Dementia series part 3 — Dementia Diagnosis and Its Process
Looxid Labs has developed the technology that analyzes EEG signals and eye-tracking data to assess cognitive performance. We are currently applying this technology to our in-home cognitive care solution, LUCY, designed to prevent dementia and spot the early signs of dementia in daily life. This dementia series aims to provide information on the basics of dementia and the latest digital technologies applied for early diagnosis, and last but not least, our technology and its use for early diagnosis of dementia through our cognitive care solution, LUCY.
Written by Shannon H. Jeon
hyungsin.jeon@looxidlabs.com
The early diagnosis of dementia followed by appropriate intervention is key to the favorable prognosis of the condition. Lifestyle changes and attentiveness to our brain health can also reduce the risk of dementia. The last article discusses the differences between normal aging and dementia, types of dementia, and their common symptoms and risk factors. In this article, we delve further into dementia, introducing how dementia is diagnosed and the means used in clinical settings.
Due to the various types of dementia and their different manifestations, clinicians and researchers use a variety of assessment tools and techniques to establish a diagnosis. To determine if someone has dementia or just experiences normal age-related changes, health professionals implement two types of tests: screening and diagnostic tests. The screening tests are to detect potential indicators of dementia or cognitive impairment. Suppose the test results indicate a person is potentially at risk of having cognitive impairment. In that case, the diagnostic tests are further executed to determine whether dementia is really present and identify the causes of the condition. This assessment process makes it possible to apply to the large numbers of potentially at-risk individuals and screen out those who may not experience pathological cognitive problems.
1. Screening Tests
When people visit public health centers and hospitals for their concerns about possible dementia or cognitive decline, health professionals would first have them take screening tests for cognitive impairment. The goal of the screening tests is to quickly check if there are any signs of pathological cognitive decline. The cognitive domains frequently used in daily life, such as orientation, memory, attention, language, and visuospatial ability, are tested in a simple questionnaire form. One screening test usually takes up to 10 minutes, easy and quick to administer. Since these tests aim to indicate suspicion of cognitive impairment, their accuracy and reliability must be secured above a certain level. Validation and reliability of each screening test are consistently researched and evaluated with an emphasis on the following factors.
- Whether the series of questions of the questionnaire can actually reflect the levels of cognitive abilities
- Whether the test measures what it is supposed to measure (cognitive abilities)
- Whether the test results have test-retest reliability and reflect the changes in cognitive decline with high sensitivity
- Whether factors other than cognitive impairment such as age, education level, etc. influence the test results
There are several screening tools for cognitive impairment, but Mini-Mental State Examination (MMSE) is the most used screening tool. MMSE was developed at Johns Hopkins in 1975 and has been heavily researched and evaluated with various groups of people over a long period of time. There are many references and a large amount of empirical evidence to use in research or clinical practice. Due to these advantages, researchers in Korea have developed the Korean version of MMSE (K-MMSE) by translating MMSE and modifying it according to Korean cultural and linguistic characteristics. The K-MMSE is widely used in public health centers and hospitals in Korea.
Although MMSE is the international instrument to assess cognitive abilities, it has a few crucial shortcomings: the low sensitivity for small changes in cognitive performance and the considerable effect of the education level and age on test results. Health professionals try to make up for these weaknesses of the MMSE by adjusting the test’s cut-off scores according to the patient’s socio-educational status or implementing other screening tests to have more conclusive information. New screening tests for cognitive impairment that perform better than the MMSE are highly needed for successful early dementia diagnosis.
The recently developed Montreal Cognitive Assessment (MoCA) is designed to be more sensitive to mild cognitive impairment, especially prefrontal functions. This test is more suitable for individuals with subtle symptoms of cognitive decline. However, it has been reported that its results also can be influenced by external factors such as education level.
To effectively identify potential individuals at risk of dementia or cognitive impairment, extensive research on improvement or development of cognitive assessments with high sensitivity and validity is required.
2. Diagnostic Tests
2.1 Neuropsychological assessments
If the screening test results indicate cognitive impairment, then diagnostic tests are performed to more closely check the patient’s cognitive abilities. Numbers of diagnostic tests are done to provide a definite diagnosis. Neuropsychological assessments are similar to screening tests but intensive, with more weight given to accuracy and precision than to simple, massive application. These tests aim to establish the presence (or absence) of cognitive impairment as a basis and determine whether the impairment is due to a pathological cause such as dementia or other diseases. As the results are adopted as a clinical basis for a possible diagnosis, these assessments and other diagnostic tests must be performed by health professionals with guaranteed expertise.
Neuropsychological assessment tools frequently used for dementia diagnosis in Korea are the Korean version of Consortium to Establish a Registry for Alzheimer’s Disease (CERAD-K) standardized by Seoul National University Hospital and the Seoul Neuropsychological Screening Battery (SNSB). The tests incorporate a range of elements related to cognitive function in various areas such as memory, concentration, language function, judgment, visuospatial ability, etc. The items of these tests are more subdivided and intensive than screening tests, providing in-depth knowledge on the patient’s overall cognitive state. It takes about 1 to 2 hours to administer. The patient’s behavior observed during the test, the content of the interview with the caregiver, and information obtained from medical history and additional cognitive tests are also used to evaluate its clinical characteristics and severity of cognitive impairment.
Neuropsychological assessments are more accurate and higher sensitivity than screening tests. A higher level of expertise is required from the health professional performing the test and interpreting test results. Since it takes considerable time and effort, patients may feel irritated or bored and have difficulty keeping their attention, likely working as an obstacle to their performance on the test. For this reason, it is essential to develop a new neuropsychological test that can provide a level of accuracy and sensitivity similar to or better than the existing test tools, and that also can be administered in a relatively simple way.
2.2 Physical and neurological examinations
If the results from the neuropsychological test are justifiable to establish a diagnosis of pathological cognitive impairment, then a set of other diagnostic tests are undertaken to find out the cause of the condition. These tests can be invasive and expensive. All diagnostic test results, including the neuropsychological test ones, are taken into account to establish a diagnosis of dementia and determine which type.
In the case of brain imaging, CT or MRI scans are used to check for neurodegenerative factors such as brain tumors, cerebrovascular diseases like cerebral hemorrhage and stroke, or atrophy of specific areas of the brain. The brain imaging findings provide a clinical basis and possible explanation of the patient’s cognitive impairment with the brain lesion’s dysfunction. PET or SPECT scans provide information on the functional aspects of the brain, such as neuronal activities in specific brain regions.
Blood tests are performed to check the presence or absence of the ApoE genes, known as a risk factor for Alzheimer’s disease. The results can also show other factors attributing to secondary dementia, such as hypothyroidism, normal-pressure hydrocephalus, or vitamin B12 deficiency. If necessary, additional tests, such as a cerebrospinal fluid test or an electroencephalogram, may also be carried out.
The health professionals construct a comprehensive finding of the patient’s condition by considering all the test results and confirm whether a diagnosis of dementia is justifiable. When dementia is diagnosed and its symptoms and characteristics are thoroughly evaluated, treatment decisions are made accordingly.
Closing
Throughout this article, we introduced the dementia diagnosis methods and how they are performed. All the tests discussed have secured accuracy and reliability through many studies, but many areas are still to be improved regarding their cost and invasive nature. A new, innovative test for early dementia diagnosis with better usability and higher accessibility is demanded to fight this war on dementia in our society. Many researchers and health professionals worldwide are making various attempts to improve the current dementia testing system. IT technologies and digital devices are developed and utilized in dementia research to accomplish the demand. We hope that these technologies and devices can soon help people check their cognitive abilities more often and lead to an earlier diagnosis of dementia.
Looxid Labs is developing a service LUCY to help prompt cognitive management by measuring and monitoring cognitive performance using virtual reality and biosignal data such as brain waves and eye movement information. You can just play fun VR games anytime and anywhere you want, and Lucy will provide you insightful information on your cognitive performance. Our excellent biosignal analysis techniques and evidence-based VR games can help you find possible cognitive decline symptoms by looking at the patterns of your brain waves and eye movements captured during the gameplay. The following article will introduce biomarkers related to dementia, with clinical evidence collected by various methods and tools. We will also delve into how our analysis techniques can be applied to the early dementia diagnosis.
References
[1] https://www.mohw.go.kr/react/al/sal0301vw.jsp?PAR_MENU_ID=04&MENU_ID=0403&page=1&CONT_SEQ=349924
[2] Clinical practice guideline for dementia by Clinical Research Center for Dementia of South Korea. (2011).
[3] Lin, J. S., O’Connor, E., Rossom, R. C., Perdue, L. A., Burda, B. U., Thompson, M., & Eckstrom, E. (2013). Screening for cognitive impairment in older adults: an evidence update for the US Preventive Services Task Force.
[4] A Validity Study on the Korean Mini-Mental State Examination (K-MMSE) in Dementia Patients. (1997).
[5] https://www.dementianews.co.kr/news/articleView.html?idxno=3484
[6] https://www.dementianews.co.kr/news/articleView.html?idxno=3334
[7] https://www.alz.org/alzheimers-dementia/diagnosis/medical_tests
