Decreased Activation Along the Dorsal Visual Pathway After... : Journal of Clinical Psychopharmacology (original) (raw)

Original Contributions

Decreased Activation Along the Dorsal Visual Pathway After a 3-Month Treatment With Galantamine in Mild Alzheimer Disease

A Functional Magnetic Resonance Imaging Study

Bokde, Arun L.W. PhD*†; Karmann, Michaela PhD*; Teipel, Stefan J. MD*; Born, Christine MD‡; Lieb, Martin MD*; Reiser, Maximilian F. MD‡; Möller, Hans-Jürgen MD*; Hampel, Harald MD, MSc*†

From the *Dementia and Neuroimaging Research Section, Alzheimer Memorial Center and Geriatric Psychiatry Branch, Department of Psychiatry, Ludwig-Maximilian University, Munich, Germany; †Discipline of Psychiatry, School of Medicine and Trinity College Institute of Neuroscience (TCIN), Trinity College, University of Dublin, The Adelaide & Meath Hospital Incorporating The National Children's Hospital (AMiNCH), Dublin, Ireland; and ‡Institute for Clinical Radiology, Ludwig-Maximilian University, Munich, Germany.

Received February 15, 2008; accepted after revision December 30, 2008.

Reprints: Arun L.W. Bokde, PhD, Discipline of Psychiatry, School of Medicine, Trinity College, Trinity Centre for the Health Sciences, The Adelaide and Meath Hospital, Incorporating The National Children's Hospital (AMiNCH), Dublin 24, Ireland (e-mail: [email protected]).

This study was an investigator-initiated project supported by an unrestricted grant from Janssen-Cilag GmbH (Neuss, Germany) to HH and ALWB.

Abstract

Visual perception has been shown to be altered in Alzheimer disease (AD) patients, and it is associated with decreased cognitive function. Galantamine is an active cholinergic agent, which has been shown to lead to improved cognition in mild to moderate AD patients. This study examined brain activation in a group of mild AD patients after a 3-month open-label treatment with galantamine. The objective was to examine the changes in brain activation due to treatment. There were 2 tasks to visual perception. The first task was a face-matching task to test the activation along the ventral visual pathway, and the second task was a location-matching task to test neuronal function along the dorsal pathway. Brain activation was measured using functional magnetic resonance imaging. There were 5 mild AD patients in the study. There were no differences in the task performance and in the cognitive scores of the Consortium to Establish a Registry for Alzheimer's Disease battery before and after treatment. In the location-matching task, we found a statistically significant decrease in activation along the dorsal visual pathway after galantamine treatment. A previous study found that AD patients had higher activation in the location-matching task compared with healthy controls. There were no differences in activation for the face-matching task after treatment. Our data indicate that treatment with galantamine leads to more efficient visual processing of stimuli or changes the compensatory mechanism in the AD patients. A visual perception task recruiting the dorsal visual system may be useful as a biomarker of treatment effects.