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This scan uses a magnetic field and not radiation. We request a special set of cognitive sequences. This allows us to look at certain key cognitive brain areas to assess brain tissue volume. We can sometimes see localised areas of volume loss (atrophy). We can detect other relevant conditions such as strokes or tumours.

An MRI brain is preferred over a CT brain because it gives a better detailed picture of brain structure. Sometimes it is not possible to complete an MRI for example if a patient has a metal object such as a pacemaker. In this case a CT brain would be recommended. A normal MRI or CT does not rule out dementia.

More information on MRI including on safety checking is provided by the referral radiology service.

This uses a small dose of a radioactive tracer injected via a drip to take a picture of the brain. PET provides an assessment of brain function by assessing the uptake of glucose by brain tissue.

Special “coloured” maps of the brain are produced. Areas of the brain that take up the glucose represent “healthy” active tissue and appear in black or blue. Areas that do not take up the glucose appear in brighter, warmer colours and are underactive (not functioning as well). It is the location of these unhealthy areas that can be very helpful in the diagnosis in certain types of dementia.

We find this information on how a brain is functioning can often provide valuable supplementary information to the structural information of an MRI brain. More safety information on PET is provided by the referral radiology service.

We complete a full set of blood tests to check for potential reversible causes of cognitive impairment including B12, folate, thyroid function tests, electrolytes, full blood count, liver function, kidney function and certain infectious disease testing.

If we are concerned about a patient’s vascular health a fasting glucose, fasting lipids, and electrocardiogram (ECG) is completed.

In certain cases we may organise a sleep study to look for evidence of sleep apnoea and an electroencephalogram (EEG) to look for seizures.

This is a time of breakthrough discovery in diagnostics in dementia. There are several newer “biomarkers” including blood tests that are currently more readily available through research studies. SMS has excellent research ties and would be able to provide more information on this area.

This is a relatively recent type of PET imaging. Like FDG-PET a small dose of a labelled radioactive tracer is injected. This looks to bind brain amyloid plaques. Amyloid is a key protein that builds up in Alzheimer’s disease. We receive a 3D colour map of the brain that looks to show the presence or absence of amyloid. With warm colours in the peripheral brain tissue demonstrating amyloid in the brain.

A normal scan effectively rules out Alzheimer’s disease. A positive scan in a patient that has cognitive symptoms is supportive of Alzheimer’s disease. However, this scan must be interpreted in the context of clinical symptoms and cognitive test results especially for patients over the age of 70. This is because approximately a third of patients in this age group will have a positive amyloid scan but have no clinical symptoms of Alzheimer’s disease. Research is still ongoing to work-up the significance in terms of future outlook of positive amyloid results in patients without symptoms.

Cognition involves a group of key brain functions including memory, concentration, problem solving, judgement, language skills, spatial awareness and socially appropriate behavior.

Dementia is a general term that describes progressive impairment of cognition to an extent that impacts on day-to-day function, such as the ability to manage one’s money or to drive a car. Many different conditions sit under the umbrella of dementia, and common causes of dementia are outlined in more detail below.

Mild Cognitive impairment (MCI) is an earlier stage diagnosis. It is not dementia. Patients with MCI have cognitive symptoms, and some mild impairments are found on cognitive testing. However, there is not the impact on day-to-day functional activities as is seen in dementia.

Patients with MCI are at a higher risk of developing dementia in the years to come and require ongoing review. There are a significant proportion of patients with MCI whose symptoms do not progress on to dementia.

At SMS we identify patients with concerning MCI symptoms using a combination of detailed history taking, cognitive testing and imaging. In all patients we take a proactive approach and discuss early instigation of lifestyle measures such as exercise and encouraging social interactions. We address any modifiable exacerbating factors such as obstructive sleep apnoea, depression, and hearing impairment, and can provide education and strategies to help our patients with MCI to manage their condition.

Delirium is a sudden state of confusion that occurs over hours to days. It can lead to agitation, disturbance of thinking and reduced alertness. Increasing age and a pre-existing diagnosis of dementia are risk factors for delirium. Causes of delirium include infections, dehydration, certain medications, pain and illness. Prompt treatment of delirium is essential as delirium can be life-threatening if left untreated.

Alzheimer’s disease is the most common cause of dementia. The disease process in Alzheimer’s disease involves the accumulation of amyloid and tau proteins in the brain, and this build up can begin up to 20-30 years prior to the onset of symptoms.

Some common symptoms include memory loss for recent events, disorientation to time, navigational issues, word-finding difficulties, problem-solving difficulties and personality change. Anxiety and mood changes can often occur early in the course of the condition.

Alzheimer’s disease is a progressive condition. In the early stages it can interfere with a person’s ability to complete their daily tasks, and over time they will become more dependent on others for assistance. There are some treatments and interventions that may help those with Alzheimer’s disease, but unfortunately, there is currently no cure.

This type of dementia has well defined clinical features. These include visual hallucinations often for animals or people, sudden changes in confusion within a day (cognitive fluctuation), sleep behavioral disturbance (kicking or shouting out whilst sleeping), mood and anxiety symptoms. There can often be Parkinson-like symptoms such as slowness of walking, difficulty getting up unaided, tremor, swallowing difficulties and speech change. Falls are also common.

As the name suggests, DLB is caused by the build-up of Lewy body protein in the brain. This is the same disease process as is seen in Parkinson’s disease, but in DLB early build up occurs the surface structures of the brain (cortices) which are important in memory, thinking and visual processing. In Parkinson’s disease motor symptoms arise first as a result of deep brain structure involvement.

There are some treatments that help symptoms. There are also key medications to avoid that can worsen symptoms. This dementia can also easily worsen suddenly in the setting of other medical problems like mild infection.

Parkinson’s disease leads to early motor symptoms including tremor, slowness of gait, muscle stiffness and speech change. Cognitive symptoms such as forgetfulness, slowed thinking and difficulty concentrating can sometimes develop after years of motor symptoms. Parkinson’s disease dementia is diagnosed when these cognitive symptoms impact the person’s day-to-day function to a significant degree.

In vascular dementia, cognitive symptoms occur when the brain is damaged due to poor blood supply. Specific symptoms and severity depend on what part of the brain is affected, and to what degree. A main focus is on managing vascular risk factors (e.g blood pressure, cholesterol and diabetes) to reduce risk of further vascular damage in the future.

Most people are aware that strokes can cause physical disabilities, but cognitive symptoms following on from a stroke are under-recognized yet common. Post-stroke cognitive impairment can affect a person’s ability to complete everyday tasks such as dressing, cooking a meal, and working.

Cognitive symptoms can occur suddenly following a stroke, or more gradually over time with the build up of vascular damage to deep wiring areas of the brain (small vessel disease). This can result in gradually progressive memory, behavioural and problem solving difficulties.

Vascular changes in the brain often occur alongside other brain conditions, including other forms of dementia such as Alzhiemer’s disease.

Frontotemporal dementia (FTD) is another umbrella term. It is used for dementias that affect the frontal and temporal lobes of the brain. There are 3 main subtypes of FTD: behavioral variant FTD and the 2 language conditions semantic dementia and progressive non-fluent aphasia. These conditions involve abnormal protein accumulation in frontal and temporal areas of the brain. These areas are important in judgement, language, and behavioral control. Frontotemporal dementias typically present at a younger age (40-70) than many other types of dementia.

Patients with bvFTD often experience a delay in obtaining a diagnosis. This type of dementia is often mistaken for a “midlife crisis” or depression. Symptoms include poor insight, personality change, inappropriate behavior (loss of “social filter”), compulsive repetitive acts (hoarding, collecting), lack of initiation in pursuing interests and hobbies (apathy), poor judgement, and planning. There can also be a change in food preference including a tendency to have fixed food preferences and an intense sweet food drive. There is less impact on memory in the early stages of the condition than is typically seen in Alzheimer’s disease.

For more information on genetics please see Is dementia inherited ?

This is the gradually progressive language subtype of frontotemporal dementia. Patients with semantic dementia show a loss of understanding of the meaning behind single words. Patients may often respond with “What do you mean by that?”. They may struggle to identify animals by their specific name or instead use a broader category term e.g. bird instead of a seagull. In free conversation the flow of speech is not interrupted but the patient uses replacement filler words such as “thingy” and can incorrectly state the wrong object (e.g. fork instead of spoon). There can be behavioral symptoms like those seen in bvFTD but commonly these occur after the language symptoms.

This is the gradually progressive language subtype of frontotemporal dementia that results in frustrating word-finding difficulties. The patient’s flow of speech becomes interrupted as they get stuck on individual words. There is decline in the use of adjoining grammar between the nouns and so speech can sound quite telegraphic. Patients may often say yes when they mean no. Sometimes there is a slurring of words and swallowing difficulties.

Posterior cortical atrophy is a visual variant of Alzheimer’s disease with typical onset between ages 50 and 65. PCA involves progressive damage to the posterior (back of the brain) structures causing atrophy (shrinkage). Early symptoms may include excessive visual glare, difficulties with depth and spatial perception, judging distances and reading. These visual symptoms can have a significant impact on daily life. Often patients are mistakenly thought to have an eye issue and anxiety is a common feature. Over time other areas of cognition, such as memory and language, become affected.