White Matter Hyperintensities in Frontotemporal Dementia Independent of Vascular Disease

Results of a study published in Neurology show that white matter hyperintensities (WMH), which are commonly linked to vascular health problems, are found in frontotemporal dementia (FTD). The study followed 64 people with FTD, 65 people with Alzheimer’s disease (AD), and 66 people without dementia for an average of 2 years. 

On brain MRI, the average WMH volume in participants with FTD was 0.6 mL compared with 0.40 mL in those with AD, and 0.12 mL in those without dementia. WMH volume was associated with the severity of FTD symptoms and effects on activities of daily living but not with vascular risk factors (eg, high blood pressure and high cholesterol). Higher WMH volume in the corpus callosum were associated with poorer cognitive performance in the domain of attention for participants with either FTD or AD. 

“We were expecting to see similar amounts of WMH in FTD and AD, but we actually found higher levels in people with FTD,” said study author Ramon Landin-Romero, PhD, University of Sydney, Australia. “We also expected to see that people with more severe disease would have more WMH, regardless of disease, but that was only true in FTD. These results suggest that WMH are partly independent of vascular factors and associated with the progressive loss of brain integrity, more specifically, the loss of brain cells due to frontotemporal dementia. White matter hyperintensities should be viewed as a core feature of frontotemporal dementia and Alzheimer’s disease that can contribute to cognitive problems, not simply a marker of vascular disease.” 

Over the course of the study, postmortem pathology studies became available for 13 participants with FTD and 5 with AD, which was too small a sample size to evaluate the molecular and cellular bases of the increased WMH volume found.