Q 2.34. Dementia: Alzheimer’s disease, vascular and mixed dementia. Differential diagnosis and management.

Q 2.34. Dementia: Alzheimer’s disease, vascular and mixed dementia. Differential diagnosis and management.

Dementia refers to a cluster of symptoms impacting memory, cognition, and social skills, stemming from various diseases. It’s not a singular disease but rather a syndrome resulting from brain damage over time, leading to cognitive decline beyond what’s typical for aging. While consciousness remains intact, cognitive impairment is often accompanied by mood swings, altered behavior, or motivational changes. Dementia involves a loss of cognitive abilities to the extent of inhibiting daily functioning, potentially leading to emotional instability and personality shifts. Its severity ranges from mild impairment to complete dependency on others for basic tasks. Alzheimer’s disease is a specific type of dementia, alongside vascular dementia, which together constitute the majority of cases.

Cognitive changes

  • Memory loss
  • Communication and language problems
  • Trouble with planning, organise, solving a problem
  • Poor coordination and movement
  • Control confusion

Psychological changes

  • difficulty controlling emotions
  • mood changes
  • inappropriate behaviour
  • hallucinations

Alzheimer’s disease

Alzheimer’s disease (AD) stands as the predominant form of dementia, characterized by a gradual progression starting with mild memory impairment and potentially advancing to the point of inhibiting communication and responsiveness to surroundings. AD is associated with the accumulation of extracellular amyloid-beta plaques and intracellular neurofibrillary tangles. This condition targets specific regions of the brain that control cognition, memory, and language, profoundly impacting an individual’s capacity to perform daily tasks. AD instigates a gradual worsening in memory, cognitive function, learning, and organizational abilities, eventually impeding the performance of primary daily activities. While most cases of AD are not directly inherited, having a first-degree relative (parent or sibling) with AD does increase the risk of developing the disease. The most significant risk factor for AD is age. Deterministic genes directly cause AD and guarantee its development. However, they are rare and account for only 1% or less of AD cases.

Stages of disease

Alzheimer’s disease gets worse over time. People go through different stages at different speeds. Even though symptoms may come and go, there’s no cure for the disease. So, overall, people’s abilities keep getting worse as the disease continues.

Early stage: In the initial stages of Alzheimer’s, individuals may notice subtle memory lapses and cognitive challenges, which may be imperceptible to them and their surroundings. It’s common for Alzheimer’s to be diagnosed during this early phase.

Middle stage: As Alzheimer’s advances into the middle stage, damage extends to brain regions governing language, reasoning, sensory perception, and conscious thinking. This phase is marked by heightened confusion and difficulty in recognizing familiar faces and surroundings.

Late stage: In the late stage of Alzheimer’s, individuals experience profound cognitive decline, rendering them unable to communicate effectively and entirely reliant on others for care. They may spend most or all of their time in bed as bodily functions deteriorate.


  • Loss of memory
  • Loss of reasoning capacity repeated questions
  • Behaviour and mood changes
  • Poor judgment

Vascular dementia

Vascular dementia is a prevalent form of dementia that affects various aspects of cognitive function, including memory, language, behavior, and personality. It typically arises following a stroke or due to other brain damage caused by compromised blood flow. When blood flow is compromised, vital oxygen and nutrients fail to reach the brain, resulting in tissue damage.

A diagnosis of vascular dementia is established when there’s a decline in at least two cognitive abilities, such as memory and language, linked to blockages in brain blood vessels, significantly impeding daily functioning. If fewer than two abilities are affected or if cognitive changes don’t significantly impact daily life, the condition may be termed vascular cognitive impairment.

After Alzheimer’s disease, vascular dementia ranks as the second most prevalent cause of dementia in older adults.

Risk factors for heart disease and stroke, such as diabetes, high blood pressure, high cholesterol, and smoking, also elevate the likelihood of developing vascular dementia. Managing these factors can potentially reduce the risk of vascular dementia.

The impact of diminished or absent blood flow on the brain hinges on the affected area’s size and location. For instance, if a small region controlling memory experiences impairment, one may experience forgetfulness without significant disruption to daily activities. Conversely, larger affected areas can lead to difficulties in thinking, problem-solving, or memory, significantly affecting normal functioning.


  • Impaired cognitive functions followed by loss of memory
  • Difficulty in paying attention and processing information
  • Language problem
  • Coordination problem
  • Aphasia
  • Apraxia

Mixed dementia

Mixed dementia occurs when multiple forms of dementia coexist within the brain simultaneously. For instance, an individual might concurrently experience Alzheimer’s disease alongside vascular dementia.

Individuals with mixed dementia typically exhibit a blend of symptoms associated with the various dementia types they possess. This condition is particularly prevalent among older adults, especially those aged 75 and above.

Identifying mixed dementia isn’t always straightforward, as symptoms from one type may overshadow or intertwine with those of another and can vary based on the affected brain region. In cases where two dementia types coexist, symptoms may be more pronounced and appear to progress more rapidly.

Diagnosis and differential diagnosis of dementia

Distinguishing between dementia and related conditions poses challenges as they share common signs and symptoms.

Diagnosing dementia doesn’t rely on a single test. Instead, doctors assess for Alzheimer’s and other forms of dementia through a comprehensive evaluation, including medical history, physical examination, laboratory analyses, and observation of characteristic cognitive, functional, and behavioral alterations associated with each variant.

Initial Assessment and Medical History: This involves the physician identifying signs and symptoms through the patient’s medical background, cognitive function, behavior, past medical records, family history, personal history, and daily activities.

Physical Examination: Conducted to assess motor function and detect neurological signs.

Cognitive Function Assessment: Various tests are administered to evaluate the individual’s cognitive abilities.

Laboratory Tests: A series of blood tests are recommended to rule out disorders such as anemia, vitamin B12 deficiency, diabetes, endocrine disorders, HIV, viral infections, and liver and kidney diseases.

Genetic Screening: Useful in diagnosing Alzheimer’s disease.

Brain Imaging (CT or MRI): Aids in detecting various intracranial abnormalities.

Cerebrospinal Fluid (CSF) Analysis: Testing cerebrospinal fluid protein can identify biomarkers.


While there’s no definitive cure for dementia, ample support is available for individuals affected by the condition and their caregivers. The approach to treating dementia varies depending on its root cause. Neurodegenerative forms, such as Alzheimer’s disease, currently lack a cure, but medications exist to either shield the brain or alleviate symptoms like anxiety or behavioral alterations. Ongoing research aims to expand treatment choices.

Those living with dementia can enhance their quality of life and overall well-being by:

Embracing a healthy lifestyle, which encompasses regular physical activity, nutritious diet, and social engagement, stimulate cognitive function and maintain daily abilities. At the same time, it serves to diminish the likelihood of developing chronic conditions and potentially lowers the incidence of dementia cases.


  • Acetylcholinesterase inhibitors work by blocking a chemical called acetylcholinesterase. This chemical normally stops signals from reaching the brain. By blocking it, these medications boost the levels of acetylcholine, which allows signals to flow smoothly without interruption. Examples are donepezil, rivastigmine.
  • Psychostimulants, like levodopa and dopamine agonists, help enhance cognitive functions.
  • Memantine is a medication prescribed for moderate to severe forms of Alzheimer’s disease. It’s usually taken by mouth and can be used by itself or alongside acetylcholinesterase inhibitors.

Regrettably, there is presently no medication specifically designed to ameliorate the symptoms of vascular dementia. Nonetheless, individuals with vascular disease can potentially prevent strokes or other related incidents by consistently adhering to their prescribed medications for conditions like high blood pressure or diabetes.

The primary medications prescribed for mixed dementia typically include cholinesterase inhibitors. These drugs enhance the levels of a neurotransmitter in the brain crucial for intercellular communication.


Mayo clinic: Dementia: https://www.mayoclinic.org/diseases-conditions/dementia/symptoms-causes/syc-203 52013

Center for disease control and prevention: About dementia: https://www.cdc.gov/aging/dementia/index.html

Alzheimer’s association: What is dementia?: https://www.alz.org/alzheimers-dementia/what-is-dementia

Word health organization: Dementia: https://www.who.int/news-room/fact-sheets/detail/dementia

National Institute on Aging: What is Dementia? Symptoms, Types, and diagnosis: https://www.nia.nih.gov/health/alzheimers-and-dementia/what-dementia-symptoms-t ypes-and-diagnosis

NHS: What is dementia: https://www.nhs.uk/conditions/dementia/about-dementia/what-is-dementia/

Alzheimer’s Society: What is dementia: https://www.alzheimers.org.uk/about-dementia/types-dementia/what-is-dementia

Cleveland clinic: Alzheimer’s disease: https://my.clevelandclinic.org/health/diseases/9164-alzheimers-disease

Alzheimers.gov: What is Alzheimer’s Disease: https://www.alzheimers.gov/alzheimers-dementias/alzheimers-disease

Johns Hopkins medicine: Vascular dementia: https://www.hopkinsmedicine.org/health/conditions-and-diseases/dementia/vascular- dementia

DementiaUK: Mixed dementia: https://www.dementiauk.org/information-and-support/types-of-dementia/mixed-deme ntia/

MYA CARE: Dementia management: https://myacare.com/procedure/dementia-management

Verified by Dr. Petya Stefanova