White matter lesions on magnetic resonance imaging in dementia with Lewy bodies, Alzheimer's disease, vascular dementia, and normal aging

摘要

OBJECTIVES—Alzheimer'sdisease and vascular dementia are associated with an increase inchanges in white matter on MRI. The aims were to investigate whetherwhite matter changes also occur in dementia with Lewy bodies and toexamine the relation between white matter lesions and the cognitive andnon-cognitive features of dementia with Lewy bodies, Alzheimer'sdisease, and vascular dementia.
METHODS—Protondensity and T2 weighted images were obtained on a 1.0 Tesla MRI scannerin patients with dementia with Lewy bodies (consensus criteria; n=27,mean age=75.9 years), Alzheimer's disease (NINCDS/ADRDA; n=28, meanage=77.4 years), vascular dementia (NINDS/AIREN; n=25, mean age=76.8years), and normal controls (n=26, mean age=76.2 years). Cognitivefunction, depressive symptoms, and psychotic features were assessedusing a standardised protocol. Periventricular hyperintensities (PVHs),white matter hyperintensities (WMHs) and basal ganglia hyperintensities(BGHs) were visually rated blind to diagnosis using a semiquantitative scale.
RESULTS—Periventricularhyperintensities were positively correlated with age and were moresevere in all dementia groups than controls. Total deephyperintensities scores (WMHs plus BGHs) were significantly higher inall dementia groups than controls and higher in patients with vasculardementia than those with dementia with Lewy bodies or Alzheimer'sdisease. In all patients with dementia, frontal WMHs were associatedwith higher depression scores and occipital WMHs were associated withan absence of visual hallucinations and delusions.
CONCLUSION—Incommon with Alzheimer's disease and vascular dementia, PVHs and WMHswere significantly more extensive in dementia with Lewy bodies than incontrols. This overlap between different dementias may reflect sharedpathological mechanisms. The link between frontal WMHs and depressionand the absence of occipital WMHs and psychotic symptoms has importantimplications for understanding the neurobiological basis of these symptoms.