Clinical significance of MRI white matter lesions in the elderly

The clinical relevance of white matter hyperintensities (WMH) seen on MRIs of elderly individuals is controversial. To resolve this issue, we performed MRI and neuropsychological testing on 46 healthy participants in the longitudinal Aging Process Study at the University of New Mexico. We graded the MRIs for severity of WMH using a scale tested on an elderly patient population. We found that 22% of normal subjects had moderate lesions and 9% had severe lesions. All subjects had normal neurologic examination findings and were within normal limits on a battery of neuropsychological tests. Neuropsychological performance decreased and the severity of WMH increased with age. However, when the data were corrected for age, there was no correlation between neuropsychological function and the presence of WMH. We conclude that white matter changes in the elderly by themselves are of doubtful clinical significance.