Dementia
From Wikipedia, the free encyclopedia
| ICD-10 | F00.-F07. |
|---|---|
| ICD-9 | 290-294 |
| DiseasesDB | 29283 |
| MedlinePlus | 000739 |
Dementia (from Latin de- "apart, away" + mens (genitive mentis) "mind") is the progressive decline in cognitive function due to damage or disease in the brain beyond what might be expected from normal ageing.
Particularly affected areas may be memory, attention, language, and problem solving. Especially in the later stages of the condition, affected persons may be disoriented in time (not knowing what day of the week, day of the month, month, or even what year it is), in place (not knowing where they are), and in person (not knowing who they are).
Symptoms of dementia can be classified as either reversible or irreversible depending upon the etiology of the disease. Less than 10% of all dementias are reversible. Dementia is a non-specific term encompassing many disease processes, just as fever is attributable to many etiologies.
Without careful assessment, delirium can easily be confused with dementia and a number of other psychiatric disorders because many of the signs and symptoms are also present in dementia (as well as other mental illnesses including depression and psychosis). [1]
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[edit] Epidemiology
The prevalence of dementia is rising as the global life expectancy is rising. Particularly in Western countries, there is increasing concern about the economic impact that dementia will have in future, older populaces. In Australia, the 2006 estimated prevalence of dementia is 1.03% of the population as a whole. It is a disease which is strongly associated with age; 1% of those aged 60-65, 6% of those aged 75-79, and 45% of those aged 95 or older suffer from the disease[2].
[edit] Diagnosis
Proper differential diagnosis between the types of dementia (see below) will require, at the least, referral to a specialist, e.g. a geriatric internist, geriatric psychiatrist, neurologist, neuropsychologist or geropsychologist. However, there are some brief (5-15 minutes) tests that have good reliability and can be used in the office or other setting to evaluate cognitive status. Examples of such tests include the abbreviated mental test score (AMTS), the mini mental state examination (MMSE), and the clock drawing test [3].
The U.S. Preventive Services Task Force (USPSTF) reviewed tests for cognitive impairment and concluded [4]:
- MMSE
- sensitivity 71% to 92%
- specificity 56% to 96%
Many other tests have been studied [5][6] [7] including the clock drawing test[8] (example form). Although some may emerge as better alternatives to the MMSE, presently the MMSE is the best studied. However, access to the MMSE is now limited by enforcement of its copyright ( details).
An AMTS score of less than six and an MMSE score under 24 suggests a need for further evaluation. Of course, this must be interpreted in the context of the person's educational and other background, and particular circumstances. Routine blood tests are usually performed to rule out treatable causes. These tests include vitamin B12, folic acid, thyroid-stimulating hormone (TSH), C-reactive protein, full blood count, electrolytes, calcium, renal function and liver enzymes. Abnormalities may suggest vitamin deficiency, infection or other problems that commonly cause confusion or disorientation in the elderly. Chronic use of substances such as alcohol can also predispose the patient to cognitive changes suggestive of dementia.
A CT scan or magnetic resonance imaging (MRI scan) is commonly performed. This may suggest normal pressure hydrocephalus, a potentially reversible cause of dementia, and can yield information relevant to other types of dementia, such as infarction (stroke) that would point at a vascular type of dementia. Sometimes neuropsychological testing is helpful as well.
The final diagnosis of dementia is made on the basis of the clinical picture. For research purposes, the diagnosis depends on both a clinical diagnosis and a pathological diagnosis (i.e., based on the examination of brain tissue, usually from autopsy).
[edit] Types
The most common types of dementia are as follows and vary according to the history and the presentation of the disease: (Where available the ICD-10 codes are provided. The first code refers to the dementia, and the second to the underlying condition.)
[edit] Most common causes
- (F00/G30) Alzheimer's disease
- (F01) Vascular dementia (also known as multi-infarct dementia), including Binswanger's disease
- (F02.3/G20) Dementia with Lewy bodies (DLB)
- Alcohol Induced Persisting Dementia
- (F02.0/G31.0) Frontotemporal lobar degenerations (FTLD), including Pick's disease
- Frontotemporal dementia (or frontal variant FTLD)
- Semantic dementia (or temporal variant FTLD)
- Progressive non-fluent aphasia
[edit] Less common causes
It can also be a consequence of:
- (F02.1/A81.0) Creutzfeldt-Jakob disease
- (F02.2/G10) Huntington's disease
- (F02.3/G20) Parkinson's disease
- (F02.4/B22.0) HIV infection (leading to AIDS dementia complex)
- (F07.2) Head trauma
- (Q90) People with Down's syndrome have an increased risk of developing dementia of the Alzheimer's type. This risk increases as the person ages.
[edit] Treatable causes
Less than 5% of a sample of dementia cases have a potentially treatable cause. These include:
- (F02.8/E01-E03) Hypothyroidism
- (F02.8/E51) Vitamin B1 (thiamine) deficiency
- (F02.8/E53.8) Vitamin B12, Vitamin A deficiency
- (F03/F32-F33) Depressive pseudodementia (note: dementia and depression can coexist in many patients and can be difficult to differentiate.)
- (G91.2) Normal pressure hydrocephalus
- Tumor
[edit] Treatment
Except for the treatable types listed above, there is no cure to this illness, although scientists are progressing in making a type of medication that will slow down the process. Cognitive and behavioral interventions may also be appropriate. Educating and providing emotional support to the caregiver (or carer) is of importance as well (see also elderly care).
A Canadian study found that a lifetime of bilingualism has a marked influence on delaying the onset of dementia by an average of four years when compared to monolingual patients. The researchers determined that the onset of dementia symptoms in the monolingual group occurred at the mean age of 71.4, while the bilingual group was 75.5 years. The difference remained even after considering the possible effect of cultural differences, immigration, formal education, employment and even gender as influences in the results. [9]
Snoezelen rooms that provide patients with a soothing and stimulating environment of light, color, music and scent have been used in the therapy of dementia patients.
[edit] References
- ^ American Family Physician, March 1, 2003 Delirium
- ^ Dementia Estimates and Projections: Australian States and Territories. Alzheimer's Australia (2005-02-01). Retrieved on 2006-10-04.
- ^ Royall, D.; Cordes J.; & Polk M. (1998). "CLOX: an executive clock drawing task". J Neurol Neurosurg Psychiatry 64 (5): 588-94. PMID 9598672.
- ^ Boustani, M.; Peterson, B.; Hanson, L.; Harris, R.; & Lohr, K. (2003). "Screening for dementia in primary care: a summary of the evidence for the U.S. Preventive Services Task Force". Ann Intern Med 138 (11): 927-37. PMID 12779304.
- ^ Sager, M.; Hermann, B.; La Rue, A.; & Woodard, J. (2006). "Screening for dementia in community-based memory clinics". WMJ 105 (7): 25-9. PMID 17163083.
- ^ Fleisher, A.; Sowell B.; Taylor C.; Gamst A.; Petersen R.; & Thal L.. "Clinical predictors of progression to Alzheimer disease in amnestic mild cognitive impairment". Neurology. PMID 17287448.
- ^ Karlawish, J. & Clark, C. (2003). "Diagnostic evaluation of elderly patients with mild memory problems". Ann Intern Med 138 (5): 411-9. PMID 12614094.
- ^ .
- ^ Bilingualism Has Protective Effect In Delaying Onset Of Dementia By Four Years, Canadian Study Shows. Medical News Today (2007-01-11). Retrieved on 2007-01-16.
[edit] External links
- Dementia Research News from ScienceDaily
- The Dementia Services Development Centre, University of Stirling
- Dementia tutorial for U.K. practitioners by the Alzheimer's Society
- Getting Started in Telecare for Patients with Dementia(pdf file)
- information and resources on alzheimer's disease and dementia
- Understanding Dementia: a primer of diagnosis and management
