Impact of homocysteine on cortical perfusion and cognitive decline in mild Alzheimer's dementia

Authors

  • C.-W. Huang,

    1. Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
    2. Department of Biological Science, National Sun Yat-sen University, Kaohsiung, Taiwan
    3. Center for Translational Research in Biomedical Sciences, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
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  • W.-N. Chang,

    1. Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
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  • S.-H. Huang,

    1. Department of Nuclear Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
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  • C.-C. Lui,

    1. Department of Radiology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
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  • N.-C. Chen,

    1. Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
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  • Y.-T. Chang,

    1. Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
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  • C.-C. Lee,

    1. Department of Radiology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
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  • C.-C. Chang,

    Corresponding author
    1. Department of Biological Science, National Sun Yat-sen University, Kaohsiung, Taiwan
    • Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
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  • A. Y. W. Chang

    Corresponding author
    1. Department of Biological Science, National Sun Yat-sen University, Kaohsiung, Taiwan
    2. Center for Translational Research in Biomedical Sciences, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
    • Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan
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Correspondence: C.-C. Chang, Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, 123 Ta-Pei Road, Niaosung, Kaohsiung 833, Taiwan (tel.: +886 7 731 7123 ext. 3389; fax: +886 7 735 1334; e-mail: neur099@adm.cgmh.org.tw), and A. Y. W. Chang, Department of Biological Science, National Sun Yat-sen University, Kaohsiung, Taiwan (tel.: +886 7 731 7123 ext. 8599; fax: +886 7 731 8762; e-mail: cgmf.kmc@gmail.com).

Abstract

Background and purpose

Elevated plasma total homocysteine level (tHcy) is associated with increased risk of dementia via increased white matter changes or reduction in cortical volume. Whether tHcy has an independent impact on regional perfusion and if it can predict a more rapid cognitive decline in mild Alzheimer dementia (AD) warrants investigation.

Methods

Eighty AD patients with a clinical dementia rating of 1 were enrolled. Their Cognitive Ability Screening Instrument (CASI) scores on enrolment and after 1 year of follow-up as well as their perfusion index (PI) from single photon emission computed tomography upon enrolment were analyzed.

Results

In cross-sectional analysis, elevated tHcy was associated with lower frontal PI independent of cerebrovascular risk factors (β = −0.35, = 0.009). The CASI scores correlated with temporo-parietal PI (Pearson r range 0.3–0.39, < 0.01) but not with tHcy or frontal PI. By longitudinal analysis, only tHcy level was related to a more rapid cognitive decline (odds ratio for executive function score 1.82; odds ratio for total CASI score 1.74).

Conclusions

Cognitive performance in mild AD can be reflected by hypo-perfusion of the temporo-parietal region while frontal hypo-perfusion may be mediated by tHcy. tHcy level is an independent risk factor for rapid cognitive decline, especially in the executive function.

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