Noticing the symptoms of Alzheimer’s disease either in yourself or in a partner, family member or friend, can be a worrying time as you consider what the future may hold. However, getting a diagnosis of Alzheimer’s disease as early as possible can help you and your loved ones plan ahead and seek as much help and information as possible to assist you.
The early stages of the condition can be hard to differentiate between simply getting older and perhaps forgetful, and having the beginnings of Alzheimer’s. If you’re concerned about yourself or someone else, an Alzheimer’s MRI (magnetic resonance imaging) scan, along with discussions with a specialist doctor and other tests is helpful in seeking a diagnosis of Alzheimer disease.
What is Alzheimer’s Disease?
Alzheimer’s disease is the most common form of dementia in the UK. Dementia is an all-encompassing term for a group of conditions that are characterised by a decline in the way the brain functions and transmits important messages. It’s a progressive condition, meaning that the symptoms gradually become worse over time.
Alzheimer’s Symptoms
The most well-known symptom of Alzheimer’s dementia is memory loss. But this form of dementia has many other symptoms that affect the functioning of the brain. Early symptoms tend to begin slowly and include:
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Forgetting minor details such as names and places
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Struggling to remember words
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Losing or misplacing possessions
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Asking the same questions multiple times
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Becoming withdrawn and anxious about visiting new places or trying new things
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Struggling to make decisions
As the condition develops, over time these symptoms may become worse and may also include:
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Hallucinations
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Disorientation and confusion
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Paranoia
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Delusional thoughts
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Depression
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Anxiety
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Feeling agitated, angry or fearful
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Insomnia
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Difficulty speaking
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Requiring help to do everyday tasks such as washing and dressing
Over time, Alzheimer’s disease progresses to its latter stages, potentially causing:
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Difficulty eating
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Significant weight loss
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Inability to move around unaided
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Loss of bladder and bowel control
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Significant short and long term memory loss
Brain Appearance - Normal vs Alzheimer's
Alzheimer’s is caused by a buildup of two proteins - beta amyloid and tau - in areas of the brain. Beta amyloid forms beta amyloid plaques in the spaces between the brain cells. Tau forms deposits that lead to neurofibrillary tangles - tangles, or knots, of brain cells. These protein plaques and tangles interfere with messages sent between brain cells.
As yet, it’s not fully understood what causes these proteins to accumulate in certain brain regions, but the risk factors mentioned below under the Causes of Alzheimer’s section, are thought to play a role.
In the early stages of the disease, the hippocampus area of the brain is most likely to be affected. The hippocampus is required for memory retrieval, forming new memories and learning new things. This explains the early symptoms of the disease. As the disease progresses, more areas of the brain become affected, including the temporal lobe, which makes recognising faces and places more difficult. An area called the medial temporal lobe will also show shrinkage and reduced blood flow compared with a healthy brain - this region is responsible for memory and spatial awareness and navigation. Another type of dementia, called frontotemporal dementia, shows shrinkage in the frontal and/or temporal lobes of the brain.
Will Alzheimer’s Show on an MRI?
Yes, an MRI scan can be used to spot the signs of Alzheimer’s disease, and ultimately diagnose the condition.
What Does Alzheimer’s Look Like on MRI?
The beta amyloid plaques and neurofibrillary tangles associated with Alzheimer’s disease can be seen using brain imaging techniques, such as on an Alzheimer’s MRI scan. Areas of the brain that have decreased in size as the disease progresses, will also show on MRI brain scans.
Diagnosing Alzheimer’s Disease
Research into dementia diagnosis is ongoing, but to date, there is no one single test to diagnose Alzheimer’s disease. (Although there is emerging evidence that a single test Alzhimer’s MRI scan could prove definitive, and clinical trials continue.) Currently, a diagnosis of Alzheimer’s disease involves a series of memory tests, blood tests and scans of the brain.
Here’s more detail on what you might expect during each step of the process.
Initial Assessment
Your GP will perform an initial assessment, to ascertain the potential for Alzheimer’s disease and whether or not they think it beneficial to refer you to a specialist for more tests.
Medical History Review
Both your GP and your specialist will ask questions about your general health and wellbeing and about your concerns over dementia. They will ask questions regarding your symptoms, and how long you’ve been experiencing or noticing them. You will also be asked about any other medical conditions, such as cardiovascular disease and type 2 diabetes, whether they’re being managed properly and whether any medications you’re taking are working for you or may need re-assessing.
Physical Examination
You can also expect a physical examination from your GP or specialist to assess for any pain, discomfort, stiffness or immobility you may be experiencing. This may not highlight anything directly related to dementia, but it may give your doctor a better idea of your overall health and wellbeing.
Cognitive and Neuropsychological Testing
Memory and thinking tests form part of a cognitive assessment and are usually performed at a memory clinic, organised by your GP. A specialist will ask a series of questions and ask you to perform some memory tests. The results cannot conclusively diagnose Alzheimer’s, but they can indicate if something may need further investigation.
Laboratory Tests
Your doctors will also organise some blood tests, and possibly urine tests to check for routine health indicators such as cholesterol and sugar levels, vitamin deficiencies, liver, kidney and thyroid function, inflammation and infection. You may also be referred for a lumbar puncture, a procedure during which a needle is used to extract fluid, called cerebrospinal fluid, or CSF, from the spine. CSF biomarkers (chemicals in the CSF that can indicate the presence of a disease) for Alzheimer’s include beta amyloid and tau, and are useful in the overall diagnosis of the condition.
MRI Scan
An MRI scan is the main type of brain scanning used to diagnose Alzheimer’s disease. It gives doctors a detailed image of the brain, highlighting which areas may be shrinking and which areas are affected by beta amyloid and tau protein buildup.
Evaluation of MRI Results
Once you’ve had an Alzheimer’s MRI, your medical team will collate all of your test results to either confirm or rule out Alzheimer’s dementia, and if necessary, confirm or rule out other potential causes of your symptoms.
Additional Imaging
Depending on the results of your tests and Alzheimer’s MRI scan, you may also be referred for one or more different brain scans to help diagnose or rule out Alzheimer’s and other conditions.
These may include:
CT Scan
A CT (Computerised Tomography) scan doesn’t provide the useful images of changes to the structure of the brain like an MRI scan does, but it can provide information on how the brain is functioning. CT scans can also help to confirm or rule out a stroke or a tumour that may be causing your symptoms.
PET Scan
PET scans (Positron Emission Tomography) use radioactive markers to detect chemicals in the body that can indicate certain diseases. PET imaging can detect certain markers in the brain that suggest Alzheimer's is present.
FDG PET
An FDG PET scan uses a radioactive marker called fluorodeoxyglucose (FDG) to detect areas of the brain that have reduced glucose metabolism - glucose metabolism is essential for normal brain functioning and can be inhibited by beta amyloid plaques and neurofibrillary tangles.
Amyloid PET
An amyloid PET is another type of PET scan that can detect beta amyloid plaques.
Tau PET
A TAU PET scan can specifically detect tau protein tangles.
SPECT Scan
Like a PET scan, a SPECT (Single Photon Emission Computed Tomography) scan will show how the brain functions, and will detect any abnormalities in the blood flow to different areas of the brain.
Functional MRI (fMRI)
This type of Alzheimer’s MRI scan is used to assess brain activity and blood flow, which can be helpful in determining if your symptoms are due to Alzheimer’s, or a different type of dementia. During a functional MRI scan, you will be given thinking and memory tasks to complete while the machine detects brain activity.
Referral to a Specialist
Given your results, your medical team will then refer you to the right specialist doctor to help you manage your symptoms and plan for the future.
Causes of Alzheimer’s
Age is perhaps the most common cause of dementia, or at least it’s the most common reason why someone may have it. 1 in 14 people over the age of 65 in the UK are affected by Alzheimer’s and this rises to 1 in 6 in those aged 80 years and over. But having a clinical diagnosis of Alzheimer’s is by no means just a normal part of the ageing process. Some level of age related memory loss and mild cognitive impairment is common as we get older, but Alzheimer’s is a separate condition entirely.
It’s a complex disease and there are no known single causes of dementia or Alzheimer's disease. Instead, there are a few “risk factors” that can put someone at an increased risk of developing Alzheimer’s or another form of dementia. These include:
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A close family member having the condition
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Cardiovascular disease (including high cholesterol, high blood pressure and type 2 diabetes) caused by obesity, a poor diet, smoking and alcohol abuse
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Loneliness and being socially isolated
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Long term undiagnosed or untreated depression (depression isn't a direct cause of dementia or Alzheimer’s, but it can be a risk factor - equally it can also be a symptom of Alzheimer’s)
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Having Down’s syndrome
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Head injuries could potentially lead to dementia, but research is currently ongoing
Genetic Predisposition
The genes we inherit from our biological parents can mean that we have a small genetic predisposition to developing Alzheimer’s if they had or have it too. However, a small number of people inherit a specific gene meaning that their risk is much higher. It may be the case that this gene exists in your family if many family members have had Alzheimer’s disease, and they began to develop symptoms early in life. If this appears to be the case for you, speak to your GP about the possibility of genetic testing to help diagnose Alzheimer’s early.
Differential Diagnosis
The symptoms of Alzheimer’s disease, especially in the early stages, can be confused with other conditions. These potentially include depression, anxiety, strokes, bleeding on the brain, tumours and Parkinson’s disease. Having a number of different tests will help your medical team diagnose, or rule out, Alzheimer’s as well as these other conditions.
Prognosis and Treatment
There is currently no cure for Alzheimer’s. However, there have been recent advancements in the area and some drugs and therapies can now help to slow down the progression of the disease to help patients and their loved ones cope better with the symptoms.
Medications include acetylcholinesterase (AChE) inhibitors that increase levels of the chemical acetylcholine that helps brain cells communicate with each other, and memantine, a drug that blocks a chemical called glutamate that can exacerbate the disease. Talking therapies can also be helpful, and include group cognitive stimulation therapy and one-to-one cognitive rehabilitation and life story reminiscence work.
Why an MRI Scan is a Good Option
An Alzheimer’s MRI brain scan is very useful as it shows the tell tale signs of the condition. Since MRI scans don’t require radiation, they can be used safely to diagnose and track the progress of the disease, without the risk of radiation exposure.
How an MRI Scan Detects Alzheimer’s Disease
MRI scanning machines use magnetic fields and radio waves to produce a detailed image of all the structures and lobes within the brain. It will show the size and shape of each area of the brain, whether or not these regions have begun to shrink, the presence of beta amyloid and tau protein buildup and the health of the blood vessels supplying these areas with blood, nutrients and oxygen. A trained specialist will be able to use these images along with their knowledge of a healthy brain to detect characteristics of Alzheimer’s disease.
Find an MRI Scan Centre
If you’re looking to get a dementia diagnosis if you suspect you may have symptoms of Alzheimer’s, having an Alzheimer’s MRI scan can be very helpful.. Book your private MRI scan with us today to begin the process of a diagnosis. If you’re unsure if an MRI scan is right for you, try our no obligation scan consultation service to help you decide.
References
Website, N. (2024, July 5). Alzheimer’s disease. nhs.uk. https://www.nhs.uk/conditions/alzheimers-disease/
Website, N. (2023b, August 18). Tests for diagnosing dementia. nhs.uk. https://www.nhs.uk/conditions/dementia/symptoms-and-diagnosis/tests/
Single brain scan can diagnose Alzheimer’s disease. (2022, June 20). Imperial News. https://www.imperial.ac.uk/news/237494/single-brain-scan-diagnose-alzheimers-disease/
Learn how Alzheimer’s is diagnosed. (n.d.). Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/alzheimers-disease/in-depth/alzheimers/art-20048075
News-Medical. (2019, February 26). Alzheimer’s tangles and plaques: what’s the difference? https://www.news-medical.net/health/Alzheimers-tangles-and-plaques-whats-the-difference.aspx
Dementia symptoms and areas of the brain. (n.d.). Alzheimer’s Society. https://www.alzheimers.org.uk/about-dementia/symptoms-and-diagnosis/how-dementia-progresses/symptoms-brain
How biomarkers help diagnose dementia. (2022, January 21). National Institute on Aging. https://www.nia.nih.gov/health/alzheimers-symptoms-and-diagnosis/how-biomarkers-help-diagnose-dementia
