Alzheimer Disease: Salonen O

Ylikoski R, Jokinen H, Andersen P, Salonen O, Madureira S, Ferro J, Barkhof F, van der Flier W, Schmidt R, Fazekas F, Scheltens P, Waldemar G, Salvadori E, Pantoni L, Inzitari D, Erkinjuntti T, Anonymous00192. · Memory Research Unit, Department of Neurology, University of Helsinki, Helsinki, Finland. · Dement Geriatr Cogn Disord. · Pubmed #17565216 No free full text.

Abstract: BACKGROUND/AIMS: The Alzheimer's Disease Assessment Scale cognitive subscale (ADAS-cog) is a widely used rating instrument. The Vascular Dementia Assessment Scale cognitive subscale (VADAS-cog) includes additional tests reflecting mental speed and executive functions. The objective of this study was to compare the results of the two scales among subjects with various degrees of white matter hyperintensities (WMHs). METHODS: In the multicentre, multinational Leukoaraiosis and Disability in the Elderly (LADIS) study, 616 non-disabled subjects between the ages of 65 and 84 were examined using MRI, the ADAS-cog and VADAS-cog. The WMH rating from the MRI divided the patients into groups of mild (n = 280), moderate (n = 187) and severe (n = 149) degrees of change. RESULTS: Covariance analysis controlling for the effect of age and education revealed that the ADAS-cog differentiated only the mild and severe WMH groups, while the differences between all three groups were highly significant with the VADAS-cog. CONCLUSIONS: The VADAS-cog significantly differentiated between all the white matter groups. In comparison, the ADAS-cog differentiated only severe changes. Accordingly, the VADAS-cog may be a more sensitive endpoint in studies of patients with white matter load and vascular burden of the brain.

Pohjasvaara T, Mäntylä R, Aronen HJ, Leskelä M, Salonen O, Kaste M, Erkinjuntti T. · Memory Research, University of Helsinki, Helsinki, Finland. · J Neurol Neurosurg Psychiatry. · Pubmed #10567490 links to  free full text

Abstract: OBJECTIVES: Stroke seems to be related to dementia more often than previously assumed and vascular factors are also related to Alzheimer's disease. The pathophysiology of poststroke dementia includes ischaemic changes in the brain, a combination of degenerative and vascular changes, and changes only related to Alzheimer's disease. Some cognitive decline recognised after a stroke may be due to pre-existing cognitive decline. The aim of this study was to determine the clinical and radiological determinants of prestroke cognitive decline. METHODS: The study group comprised 337 of 486 consecutive patients aged 55 to 85 years who 3 months after ischaemic stroke completed a comprehensive neuropsychological test battery; structured medical, neurological, and mental status examination; interview of a knowledgeable informant containing structured questions on abnormality in the cognitive functions; assessment of social functions before the index stroke; and MRI. RESULTS: Frequency of prestroke cognitive decline including that of dementia was 9.2% (31/337). The patients with prestroke cognitive decline were older, more often had less than 6 years of education, and had history of previous stroke. Vascular risk factors did not differ significantly between these two groups. White matter changes (p=0.004), cortical entorhinal, hippocampal, and medial temporal atrophy (p<0.001), cortical frontal atrophy (p=0.008); and any central atrophy (p<0.01), but not the frequencies or volumes of old, silent, or all infarcts on MRI differentiated those with and without prestroke cognitive decline. The correlates of prestroke cognitive decline in logistic regression analysis were medial temporal cortical atrophy (odds ratio (OR) 7.5, 95% confidence interval (95%CI) 3.2-18.2), history of previous ischaemic stroke (OR 4.4, 95% CI 1.8-10.6), and education (OR 0.9, 95% CI 0.8-0.9). CONCLUSIONS: History of previous stroke, but not volumes or frequencies was found to correlate with prestroke cognitive decline. Other associating factors were rather those usually associated with degenerative dementia: white matter changes and cerebral atrophy; and in multiple models medial temporal cortical atrophy and education. The possible overlap between two or more underlying diseases must be remembered in diagnosis and treatment of patients with vascular cognitive impairment.