%0 Journal Article %J J Alzheimers Dis %D 2018 %T Homocysteine and Cerebral Atrophy: The Epidemiology of Dementia in Singapore Study. %A Tan, Bryce %A Venketasubramanian, Narayanaswamy %A Vrooman, Henri %A Cheng, Ching-Yu %A Wong, Tien Yin %A Ikram, Mohammad Kamran %A Chen, Christopher %A Hilal, Saima %K Aged %K Atrophy %K Biomarkers %K Dementia %K Female %K Homocysteine %K Humans %K Magnetic Resonance Imaging %K Male %K Middle Aged %K Organ Size %K Risk Factors %K Singapore %K White Matter %X

BACKGROUND: Plasma homocysteine levels are increasingly studied as a potential risk factor for dementia. Elevated homocysteine levels have been linked with gray and white matter volume reduction among individuals with mild cognitive impairment and Alzheimer's disease. However, the effects of homocysteine on brain changes in preclinical stages of dementia remain unexplored.

OBJECTIVE: To examine the association of elevated homocysteine levels with markers of neurodegeneration, i.e., white and gray matter volume in an elderly population.

METHODS: The study included 768 participants (mean age: 69.6±6.5 years, 51.3% women) from the Epidemiology of Dementia In Singapore study. Participants underwent a brain MRI scan and blood tests. Serum homocysteine was measured using competitive immunoassay. Cortical thickness and subcortical structural volume were quantified using FreeSurfer whereas white matter volume was quantified using a previous validated method.

RESULTS: Higher homocysteine levels were significantly associated with decreased global white matter volume [mean difference (β) in volume (ml) per micromole per liter (μmol/l) increase in homocysteine levels: - 0.555, 95% Confidence Interval (CI): - 0.873; - 0.237], decreased parietal cortical thickness [β in thickness (μm) per μmol/l increase in homocysteine levels:- 1.429, 95% CI: - 2.781; - 0.077], and smaller volumes of the thalamus [β: - 0.017, 95% CI: - 0.026; - 0.008], brainstem [β: - 0.037, 95% CI: - 0.058; - 0.016], and accumbens [β: - 0.004, 95% CI: - 0.006; - 0.002].

CONCLUSION: Higher homocysteine levels were associated with cerebral atrophy. Further studies are required to assess whether lowering plasma homocysteine levels may prevent neurodegenerative changes or delay progression of clinical symptoms before the development of dementia.

%B J Alzheimers Dis %V 62 %P 877-885 %8 2018 %G eng %N 2 %1 http://www.ncbi.nlm.nih.gov/pubmed/29480177?dopt=Abstract %R 10.3233/JAD-170796 %0 Journal Article %J J Alzheimers Dis %D 2017 %T Neuroimaging Feature Terminology: A Controlled Terminology for the Annotation of Brain Imaging Features. %A Iyappan, Anandhi %A Younesi, Erfan %A Redolfi, Alberto %A Vrooman, Henri %A Khanna, Shashank %A Frisoni, Giovanni B %A Hofmann-Apitius, Martin %X

Ontologies and terminologies are used for interoperability of knowledge and data in a standard manner among interdisciplinary research groups. Existing imaging ontologies capture general aspects of the imaging domain as a whole such as methodological concepts or calibrations of imaging instruments. However, none of the existing ontologies covers the diagnostic features measured by imaging technologies in the context of neurodegenerative diseases. Therefore, the Neuro-Imaging Feature Terminology (NIFT) was developed to organize the knowledge domain of measured brain features in association with neurodegenerative diseases by imaging technologies. The purpose is to identify quantitative imaging biomarkers that can be extracted from multi-modal brain imaging data. This terminology attempts to cover measured features and parameters in brain scans relevant to disease progression. In this paper, we demonstrate the systematic retrieval of measured indices from literature and how the extracted knowledge can be further used for disease modeling that integrates neuroimaging features with molecular processes.

%B J Alzheimers Dis %V 59 %P 1153-1169 %8 2017 %G eng %N 4 %1 http://www.ncbi.nlm.nih.gov/pubmed/28731430?dopt=Abstract %R 10.3233/JAD-161148