Rethinking the Dementia Diagnoses in a Population-Based Study: What Is Alzheimer’s Disease and What Is Vascular Dementia?

Objective: To explore the hypothesis that older adults often are affected by more than one disease, making the differential diagnosis between Alzheimer’s disease (AD) and vascular dementia (VaD) difficult. Methods: Incident dementia cases (n = 308) from a population-based longitudinal study of people 75+ years were investigated. The DSM-III-R criteria were used for the clinical diagnosis of dementia. Data on vascular disorders (hypertension, cerebrovascular and ischemic heart diseases, heart failure, atrial fibrillation, diabetes) as well as type of onset/course of dementia were used retrospectively to reclassify dementias. Results: Only 47% of the AD cases were reclassified as pure AD without any vascular disorder. Among subjects with AD and with a vascular component, cerebrovascular disease was the most common (41%). Only 25% of VaD were reclassified as pure VaD. Further, 26% of the pure AD subjects developed a vascular disorder in the following 3 years. Conclusions: Both vascular and degenerative mechanisms may often contribute to the expression of dementia among the elderly. Most of the AD cases have vascular involvements, and pure dementia types in very old subjects constitute only a minority of dementia cases.

[1]  R. Stewart.  Vascular dementia: A diagnosis running out of time , 2002, British Journal of Psychiatry.

[2]  M. D. O'Brien,et al.  Cerebral blood flow in dementia , 1986, Neurology.

[3]  R. Havlik,et al.  Midlife blood pressure and dementia: the Honolulu–Asia aging study☆ , 2000, Neurobiology of Aging.

[4]  M Haupt,et al.  [Clinical diagnosis of Alzheimer's disease]. , 1988, Deutsche medizinische Wochenschrift.

[5]  A. Hofman,et al.  Silent brain infarcts and the risk of dementia and cognitive decline. , 2003, The New England journal of medicine.

[6]  S. Folstein,et al.  "Mini-mental state". A practical method for grading the cognitive state of patients for the clinician. , 1975, Journal of psychiatric research.

[7]  P. Luiten,et al.  Cerebral microvascular pathology in aging and Alzheimer's disease , 2001, Progress in Neurobiology.

[8]  D. W. Desmond,et al.  The neuropsychology of vascular cognitive impairment: is there a specific cognitive deficit? , 2004, Journal of the Neurological Sciences.

[9]  D. Royall,et al.  A diagnostic dilemma: is “Alzheimer's dementia” Alzheimer's disease, vascular dementia, or both? , 2004, The Lancet Neurology.

[10]  C. Lyketsos,et al.  Vascular dementia and Alzheimer's disease: is there a difference? A comparison of symptoms by disease duration. , 2000, The Journal of neuropsychiatry and clinical neurosciences.

[11]  K. Holmen,et al.  Prevalence of Alzheimer's disease and other dementias in an elderly urban population , 1991, Neurology.

[12]  D. Royall,et al.  Alzheimer disease as a vascular disorder: nosological evidence. , 2002, Stroke.

[13]  W. Markesbery,et al.  Brain infarction and the clinical expression of Alzheimer disease. The Nun Study. , 1997, JAMA.

[14]  W. Markesbery,et al.  Cerebrovascular Pathology and Dementia in Autopsied Honolulu‐Asia Aging Study Participants , 2002, Annals of the New York Academy of Sciences.

[15]  P. Scheltens,et al.  The influence of coincidental vascular pathology on symptomatology and course of Alzheimer's disease. , 1998, Journal of neural transmission. Supplementum.

[16]  B. Winblad,et al.  Mortality from dementia in advanced age: a 5-year follow-up study of incident dementia cases. , 1999, Journal of clinical epidemiology.

[17]  B. Winblad,et al.  Aging and the occurrence of dementia: findings from a population-based cohort with a large sample of nonagenarians. , 1999, Archives of neurology.

[18]  H. Agüero-Torres,et al.  Dementia is the major cause of functional dependence in the elderly: 3-year follow-up data from a population-based study. , 1998, American journal of public health.

[19]  K. Langa,et al.  Mixed dementia: emerging concepts and therapeutic implications. , 2004, JAMA.

[20]  V. Hachinski,et al.  Meta-analysis of the Hachinski Ischemic Score in pathologically verified dementias , 1997, Neurology.

[21]  L. Launer.  Demonstrating the case that AD is a vascular disease: epidemiologic evidence , 2002, Ageing Research Reviews.

[22]  B. Shukitt-Hale,et al.  Copernicus revisited: amyloid beta in Alzheimer’s disease , 2001, Neurobiology of Aging.

[23]  Ian G. McKeith,et al.  Pathological correlates of late-onset dementia in a multicentre, community-based population in England and Wales , 2001, The Lancet.

[24]  R. Kalaria.  Similarities between Alzheimer's disease and vascular dementia , 2002, Journal of the Neurological Sciences.

[25]  Paul G. Ince,et al.  Vascular pathologies and cognition in a population-based cohort of elderly people , 2004, Journal of the Neurological Sciences.

[26]  A. Wallin,et al.  Subtypes of vascular dementia. , 1999, Alzheimer disease and associated disorders.

[27]  J Tuomilehto,et al.  Midlife vascular risk factors and Alzheimer's disease in later life: longitudinal, population based study , 2001, BMJ.

[28]  D. Sparks,et al.  Increased incidence of neurofibrillary tangles (NFT) in non-demented individuals with hypertension , 1995, Journal of the Neurological Sciences.

[29]  W. Jagust,et al.  Clinical criteria for the diagnosis of vascular dementia: a multicenter study of comparability and interrater reliability. , 2000, Archives of neurology.

[30]  R N Kalaria,et al.  Overlap between pathology of Alzheimer disease and vascular dementia. , 1999, Alzheimer disease and associated disorders.

[31]  B. Winblad,et al.  Very Old Women at Highest Risk of Dementia and Alzheimer's Disease , 1997, Neurology.

[32]  James A. Mortimer,et al.  Brain Infarction and the Clinical Expression of Alzheimer Disease-Reply , 1997 .

[33]  J. O'Brien,et al.  NINDS AIREN neuroimaging criteria do not distinguish stroke patients with and without dementia , 2004, Neurology.

[34]  D. Libon,et al.  The Clinical Diagnosis of Vascular Dementia: A Comparison Among Four Classification Systems and a Proposal for a new Paradigm , 2004, The Clinical neuropsychologist.

[35]  J. Orgogozo,et al.  Vascular cognitive disorder: a new diagnostic category updating vascular cognitive impairment and vascular dementia , 2004, Journal of the Neurological Sciences.

[36]  J R Hodges,et al.  Distinctive cognitive profiles in Alzheimer's disease and subcortical vascular dementia. , 2004, Journal of neurology, neurosurgery, and psychiatry.

[37]  H. Chui,et al.  Subcortical ischaemic vascular dementia , 2002, The Lancet Neurology.

[38]  T. Erkinjuntti,et al.  Diagnosis and management of vascular cognitive impairment and dementia. , 2002, Journal of neural transmission. Supplementum.

[39]  B. Winblad,et al.  Clinical diagnosis of Alzheimer's disease and other dementias in a population survey. Agreement and causes of disagreement in applying Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition, Criteria. , 1992, Archives of neurology.

[40]  B. Lernfelt,et al.  15-year longitudinal study of blood pressure and dementia , 1996, The Lancet.

[41]  W. Markesbery,et al.  Midlife blood pressure and neuritic plaques, neurofibrillary tangles, and brain weight at death: the HAAS☆ , 2000, Neurobiology of Aging.

[42]  B. Winblad,et al.  Alzheimer's Disease and Vascular Dementia: Some Points of Confluence , 2000, Annals of the New York Academy of Sciences.

[43]  Arto Mannermaa,et al.  Apolipoprotein E 4 Allele, Elevated Midlife Total Cholesterol Level, and High Midlife Systolic Blood Pressure Are Independent Risk Factors for Late-Life Alzheimer Disease , 2002, Annals of Internal Medicine.