Summary:The relationship between cognitive deterioration and abnormalities detected by magnetic resonance imaging (MRI) was investigated to determine the radiological correlates of cognitive deterioration in hereditary cerebral hemorrhage with amyloidosis- Dutch type (HCHWA-D). Twenty HCHWA-D subjects (12 patients who had suffered one or more strokes and eight who had not suffered a stroke) were studied with MRI and underwent extensive neuropsychological examination. On MRI the number of focal lesions was counted, and white matter hyperintensities (WMHs) were scored semiquantitatively. A significant correlation between cognitive deterioration and WMH score and number of focal lesions was found. However, cognitive deterioration, WMH score, and the number of focal lesions all increase with age, and therefore their mutual correlation can be explained as an age effect. This study shows that cognitive deterioration in HCHWA-D is not correlated with abnormalities detected by MRI (number of focal lesions and subcortical WMHs) independently of age. Although a contribution of white matter changes and/or focal lesions, possibly in combination with age, to cognitive deterioration cannot be excluded. Cognitive deterioration in these HCHWA-D patients is probably primarily the result of chronic damage of amyloid angiopathy to the brain, to which may be superimposed cognitive impairment from focal cerebral hemorrhage or infarction