What is Mild Cognitive Impairment?
According to the Alzheimer’s Association, there are two subtypes of MCI—amnestic (the most common subtype and primarily affecting the memory) and nonamnestic (affecting thinking skills other than memory).4
People with nonamnestic MCI show deficits in areas other than memory, including difficulty organizing and planning,6 getting lost in a familiar environment, poor judgment, and skewed depth perception.1
Same Symptoms, Different Diagnosis
• Infections (e.g., delirium from neurosyphilis, pneumonia, and urinary tract infections)
• Non-Alzheimer’s neurodegenerative diseases (e.g., Parkinson’s disease, Lyme disease)
• Psychiatric illnesses (e.g., bipolar disorder, schizophrenia, major depression)
• Physical phenomena (e.g., strokes, subdural hematoma, cancer)
• Thyroid disease
• Vitamin B12 deficiency
• Medication side effects (e.g., anticholinergics, benzodiazepines, opioid analgesics, and “chemo fog” from cancer chemotherapy
• Sleep apnea
Cognitive function is assessed in four cognitive categories, known as cognitive domains.9
• Executive functioning (e.g., reasoning, problem-solving, and planning)
• Language (e.g., comprehension, fluency, and semantic paraphasia [when an entire word is substituted for another word, such as saying “orange” instead of “apple” to refer to describe an apple])
• Visuospatial skills (movement, depth and distance perception, and spatial navigation – abilities needed for driving, for example)
• Attentional control (e.g., an individual’s ability to concentrate)
People with nonamestic MCI are thought to be more likely to progress to other neurodegenerative diseases (e.g., Lewy body dementia).13
2. Chehrehnegar N, et al. Early detection of cognitive disturbances in mild cognitive impairment: a systematic review of observational studies. Psychogeriatrics. 2020;20(2):212-228. doi: 10.1111/psyg.12484.
3. Older population and Aging. The United States Census Bureau website. https://www.census.gov/topics/population/older-aging.
4. About mild cognitive impairment. The Alzheimer’s Association website. https://www.alz.org/alzheimers-dementia/what-is-dementia/related_conditions/mild-cognitive-impairment.
5. Alzheimer Society of Canada. Mild cognitive impairment. https://alzheimer.ca/sites/default/files/files/national/other-dementias/other-dementias_mild-cognitive-impairment.pdf.
6. Executive function. The Psychology Today website. www.psychologytoday.com/us/basics/executive-function.
7. What is Mild Cognitive Impairment? The National Institute on Aging website. https:www.nia.nih.gov/health/what-mild-cognitive-impairment.
8. Cognitive testing. MedlinePlus website. https://medlineplus.gov/lab-tests/cognitive-testing.
9. Petersen RC, et al. Practice guideline update summary: mild cognitive impairment. Neurology. 2018;90:126-135. doi: 10.1212/WNL.0000000000004826.
10. Rosenberg PB, Lyketsos C. Mild cognitive impairment: searching for the prodome of Alzheimer’s disease. World Psychiatr. 2008;7(2):72-78. doi: 10.1002/j.2051-5545.2008.tb00159.x.
11. Palmqvist S, et al. Discriminative accuracy of plasma phosphor-tau 217 for Alzheimer disease vs other neurodegenerative disorders [published online ahead of print July 28, 2020]. JAMA. doi: 10.1001/jama.2020.12134.
12. Busse A, Angermeyer MC, Riedel-Heller SG. Progression of mild cognitive impairment to dementia. A challenge to current thinking. Br J Psychiatr. 2006;189:399-404. https://www.healthline.com/health/mild-cognitive-impairment. June 6, 2016. doi: 10.1192/bjp.bp.105.014779.
13. Spotting the signs of mild cognitive impairment. The American Psychology Association website. https://www.apa.org/monitor/2019/10/ce-corner-impairment. 2019.