Neurodegenerative Research Program

The Neurodegenerative Research Program uses advanced quantitative MRI techniques to understand pathophysiological changes in the brain and improve clinical diagnosis.

The aim is to assess the utility of multimodal MR imaging in evaluating the brain in patients with various neurological disorders and to identify potential radiological biomarkers.

The program focuses on neuroimaging of the Parkinsonism, normal pressure hydrocephalus and dementia. The team utilises radiographic markers and multimodal MRI imaging to differentiate different types of parkinsonism and dementia, localize and characterize brain atrophy, midbrain and white matter changes, and quantitate microstructural and functional connectivity changes in the evaluation of clinical parkinsonism, gait and cognitive dysfunction. More information is available at the SGH MRI Research Lab

Neuromelanin-sensitive MRI (left), QSM (middle) and SMWI (right) in healthy subject (top) and PD patient (bottom). Neuromelanin hyperintensity was reduced while there was an increase of iron deposition in QSM and elevated SMWI signals in PD patient. Nigrosome-1 (yellow arrow) was clearly seen in healthy subject but was lost in PD patient.

Axial FLAIR, sagittal 3D SPACE and coronal MPRAGE (extreme columns) and axial color FA (mid panels) images of a patient with normal pressure hydrocephalus (left) demonstrating an enlarged Evans’ index >0.3, dynamic high velocity flow void in the patent cerebral aqueduct and an acute callosal angle. The splenial angle, a novel angular index for evaluation of normal pressure hydrocephalus, is narrowed on the axial color FA map when compared to that in the healthy elderly (right).

Contact

Please contact A/Prof Chan Ling Ling at chan.ling.ling@singhealth.com.sg for more information.

Publications:

1. Chan LL, Rumpel H, Yap K, Lee E, Loo HV, Ho GL, Fook-Chong S, Yuen Y, Tan EK. Case control study of diffusion tensor imaging in Parkinson's disease. J Neurol Neurosurg Psychiatry. 2007 Dec; 78(12): 1383–1386.
2. Chan LL, Ng KM, Rumpel H, Fook-Chong S, Li HH, Tan EK. Transcallosal diffusion tensor abnormalities in predominant gait disorder parkinsonism. Parkinsonism Relat Disord. 2014 Jan;20(1):53-9.
3. Tan WQ, Yeoh CS, Rumpel H, Nadkarni N, Lye WK, Tan EK, Chan LL. Deterministic Tractography of the Nigrostriatal-Nigropallidal Pathway in Parkinson's Disease. Sci Rep 2015 Dec 1;5:17283.
4. Wen MC, Ng SYE, Heng HSE, Chao YX, Chan LL, Tan EK, Tan LCS. Neural substrates of excessive daytime sleepiness in early drug naive Parkinson's disease: A resting state functional MRI study. Parkinsonism Relat Disord. 2016;24:63-8.
5. Ooi LQR, Wen MC, Ng SYE, Chia NSY, Chew IHM, Lee WL, Xu Z, Hartono S, Tan EK, Chan LL, Tan LCS. Increased activation of default mode network in early Parkinson’s with excessive daytime sleepiness. Increased Activation of Default Mode Network in Early Parkinson's With Excessive Daytime Sleepiness. Front Neurosci. 2019 Dec 12;13:1334.
6. Tan SYZ, Keong NCH, Malathi R, Li HH, Ooi LQR, Tan EK, Chan LL. Periventricular White Matter Abnormalities on Diffusion Tensor Imaging of Postural Instability Gait Disorder Parkinsonism. AJNR Am J Neuroradiol. 2019 Apr;40(4):609-613. doi: 10.3174/ajnr.A5993.
7. Fang E, Ann CN, Marechal B, Lim JX, Tan SYZ, Li HH, Gan J, Tan EK, Chan LL. Differentiating Parkinson’s disease motor subtypes using automated volume‐based morphometry incorporating white matter and deep gray nuclear lesion load. J Magn Reson Imaging. 2020 51(3):748-756.
8. Lee WL, Lee A, Li HH, Ong NYX, Keong N, Chen R, Chan LL. Callosal angle in idiopathic normal pressure hydrocephalus: small angular mal-rotations of the coronal plane affect measurement reliability. Neuroradiology 2021 Feb 5:1-9.
9. Fang E, Fartaria MJ, Ann CN, Maréchal B, Kober T, Lim JX, Ooi LQR, Chen C, Lim SL, Tan EK, Chan LL. Clinical Correlates of White Matter Lesions in Parkinson’s Disease Using Automated Multi-Modal Segmentation Measures. J Neurol Sci. 2021 May 31. Doi: 10.1016/j.jns.2021.117518
10. Chan LL, Chen R, Li H, Lee AJY, Go WY, Lee W, Lock C, Kumar S, Ng ASL, Kandiah N, Tan LCS, Tan EK, Keong NCH. The splenial angle: a novel radiological index for idiopathic normal pressure hydrocephalus. Eur Radiol. 2021 May 15. Doi: 10.1007/s00330-021-07871-4.