dementia dementia dementia is a disorder which manifests as a set of related symptoms which results from a variety injuries and diseases. the most common form of dementia is alzheimer disease. the symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affects a person's ability to function and carry out everyday activities. aside from memory impairment and a disruption in thought patterns, the most common symptoms include emotional problems, difficulties with language, and decreased motivation. the symptoms may be described as occurring in a continuum over several stages. dementia ultimately has a significant effect on the individual, caregivers, and on social relationships in general. a diagnosis of dementia requires the observation of a change from a person's usual mental functioning and a greater cognitive decline than what is caused by normal aging. dementiaother namessenility, senile dementialithography of a man diagnosed with dementia in the 1800sspecialtyneurology, psychiatrysymptomsdecreased ability to think and remember, emotional problems, problems with language, decreased motivationcomplicationspoor nutrition, pneumonia, inability to perform self-care tasks, personal safety challenges, death.usual onsetgradualdurationlong termcausesalzheimer's disease, vascular disease, lewy body disease and frontotemporal lobar degeneration.diagnostic methodcognitive testing (mini-mental state examination)differential diagnosisdelirium, hypothyroidismpreventionearly education, prevent high blood pressure, prevent obesity, no smoking, social engagementtreatmentsupportive caremedicationacetylcholinesterase inhibitors (small benefit)frequency55 million (2021)deaths2.4 million (2016) several diseases and injuries to the brain such as a stroke can give rise to dementia. however, the most common cause is alzheimer's disease, a neurodegenerative disorder. the diagnostic and statistical manual of mental disorders, fifth edition (dsm-5), has re-described dementia as either a mild or major neurocognitive disorder with varying degrees of severity and many causative subtypes. the international classification of diseases (icd-11) also classes dementia as a neurocognitive disorder (ncd) with many forms or subclasses. dementia is listed as an acquired brain syndrome, marked by a decline in cognitive function, and is contrasted with neurodevelopmental disorders. dementia is also described as a spectrum of disorders with causative subtypes of dementia based on a known disorder, such as parkinson's disease, for parkinson's disease dementia; huntington's disease, for huntington's disease dementia; vascular disease, for vascular dementia; hiv infection, causing hiv dementia; frontotemporal lobar degeneration for frontotemporal dementia; or lewy body disease for dementia with lewy bodies, and prion diseases. subtypes of neurodegenerative dementias may also be based on the underlying pathology of misfolded proteins such as synucleinopathies, and tauopathies. more than one type of dementia existing together is known as mixed dementia. many neurocognitive disorders may be caused by another medical condition or disorder that includes brain tumours, and subdural hematoma; endocrine disorders such as hypothyroidism, and hypoglycemia; nutritional deficiencies including thiamine, and niacin; infections, immune disorders, liver or kidney failure, metabolic disorders such as kufs disease, and some leukodystrophies, and neurological disorders such as epilepsy, and multiple sclerosis. some of the neurocognitive deficits may sometimes show improvement with treatment of the medical condition. diagnosis is usually based on history of the illness and cognitive testing with imaging. blood tests may be taken to rule out other possible causes that may be reversible, such as hypothyroidism (an underactive thyroid), and to determine the dementia subtype. one commonly used cognitive test is the mini-mental state examination. the greatest risk factor for developing dementia is aging, however dementia is not a normal part of aging. many people aged 90 and above show no signs of dementia. several risk factors for dementia, such as smoking and obesity, are preventable by lifestyle changes. screening the general older population for the disorder is not seen to affect the outcome. dementia is currently the seventh leading cause of death worldwide and has 10 million new cases reported every year (one every ~3 seconds). there is no known cure for dementia. acetylcholinesterase inhibitors such as donepezil are often used and may be beneficial in mild to moderate disorder. the overall benefit, however, may be minor. there are many measures that can improve the quality of life of people with dementia and their caregivers. cognitive and behavioral interventions may be appropriate for treating associated symptoms of depression. signs and symptoms a drawing of a woman diagnosed with dementia a drawing of an old man diagnosed with senile dementia the signs and symptoms of dementia are termed as the neuropsychiatric symptoms, also known as the behavioral and psychological symptoms of dementia. behavioral symptoms can include agitation, restlessness, inappropriate behavior, sexual disinhibition, and aggression, which can be verbal or physical. these symptoms may result from impairments in cognitive inhibition. psychological symptoms can include depression, hallucinations (most often visual), and delusions, apathy, and anxiety. the most commonly affected areas include memory, visuospatial function affecting perception and orientation, language, attention and problem solving. the rate at which symptoms progress occurs on a continuum over several stages, and they vary across the dementia subtypes. most types of dementia are slowly progressive with some deterioration of the brain well established before signs of the disorder become apparent. often there are other conditions present such as high blood pressure, or diabetes, and there can sometimes be as many as four of these comorbidities. people with dementia are also more likely to have problems with incontinence: they are three times more likely to have urinary and four times more likely to have fecal incontinence compared to people of similar ages. dementia symptoms can vary widely from person to person. it affects memory, attention span, communication, reasoning, judgement, problem solving and visual perception, etc. signs that may point to dementia include getting lost in a familiar neighborhood, using unusual words to refer to familiar objects, forgetting the name of a close family member or friend, forgetting old memories, not being able to complete tasks independently, etc. stages the course of dementia is often described in four stages that show a pattern of progressive cognitive and functional impairment. however, the use of numeric scales allows for more detailed descriptions. these scales include the global deterioration scale for assessment of primary degenerative dementia (gds or reisberg scale), the functional assessment staging test (fast), and the clinical dementia rating (cdr). 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. pre-dementia pre-dementia states include pre-clinical and prodromal stages. the prodromal stages includes (1) mild cognitive impairment (mci), (2) delirium-onset, and psychiatric-onset presentations. pre-clinical sensory dysfunction is claimed for this stage which may precede the first clinical signs of dementia by up to ten years. most notably the sense of smell is lost. the loss of the sense of smell is associated with depression and loss of appetite leading to poor nutrition. it is suggested that this dysfunction may come about because the olfactory epithelium is exposed to the environment. the lack of blood–brain barrier protection here means that toxic elements can enter and cause damage to the chemosensory networks. prodromal pre-dementia states considered as prodromal are mild cognitive impairment (mci), and mild behavioral impairment (mbi). kynurenine is a metabolite of tryptophan that regulates microbiome signalling, 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. in this stage signs and symptoms may be subtle. often, the early signs become apparent when looking back. 70% of those diagnosed with mci later progress to dementia. in mci, changes in the person's brain have been happening for a long time, but 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. they may have some memory trouble and trouble finding words, but they solve everyday problems and competently handle their life affairs. during this stage, it is ideal to ensure that advance care planning has occurred to protect the wishes of the person. advance directives which are specific to dementia exist, which 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 – milder forms of the major neurocognitive disorder (dementia) subtypes. 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. the symptoms of early dementia usually include memory difficulty, but can also include some word-finding problems, and problems with executive functions of planning and organization. managing finances may prove difficult. other signs might be getting lost in new places, repeating things, and personality changes. 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. middle as dementia progresses, initial symptoms generally worsen. the rate of decline is different for each person. mmse scores between 6–17 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 usually also 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. a lack of insight into having the condition will become evident. late 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 their personal safety, and meeting of basic needs. if left unsupervised, they may 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 incontinent. 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. 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. 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. in some cases, there is a paradoxical lucidity immediately before death, where there is an unexpected recovery of mental clarity. subtypes many of the subtypes of dementia are neurodegenerative, and protein misfolding is a cardinal feature of these. alzheimer's disease main article: alzheimer's diseasebrain atrophy in severe alzheimer's alzheimer's disease accounts for 60–70% of cases of dementia worldwide. the most common symptoms of alzheimer's disease are short-term memory loss and word-finding difficulties. trouble with visuospatial functioning (getting lost often), reasoning, judgment and insight fail. insight refers to whether or not the person realizes they have memory problems. the part of the brain most affected by alzheimer's is the hippocampus. other parts that show atrophy (shrinking) include the temporal and parietal lobes. although this pattern of brain shrinkage suggests alzheimer's, it is variable and a brain scan is insufficient for a diagnosis. the relationship between general anesthesia and alzheimer's in elderly people is unclear. little is known about the events that occur during and that actually cause alzheimer's disease. this is due to the fact that brain tissue from patients with the disease can only be studied after the person's death. however, it is known that one of the first aspects of the disease is a dysfunction in the gene that produces amyloid. extracellular senile plaques (sps), consisting of beta-amyloid (aβ) peptides, and intracellular neurofibrillary tangles (nfts) that are