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Classification and external resources
Comparison of a normal aged brain (left) and the brain of a person with Alzheimer's (right). Differential characteristics are pointed out.
ICD-10 F00-F07
ICD-9 290-294
DiseasesDB 29283
MedlinePlus 000739
Patient UK Dementia
MeSH D003704

Dementia is a broad category of brain diseases that cause a long term and often gradual decrease in the ability to think and remember such that a person's daily functioning is affected.[1] Other common symptoms include emotional problems, problems with language, and a decrease in motivation.[1][2] A person's consciousness is not affected.[1] For the diagnosis to be present it must be a change from a person's usual mental functioning and a greater decline than one would expect due to aging.[1][3] These diseases also have a significant effect on a person's caregivers.[1] The most common type of dementia is Alzheimer's disease which makes up 50% to 70% of cases. Other common types include vascular dementia (25%), Lewy body dementia (15%), and frontotemporal dementia.[1][2] Less common causes include normal pressure hydrocephalus, Parkinson disease, syphilis, and Creutzfeldt–Jakob disease among others.[4] More than one type of dementia may exist in the same person.[1] A small proportion of cases run in families.[5] In the DSM-5, dementia was reclassified as a neurocognitive disorder, with various degrees of severity.[6] Diagnosis is usually based on history of the illness and cognitive testing with medical imaging and blood work used to rule out other possible causes.[7] The mini mental state examination is one commonly used cognitive test.[2] Efforts to prevent dementia include trying to decrease risk factors such as high blood pressure, smoking, diabetes and obesity.[1] Screening the general population for the disease is not recommended.[8] There is no cure for dementia.[1] Cholinesterase inhibitors such as donepezil are often used and may be beneficial in mild to moderate disease.[9][10][11] Overall benefit; however, maybe small.[11][12] For people with dementia and those who care for them many measures can improve their lives.[1] Cognitive and behavioral interventions may be appropriate.[1] Educating and providing emotional support to the caregiver is important.[1] Exercise programs are beneficial with respect to activities of daily living and potentially improve outcomes.[13] Treatment of behavioral problems or psychosis due to dementia with antipsychotics is common but not usually recommended due to there often being little benefit and an increased risks of death.[14][15] Globally dementia affects 36 million people.[1] About 10% of people develop the disease at some point in their lives.[5] It becomes more common with age.[16] About 3% of people between the ages of 65–74 have dementia, 19% between 75 and 84 and nearly half of those over 85 years of age.[17] In 2010 dementia resulted in about 486,000 deaths.[18] As more people are living longer, dementia is becoming more common in the population as a whole.[16] For people of a specific age; however, it may be becoming less frequent, at least in the developed world, due to a decrease in risk factors.[16] It is one of the most common causes of disability among the old.[2] It is believed to result in economic costs of 604 billion USD a year.[1] People with dementia are often physically or chemically restrained to a greater degree than necessary, raising issues of human rights.[1] Social stigma against those affected is common.[2]


  • Signs and symptoms 1
    • Mild cognitive impairment 1.1
    • Early stages 1.2
    • Middle stages 1.3
    • Late stages 1.4
  • Causes 2
    • Reversible causes 2.1
    • Alzheimer's disease 2.2
    • Vascular dementia 2.3
    • Dementia with Lewy bodies 2.4
    • Frontotemporal dementia 2.5
    • Progressive supranuclear palsy 2.6
    • Corticobasal degeneration 2.7
    • Rapidly progressive 2.8
    • Other conditions 2.9
    • Mild cognitive impairment 2.10
    • Fixed cognitive impairment 2.11
    • Slowly progressive 2.12
  • Diagnosis 3
    • Cognitive testing 3.1
    • Laboratory tests 3.2
    • Imaging 3.3
  • Prevention 4
  • Management 5
    • Psychological therapies 5.1
    • Medications 5.2
    • Pain 5.3
    • Eating difficulties 5.4
    • Alternative medicine 5.5
    • Palliative care 5.6
  • Epidemiology 6
  • History 7
  • Society and culture 8
  • References 9
  • External links 10

Signs and symptoms

Dementia affects the brain's ability to think, reason and remember clearly. The most common affected areas include memory, visual-spatial, language, attention, and executive function (problem solving). Most types of dementia are slow and progressive. By the time the person shows signs of the disease, the process in the brain has been happening for a long time. It is possible for a patient to have two types of dementia at the same time. About 10% of people with dementia have what is known as mixed dementia, which is usually a combination of Alzheimer's disease and another type of dementia such as frontotemporal dementia or vascular dementia.[19][20] Additional psychological and behavioral problems that often affect people who have dementia include:

  • Disinhibition and impulsivity
  • Depression and/or anxiety
  • Agitation
  • Balance problems
  • Tremor
  • Speech and language difficulty
  • Trouble eating or swallowing
  • Delusions (often believing people are stealing from them) or hallucinations
  • Memory distortions (believing that a memory has already happened when it has not, thinking an old memory is a new one, combining two memories, or confusing the people in a memory)
  • Wandering or restlessness

When people with dementia are put in circumstances beyond their abilities, there may be a sudden change to tears or anger (a "catastrophic reaction").[21]

Depression affects 20–30% of people who have dementia, and about 20% have anxiety.[22] Psychosis (often delusions of persecution) and agitation/aggression also often accompany dementia. Each of these must be assessed and treated independently of the underlying dementia.[23]

Mild cognitive impairment

In the first stages of dementia, the signs and symptoms of the disease may be subtle. Often, the early signs of dementia only become apparent when looking back in time. The earliest stage of dementia is called mild cognitive impairment (MCI). 70% of those diagnosed with MCI will progress to dementia at some point.[3] In MCI, changes in the person's brain have been happening for a long time, but the symptoms of the disease are just beginning to show. These problems, however, are not yet severe enough to affect the person’s daily function. If they do, it is considered dementia. A person with MCI will score between 27 and 30 on the Mini-Mental State Examination (MMSE), which is a normal score. They may have some memory trouble and trouble finding words but they solve everyday problems and handle their own life affairs well.

Early stages

In the early stage of dementia, the person will begin to show symptoms noticeable to the people around them. In addition, the symptoms begin to interfere with daily activities. The person will usually score between a 20 and 25 on the MMSE. The symptoms are dependent on the type of dementia a person has. The person may begin to have difficulty with more complicated chores and tasks around the house. The person can usually still take care of him or herself but may forget things like taking pills or doing laundry and may need prompting or reminders.

The symptoms of early dementia usually include memory difficulty, but can also include some word-finding problems (anomia) and problems with planning and organizational skills (executive function). One very good way of assessing a person's impairment is by asking if he or she is still able to handle his/her finances independently. This is often one of the first things to become problematic. Other signs might be getting lost in new places, repeating things, personality changes, social withdrawal and difficulties at work.

When evaluating a person for dementia, it is important to consider how the person was able to function five or ten years earlier. It is also important to consider a person's level of education when assessing for loss of function. For example, an accountant who can no longer balance a checkbook would be more concerning than a person who had not finished high school or had never taken care of his/her own finances.[3]

In Alzheimer's dementia the most prominent early symptom is memory difficulty. Others include word-finding problems and getting lost. In other types of dementia, like dementia with Lewy bodies and fronto-temporal dementia, personality changes and difficulty with organization and planning may be the first signs.

Middle stages

As dementia progresses, the symptoms first experienced in the early stages of the dementia generally worsen. The rate of decline is different for each person. A person with moderate dementia will score between 6-17 on the MMSE. For example, if the person has Alzheimer's dementia, in the moderate stages almost all new information will be lost very quickly. The person may be severely impaired in solving problems and their social judgment is usually also impaired. The person cannot usually function outside of his or her own home, and generally should not be left alone. He or she may be able to do simple chores around the house but not much else and begins to require assistance for personal care and hygiene other than simple reminders.[3]

Late stages

People with late-stage dementia typically turn increasingly inward and need assistance with most or all of their personal care. Persons with dementia in the late stages usually need 24-hour supervision to ensure personal safety, as well as to ensure that basic needs are being met. If left unsupervised, a person with late-stage dementia may wander and fall, may not recognize common dangers around them such as a hot stove, may not realize that they need to use the bathroom or become unable to control their bladder or bowels (incontinent). Changes in eating frequently occur, and those with late-stage dementia often need pureed diets, thickened liquids, and assistance in eating. Their appetite may decline to the point that the person does not want to eat at all. He or she may not want get out of bed, or may need complete assistance doing so. They may no longer recognize familiar people. He or she may have significant changes in sleeping habits or have trouble sleeping at all.[3]


Reversible causes

There are four main causes of easily reversible dementia: hypothyroidism, vitamin B12 deficiency, Lyme disease, and neurosyphillis. All people with memory difficulty should be checked for hypothyroidism and B12 deficiency. For Lyme disease and neurosyphilis, testing should be done if there are risk factors for those diseases in the person.[3]

Alzheimer's disease

Brain atrophy in severe Alzheimer's

Alzheimer's disease is the most common form of dementia.[24] Its most common symptoms are short-term memory loss and word-finding difficulties. People with Alzheimer's also have trouble with visual-spatial areas (for example they may begin to get lost often), reasoning, judgement, and insight. Insight refers to whether or not the person realizes he/she has memory problems.

Common early symptoms of Alzheimer's include repetition, getting lost, difficulties keeping track of bills, problems with cooking especially new or complicated meals, forgetting to take medication, and word-finding problems.

The part of the brain most affected by Alzheimer's is the hippocampus. Other parts of the brain that will show shrinking (atrophy) include the temporal and parietal lobes.[3] Although this pattern suggests Alzheimer's, the brain shrinkage in Alzheimer's disease is very variable, and a scan of the brain cannot actually make the diagnosis.

Vascular dementia

Vascular dementia is the cause of at least 20% of dementia cases, making it the second most common cause of dementia.[25] It is caused by disease or injury to blood vessels that damage the brain, including strokes. The symptoms of this dementia depend on where in the brain the strokes have occurred and whether the vessels are large or small.[3] Multiple injuries can cause progressive dementia over time, while a single injury located in an area critical for cognition (i.e., hippocampus, thalamus) can lead to sudden cognitive decline.[25]

On scans of the brain, a person with vascular dementia may show evidence of multiple different strokes of different sizes. They tend to have risk factors for artery disease such as tobacco smoking, high blood pressure, atrial fibrillation, high cholesterol or diabetes, or other signs of blood vessel disease such as a previous heart attack or angina.

Dementia with Lewy bodies

multi-infarct dementias or vascular dementias.

In the 21st century, a number of other types of dementia have been differentiated from Alzheimer's disease and vascular dementias (these two being the most common types). This differentiation is on the basis of pathological examination of brain tissues, symptomatology, and by different patterns of brain metabolic activity in nuclear medical imaging tests such as SPECT and PETscans of the brain. The various forms of dementia have differing prognoses (expected outcome of illness), and also differing sets of epidemologic risk factors. The causal etiology of many of them, including Alzheimer's disease, remains unclear, although many theories exist such as accumulation of protein plaques as part of normal aging, inflammation (either from bacterial pathogens or exposure to toxic chemicals), inadequate blood sugar, and traumatic brain injury.

Society and culture

Many countries consider the care of people living with dementia to be a national priority, and invest in resources and education to better inform health and social service workers, unpaid caregivers, relatives and members of the wider community. Several countries have national plans or strategies.[98] In these national plans, there is recognition that people can live well with dementia for a number of years, as long as there is the right support and timely access to a diagnosis. David Cameron has described dementia as being a "national crisis", affecting 800,000 people in the United Kingdom.[99]

In the United States, Florida's Baker Act allows law-enforcement authorities and the judiciary to force mental evaluation for those suspected of having developed dementia or other mental incapacities. In the United Kingdom, as with all mental disorders, where a person with dementia could potentially be a danger to themselves or others, they can be detained under the Mental Health Act 1983 for the purposes of assessment, care and treatment. This is a last resort, and usually avoided if the patient has family or friends who can ensure care.

Driving with dementia could lead to severe injury or even death to self and others. Doctors should advise appropriate testing on when to quit driving.[100] The United Kingdom DVLA (Driver & Vehicle Licensing Agency) states that people with dementia who specifically have poor short term memory, disorientation, lack of insight or judgment are not fit to drive, and in these instances the DVLA must be informed so that the driving licence can be revoked. They do, however, acknowledge low-severity cases and those with an early diagnosis, and those drivers may be permitted to drive pending medical reports.

There are many support networks available to those who have a diagnosis of dementia, and their families and caregivers. There are also charitable organisations which aim to raise awareness and campaign for the rights of people living with dementia. There is also support and guidance on assessing testamentary capacity in people who have dementia.[101]


  1. ^ a b c d e f g h i j k l m n o "Dementia Fact sheet N°362". April 2012. Retrieved 28 November 2014. 
  2. ^ a b c d e Burns, A; Iliffe, S (5 February 2009). "Dementia.". BMJ (Clinical research ed.) 338: b75.  
  3. ^ a b c d e f g h i j k l m n o p q r s t u v Solomon, Andrew E. Budson, Paul R. (2011). Memory loss : a practical guide for clinicians. [Edinburgh?]: Elsevier Saunders.  
  4. ^ Gauthier, Serge (2006). Clinical diagnosis and management of Alzheimer's disease (3rd ed. ed.). Abingdon, Oxon: Informa Healthcare. pp. 53–54.  
  5. ^ a b Loy, CT; Schofield, PR; Turner, AM; Kwok, JB (1 March 2014). "Genetics of dementia.". Lancet 383 (9919): 828–40.  
  6. ^ Association, American Psychiatric (2013). Diagnostic and statistical manual of mental disorders : DSM-5. (5th ed. ed.). Washington, D.C.: American Psychiatric Association. pp. 591–603.  
  7. ^ "Dementia diagnosis and assessment". Retrieved 30 November 2014. 
  8. ^ "Dementia overview". Retrieved 30 November 2014. 
  9. ^ Birks, J (25 January 2006). "Cholinesterase inhibitors for Alzheimer's disease.". The Cochrane database of systematic reviews (1): CD005593.  
  10. ^ Rolinski, M; Fox, C; Maidment, I; McShane, R (14 March 2012). "Cholinesterase inhibitors for dementia with Lewy bodies, Parkinson's disease dementia and cognitive impairment in Parkinson's disease.". The Cochrane database of systematic reviews 3: CD006504.  
  11. ^ a b Kavirajan, H; Schneider, LS (September 2007). "Efficacy and adverse effects of cholinesterase inhibitors and memantine in vascular dementia: a meta-analysis of randomised controlled trials.". The Lancet. Neurology 6 (9): 782–92.  
  12. ^ a b c Commission de la transparence (June 2012). "Médicaments de la maladie d'Alzheimer : à éviter" [Drugs for Alzheimer's disease: best avoided. No therapeutic advantage]. Prescrire Int 21 (128): 150.  
  13. ^ a b Forbes, D.; Thiessen, E.J.; Blake, C.M.; Forbes, S.C.; Forbes, S. (4 December 2013). "Exercise programs for people with dementia.". The Cochrane database of systematic reviews 12: CD006489.  
  14. ^ National Institute for Health and Clinical Excellence. "Low-dose antipsychotics in people with dementia". Retrieved 29 November 2014. 
  15. ^ "Information for Healthcare Professionals: Conventional Antipsychotics". 2008-06-16. Retrieved 29 November 2014. 
  16. ^ a b c Larson, EB; Yaffe, K; Langa, KM (12 December 2013). "New insights into the dementia epidemic.". The New England journal of medicine 369 (24): 2275–7.  
  17. ^ Umphred, Darcy (2012). Neurological rehabilitation (6th ed. ed.). St. Louis, Mo.: Elsevier Mosby. p. 838.  
  18. ^ a b Lozano, R; Naghavi, M; Foreman, Ktitle=Global and regional mortality from 235 causes of death for 20 age groups in 1990 and 2010: a systematic analysis for the Global Burden of Disease Study 2010. (15 December 2012). Lancet 380 (9859): 2095–128.  
  19. ^ What is vascular dementia? Alzheimer's Society.
  20. ^ Lee AY (2011). "Vascular dementia". Chonnam Med J 47 (2): 66–71.  
  21. ^ Geddes, John; Gelder, Michael G.; Mayou, Richard (2005). Psychiatry. Oxford [Oxfordshire]: Oxford University Press. p. 141.  
  22. ^ Calleo J, Stanley M (2008). "Anxiety Disorders in Later Life Differentiated Diagnosis and Treatment Strategies". Psychiatric Times 25 (8). 
  23. ^ Shub, Denis; Kunik, Mark E (April 16, 2009). "Psychiatric Comorbidity in Persons With Dementia: Assessment and Treatment Strategies". Psychiatric Times 26 (4). 
  24. ^ Thompson, S.B.N. "Dementia and memory: a handbook for students and professionals" Aldershot: Ashgate 2006.
  25. ^ a b Iadecola, C (Nov 20, 2013). "The pathobiology of vascular dementia". Neuron 80 (4): 844–66.  
  26. ^ Galvin JE et al. (2006). "Clinical phenotype of Parkinson disease dementia". Neurology 67 (9): 1605–11.  
  27. ^ Lamont P (2004). "Cognitive Decline in a Young Adult with Pre-Existent Developmental Delay – What the Adult Neurologist Needs to Know". Practical Neurology 4 (2): 70–87.  
  28. ^ Neuropathology Group. Medical Research Council Cognitive Function and Aging Study (2001). "Pathological correlates of late-onset dementia in a multicentre, community-based population in England and Wales. Neuropathology Group of the Medical Research Council Cognitive Function and Ageing Study (MRC CFAS)". Lancet 357 (9251): 169–75.  
  29. ^ Wakisaka Y et al. (2003). "Age-associated prevalence and risk factors of Lewy body pathology in a general population: the Hisayama study". Acta Neuropathol 106 (4): 374–82.  
  30. ^ White L et al. (2002). "Cerebrovascular pathology and dementia in autopsied Honolulu-Asia Aging Study participants". Ann N Y Acad Sci 977 (9): 9–23.  
  31. ^ Ratnavalli E et al. (2002). "The prevalence of frontotemporal dementia". Neurology 58 (11): 1615–21.  
  32. ^ McKee A et al. (2009). "Chronic Traumatic Encephalopathy in Athletes: Progressive Tauopathy following Repetitive Head Injury". J Neuropathol Exp Neurol 68 (7): 709–735.  
  33. ^ Lin, J.S.; O'Connor, E.; Rossom, R.C.; Perdue, L.A.; Eckstrom, E. (22 October 2013). "Screening for Cognitive Impairment in Older Adults: A Systematic Review for the U.S. Preventive Services Task Force.". Annals of internal medicine 159 (9): 601–12.  
  34. ^ "Dementia definition". MDGuidelines. Reed Group. Retrieved 2009-06-04. 
  35. ^ Caplan, J.P., & Rabinowitz, T. (2010). "An approach to the patient with cognitive impairment: Delirium and dementia". The Medical clinics of North America 94 (6): 1103–16, ix.  
  36. ^ Gleason OC (2003). "Delirium". American Family Physician 67 (5): 1027–34.  
  37. ^ Boustani, M; Peterson, B; Hanson, L; Harris, R; & Lohr, K; U.S. Preventive Services Task Force (3 June 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.  
  38. ^ a b Cullen B, O'Neill B, Evans JJ, Coen RF, Lawlor BA (2007). "A review of screening tests for cognitive impairment". Journal of Neurology, Neurosurgery, and Psychiatry 78 (8): 790–9.  
  39. ^ Sager MA, Hermann BP, La Rue A, Woodard JL (2006). "Screening for dementia in community-based memory clinics" (PDF). Wisconsin medical journal 105 (7): 25–9.  
  40. ^ Fleisher, A; Sowell, B; Taylor, C; Gamst, A; Petersen, R; Thal, L; Alzheimer's Disease Cooperative Study (2007). "Clinical predictors of progression to Alzheimer disease in amnestic mild cognitive impairment". Neurology 68 (19): 1588–95.  
  41. ^ Karlawish, J & Clark, C (2003). "Diagnostic evaluation of elderly patients with mild memory problems". Ann Intern Med 138 (5): 411–9.  
  42. ^ Teng EL, Chui HC (1987). "The Modified Mini-Mental State (3MS) examination". The Journal of Clinical Psychiatry 48 (8): 314–8.  
  43. ^ Teng EL, Hasegawa K, Homma A et al. (1994). "The Cognitive Abilities Screening Instrument (CASI): a practical test for cross-cultural epidemiological studies of dementia". International Psychogeriatrics / IPA 6 (1): 45–58; discussion 62.  
  44. ^ Tombaugh, T.N.T.N (2004). "Trail Making test A and B: Normative Data Stratified by Age and Education". Archives of Clinical Neuropsychology 19 (2): 203–214.  
  45. ^ Royall, D; Cordes, J.; Polk, M. (1998). "CLOX: an executive clock drawing task". J Neurol Neurosurg Psychiatry 64 (5): 588–94.  
  46. ^ Nasreddine, ZS; Phillips, NA; Bédirian, V; Charbonneau, S; Whitehead, V; Collin, I; Cummings, JL; Chertkow, H (Apr 2005). "The Montreal Cognitive Assessment, MoCA: a brief screening tool for mild cognitive impairment.". Journal of the American Geriatrics Society 53 (4): 695–9.  
  47. ^ Jorm AF (2004). "The Informant Questionnaire on cognitive decline in the elderly (IQCODE): a review". International Psychogeriatrics / IPA 16 (3): 275–93.  
  48. ^ Bonte, F.J.; Harris, T.S.; Hynan, L.S.; Bigio, E.H.; White, III, C.L. (2006). "Tc-99m HMPAO SPECT in the differential diagnosis of the dementias with histopathologic confirmation". Clinical Nuclear Medicine 31 (7): 376–8.  
  49. ^ Dougall, N.J.; Bruggink, S.; Ebmeier, K.P. (2004). "Systematic review of the diagnostic accuracy of 99mTc-HMPAO-SPECT in dementia". The American Journal of Geriatric Psychiatry 12 (6): 554–70.  
  50. ^ Abella HA (June 16, 2009). "Report from SNM: PET imaging of brain chemistry bolsters characterization of dementias". Diagnostic Imaging. 
  51. ^ Schneider, LS; Mangialasche, F; Andreasen, N; Feldman, H; Giacobini, E; Jones, R; Mantua, V; Mecocci, P; Pani, L; Winblad, B; Kivipelto, M (March 2014). "Clinical trials and late-stage drug development for Alzheimer's disease: an appraisal from 1984 to 2014.". Journal of internal medicine 275 (3): 251–83.  
  52. ^ Vink, AC; Birks, JS; Bruinsma, MS; Scholten, RJ (2004). "Music therapy for people with dementia.". The Cochrane database of systematic reviews (3): CD003477.  
  53. ^ Woods, B; Spector, A; Jones, C; Orrell, M; Davies, S (Apr 18, 2005). "Reminiscence therapy for dementia.". The Cochrane database of systematic reviews (2): CD001120.  
  54. ^ Vernooij-Dassen, M; Draskovic, I; McCleery, J; Downs, M (Nov 9, 2011). "Cognitive reframing for carers of people with dementia.". The Cochrane database of systematic reviews (11): CD005318.  
  55. ^ Neal, M; Briggs, M (2003). "Validation therapy for dementia.". The Cochrane database of systematic reviews (3): CD001394.  
  56. ^ Woods, B; Aguirre, E; Spector, AE; Orrell, M (Feb 15, 2012). "Cognitive stimulation to improve cognitive functioning in people with dementia.". The Cochrane database of systematic reviews 2: CD005562.  
  57. ^ Barker, Philip (2003). Psychiatric and mental health nursing: the craft of caring. London: Arnold.  
  58. ^ Weitzel T, Robinson S, Barnes MR et al. (2011). "The special needs of the hospitalized patient with dementia". Medsurg Nurs 20 (1): 13–8; quiz 19.  
  59. ^ Cunningham, C (2006). "Understanding challenging behaviour in patients with dementia". Nursing standard 20 (47): 42–5.  
  60. ^ Rafii, M. S. & Aisen, P. S. (2009). "Recent developments in Alzheimer's disease therapeutics". BMC medicine 7: 1–4.  
  61. ^ a b Lleó A, Greenberg SM, Growdon JH (2006). "Current pharmacotherapy for Alzheimer's disease". Annu. Rev. Med. 57: 513–33.  
  62. ^ Bond, M; Rogers, G; Peters, J; Anderson, R; Hoyle, M; Miners, A; Moxham, T; Davis, S; Thokala, P; Wailoo, A; Jeffreys, M; Hyde, C (2012). "The effectiveness and cost-effectiveness of donepezil, galantamine, rivastigmine and memantine for the treatment of Alzheimer's disease (review of Technology Appraisal No. 111): a systematic review and economic model.". Health technology assessment (Winchester, England) 16 (21): 1–470.  
  63. ^ Rodda, J.; Morgan, S.; Walker, Z. (October 2009). "Are cholinesterase inhibitors effective in the management of the behavioral and psychological symptoms of dementia in Alzheimer's disease? A systematic review of randomized, placebo-controlled trials of donepezil, rivastigmine and galantamine.". International psychogeriatrics / IPA 21 (5): 813–24.  
  64. ^ Birks, J (25 January 2006). "Cholinesterase inhibitors for Alzheimer's disease.". Cochrane database of systematic reviews (Online) (1): CD005593.  
  65. ^ Gill S. S., Anderson, G. M., Fischer, H.D., Li, P., Normand, S. T. & Rochon, P. A. (2009). "Syncope and its consequences in patients with dementia receiving cholinesterase inhibitors: A population-based cohort study". Archives of Internal Medicine 169 (9): 867–873.  
  66. ^ a b c d  , which cites
    • American Geriatrics Society 2012 Beers Criteria Update Expert Panel (2012). "American Geriatrics Society Updated Beers Criteria for Potentially Inappropriate Medication Use in Older Adults". Journal of the American Geriatrics Society 60 (4): 616–631.  
    • Maher, A. R.; Maglione, M.; Bagley, S.; Suttorp, M.; Hu, J. H.; Ewing, B.; Wang, Z.; Timmer, M.; Sultzer, D.; Shekelle, P. G. (2011). "Efficacy and Comparative Effectiveness of Atypical Antipsychotic Medications for Off-Label Uses in Adults". JAMA 306 (12): 1359–1369.  
    • Yamada, A.; Nobusawa, E.; Cao, M. S.; Imanishi, J.; Oyama, S.; Abe, A.; Katagiri, S.; Kim, D. W.; Nakajima, K.; Nakajima, S. (1991). "Epitope changes on the haemagglutinin molecule of recently isolated H1N1 influenza viruses". The Journal of general virology 72 (1): 97–102.  
    • See also  
  67. ^ Declercq, T.; Petrovic, M.; Azermai, M.; Vander Stichele, R.; De Sutter, A.I.; van Driel, M.L.; Christiaens, T. (28 March 2013). "Withdrawal versus continuation of chronic antipsychotic drugs for behavioural and psychological symptoms in older people with dementia.". The Cochrane database of systematic reviews 3: CD007726.  
  68. ^ Bond, M.; Rogers, G.; Peters, J.; Anderson, R.; Hoyle, M.; Miners, A.; Moxham, T.; Davis, S.; Thokala, P.; Wailoo, A.; Jeffreys, M.; Hyde, C. (2012). "The effectiveness and cost-effectiveness of donepezil, galantamine, rivastigmine and memantine for the treatment of Alzheimer's disease (review of Technology Appraisal No. 111): a systematic review and economic model". Health technology assessment (Winchester, England) 16 (21): 1–470.  
  69. ^ Raina P, Santaguida P, Ismaila A et al. (2008). "Effectiveness of cholinesterase inhibitors and memantine for treating dementia: evidence review for a clinical practice guideline". Annals of Internal Medicine 148 (5): 379–97.  
  70. ^ Atri A, Shaughnessy LW, Locascio JJ, Growdon JH (2008). "Long-term Course and Effectiveness of Combination Therapy in Alzheimer's Disease". Alzheimer Disease and Associated Disorders 22 (3): 209–21.  
  71. ^ Thompson S, Herrmann N, Rapoport MJ, Lanctôt KL (2007). "Efficacy and safety of antidepressants for treatment of depression in Alzheimer's disease: a metaanalysis" (PDF). Canadian Journal of Psychiatry 52 (4): 248–55.  
  72. ^ Bains J, Birks JS, Dening TR (2002). Dening, Tom, ed. "The efficacy of antidepressants in the treatment of depression in dementia". Cochrane Database of Systematic Reviews (4): CD003944.  
  73. ^ American Geriatrics Society 2012 Beers Criteria Update Expert, Panel (April 2012). "American Geriatrics Society updated Beers Criteria for potentially inappropriate medication use in older adults.". Journal of the American Geriatrics Society 60 (4): 616–31.  
  74. ^ Lolk A, Gulmann NC (2006). "[Psychopharmacological treatment of behavioral and psychological symptoms in dementia]". Ugeskr Laeg (in Danish) 168 (40): 3429–32.  
  75. ^ Malouf, Reem; Evans, John Grimley (8 October 2008). "Folic acid with or without vitamin B12 for the prevention and treatment of healthy elderly and demented people". Cochrane database of systematic reviews (Online) (4): CD004514.  
  76. ^ a b c d e Hadjistavropoulos, T; Herr, K; Turk, DC; Fine, PG; Dworkin, RH; Helme, R; Jackson, K; et al. (2007). "An interdisciplinary expert consensus statement on assessment of pain in older persons". Clinical Journal of Pain 23 (1 suppl): S1–43.  
  77. ^ a b Shega, J; Emanuel, L; Vargish, L; Levine, S.K.; Bursch, H; Herr, K; Karp, J.F.; Weiner, D.K. (2007). "Pain in persons with dementia: complex, common, and challenging". Journal of Pain 8 (5): 373–8.  
  78. ^ Blyth, F; Cumming, M.R.; Mitchell, P; Wang, J.J. (2007). "Pain and falls in older people". European Journal of Pain 11 (5): 564–71.  
  79. ^ Brown, C. (2009). "Pain, aging and dementia: The crisis is looming, but are we ready?". British Journal of Occupational Therapy 72 (8): 371–75. 
  80. ^ Herr, K; Bjoro, K; Decker, S; Wang (2006). "Tools for assessment of pain in nonverbal older adults with dementia: a state-of-the-science review". Journal of pain and symptom management 31 (2): 170–92.  
  81. ^ Stolee, P; Hillier, LM; Esbaugh, et al.; Bol, N; McKellar, L; Gauthier, N (2005). "Instruments for the assessment of pain in older persons with cognitive impairment". Journal of the American geriatrics society 53 (2): 319–26.  
  82. ^ a b c  
  83. ^ Sampson, E.L.; Candy, B.; Jones, L. (15 April 2009). "Enteral tube feeding for older people with advanced dementia.". Cochrane database of systematic reviews (Online) (2): CD007209.  
  84. ^ Lockett MA, Templeton ML, Byrne TK, Norcross ED; Templeton; Byrne; Norcross (2002). "Percutaneous endoscopic gastrostomy complications in a tertiary-care center". Am Surg 68 (2): 117–20.  
  85. ^ Finocchiaro C, Galletti R, Rovera G et al. (1997). "Percutaneous endoscopic gastrostomy: a long-term follow-up". Nutrition 13 (6): 520–3.  
  86. ^ Thorgrimsen, L; Spector, A; Wiles, A; Orrell, M; Wiles, Anne; Orrell, Martin (2003). "Aroma therapy for dementia". The Cochrane database of systematic reviews (3): CD003150.  
  87. ^ Viggo Hansen, N; Jørgensen, T; Ørtenblad, L (Oct 18, 2006). "Massage and touch for dementia.". The Cochrane database of systematic reviews (4): CD004989.  
  88. ^ Sampson EL, Ritchie CW, Lai R, Raven PW, Blanchard MR; Ritchie; Lai; Raven; Blanchard (2005). "A systematic review of the scientific evidence for the efficacy of a palliative care approach in advanced dementia". Int Psychogeriatr 17 (1): 31–40.  
  89. ^ Van den Block L (2014). "The need for integrating palliative care in ageing and dementia policies". Eur J Public Health 24 (5): 705–6.  
  90. ^
  91. ^ Birch D, Draper J; Draper (2008). "A critical literature review exploring the challenges of delivering effective palliative care to older people with dementia". J Clin Nurs 17 (9): 1144–63.  
  92. ^ Prince, M; Jackson, J (2009). "World Alzheimer Report 2009". Alzheimer's Disease International: 38. Retrieved 11 March 2012. 
  93. ^ a b Sadock, Benjamin James Sadock, Virginia Alcott (2008). Kaplan & Sadock's concise textbook of clinical psychiatry (3rd ed.). Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins. p. 52.  
  94. ^ Prince, M.; Jackson, J. (2009). "World Alzheimer Report 2009". Alzheimer's Disease International: 36. Retrieved 11 March 2012. 
  95. ^ Berrios GE (1987). "Dementia during the seventeenth and eighteenth centuries: a conceptual history". Psychological Medicine 17 (4): 829–37.  
  96. ^  
  97. ^ Katzman, R. (1976). "The Prevalence and Malignancy of Alzheimer Disease: A Major Killer". Archives of Neurology 33 (4): 217–218.  
  98. ^ "National Alzheimer and Dementia Plans Planned Policies and Activities (PDF)".  
  99. ^ Boseley, Sarah (26 March 2012). "Dementia research funding to more than double to £66m by 2015".  
  100. ^ "Drivers with dementia a growing problem, MDs warn". CBC News, Canada. September 19, 2007. 
  101. ^ Thompson, S.B.N. "Testamentary capacity and cognitive rehabilitation: implications for head-injured and neurologically impaired individuals." Journal of Cognitive Rehabilitation 2009; 27(Fall): 11-13.

External links

Also, after 1952, mental illnesses like schizophrenia were removed from the category of

This suggestion opened the view that dementia is never normal, and must always be the result of a particular disease process, and is not part of the normal healthy aging process, per se. The ensuing debate led for a time to the proposed disease diagnosis of "senile dementia of the Alzheimer's type" (SDAT) in persons over the age of 65, with "Alzheimer's disease" diagnosed in persons younger than 65 who had the same pathology. Eventually, however, it was agreed that the age limit was artificial, and that Alzheimer's disease was the appropriate term for persons with the particular brain pathology seen in this disease, regardless of the age of the person with the diagnosis. A helpful finding was that although the incidence of Alzheimer's disease increased with age (from 5–10% of 75-year-olds to as many as 40–50% of 90-year-olds), there was no age at which all persons developed it, so it was not an inevitable consequence of aging, no matter how great an age a person attained. Evidence of this is shown by numerous documented supercentenarians (people living to 110+) that experienced no serious cognitive impairment. There is some evidence that dementia is most likely to develop between the ages of 80-84 and individuals who pass that point without being affected have a lower chance of developing it. Women account for a larger percentage of dementia cases than men, although this can be attributed to their longer overall lifespan and greater odds of attaining an age where the condition is likely to occur.

In 1976, neurologist Robert Katzmann suggested a link between senile dementia and Alzheimer's disease.[96] Katzmann suggested that much of the senile dementia occurring (by definition) after the age of 65, was pathologically identical with Alzheimer's disease occurring before age 65 and therefore should not be treated differently. He noted that the fact that "senile dementia" was not considered a disease, but rather part of aging, was keeping millions of aged patients experiencing what otherwise was identical with Alzheimer's disease from being diagnosed as having a disease process, rather than simply considered as aging normally.[97] Katzmann thus suggested that Alzheimer's disease, if taken to occur over age 65, is actually common, not rare, and was the 4th or 5th leading cause of death, even though rarely reported on death certificates in 1976.

By the period of 1913–20, schizophrenia had been well-defined in a way similar to today, and also the term dementia praecox had been used to suggest the development of senile-type dementia at a younger age. Eventually the two terms fused, so that until 1952 physicians used the terms dementia praecox (precocious dementia) and schizophrenia interchangeably. The term precocious dementia for a mental illness suggested that a type of mental illness like schizophrenia (including paranoia and decreased cognitive capacity) could be expected to arrive normally in all persons with greater age (see paraphrenia). After about 1920, the beginning use of dementia for what we now understand as schizophrenia and senile dementia helped limit the word's meaning to "permanent, irreversible mental deterioration." This began the change to the more recognizable use of the term today.

Much like other diseases associated with aging, dementia was comparatively rare before the 20th century, due to the fact that it is most common in people over 80, and such lifespans were uncommon in preindustrial times. Conversely, syphilitic dementia was widespread in the developed world until largely being eradicated by the use of penicillin after WWII. With significant increases in life expectancy following WWII, the number of people in developed countries over 65 started rapidly climbing. While elderly persons constituted an average of 3-5% of the population prior to 1945, by 2010 it was common in many countries to have 10-14% of people over 65 and in Germany and Japan, this figure exceeded 20%. Public awareness of Alzheimer's Disease was greatly increased in 1994 when former US president Ronald Reagan announced that he was suffering from the condition.

During the 19th century, doctors generally came to believe that dementia in the elderly was the result of cerebral atheroslerosis, although opinions fluctuated between the idea that it was due to blockage of the major arteries supplying the brain or small strokes within the vessels of the cerebral cortex. This viewpoint remained conventional medical wisdom through the first half of the 20th century, but by the 1960s was increasingly challenged as the link between neurodegenerative diseases and age-related cognitive decline was established. By the 1970s, the medical community maintained that vascular dementia was rarer than previously thought and Alzheimer's Disease caused the vast majority of mental impairments in old age. More recently however, it is believed that dementia is often a mixture of both conditions.

Dementia in the elderly was called senile dementia or senility, and viewed as a normal and somewhat inevitable aspect of growing old, rather than as being caused by any specific diseases. At the same time, in 1907, a specific organic dementing process of early onset, called Alzheimer's disease, had been described. This was associated with particular microscopic changes in the brain, but was seen as a rare disease of middle age because the first patient diagnosed with it was a 50-year old woman.

Poets, playwrights, and other writers however made frequent allusions to the loss of mental function in old age. Shakespeare notably mentions it in some of his plays including Hamlet and King Lear.

Otherwise, little is recorded about senile dementia in Western medical texts for nearly 1700 years. One of the few references to it was the 13th century friar Roger Bacon, who viewed old age as divine punishment for original sin. Although he repeated existing Aristotelian beliefs that dementia was inevitable after a long enough lifespan, he did make the extremely progressive assertion that the brain was the center of memory and thought rather than the heart.

Byzantine physicians sometimes wrote of dementia, and it is recorded that at least seven emperors whose lifespans exceeded the age of 70 displayed signs of cognitive decline. In Constantinople, there existed special hospitals to house those diagnosed with dementia or insanity, but these naturally did not apply to the emperors who were above the law and whose health conditions could not be publicly acknowledged.

For comparison, the Roman statesman Cicero held a view much more in line with modern-day medical wisdom that loss of mental function was not inevitable in the elderly and "affected only those old men who were weak-willed". He spoke of how those who remained mentally active and eager to learn new things could stave off dementia. However, Cicero's views on aging, although progressive, were largely ignored in a world that would be dominated by Aristotle's medical writings for centuries. Subsequent physicians during the time of Roman Empire such as Galen and Celsus simply repeated the beliefs of Aristotle while adding few new contributions to medical knowledge.

Aristotle and Plato both spoke of the mental decay of advanced age, but apparently simply viewed it as an inevitable process that affected all old men and which nothing could be done to prevent. The latter stated that the elderly were unsuited for any position of responsibility because "There is not much acumen of the mind that once carried them in their youth, those characteristics one would call judgement, imagination, power of reasoning, and memory. They see them gradually blunted by deterioration and can hardly fulfill their function."

Dementia has been referred to in medical texts since antiquity. One of the earliest known accounts was by the 7th century BC physician and mathematician Pythagoras, who divided the human lifespan into six distinct phases, which were 0-6 (infancy), 7-21 (adolescence), 22-49 (young adulthood), 50-62 (middle age), 63-79 (old age), and 80- (advanced age). The last two he described as the "senium", a period of mental and physical decay, and of the final phase being where "the scene of mortal existence closes after a great length of time that very fortunately, few of the human species arrive at, where the mind is reduced to the imbecility of the first epoch of infancy". In 550 BC, the Athenian statesman and poet Solon argued that the terms of a man's will might be invalidated if he exhibited loss of judgement due to advanced age. Chinese medical texts made allusions to the condition as well, and the characters for "dementia" translate literally to "foolish old person".

Until the end of the 19th century, dementia was a much broader clinical concept. It included mental illness and any type of psychosocial incapacity, including conditions that could be reversed.[95] Dementia at this time simply referred to anyone who had lost the ability to reason, and was applied equally to psychosis of mental illness, "organic" diseases like syphilis that destroy the brain, and to the dementia associated with old age, which was attributed to "hardening of the arteries."


In 2010 dementia resulted in about 486,000 deaths up from 141,000 in 1990.[18]

The number of cases of dementia worldwide in 2010 was estimated at 35.6 million.[92] Rates increase significantly with age, with dementia affecting 5% of the population older than 65 and 20–40% of those older than 85.[93] Around two thirds of individuals with dementia live in low and middle income countries, where the sharpest increases in numbers are predicted.[94] Rates are slightly higher in women than men at ages 65 and greater.[93]

Disability-adjusted life year for Alzheimer and other dementias per 100,000 inhabitants in 2002.


Given the progressive and terminal nature of dementia, palliative care can be helpful to patients and their caregivers by helping both people with the disease and their caregivers understand what to expect, deal with loss of physical and mental abilities, plan out a patient’s wishes and goals including surrogate decision making, and discuss wishes for or against CPR and life support.[88][89] Because the decline can be rapid, and because most people prefer to allow the person with dementia make his or her own decisions, palliative care involvement before the late stages of dementia is recommended.[90][91]

Palliative care

Other therapies that have been studied for effectiveness include aromatherapy with slight evidence,[86] massage with unclear evidence.[87]

Alternative medicine

Benefits of this procedure in those with advanced dementia has not been shown.[83] The risks of using tube feeding include agitation, the person pulling out the tube or otherwise being physically or chemically immobilized to prevent them from doing this, or getting pressure ulcers.[82] There is about a 1% fatality rate directly related to the procedure[84] with a 3% major complication rate.[85]

Persons with dementia may have difficulty eating. Whenever it is available as an option, the recommended response to eating problems is having a caretaker do assisted feeding for the patient.[82] A secondary option for patients who cannot swallow effectively is to consider gastrostomy feeding tube placement as a way to give nutrition. However, in bringing patient comfort and keeping functional status while lowering risk of aspiration pneumonia and death, assistance with oral feeding is at least as good as tube feeding.[82] Tube-feeding is associated with agitation, increased use of physical and chemical restraints and worsening pressure ulcers.

Eating difficulties

Although persistent pain in the person with dementia is difficult to communicate, diagnose and treat, failure to address persistent pain has profound functional, psychosocial and quality of life implications for this vulnerable population. Health professionals often lack the skills and usually lack the time needed to recognize, accurately assess and adequately monitor pain in people with dementia.[76][79] Family members and friends can make a valuable contribution to the care of a person with dementia by learning to recognize and assess their pain. Educational resources (such as the tutorial) and observational assessment tools are available.[76][80][81]

As people age, they experience more health problems, and most health problems associated with aging carry a substantial burden of pain; so, between 25% and 50% of older adults experience persistent pain. Seniors with dementia experience the same prevalence of conditions likely to cause pain as seniors without dementia.[76] Pain is often overlooked in older adults and, when screened for, often poorly assessed, especially among those with dementia since they become incapable of informing others that they're in pain.[76][77] Beyond the issue of humane care, unrelieved pain has functional implications. Persistent pain can lead to decreased ambulation, depressed mood, sleep disturbances, impaired appetite and exacerbation of cognitive impairment,[77] and pain-related interference with activity is a factor contributing to falls in the elderly.[76][78]


There is no solid evidence that folate or vitamin B12 improves outcomes in those with cognitive problems.[75]

It is recommended that benzodiazepines such as diazepam be avoided in dementia due to the risks of increased cognitive impairment and falls.[73] There is little evidence for the effectiveness in this population.[74]

Antidepressant drugs: Depression is frequently associated with dementia and generally worsens the degree of cognitive and behavioral impairment. Antidepressants effectively treat the cognitive and behavioral symptoms of depression in patients with Alzheimer's disease,[71] but evidence for their use in other forms of dementia is weak.[72]

N-methyl-D-aspartate (NMDA) receptor blockers such as memantine may be of benefit but the evidence is less conclusive than for AChEIs.[68] Due to their differing mechanisms of action memantine and acetylcholinesterase inhibitors can be used in combination however the benefit is slight.[69][70]

Antipsychotic drugs should be used to treat dementia only if non-drug therapies have failed to be effective and the person's actions threaten themselves or others.[66] Aggressive behavior changes are sometimes the result of other solvable problems, that could make treatment with antipsychotics unnecessary.[66] Because people with dementia can be aggressive, resistant to their treatment, and otherwise disruptive, sometimes antipsychotic drugs are considered as a therapy in response.[66] These drugs have risky adverse effects, including increasing the patient's chance of stroke and death.[66] Generally stopping antipsychotics for people with dementia does not cause problems, even in those who have been on them a long time.[67]

In a minority of people side effects include bradycardia and syncope.[65]

Acetylcholinesterase inhibitors, such as donepezil, may be useful for Alzheimer disease[62] and dementia in Parkinson's, DLB, or vascular dementia.[61] The quality of the evidence however is poor[63] and the benefit is small.[12] No difference has been shown between the agents in this family.[64]

Currently, no medications have been shown to prevent or cure dementia.[60] Medications may be used to treat the behavioural and cognitive symptoms but have no effect on the underlying disease process.[3][61]


Since dementia impairs normal communication due to changes in receptive and expressive language, as well as the ability to plan and problem solve, agitated behaviour is often a form of communication for the person with dementia and actively searching for a potential cause, such as pain, physical illness, or overstimulation can be helpful in reducing agitation.[58] Additionally, using an "ABC analysis of behaviour" can be a useful tool for understanding behavior in people with dementia. It involves looking at the antecedents (A), behavior (B), and consequences (C) associated with an event to help define the problem and prevent further incidents that may arise if the person's needs are misunderstood.[59]

Psychological therapies which are considered as a treatment for dementia include music therapy with unclear evidence,[52] tentative evidence for reminiscence therapy,[53] some benefit for cognitive reframing for caretakers,[54] unclear evidence for validation therapy,[55] and tentative evidence for mental exercise.[56] Adult daycare centers as well as special care units in nursing homes often provide specialized care for dementia patients. Adult daycare centers offer supervision, recreation, meals, and limited health care to participants, as well as providing respite for caregivers. In addition, home care can provide one-on-one support and care in the home allowing for more individualized attention that is needed as the disease progresses. Psychiatric nurses can make a distinctive contribution to people's mental health.[57]

Psychological therapies

Except for the treatable types listed above, there is no cure. Cholinesterase inhibitors are often used early in the disease course; however, benefit is generally small.[12][51] Cognitive and behavioral interventions may be appropriate. Educating and providing emotional support to the caregiver is of importance as well. Exercise programs are beneficial with respect to activities of daily living and potentially improve dementia.[13]


Many prevention measures have been proposed, including both lifestyle changes and medication although none has been reliably shown to be effective.


Recent research has established the value of PET imaging using carbon-11 Pittsburgh Compound B as a radiotracer (PIB-PET) in predictive diagnosis of various kinds of dementia, in particular Alzheimer's disease. Studies from Australia have found PIB-PET 86% accurate in predicting which patients with mild cognitive impairment would develop Alzheimer's disease within two years. In another study, carried out using 66 patients seen at the University of Michigan, PET studies using either PIB or another radiotracer, carbon-11 dihydrotetrabenazine (DTBZ), led to more accurate diagnosis for more than one-fourth of patients with mild cognitive impairment or mild dementia.[50]

The functional neuroimaging modalities of SPECT and PET are more useful in assessing long-standing cognitive dysfunction, since they have shown similar ability to diagnose dementia as a clinical exam and cognitive testing.[48] The ability of SPECT to differentiate the vascular cause (i.e., multi-infarct dementia) from Alzheimer's disease dementias, appears superior to differentiation by clinical exam.[49]

A CT scan or magnetic resonance imaging (MRI scan) is commonly performed, although these tests do not pick up diffuse metabolic changes associated with dementia in a person that shows no gross neurological problems (such as paralysis or weakness) on neurological exam. CT or MRI 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.


Testing for alcohol and other known dementia-inducing drugs may be indicated.

Routine blood tests are also 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. The problem is complicated by the fact that these cause confusion more often in persons who have early dementia, so that "reversal" of such problems may ultimately only be temporary.

Laboratory tests

Clinical neuropsychologists provide diagnostic consultation following administration of a full battery of cognitive testing, often lasting several hours, to determine functional patterns of decline associated with varying types of dementia. Tests of memory, executive function, processing speed, attention, and language skills are relevant, as well as tests of emotional and psychological adjustment. These tests assist with ruling out other etiologies and determining relative cognitive decline over time or from estimates of prior cognitive abilities.

Another approach to screening for dementia is to ask an informant (relative or other supporter) to fill out a questionnaire about the person's everyday cognitive functioning. Informant questionnaires provide complementary information to brief cognitive tests. Probably the best known questionnaire of this sort is the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE).[47] The Alzheimer's Disease Caregiver Questionnaire is another tool. It is about 90% accurate for Alzheimer's and can be completed online or in the office by a caregiver.[3] On the other hand the General Practitioner Assessment Of Cognition combines both, a patient assessment and an informant interview. It was specifically designed for the use in the primary care setting.

There are some brief tests (5–15 minutes) that have reasonable reliability to screen for dementia. While many tests have been studied,[39][40][41] presently the mini mental state examination (MMSE) is the best studied and most commonly used, albeit some may emerge as better alternatives. Other examples include the abbreviated mental test score (AMTS), the, Modified Mini-Mental State Examination (3MS),[42] the Cognitive Abilities Screening Instrument (CASI),[43] the Trail-making test,[44] and the clock drawing test.[45] The MOCA (Montreal Cognitive Assessment) is a very reliable screening test and is available online for free in 35 different languages.[3] The MOCA has also been shown to be somewhat better at detecting mild cognitive impairment than the MMSE.[46]

Sensitivity and specificity of common tests for dementia
Test Sensitivity Specificity Reference
MMSE 71%–92% 56%–96% [37]
3MS 83%–93.5% 85%–90% [38]
AMTS 73%–100% 71%–100% [38]

Cognitive testing

Some mental illnesses, including depression and psychosis, may produce symptoms that must be differentiated from both delirium and dementia.[36] Therefore, any dementia evaluation should include a depression screening such as the Neuropsychiatric Inventory or the Geriatric Depression Scale.[3] It used to be thought that anyone who came in with memory complaints had depression and not dementia (because it was thought that those with dementia are generally unaware of their memory problems). This is called pseudodementia. However, in recent years we have realized that many older people with memory complaints in fact have MCI, the earliest stage of dementia. Depression should always remain high on the list of possibilities, however, for an elderly person with memory trouble.

Normally, symptoms must be present for at least six months to support a diagnosis.[34] Cognitive dysfunction of shorter duration is called delirium. Delirium can be easily confused with dementia due to similar symptoms. Delirium is characterized by a sudden onset, fluctuating course, a short duration (often lasting from hours to weeks), and is primarily related to a somatic (or medical) disturbance. In comparison, dementia has typically a long, slow onset (except in the cases of a stroke or trauma), slow decline of mental functioning, as well as a longer duration (from months to years).[35]

As seen above, there are many specific types and causes of dementia, often showing slightly different symptoms. However, the symptoms are very similar and it is usually difficult to diagnose the type of dementia by symptoms alone. Diagnosis may be aided by brain scanning techniques. In many cases, the diagnosis cannot be absolutely sure except with a brain biopsy, but this is very rarely recommended (though it can be performed at autopsy). In those who are getting older, general screening for cognitive impairment using cognitive testing or early diagnosis of dementia has not been shown to improve outcomes.[33] However, it has been shown that screening exams are useful in those people over the age of 65 with memory complaints.[3]


At all ages, a substantial proportion of patients who complain of memory difficulty or other cognitive symptoms have depression rather than a neurodegenerative disease. Vitamin deficiencies and chronic infections may also occur at any age; they usually cause other symptoms before dementia occurs, but occasionally mimic degenerative dementia. These include deficiencies of vitamin B12, folate or niacin, and infective causes including cryptococcal meningitis, HIV, Lyme disease, progressive multifocal leukoencephalopathy, subacute sclerosing panencephalitis, syphilis and Whipple's disease.

In young adults (up to 40 years of age) who were previously of normal intelligence, it is very rare to develop dementia without other features of neurological disease, or without features of disease elsewhere in the body. Most cases of progressive cognitive disturbance in this age group are caused by psychiatric illness, alcohol or other drugs, or metabolic disturbance. However, certain genetic disorders can cause true neurodegenerative dementia at this age. These include familial Alzheimer's disease, SCA17 (dominant inheritance); adrenoleukodystrophy (X-linked); Gaucher's disease type 3, metachromatic leukodystrophy, Niemann-Pick disease type C, pantothenate kinase-associated neurodegeneration, Tay-Sachs disease and Wilson's disease (all recessive). Wilson's disease is particularly important since cognition can improve with treatment.

Dementia is much less common under 65 years of age. Alzheimer's disease is still the most frequent cause, but inherited forms of the disease account for a higher proportion of cases in this age group. Frontotemporal lobar degeneration and Huntington's disease account for most of the remaining cases.[31] Vascular dementia also occurs, but this in turn may be due to underlying conditions (including antiphospholipid syndrome, CADASIL, MELAS, homocystinuria, moyamoya and Binswanger's disease). People who receive frequent head trauma, such as boxers or football players, are at risk of chronic traumatic encephalopathy[32] (also called dementia pugilistica in boxers).

Causes of dementia depend on the age at which symptoms begin. In the elderly population (usually defined in this context as over 65 years of age), a large majority of dementia cases are caused by Alzheimer's disease, vascular dementia, or both. Dementia with Lewy bodies is another commonly exhibited form, which again may occur alongside either or both of the other causes.[28][29][30] Hypothyroidism sometimes causes slowly progressive cognitive impairment as the main symptom, and this may be fully reversible with treatment. Normal pressure hydrocephalus, though relatively rare, is important to recognize since treatment may prevent progression and improve other symptoms of the condition. However, significant cognitive improvement is unusual.

Dementia that begins gradually and worsens progressively over several years is usually caused by neurodegenerative disease—that is, by conditions that affect only or primarily the neurons of the brain and cause gradual but irreversible loss of function of these cells. Less commonly, a non-degenerative condition may have secondary effects on brain cells, which may or may not be reversible if the condition is treated.

Slowly progressive

Various types of brain injury may cause irreversible cognitive impairment that will not get worse over time. Traumatic brain injury may cause generalized damage to the white matter of the brain (diffuse axonal injury), or more localized damage (as also may neurosurgery). A temporary reduction in the brain's supply of blood or oxygen may lead to hypoxic-ischemic injury. Strokes (ischemic stroke, or intracerebral, subarachnoid, subdural or extradural hemorrhage) or infections (meningitis and/or encephalitis) affecting the brain, prolonged epileptic seizures and acute hydrocephalus may also have long-term effects on cognition. Excessive alcohol use may cause alcohol dementia, Wernicke's encephalopathy and/or Korsakoff's psychosis.

Fixed cognitive impairment

  • Memory or other cognitive (thought-processing) complaint by the person or a person who knows the patient well.
  • The person must have a memory or other cognitive problem as compared to a person of the same age and level of education.
  • The problem must not be severe enough to affect the person's daily function.
  • The person must not have dementia.

Diagnosis of MCI is often difficult, as cognitive testing may be normal. Often, more in-depth neuropsychological testing is necessary to make the diagnosis. the most commonly used criteria are called the Peterson criteria and include:

Mild cognitive impairment basically means that the person is exhibiting memory or thinking difficulties, but it is not severe enough yet to be given a diagnosis. He or she should score between 25-30 on the MMSE.[3] Around 70% of people with MCI will go on to develop some form of dementia.[3] MCI is generally divided into two categories. The first is one that is primarily memory loss (amnestic MCI). The second category is anything that is not primarily memory difficulties (non-amnestic MCI). People with primarily memory problems generally go on to develop Alzheimer's disease. People with the other type of MCI may go on to develop other types of dementia.

Mild cognitive impairment

Aside from those mentioned above, inherited conditions that can cause dementia (alongside other symptoms) include:[27]

There are many other medical and neurological conditions in which dementia only occurs late in the illness. For example, a proportion of patients with Parkinson's disease develop dementia, though widely varying figures are quoted for this proportion. When dementia occurs in Parkinson's disease, the underlying cause may be dementia with Lewy bodies or Alzheimer's disease, or both.[26] Cognitive impairment also occurs in the Parkinson-plus syndromes of progressive supranuclear palsy and corticobasal degeneration (and the same underlying pathology may cause the clinical syndromes of frontotemporal lobar degeneration). Chronic inflammatory conditions of the brain may affect cognition in the long term, including Behçet's disease, multiple sclerosis, sarcoidosis, Sjögren's syndrome and systemic lupus erythematosus. Although the acute porphyrias may cause episodes of confusion and psychiatric disturbance, dementia is a rare feature of these rare diseases.

Other conditions

On the other hand, encephalopathy or delirium may develop relatively slowly and resemble dementia. Possible causes include brain infection (viral encephalitis, subacute sclerosing panencephalitis, Whipple's disease) or inflammation (limbic encephalitis, Hashimoto's encephalopathy, cerebral vasculitis); tumors such as lymphoma or glioma; drug toxicity (e.g. anticonvulsant drugs); metabolic causes such as liver failure or kidney failure; and chronic subdural hematoma.

Creutzfeldt-Jakob disease typically causes a dementia that worsens over weeks to months, being caused by prions. The common causes of slowly progressive dementia also sometimes present with rapid progression: Alzheimer's disease, dementia with Lewy bodies, frontotemporal lobar degeneration (including corticobasal degeneration and progressive supranuclear palsy).

Rapidly progressive

The area of the brain most often affected in corticobasal degeneration is the posterior frontal lobe and parietal lobe. Still, many other part of the brain can be affected.[3]

Corticobasal degeneration is a rare form of dementia that is characterized by many different types of neurological problems that get progressively worse over time. This is because the disease affects the brain in many different places, but at different rates. One common sign is difficulty with using only one limb. One symptom that is extremely rare in any condition other than corticobasal degeneration is the "alien limb." The alien limb is a limb of the person that seems to have a mind of its own, it moves without control of the person's brain. Other common symptoms include jerky movements of one or more limbs (myoclonus), symptoms that are different in different limbs (asymmetric), difficulty with speech that is due to not being able to move the mouth muscles in a coordinated way, numbness and tingling of the limbs and neglecting one side of the person's vision or senses. In neglect, a person will ignore the opposite side of the body than the one that has the problem. For example, a person may not feel pain on one side, or may only draw half of a picture when asked. In addition, the person's affected limbs may be rigid or have muscle contractions causing strange repetitive movements (dystonia).[3]

Corticobasal degeneration

On scans of the brain, the midbrain of people with PSP is generally shrunken (atrophied), but there are no other common brain abnormalities visible on images of the person's brain.

Progressive supranuclear palsy (PSP) is a form of dementia that is characterized by problems with eye movements. Generally the problems begin with difficulty moving the eyes up and/or down (vertical gaze palsy). Since difficulty moving the eyes upward can sometimes happen in normal aging, problems with downward eye movements are the key in PSP. Other key symptoms of PSP include falls backwards, balance problems, slow movements, rigid muscles, irritability, apathy, social withdrawal and depression. The person may also have certain "frontal lobe signs" such as perseveration, a grasp reflex and utilization behavior (the need to use an object once you see it). People with PSP often have progressive difficulty eating and swallowing, and eventually with talking as well. Because of the rigidity and slow movements, PSP is sometimes misdiagnosed as Parkinson's disease.

Progressive supranuclear palsy

With both TV-FTD and PNFA the symptoms of behavior may be present, but milder and later than in bv-FTD. On imaging studies, there will be shrinking of the frontal and temporal lobes of the brain.

The last type of FTD is called progressive non-fluent aphasia (PNFA). This is mainly a problem with producing speech. They have trouble finding the right words, but mostly they have a difficulty coordinating the muscles they need to speak. Eventually, someone with PNFA will only use one-syllable words or may become totally mute.

The other two types of FTD feature language problems as the main symptom. The second type is called semantic dementia or temporal variant dementia (TV-FTD). The main feature of this is the loss of the meaning of words. It may begin with difficulty naming things. The person eventually may also lose the meaning of objects as well. For example, a drawing of a bird, dog, and an airplane in someone with FTD may all appear just about the same.[3] In a classic test for this, a patient is shown a picture of a pyramid and below there is a picture of both a palm tree and a pine tree. The person is asked to say which one goes best with the pyramid. In TV-FTD the person would not be able to answer that question.

There are three main types of FTD. The first has major symptoms in the area of personality and behavior. This is called behavioral variant FTD (bv-FTD) and is the most common. In bv-FTD, the person will have a change in personal hygiene, they will become rigid in their thinking, they rarely recognize that there is a problem, they will be socially withdrawn, and they will often have a drastic increase in appetite. The person may also be socially inappropriate. For example, the person may make inappropriate sexual comments, or may begin using pornography openly when they had not before. One of the most common signs is apathy, or not caring about anything. Apathy, however, is a common symptom in many different dementias.[3]

Frontotemporal dementia (FTD) is a dementia that is characterized by drastic personality changes and language difficulties. In all FTD the person will have a relatively early social withdrawal and early lack of insight into the disease. Memory problems are not a main feature of this disease.[3]

Frontotemporal dementia

Again, imaging studies cannot necessarily make the diagnosis of DLB, but some signs are particularly common. A person with DLB will often show occipital hypoperfusion on SPECT scan or occipital hypometabolism on a PET scan. Generally, a diagnosis of DLB is straightforward and unless it is complicated; a brain scan is not always necessary.[3]


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