Influence of Confluent White Matter Hyperintensities on the Mechanics of Memory

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Christen Rui En Teo
Yi Jin Leow
Dilip Kumar
Kandiah Nagaendran



Dementia affects approximately 55 million people worldwide and is characterised by cognitive function deterioration in areas like attention and memory. Given the high prevalence of dementia and its contribution to significant psychiatric morbidity globally, it is a critical health issue in geriatric care.

White matter hyperintensities (WMH) are associated with an increased risk of dementia and cognitive impairment. Confluent WMH (C-WMH), with larger WMH volumes, are associated with greater cognitive decline than non-confluent WMH (NC-WMH).

Presently, the pathogenesis of cognitive impairment due to WMH remains largely unknown. A better understanding of the type of memory loss in C-WMH would allow for earlier detection of individuals at risk of cognitive decline and opportunities for early interventions to slow down memory loss.


To identify the stage(s) of memory (attention, encoding, and retrieval) affected in non-demented individuals with and without C-WMH in a Southeast Asian population.


In this cross-sectional study, 496 non-demented adults were recruited from Singapore. Using magnetic resonance imaging, they were classified as either having C-WMH or NC-WMH based on the Staals’ criteria. Neuropsychological assessment tests were conducted to assess the global cognition scores and attention, encoding, and retrieval abilities of the subjects. A one-way ANCOVA with Bonferroni correction for age and years of education was performed.


Individuals with C-WMH had significantly lower global cognition scores and significantly worse encoding abilities (P=0.037) compared to those with NC-WMH. However, the attention (P=0.813) and retrieval abilities (P=0.215) were not significantly different in C-WMH & NC-WMH adults.


C-WMH is associated with significantly poorer performances in encoding abilities, but not in attention and retrieval, even in adults without dementia. Understanding the specific stage of memory affected in C-WMH individuals could help guide cognitive training interventions for non-demented individuals with pre-existing WMH to reduce the future risk of cognitive decline.

Article Details

How to Cite
Teo, C. R. E., Leow, Y. J., Kumar, D., Vipin, A. and Nagaendran, K. (2023) “Influence of Confluent White Matter Hyperintensities on the Mechanics of Memory”, Journal of Asian Medical Students’ Association. Kuala Lumpur, Malaysia. Available at: (Accessed: 21May2024).
Scientific Papers (AMSC 2023 Taiwan)


(1) Shin J-H. Dementia Epidemiology Fact Sheet 2022. Annals of Rehabilitation Medicine. 2022 Apr 30;46(2):53–9.

(2) Wardlaw JM, Valdés Hernández MC, Muñoz‐Maniega S. What are White Matter Hyperintensities Made of? Journal of the American Heart Association. 2015 Jun 15;4(6).

(3) Meng F, Yang Y, Jin G. Research progress on MRI for white matter hyperintensity of presumed vascular origin and cognitive impairment [Internet]. Frontiers. Frontiers; 2022 [cited 2023Mar29]. Available from:

(4) Kumar D, Vipin A, Wong B, Ng KP, Kandiah N. Differential effects of confluent and non-confluent white matter hyperintensities on functional connectivity in mild cognitive impairment. Brain Connectivity. 2020 Oct 14.

(5) Staals J, Makin SDJ, Doubal FN, Dennis MS, Wardlaw JM. Stroke subtype, vascular risk factors, and total MRI brain small-vessel disease burden. Neurology. 2014 Aug 27;83(14):1228–34.