Editing Dementia (section)

== Stages ==
The course of dementia is often described in four stages (pre-dementia, early, middle, and late) that show a pattern of progressive cognitive and functional impairment. 

More detailed descriptions can be arrived at by the use of numeric scales. These scales include:
* The GDS/FAST Staging System<ref>{{cite journal  |title= The GDS/FAST Staging System |vauthors= Auer S, Reisbert B |journal= International Psychogeriatrics |date= December 1997 |volume= 9 |issue= Supplement 1 |pages= 167–171 |doi= 10.1017/S1041610297004869|doi-access= free |pmid= 9447440 }}</ref>
** Global Deterioration Scale (GDS or Reisberg Scale)<ref>{{cite journal |vauthors=Reisberg B, Ferris SH, de Leon MJ, Crook T |date=September 1982 |volume=139 |issue=9 |pages=1136–1139 |title=The Global Deterioration Scale for assessment of primary degenerative dementia |journal=Am J Psychiatry |pmid=7114305 |doi=10.1037/t48466-000}}</ref>
** Functional Assessment Staging Tool (FAST)<ref>{{cite journal |vauthors=Reisberg B, Ferris SH, Franssen E |title=An ordinal functional assessment tool for Alzheimer's-type dementia |journal=Hosp Community Psychiatry |date=June 1985 |volume=36 |issue=6 |pages=593–595 |doi=10.1176/ps.36.6.593 |pmid=4007814}}</ref>
** Brief Cognitive Rating Scale (BCRS)<ref>{{cite journal |vauthors= Reisberg B, Ferris SH |title= Brief Cognitive Rating Scale (BCRS) |journal= Psychopharmacol Bull |year= 1988 |volume= 24  |issue= 4  |pages=629–36 |pmid= 3249764 }}</ref><ref>Allen, D.N. (2011). Brief Cognitive Rating Scale. In: Kreutzer, J.S., DeLuca, J., Caplan, B. (eds) Encyclopedia of Clinical Neuropsychology. Springer, New York, NY. https://doi.org/10.1007/978-0-387-79948-3_168</ref>
* [[Clinical Dementia Rating]] (CDR)<ref>{{cite web |author=<!-- not stated --> |date= 2025 |title= CDR® Dementia Staging Instrument |url= https://knightadrc.wustl.edu/professionals-clinicians/cdr-dementia-staging-instrument/ |website= Knight Alzheimer Disease Research Center |location= |publisher= [[Washington University School of Medicine|Washington University School of Medicine in St. Louis]] |access-date= January 23, 2025}}</ref><ref name="Sheehan"/> 
Using the GDS, which more accurately identifies each stage of the disease progression, a more detailed course is described in seven stages – two of which are broken down further into five and six degrees. Stage 7(f) is the final stage.<ref name="DCC">{{cite web |title=Seven Stages of Dementia {{!}} Symptoms, Progression & Durations |url=https://www.dementiacarecentral.com/aboutdementia/facts/stages/ |access-date=December 19, 2020}}</ref><ref name="ALZ">{{cite web |title=Clinical Stages of Alzheimer's |url=https://www.alzinfo.org/understand-alzheimers/clinical-stages-of-alzheimers/ |website=Fisher Center for Alzheimer's Research Foundation |access-date=December 19, 2020 |date=January 29, 2014}}</ref>

===Pre-dementia===
Pre-dementia includes pre-clinical and [[prodromal]] stages. The latter stage includes [[mild cognitive impairment]] (MCI), delirium-onset, and psychiatric-onset presentations.<ref>{{Cite web |author=Scharre DW |title=Preclinical, Prodromal, and Dementia Stages of Alzheimer's Disease |url=https://practicalneurology.com/articles/2019-june/preclinical-prodromal-and-dementia-stages-ofalzheimers-disease |date=June 2019 |access-date=June 28, 2022 |website=Practical Neurology |language=en}}</ref>

====Pre-clinical====
Sensory dysfunction is claimed for the pre-clinical stage, which may precede the first clinical signs of dementia by up to ten years.<ref name="Bathini"/> Most notably the [[sense of smell]] is lost,<ref name="Bathini">{{cite journal | vauthors = Bathini P, Brai E, Auber LA | title = Olfactory dysfunction in the pathophysiological continuum of dementia | journal = Ageing Research Reviews | volume = 55 | page = 100956 | date = November 2019 | pmid = 31479764 | doi = 10.1016/j.arr.2019.100956 | url = http://doc.rero.ch/record/327719/files/alb_odp.pdf | s2cid = 201742825 }}</ref><ref name="Bhatia-Dey">{{cite journal |vauthors=Bhatia-Dey N, Heinbockel T |title=The Olfactory System as Marker of Neurodegeneration in Aging, Neurological and Neuropsychiatric Disorders |journal=Int J Environ Res Public Health |volume=18 |issue=13 |date=June 2021 |page=6976 |pmid=34209997 |doi=10.3390/ijerph18136976 |pmc=8297221 |doi-access=free }}</ref> associated with depression and a loss of appetite leading to poor nutrition.<ref name=Boesveldt>{{cite journal |vauthors=Boesveldt S, Parma V |title=The importance of the olfactory system in human well-being, through nutrition and social behavior |journal=Cell Tissue Res |volume=383 |issue=1 |pages=559–567 |date=January 2021 |pmid=33433688 |pmc=7802608 |doi=10.1007/s00441-020-03367-7}}</ref> It is suggested that [[Anosmia|this dysfunction]] may come about because the [[olfactory epithelium]] is exposed to the environment, and the lack of [[blood–brain barrier]] protection allows toxic elements to enter and cause damage to the [[chemosensory]] networks.<ref name="Bathini"/>

====Prodromal====
Pre-dementia states considered as prodromal are [[mild cognitive impairment]] (MCI) and ''mild behavioral impairment'' (MBI).<ref name=Sherman>{{cite journal |vauthors=Sherman C, Liu CS, Herrmann N, Lanctôt KL |title=Prevalence, neurobiology, and treatments for apathy in prodromal dementia |journal=Int Psychogeriatr |volume=30 |issue=2 |pages=177–184 |date=February 2018 |pmid=28416030 |doi=10.1017/S1041610217000527 |s2cid=46788701 |doi-access=free }}</ref><ref name="Breton">{{cite journal | vauthors = Breton A, Casey D, Arnaoutoglou NA | title = Cognitive tests for the detection of mild cognitive impairment (MCI), the prodromal stage of dementia: Meta-analysis of diagnostic accuracy studies | journal = International Journal of Geriatric Psychiatry | volume = 34 | issue = 2 | pages = 233–242 | date = February 2019 | pmid = 30370616 | doi = 10.1002/gps.5016 | s2cid = 53097138 }}</ref><ref name="Bateman">{{cite journal |vauthors=Bateman DR, Gill S, Hu S, Foster ED, Ruthirakuhan MT, Sellek AF, Mortby ME, Matušková V, Ng KP, Tarawneh RM, Freund-Levi Y, Kumar S, Gauthier S, Rosenberg PB, Ferreira de Oliveira F, Devanand DP, Ballard C, Ismail Z |title=Agitation and impulsivity in mid and late life as possible risk markers for incident dementia |journal= Alzheimer's & Dementia: Translational Research & Clinical Interventions|volume=6 |issue=1 |page=e12016 |date=2020 |pmid=32995467 |pmc=7507499 |doi=10.1002/trc2.12016}}</ref> Signs and symptoms at the prodromal stage may be subtle, and the early signs often become apparent only in hindsight.<ref name="ADCS">{{cite journal |vauthors=Atri A |title=The Alzheimer's Disease Clinical Spectrum: Diagnosis and Management |journal=Med Clin North Am |volume=103 |issue=2 |pages=263–293 |date=March 2019 |pmid=30704681 |doi=10.1016/j.mcna.2018.10.009 |doi-access=free }}</ref> Of those diagnosed with MCI, 70% later progress to dementia.<ref name="Memory Loss" /> In mild cognitive impairment, changes in the person's brain have been happening for a long time, but the symptoms are just beginning to appear. These problems, however, are not severe enough to affect daily function. If and when they do, the diagnosis becomes dementia. The person may have some memory problems and trouble finding words, but they can solve everyday problems and competently handle their life affairs.<ref name="hugo">{{cite journal | vauthors = Hugo J, Ganguli M | title = Dementia and cognitive impairment: epidemiology, diagnosis, and treatment | journal = Clinics in Geriatric Medicine | volume = 30 | issue = 3 | pages = 421–442 | date = August 2014 | pmid = 25037289 | pmc = 4104432 | doi = 10.1016/j.cger.2014.04.001 }}</ref> During this stage, it is ideal to ensure that [[advance care planning]] has occurred to protect the person's wishes. [[Advance healthcare directive|Advance directives]] exist that are specific to people living with dementia.<ref>{{Cite web |title=Advance Directive for Dementia |url=https://dementia-directive.org/ |access-date=January 12, 2023 |website=dementia-directive.org |language=en-US}}</ref> These can be particularly helpful in addressing the decisions related to feeding which come with the progression of the illness. Mild cognitive impairment has been relisted in both [[DSM-5]] and [[ICD-11]] as "mild neurocognitive disorders", i.e. milder forms of the major neurocognitive disorder (dementia) subtypes.<ref name="DSM5">{{cite book | author = American Psychiatric Association |url=https://archive.org/details/diagnosticstatis0005unse/page/591|title=Diagnostic and statistical manual of mental disorders : DSM-5|date=2013|publisher=American Psychiatric Association|isbn=978-0-89042-554-1|edition=5th|location=Washington, DC|pages=[https://archive.org/details/diagnosticstatis0005unse/page/591 591–603]}}</ref>

[[Kynurenine]] is a metabolite of [[tryptophan]] that regulates microbiome signaling, immune cell response, and neuronal excitation. A disruption in the [[kynurenine pathway]] may be associated with the neuropsychiatric symptoms and cognitive prognosis in mild dementia.<ref name=Cervenka>{{cite journal |vauthors=Cervenka I, Agudelo LZ, Ruas JL |title=Kynurenines: Tryptophan's metabolites in exercise, inflammation, and mental health |journal=Science |volume=357 |issue=6349 |at=eaaf9794 |date=July 2017 |pmid=28751584 |doi=10.1126/science.aaf9794 |doi-access=free}}</ref><ref name=Solvang>{{cite journal |vauthors=Solvang SH, Nordrehaug JE, Aarsland D, et al |title=Kynurenines, Neuropsychiatric Symptoms, and Cognitive Prognosis in Patients with Mild Dementia |journal=Int J Tryptophan Res |volume=12 |issue= |page=1178646919877883 |date=2019 |pmid=31632053 |pmc=6769202 |doi=10.1177/1178646919877883}}</ref>

=== Early ===
In the early stage of dementia, symptoms become noticeable to other people. In addition, the symptoms begin to interfere with daily activities, and will register a score on a [[mini–mental state examination]] (MMSE). MMSE scores are set at 24 to 30 for a normal cognitive rating and lower scores reflect severity of symptoms. The symptoms are dependent on the type of dementia. More complicated chores and tasks around the house or at work become more difficult. The person can usually still take care of themselves but may forget things like taking pills or doing laundry and may need prompting or reminders.<ref>{{Cite book|title=Dementia care at a glance| vauthors = Jenkins C, Ginesi L, Keenan B |isbn=978-1-118-85998-8|location=Chichester, West Sussex | publisher = John Wiley & Sons |oclc=905089525|year = 2016}}</ref>

The symptoms of early dementia usually include memory difficulty, but can also include some [[anomic aphasia|word-finding problems]], and problems with [[executive functions]] of planning and organization.<ref>{{cite journal |author5-link=Martin Rossor | vauthors = Rohrer JD, Knight WD, Warren JE, Fox NC, Rossor MN, Warren JD | title = Word-finding difficulty: a clinical analysis of the progressive aphasias | journal = Brain | volume = 131 | issue = Pt 1 | pages = 8–38 | date = January 2008 | pmid = 17947337 | pmc = 2373641 | doi = 10.1093/brain/awm251 }}</ref> Managing finances may prove difficult. Other signs might be getting lost in new places, repeating things, and personality changes.<ref>{{cite journal | vauthors = Islam M, Mazumder M, Schwabe-Warf D, Stephan Y, Sutin AR, Terracciano A | title = Personality Changes With Dementia From the Informant Perspective: New Data and Meta-Analysis | journal = Journal of the American Medical Directors Association | volume = 20 | issue = 2 | pages = 131–137 | date = February 2019 | pmid = 30630729 | pmc = 6432780 | doi = 10.1016/j.jamda.2018.11.004 }}</ref>

In some types of dementia, such as [[dementia with Lewy bodies]] and [[frontotemporal dementia]], personality changes and difficulty with organization and planning may be the first signs.<ref>{{cite web | title = Diagnosing Lewy Body Dementia | publisher = National Institute on Aging | url = https://www.nia.nih.gov/health/diagnosing-lewy-body-dementia | access-date = May 10, 2020}}</ref>

=== Middle ===
As dementia progresses, initial symptoms generally worsen. The rate of decline is different for each person. MMSE scores between 6 and 17 signal moderate dementia. For example, people with moderate Alzheimer's dementia lose almost all new information. People with dementia may be severely impaired in solving problems, and their social judgment is often impaired. They cannot usually function outside their own home, and generally should not be left alone. They may be able to do simple chores around the house but not much else, and begin to require assistance for personal care and hygiene beyond simple reminders.<ref name="Memory Loss" /> A [[anosognosia|lack of insight]] into having the condition will become evident.<ref name="Wilson">{{cite journal |vauthors=Wilson RS, Sytsma J, Barnes LL, Boyle PA |title=Anosognosia in Dementia |journal=Current Neurology and Neuroscience Reports |volume=16 |issue=9 |page=77 |date=September 2016 |pmid=27438597 |doi=10.1007/s11910-016-0684-z|s2cid=3331009 }}</ref><ref name="CNN">{{cite journal |vauthors=Sunderaraman P, Cosentino S |title=Integrating the Constructs of Anosognosia and Metacognition: a Review of Recent Findings in Dementia |journal=Current Neurology and Neuroscience Reports |volume=17 |issue=3 |page=27 |date=March 2017 |pmid=28283961 |doi=10.1007/s11910-017-0734-1|pmc=5650061 }}</ref>

=== Late ===
People with late-stage dementia typically turn increasingly inward and need assistance with most or all of their personal care. People with dementia in the late stages usually need 24-hour supervision to ensure their personal safety, and meeting of basic needs. If left unsupervised, they may [[Wandering (dementia)|wander]] or fall; may not recognize common dangers such as a hot stove; or may not realize that they need to use the bathroom and become [[Urinary incontinence|incontinent]].<ref name=hugo/> They may not want to get out of bed, or may need assistance doing so. Commonly, the person no longer recognizes familiar faces. They may have significant changes in sleeping habits or have trouble sleeping at all.<ref name="Memory Loss" />

Changes in eating frequently occur. Cognitive awareness is needed for eating and swallowing and progressive cognitive decline results in eating and [[swallowing difficulties]]. This can cause food to be refused, or choked on, and help with feeding will often be required.<ref name="Payne">{{cite journal | vauthors = Payne M, Morley JE | title = Editorial: Dysphagia, Dementia and Frailty | journal = The Journal of Nutrition, Health & Aging | volume = 22 | issue = 5 | pages = 562–565 | date = May 1, 2018 | pmid = 29717753 | doi = 10.1007/s12603-018-1033-5 | s2cid = 13753522 | doi-access = free }}</ref> For ease of feeding, food may be liquidized into a thick purée. They may also struggle to walk, particularly among those with [[Alzheimer's disease]].<ref name="Sala Della et al. 2004">{{cite journal | vauthors = Della Sala S, Spinnler H, Venneri A | title = Walking difficulties in patients with Alzheimer's disease might originate from gait apraxia | journal = Journal of Neurology, Neurosurgery, and Psychiatry | volume = 75 | issue = 2 | pages = 196–201 | date = February 2004 | pmid = 14742586 | pmc = 1738895 | url = https://jnnp.bmj.com/content/jnnp/75/2/196.full.pdf | url-status = live | archive-url = https://ghostarchive.org/archive/20221009/https://jnnp.bmj.com/content/jnnp/75/2/196.full.pdf | archive-date = October 9, 2022 }}</ref><ref>{{cite journal | vauthors = Mc Ardle R, Galna B, Donaghy P, Thomas A, Rochester L | title = Do Alzheimer's and Lewy body disease have discrete pathological signatures of gait? | journal = Alzheimer's & Dementia | volume = 15 | issue = 10 | pages = 1367–1377 | date = October 2019 | pmid = 31548122 | doi = 10.1016/j.jalz.2019.06.4953 | doi-access = free }}</ref><ref>{{cite web |title=Mental, physical and speech abilities in later stages of dementia |url=https://www.alzheimers.org.uk/about-dementia/symptoms-and-diagnosis/how-dementia-progresses/mental-and-physical-activities |website=Alzheimer's Society |date=June 29, 2022 |access-date=July 30, 2022}}</ref> In some cases, [[terminal lucidity]], a form of [[paradoxical lucidity]], occurs immediately before death; in this phenomenon, there is an unexpected recovery of mental clarity.<ref>{{cite journal | vauthors = Mashour GA, Frank L, Batthyany A, Kolanowski AM, Nahm M, Schulman-Green D, Greyson B, Pakhomov S, Karlawish J, Shah RC | display-authors = 6 | title = Paradoxical lucidity: A potential paradigm shift for the neurobiology and treatment of severe dementias | journal = Alzheimer's & Dementia | volume = 15 | issue = 8 | pages = 1107–1114 | date = August 2019 | pmid = 31229433 | doi = 10.1016/j.jalz.2019.04.002 | doi-access = free | hdl = 2027.42/153062 | hdl-access = free }}</ref>