.012

« Previous Next »Neurobiology of Aging
Volume 28, Issue 3 , Pages 404-413, March 2007

Mild cognitive impairment (MCI) and actual retrieval performance affect cerebral activation in the elderly

Reinhard Heun
- Department of Psychiatry, University of Bonn, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany
- Department of Psychiatry, University of Birmingham, Mindelsohn Way, Birmingham B15 2QZ, UK
- Corresponding author. Tel.: +44 121 678 2360; fax: +44 121 678 2351.
Katrin Freymann
- Department of Psychiatry, University of Bonn, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany
Michael Erb
- Section on Experimental Magnetic Resonance of CNS, Department of Neuroradiology, University of Tuebingen, Hoppe-Seyler-Strasse 3, D-72076 Tuebingen, Germany
Dirk T. Leube
- Department of Psychiatry, University of Tuebingen, Osianderstrasse 24, 72076 Tuebingen, Germany
Frank Jessen
- Department of Psychiatry, University of Bonn, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany
Tilo T. Kircher
- Department of Psychiatry, University of Tuebingen, Osianderstrasse 24, 72076 Tuebingen, Germany
- Department of Psychiatry, RWTH Aachen University Hospital, Pauwelstr. 30, D-52074 Aachen, Germany
Wolfgang Grodd
- Section on Experimental Magnetic Resonance of CNS, Department of Neuroradiology, University of Tuebingen, Hoppe-Seyler-Strasse 3, D-72076 Tuebingen, Germany

Received 5 August 2005; received in revised form 16 January 2006; accepted 27 January 2006. published online 15 March 2006.

Abstract

Cerebral activation in the elderly may depend on general cognitive decline as well as actual retrieval performance. Consequently, activation between subjects with and without Mild Cognitive Impairment (MCI), and between remembered and non-remembered words was compared. Twenty-one MCI and 29 healthy control subjects learned 180 nouns. During retrieval, subjects had to discriminate these and 180 distractor words. fMRI identified response-related activation. Most retrieval-related activation was comparable in both groups. However, MCI subjects showed more activation in the prefrontal cortex than controls during processing of hits and correct rejections. Hits showed increased activation than misses in the precuneus and left lateral parieto-occipital cortex; misses showed more activation than correct rejections in the precuneus to cuneus. Verbal retrieval activated a large common network in the elderly independently of MCI. Increased activation in MCI subjects in prefrontal cortex depends on response category. Activation differences between response categories might reflect success (hits) and effort (misses). Increased retrieval-related activation may be used as early marker in subjects at risk of Alzheimer's disease.

Keywords: Mild cognitive impairment (MCI), Elderly, Functional imaging, Memory, Retrieval, Retrieval effort, Retrieval success