Cognitive disorders (CDs), also known as neurocognitive disorders (NCDs), are a category of mental health disorders that primarily affect cognitive abilities including learning, memory, perception, and problem-solving. Neurocognitive disorders include delirium, mild neurocognitive disorders, and major neurocognitive disorder (also known as dementia). They are defined by deficits in cognitive ability that are acquired (as opposed to developmental), typically represent decline, and may have an underlying brain pathology.[1] The DSM-5 defines six key domains of cognitive function: executive function, learning and memory, perceptual-motor function, language, complex attention, and social cognition.[2]
Although Alzheimer's disease accounts for the majority of cases of neurocognitive disorders, there are various medical conditions that affect mental functions such as memory, thinking, and the ability to reason, including frontotemporal degeneration, Huntington's disease, dementia with Lewy bodies, traumatic brain injury (TBI), Parkinson's disease, prion disease, and dementia/neurocognitive issues due to HIV infection.[3] Neurocognitive disorders are diagnosed as mild and major based on the severity of their symptoms. While anxiety disorders, mood disorders, and psychotic disorders can also have an effect on cognitive and memory functions, they are not classified under neurocognitive disorders because loss of cognitive function is not the primary (causal) symptom.[4][5] Additionally, developmental disorders such as autism typically have a genetic basis and become apparent at birth or early in life as opposed to the acquired nature of neurocognitive disorders.
Causes vary between the different types of disorders but most include damage to the memory portions of the brain.[6][7][8] Treatments depend on how the disorder is caused. Medication and therapies are the most common treatments; however, for some types of disorders such as certain types of amnesia, treatments can suppress the symptoms but there is currently no cure.[7][8]
Classifications
editThe previous edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) included a section entitled "Delirium, Dementia and Amnestic and Other Cognitive Disorders," which was revised in DSM-5 to the broader "Neurocognitive Disorders." Neurocognitive disorders are described as those with "a significant impairment of cognition or memory that represents a marked deterioration from a previous level of function".[4] The main principle distinguishing neurocognitive disorders from mood disorders and other psychiatric conditions that involve a cognitive component (i.e. increased lapses in memory noted by patients with depression) is that cognitive decline is the "defining characteristic" of the disorder.[2][5] Additionally, the term "neurocognitive" was added because these disorders most often have alterations/disfunction in neural physiology (i.e. amyloid plaque build-up in Alzheimer disease).[5] The subsections include delirium, mild neurocognitive disorder, and major neurocognitive disorder.
Delirium
editDelirium is a type of neurocognitive disorder that develops rapidly over a short period of time. Delirium may be described using many other terms, including: encephalopathy, altered mental status, altered level of consciousness, acute mental status change, and brain failure. It is described in the DSM-5 as a fluctuating acute change in mental status with associated changes in cognition, attention, and level of consciousness.[9] The onset of delirium can vary from minutes to hours and sometimes days. However, the course of the delirium typically lasts from a few hours to weeks, depending on the underlying cause.[4] Delirium can also be accompanied by a shift in attention, mood swings, violent or unordinary behaviors, and hallucinations. Additionally, changes in cognition can makes situational awareness and processing new information very difficult for patients. Delirium is most common in hospitalized patients, appearing in 18-35% of patients requiring hospital admission.[9] It is also a diagnosis which can be acquired during hospital stays, typically by elderly patients or those with risk factors of delirium. While it is a common diagnosis, delirium can increase the risk of a longer hospital stay and the risk of complications throughout the hospital stay.[9][10]
Mild Neurocognitive Disorder
editMild neurocognitive disorders, also referred to as mild cognitive impairment (MCI), can be thought of as a middle ground between normal aging and major neurocognitive disorder.[11] Unlike delirium, mild neurocognitive disorders tend to develop slowly and are characterized by a progressive memory loss which may or may not progress to major neurocognitive disorder.[11] Studies have shown that between 5-17% of patients with mild cognitive disorder will progress to major neurocognitive disorder each year.[11][12] The likelihood of developing mild neurocognitive disorder increases with age, affecting 10-20% of adults ages 65 and older. Men also seem to be at a higher risk of developing mild neurocognitive disorder.[13] In addition to memory loss and cognitive impairment, other symptoms include aphasia, apraxia, agnosia, loss of abstract thought, behavioral/personality changes, and impaired judgment.
Major Neurocognitive Disorder
editMild and major neurocognitive disorders are differentiated based on the severity of their symptoms. Also still known as dementia, major neurocognitive disorder is characterized by significant cognitive decline and interference with independence, while mild neurocognitive disorder is characterized by moderate cognitive decline and does not interfere with independence. To be diagnosed, it must not be due to delirium or other mental disorder. They are also usually accompanied by another cognitive dysfunction.[4] For non-reversible causes of dementia such as age, the slow decline of memory and cognition is lifelong.[4]
Diagnostic Methods
editThere are multiple testing methods used to assess a patient's cognition and level of consciousness, including the Mini Mental Status Exam (MMSE), Montreal Cognitive Assessment (MoCA), Mini-Cog, and Cognitive Assessment Method (CAM), Glasgow Coma Score (GCS), Richmond Agitation and Sedation Scale (RASS), etc. The CAM has been shown to be the most commonly used tool to assess for delirium.[9][14][15] Additionally, a meta-analysis looking at the accuracy and usefulness of the various testing methods reported that the MMSE was the most commonly used tool to evaluate major neurocognitive disorder, while the MoCA appeared to be the most useful when screening for minor neurocognitive disorder.[15] More recent systematic reviews have demonstrated the need for further, well designed research on the Mini-Cog and MoCA for evaluating cognitive decline and the development of clinical guidelines on their use in various settings. [16][17]
Causes
editDelirium
editThere are many causes of delirium, and many times there are multiple factors that can be contributing to delirium, particularly in the hospital setting. Common potential causes of delirium include new or worsening infections (i.e. urinary tract infections, pneumonia, and sepsis), neurological injury/infections (i.e. stroke and meningitis), environmental factors (i.e. immobilization and sleep deprivation), and medication/drug use (i.e. side effects of new medications, drug interactions, and use/withdrawal from recreational drugs).[6][14][18][19]
Mild and major neurocognitive disorder
editNeurocognitive disorders can have numerous causes: genetics, brain trauma, stroke, and heart issues. The main causes are neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Huntington's disease because they affect or deteriorate brain functions.[7] Other diseases and conditions that cause NCDs include vascular dementia, frontotemporal degeneration, Lewy body disease, prion disease, normal pressure hydrocephalus, and dementia/neurocognitive issues due to HIV infection (AIDS).[20] They may also include dementia due to substance abuse or exposure to toxins.
Neurocognitive disorders may also be caused by brain trauma, including concussions and traumatic brain injuries, as well as post-traumatic stress and alcoholism. This is referred to as amnesia, and is characterized by damage to major memory encoding parts of the brain such as the hippocampus.[8] Difficulty creating recent term memories is called anterograde amnesia and is caused by damage to the hippocampus part of the brain, which is a major part of the memory process.[8] Retrograde amnesia is also caused by damage to the hippocampus, but the memories that were encoded or in the process of being encoded in long-term memory are erased[8]
Treatment
editDelirium
editThe overarching principle of delirium treatment is finding and treating the underlying cause. If the patient is truly experiencing delirium, their symptoms should begin improving/resolving with proper treatment of their illness, intoxication, etc.[9] Medication such as antipsychotics or benzodiazepines can help reduce the symptoms for some cases. For alcohol or malnourished cases, vitamin B supplements are recommended and for extreme cases, life-support can be used.[6]
Mild and Major Neurocognitive Disorder
editThere is no cure for neurocognitive disorder or the diseases that cause it. Antidepressants, antipsychotics, and other medications that help slow the progression of memory loss/behavioral symptoms are available and may help to treat the diseases.[citation needed] Ongoing psychotherapy and psychosocial support for patients and families are usually necessary for clear understanding and proper management of the disorder and to maintain a better quality of life for everyone involved; although older patients with major neurocognitive disorders usually require assistance with their daily activities leading to placement in long-term care homes.[21][22][23] Speech therapy has been shown to help with language impairment, therefore improving long-term development and academic outcome.[24]
Studies suggest that diets with high Omega 3 content, low in saturated fats and sugars, along with regular exercise can increase the level of brain plasticity.[25] Other studies have shown that mental exercise such a newly developed "computerized brain training programs" can also help build and maintain targeted specific areas of the brain. These studies have been very successful for those diagnosed with schizophrenia and can improve fluid intelligence, the ability to adapt and deal with new problems or challenges the first time encountered, and in young people, it can still be effective in later life.[8]
See also
editReferences
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- ^ a b American Psychiatric Association (2013). Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5®). American Psychiatric Publishing. ISBN 978-0-89042-557-2. OCLC 1027531237.
- ^ Simpson JR (2014). "DSM-5 and neurocognitive disorders". J. Am. Acad. Psychiatry Law. 42 (2): 159–64. PMID 24986342.
- ^ a b c d e Guerrero, Anthony (2008). Problem-Based Behavioral Science of Medicine. New York: Springer. pp. 367–79.
- ^ a b c Sachdev, Perminder S.; Blacker, Deborah; Blazer, Dan G.; Ganguli, Mary; Jeste, Dilip V.; Paulsen, Jane S.; Petersen, Ronald C. (2014-11-01). "Classifying neurocognitive disorders: the DSM-5 approach". Nature Reviews Neurology. 10 (11): 634–643. doi:10.1038/nrneurol.2014.181. PMID 25266297. S2CID 20635070.
- ^ a b c Torpy, Janet (2008). "Delirium". The Journal of the American Medical Association. 300 (19): 2936. doi:10.1001/jama.300.24.2936. PMID 19109124.
- ^ a b c Torpy, Janet (2010). "Dementia". The Journal of the American Medical Association. 304 (7): 1972. doi:10.1001/jama.304.17.1972. PMID 21045107.
- ^ a b c d e f Ciccarelli, Saundra K.; White, J. Noland (2014). Psychology. Pearson Education. ISBN 978-0-205-97245-6.{
- ^ a b c d e Setters, Belinda; Solberg, Laurence M. (2017). "Delirium". Primary Care: Clinics in Office Practice. Geriatrics. 44 (3): 541–559. doi:10.1016/j.pop.2017.04.010. PMID 28797379.
- ^ McGohan (2005). "Clinical Updates. Delirium". The Journal of Continuing Education in Nursing. 36 (3): 102–3. doi:10.3928/0022-0124-20050501-05. PMID 16022028.
- ^ a b c Jongsiriyanyong, Sukanya; Limpawattana, Panita (2018). "Mild Cognitive Impairment in Clinical Practice: A Review Article". American Journal of Alzheimer's Disease & Other Dementias. 33 (8): 500–7. doi:10.1177/1533317518791401. PMC 10852498. PMID 30068225. S2CID 51891998.
- ^ Li, Jie-Qiong; Tan, Lan; Wang, Hui-Fu; Tan, Meng-Shan; Tan, Lin; Xu, Wei; Zhao, Qing-Fei; Wang, Jun; Jiang, Teng; Yu, Jin-Tai (2015). "Risk factors for predicting progression from mild cognitive impairment to Alzheimer's disease: a systematic review and meta-analysis of cohort studies". Journal of Neurology, Neurosurgery & Psychiatry. 87 (5): 476–484. doi:10.1136/jnnp-2014-310095. PMID 26001840. S2CID 15092127.
- ^ Langa, Kenneth M.; Levine, Deborah A. (2014). "The Diagnosis and Management of Mild Cognitive Impairment: A Clinical Review". JAMA. 312 (23): 2551–61. doi:10.1001/jama.2014.13806. PMC 4269302. PMID 25514304.
- ^ a b Wilber, Scott T.; Ondrejka, Jason E. (2016). "Altered Mental Status and Delirium". Emergency Medicine Clinics of North America. Geriatric Emergencies. 34 (3): 649–665. doi:10.1016/j.emc.2016.04.012. PMID 27475019.
- ^ a b Tsoi, Kelvin K. F.; Chan, Joyce Y. C.; Hirai, Hoyee W.; Wong, Samuel Y. S.; Kwok, Timothy C. Y. (2015). "Cognitive Tests to Detect Dementia: A Systematic Review and Meta-analysis". JAMA Internal Medicine. 175 (9): 1450–8. doi:10.1001/jamainternmed.2015.2152. PMID 26052687.
- ^ Davis, Daniel HJ; Creavin, Samuel T; Yip, Jennifer LY; Noel-Storr, Anna H; Brayne, Carol; Cullum, Sarah (2021-07-13). Cochrane Dementia and Cognitive Improvement Group (ed.). "Montreal Cognitive Assessment for the detection of dementia". Cochrane Database of Systematic Reviews. 2021 (7): CD010775. doi:10.1002/14651858.CD010775.pub3. PMC 8407452. PMID 34255351.
- ^ Fage, Bruce A; Chan, Calvin CH; Gill, Sudeep S; Noel-Storr, Anna H; Herrmann, Nathan; Smailagic, Nadja; Nikolaou, Vasilis; Seitz, Dallas P (2021-07-14). Cochrane Dementia and Cognitive Improvement Group (ed.). "Mini-Cog for the detection of dementia within a community setting". Cochrane Database of Systematic Reviews. 2021 (7): CD010860. doi:10.1002/14651858.CD010860.pub3. PMC 8278980. PMID 34259337.
- ^ Inouye, Sharon K. (2006). "Delirium in Older Persons". New England Journal of Medicine. 354 (11): 1157–65. doi:10.1056/nejmra052321. PMID 16540616. S2CID 245337.
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- ^ Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text revision. pp. 717–719.
Major or Mild Neurocognitive Disorder Due to HIV Infection
- ^ Forbes D, Forbes SC, Blake CM, Thiessen EJ, Forbes S (April 2015). "Exercise programs for people with dementia". Cochrane Database Syst Rev. 2015 (4): CD006489. doi:10.1002/14651858.CD006489.pub4. PMC 9426996. PMID 25874613.
- ^ Swinnen N, de Bruin ED, Dumoulin C, Thalmann M, Guimarães V, De Jong J, Vandenbulcke M, Vancampfort D (2021). "The VITAAL Stepping Exergame Prototype for Older Adults With Major Neurocognitive Disorder: A Usability Study". Front Aging Neurosci. 13: 701319. doi:10.3389/fnagi.2021.701319. PMC 8600328. PMID 34803650.
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- ^ Ullrich, Dieter; Ullrich, Katja; Marten, Magret (September 2014). "A longitudinal assessment of early childhood education with integrated speech therapy for children with significant language impairment in Germany: Longitudinal assessment of early childhood education with integrated speech therapy". International Journal of Language & Communication Disorders. 49 (5): 558–566. doi:10.1111/1460-6984.12092. PMID 24939594.
- ^ Gomez-Pinilla, Fernando (2011). "The Combined Effects of Exercise and Foods in Preventing Neurological and Cognitive Disorders". Preventive Medicine. 52 (Suppl 1): S75–S80. doi:10.1016/j.ypmed.2011.01.023. PMC 3258093. PMID 21281667.