Alzheimer Disease: Ylikoski R

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.

Osipova D, Rantanen K, Ahveninen J, Ylikoski R, Häppölä O, Strandberg T, Pekkonen E. · Cognitive Brain Research Unit, Department of Psychology, University of Helsinki, Helsinki, Finland. <> · Neurosci Lett. · Pubmed #16854528 No free full text.

Abstract: Mild cognitive impairment (MCI) is a memory disorder often preceding Alzheimer's disease (AD). AD has been shown to be associated with abnormal generation of spontaneous electromagnetic activity. We investigated whether the cortical generation of spontaneous brain oscillations in MCI shows changes resembling those observed in AD. A minimum current estimates algorithm was applied to identify cortical sources of magnetoencephalographic (MEG) spontaneous brain oscillations in male MCI patients with a clear memory disorder and in healthy elderly controls. This data was subsequently compared to a male subsample of AD patients from an earlier study. While there were clear oscillatory abnormalities in AD patients, there was no evidence of significant changes in the alpha source distribution in MCI patients as compared to healthy controls. Deficits in the distribution of oscillatory sources in the resting state are thus likely to occur at later stages of cognitive impairment than MCI.

Verkkoniemi A, Ylikoski R, Rinne JO, Somer M, Hietaharju A, Erkinjuntti T, Viitanen M, Kalimo H, Haltia M. · Department of Clinical Neurosciences, Helsinki University Central Hospital, Helsinki FIN-00290, Finland. · J Neurol Sci. · Pubmed #14759630 No free full text.

Abstract: Few data exist on the effects of specific Alzheimer's disease (AD)-related mutations on cognitive function. We present neuropsychological test results in eight members of a large kindred with variant Alzheimer's disease (VarAD) due to a deletion of the presenilin 1 (PS-1) gene, encompassing exon 9. The disease was neuropathologically characterized by the presence of large, unusual, "cotton wool" plaques (CWP). Four surviving patients were prospectively tested, and retrospective neuropsychological data were collected from additional four deceased patients. The neuropsychological evaluation was based on tests of verbal and visual memory, abstract thinking, and visuoconstructive and spatial functions. In addition, psychiatric symptoms were evaluated. In four patients, brain glucose metabolism was examined by positron emission tomography (PET). PET showed temporoparietal hypometabolism typical of AD. In addition, variable patterns of hypometabolism (hemispherical asymmetry and occipital accentuation) were related to individual deficits of cognitive performance. However, all these early-onset patients (age range 43-63 years) with a deletion mutation of PS-1 gene showed prominent memory impairment and deficits in visuoconstructive and intellectual functions.

Pohjasvaara T, Ylikoski R, Leskelä M, Kalska H, Hietanen M, Kaste M, Erkinjuntti T. · Memory Research and Stroke Unit, Department of Clinical Neuroscience, Helsinki University Central Hospital, Helsinki, Finland. · Alzheimer Dis Assoc Disord. · Pubmed #11723369 No free full text.

Abstract: BACKGROUND AND PURPOSE: The effect of different diagnostic criteria for detecting dementia in both epidemiological and stroke cohort studies has been shown, but comparison between different assessment methods has only seldom been done. We compared both assessment methods and diagnostic criteria for dementia in a large well-defined stroke cohort. SUBJECT AND METHODS: A group of 227 of 486 patients aged 55 to 85 years who 3 months after ischemic stroke completed a comprehensive neuropsychological test battery, structured clinical mental status examination of defined cognitive domains with expanded Mini-Mental State Examination. The criteria for dementia were those of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III, DSM-III-R) and the National Institute of Neurological Disorders and Stroke-Associated Internationale pour la Recherche et l'Enseignement en Neurosciences (NINDS-AIREN). RESULTS: The main differences between clinical and neuropsychological examinations were seen in memory functions: clinically 24.7% and neuropsychologically 54.2% had impairment in short-term memory and 10.4% versus 5.3% in long-term memory. Accordingly, the prevalence of dementia varied greatly: It was clinically 14.1% by DSM-III, 9.7% by DSM-III-R and 8.4% by NINDS-AIREN criteria. The corresponding frequencies based on neuropsychological evaluation were 27.3%, 4.0% and 25.6%. Between these 3 diagnostic criteria the concordance varied in clinical testing between 59.4%-68.8% (kappa 0.72-0.79) and in neuropsychological testing between 14.5%-81.1% (kappa 0.20-0.86). The concordance between clinical and neuropsychological testing was 56.8% (kappa 0.42) by DSM-III, 31.6% (kappa 0.35) by DSM-III-R and 25.5% (kappa 0.24) by NINDS-AIREN. CONCLUSIONS: The frequency of poststroke dementia and cognitive decline varied sharply when different systems of diagnostic classification and methods were used. This may have serious influences on investigation and treatment of patients. We underline the importance of further debate and studies to refine the categories of cognitive impairment used in the setting of CVD.