Prevalence of white matter hyperintensities and radiological cerebral small vessel disease: an insight from routinely collected data.

backgroundApproximately 900,000 MRI brain scans are performed annually in the United Kingdom alone, with incidental findings frequently encountered. One of the most prevalent findings is white matter hyperintensities (WMHs). WMHs often indicate cerebral small vessel disease (cSVD) but can also be associated with migraine and demyelination. Prospective population studies have already confirmed a high prevalence of WMHs in elderly patients. In younger patients, or when the radiological burden is low, WMHs are commonly considered non-specific. Routinely collected data represents a valuable resource to facilitate further study. We aimed to describe the prevalence of WMHs in a direct to scan referral population and to understand associations with age, demographics, performance status and referral criteria.

methodsWe performed a service evaluation of our local two-week wait suspected central nervous system cancer pathway to understand the association between age, demographics, performance status, referral criteria, imaging outcomes and both the prevalence and radiological characteristics of WMHs. Analysis was performed using R version 4.1.3.

resultsWe identified 1033 patients, referred over a 30-month period. Mean patient age was 51.3±18.3 years with 65% females. As expected, WMHs were present on 89.7% of scans in patients aged over 80, with 98.1% of these consistent with cSVD upon review by an experienced neuroradiologist. We show an important association between WMHs deemed representative of cSVD and both performance status and levels of deprivation. However, WMHs were also present in approximately 1 in 5 patients under 50 years old and were typically deemed non-specific. Our analysis showed prevalence of WMH, its radiological burden and likelihood of WMHs being attributed to cSVD all increased with age. It is therefore feasible to consider that these changes may represent early cSVD.

conclusionsWe demonstrate a prevalence of radiological cSVD comparable to the wider literature in elderly patients whilst highlighting the potential underestimation of cSVD in the younger population, in whom further study of WMHs is required. There is potential for routinely collected data to define the prevalence and characteristics of radiological cSVD more accurately whilst facilitating further research.