Background/Aims: α-Synuclein (SNCA) may be a key factor in dopaminergic neurotransmission, reward processing, and neurodegeneration in Parkinson’s disease (PD). We investigated delay discounting of reward and caudate volume in SNCA gene duplication carriers before and after the development of PD. Methods: Participants were 7 presymptomatic SNCA duplication carriers who later developed PD (follow-up period: 5.4 years) and 10 matched non-carrier controls. At the follow-up assessment, patients received levodopa (l-DOPA) therapy. Delay discounting of reward was assessed with the Kirby discounting questionnaire. We measured the volume of the caudate nucleus and cerebral cortex using structural MRI and FreeSurfer software. Results: In the presymptomatic stage, carriers showed similar delay discounting and caudate volume to that of non-carrier controls. However, after the development of PD, we observed a significant elevation in delay discounting (impulsive decisions) and reduced caudate volume. There was no cortical atrophy. Conclusion: Impaired reward-related decision making and caudate volume loss are not detectable in the presymptomatic stage in SNCA duplication carriers. These behavioral and neuroanatomical alterations are observed after the development of clinical symptoms when there is extensive neurodegeneration. Study limitations include a small sample size as well as the potential confounding effect of general cognitive decline.
Copyright / Drug Dosage
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher or, in the case of photocopying, direct payment of a specified fee to the Copyright Clearance Center.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in goverment regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.