Mild or major neurocognitive disorder (NCD) due to Alzheimer's disease is a neurological disorder where a person experiences slow and progressive mental dysfunction. Medicines can help slow the progression of the disease, but there is currently no drug that can halt its course.[1]

What is Neurocognitive Disorder Due to Alzheimer's Disease?

Neurocognitive disorder (NCD) due to Alzheimer's disease is more commonly known as Alzheimer's dementia (AD). Alzheimer's dementia is the most common clinical diagnosis of dementia.[2] NCD is a progressive disease that begins with mild symptoms of dementia such as memory loss. As the disease progresses, there is a gradual decline in memory, thinking, and reasoning skills. The rate of cognitive decline varies between individuals and can be slowed down with medications. Therefore, NCD can last several years or be lifelong.

People living with AD may notice their early symptoms when they forget the names of things or places they are familiar with and when they begin misplacing items. In addition, family and friends will see that they regularly repeat themselves, e.g., asking the same question several times.

Unfortunately, these seemingly benign symptoms may become troublesome and interfere with daily life and work, especially as they progress to middle-stage symptoms. Here there is increasing confusion and disorientation. In addition, those with the cognitive disorder have trouble performing tasks and judging distances.

NCD also affects the personality, where the person will experience mood swings, agitation, depression, and increasing anxiety or frustration.

Types of Alezheimer's dementia

Neurocognitive disorder due to Alzheimer's can be classified into two types, depending on the symptoms experienced. Mild neurocognitive disorder (NCD) can progress to 'major' NCD (otherwise simply refered to as dementia), and the speed at which this might happen varies from person to person.

Mild NCD is usually diagnosed when a person is beginning to experience symptoms of NCD, but are still able to function on a day to day basis.[3]

Symptoms of mild neurocognitive disorder due to Alzheimer's disease include:

  • Difficulty handling more than one task at a time
  • Taking longer to complete everyday tasks
  • Struggling with names of familiar people or objects
  • Difficulty remembering recent events
  • Subtle personality changes, e.g., decreased inhibition or sudden frustration

Major NCD, or dementia, is usually diagnosed when a person's cognitive impairment has become acute enough that they are unable to function as they used to socially or occupationaly (e.g. unable to work anymore). [3]

Symptoms of major neurocognitive disorder due to Alzheimer's disease include:

  • Memory loss
  • Forgetting names of familiar people or objects
  • Struggling to retain new information
  • Experiencing disorientation related to time and space
  • Experiencing problems with physical movements and balance
  • Extreme changes in personality, e.g., being offensive and disregarding others' feelings, making impulsive decisions that ignore personal safety 

Alzheimer's and dementia: What's the difference?

Dementia is a group of symptoms that affect memory loss, while Alzheimer's is a specific disease that causes increasing memory and brain function deterioration. Dementia might have different causes, depending on which brain area is affected. While Alzheimer's is the more prevalent cause of dementia, many other possible factors can lead to dementia.

While the symptoms, treatments, and outlooks of Alzheimer's and dementia overlap, there are also some differences. For example, in Lewy body dementia, the initial signs are more likely visual hallucinations, physical imbalances, and disturbed sleep. People with dementia due to Huntington's disease or Parkinson's exhibit tremors and involuntary movements in the beginning stages of the disease.

Some types of dementia can be slowed down with treatment, depending on the cause. A few types of dementia are reversible (e.g., dementia caused by tumors or drugs), but most are not.

Unfortunately, there is no current cure for Alzheimer's. It is a terminal illness where most people over 65 will live an average of four to eight years following diagnosis. However, some people with Alzheimer's may live up to 20 years after diagnosis.[4]

Symptoms of Alzheimer's dementia

The main clinical symptoms of Alzheimer's dementia can be classified into early-, middle-, and late-stage depending on the symptoms observed. However, identifying which stage the person is living with AD is not always clear, especially as the decline may be gradual.

Early symptoms include:

  • Memory loss
  • Misplacing objects (possibly placing objects in unexpected places)
  • Difficulty recalling the names of people or objects that should be familiar
  • Repeating stories and questions
  • Hesitation to try new things

Middle-stage symptoms include:

  • Increased memory loss, including recent events
  • Increased confusion and disorientation
  • Obsessive and repetitive actions
  • Problems with speech and language
  • Delusions
  • Mental blockage
  • Changes in mood that are different from their usual personality
  • Disturbances in sleep

Late-stage symptoms include:

  • Gradual loss of speech and difficulty communicating
  • Loss of awareness of surroundings
  • Significant problems with memory, including past and recent events[4]

Diagnosing neurocognitive disorder due to Alzheimer's disease

Changes detected in the brain and blood help to diagnose NCD and eliminate the possibility of another disease.

Early diagnosis. Substances found in the blood of those with NCD can help early detection of Alzheimer's dementia and other forms of dementia.

In brain imaging, magnetic resonance imaging (MRI) and computerized tomography (CT) help professionals see the brain's structure in detail to detect changes. For example, when the area of the brain known as the hippocampus starts to shrink, this is considered a sign of Alzheimer's disease progression.

Functional brain imaging shows how cells in various brain regions operate through positron emission tomography (PET) scans and functional MRIs (fMRI). In addition, patterns in the brain cells' function reveal the type of dementia present.

Molecular brain imaging uses technologies such as PET, fMRI and single photon emission computed tomography (SPECT) to observe changes in cells or chemicals linked to neurodegenerative disease.

Samples of cerebrospinal fluid (CSF) proteins reveal changes in proteins found as abnormal deposits in the brain of people with Alzheimer's and dementia can indicate the type of dementia present.

Like in early diagnosis, blood or urine biomarkers can help researchers get a better diagnosis through measurable changes in protein levels.[5]

Prevention of Alzheimer's disease

Since the causes of NCD are not fully known, there is no definite way to prevent dementia. However, there are things you can do to decrease the risk:

  • Take care of your heart by eating healthy, exercising, managing stress, and reducing smoking.
  • Keep your body healthy with physical activity.
  • Stay mentally active by socializing, taking up hobbies, reading, playing instruments, and taking up group sports.[6]

Treatment for Alezheimer's dementia

Drugs that treat NCD due to Alzheimer's disease are:

  • Cholinesterase inhibitors treat symptoms related to thinking, memory, language, and other thought processes. E.g., Donepezil, Rivastigmine, and Galantamine
  • Glutamate regulators are often prescribed to improve attention, reason, memory, and the ability to perform tasks. E.g., Memantine [7]

Frequently asked questions about Alzheimer's dementia

Who is likely to get neurocognitive disorder due to Alzheimer's disease?

Although experts have not identified a single cause of the disease, they think certain factors may put individuals at risk of developing neurocognitive disorder due to Alzheimer's disease.

  • Age is a known risk factor – those 65 years or older are more at risk of dementia. Of those 85 and up, almost one-third will develop some form of dementia, with NCD being the most common type.
  • Other health conditions, including high blood pressure, a weak immune system, and slower ability to heal from injury also increase risk.
  • Concurrent diseases such as heart problems, depression, and hearing loss may increase the risk of developing NCD.
  • Genetic factors inherited from a parent.
  • Cognitive reserve – an individual's capacity to cope with disease in the brain. This resilience depends on the level of education, job complexity, and social interactions throughout life.
  • Women over 80 are more likely to have dementia than their male peers. The reason is unknown but may have to do with generational upbringing. This may change as new generations with more equal opportunities reach that age.
  • Air pollution – small particles from exhaust fumes, for example, may cause damage to blood vessels in the brain.

Is it Alzheimer's/dementia or a typical age-related change?

Some people think that specific symptoms are a normal part of aging. However, even though there is a certain degree of decline in cognitive function, this cognitive impairment does not interfere with everyday activities. Therefore, it is essential to know the difference and to seek help as soon as possible when there are signs of Alzheimer's disease or Alzheimer's dementia. The following are some examples.[8]

Signs of Alzheimer's or other dementias

Typical symptoms of normal aging

· Forgetting recent events

· Problems recalling names

· Asking the same questions repeatedly

· Sometimes forgetting appointments or names but remembering them later

· Needing much more time for familiar tasks

· Difficulty focusing

· Difficulty following a familiar recipe

· Making occasional mistakes in ordinary tasks

· Trouble driving to a familiar place

· Trouble driving to a new place

· Getting confused about where they are and forgetting how they got there

· Temporarily forgetting what day it is but remembering later

· Problems following a conversation

· Having trouble finding the right word

· Loses things and has trouble finding them

· Places objects in unusual places

· Misplaces objects but can find them later

· May suddenly become upset or frustrated

· Becomes irritable when their routine is disrupted

Resources:

  1. Hategan, A., & Xiong, G. L. (2017, November 7). Major or Mild Neurocognitive Disorder Due to Alzheimer Disease. Geriatric Psychiatry, 369–401. https://doi.org/10.1007/978-3-319-67555-8_18
  2. Focus on Alzheimer’s Disease and Related Dementias | National Institute of Neurological Disorders and Stroke. (n.d.). Retrieved October 12, 2022, from https://www.ninds.nih.gov/current-research/focus-disorders/focus-alzheimers-disease-and-related-dementias
  3. Hugo, J., & Ganguli, M. (2014). Dementia and cognitive impairment: epidemiology, diagnosis, and treatment. Clinics in geriatric medicine, 30(3), 421–442. https://doi.org/10.1016/j.cger.2014.04.001
  4. Stages of Alzheimer’s. (n.d.). Alzheimer’s Disease and Dementia. Retrieved October 12, 2022, from https://alz.org/alzheimers-dementia/stages
  5. Diagnostic criteria for dementia. (n.d.). Dementia Australia. Retrieved October 12, 2022, from https://www.dementia.org.au/information/for-health-professionals/clinical-resources/diagnostic-criteria-for-dementia
  6. NHS website. (2022, May 30). Prevention. nhs.uk. https://www.nhs.uk/conditions/alzheimers-disease/prevention/
  7. Medications for Memory, Cognition and Dementia-Related Behaviors. (n.d.). Alzheimer’s Disease and Dementia. https://www.alz.org/alzheimers-dementia/treatments/medications-for-memory
  8. Identifying Alzheimer’s Symptoms | All For Alz. (n.d.). Allforalz. Retrieved October 12, 2022, from https://www.allforalz.com/alzheimers-symptoms/identifying-symptoms.html