The BRC spoke with Dr Jonathan Schott, consultant neurologist and dementia researcher from the UCL Institute of Neurology about detection, trends and the future for Alzheimer’s disease during World Alzheimer’s Month.
Q.1 Tell us about yourself as a researcher/clinician and how you became interested in Alzheimer’s/dementia research?
I have been involved in Alzheimer’s disease research and clinical practice for over 15 years and every week see the effects this condition has on patients and their families. Alzheimer’s disease is one of the most pressing unmet health needs of the 21st century. As the population ages the number of people affected is predicted to increase dramatically, with huge implications for individuals and for society. At the moment, the treatments that we have are limited, and we desperately need new ways of treating people who have established dementia, and of delaying or preventing its onset in individuals who do not have symptoms.
Q.2 What is Alzheimer’s disease and how does it develop?
Alzheimer's disease is a physical disease that affects the brain, it is the most common cause of dementia. During the course of the disease, abnormal proteins build up in the brain in the form of 'plaques' and 'tangles'. This leads to the loss of connections between nerve cells, a reduction in the chemical messengers within the brain which help transmit signals between nerves, and eventually to the death of nerve cells and loss of brain tissue. These processes are thought to start several years before symptoms start. It is only when enough damage has been done, symptoms – usually memory loss – start emerging. Alzheimer's is a progressive disease, so gradually over time, more parts of the brain are damaged, and symptoms become more severe and more widespread. This leads to increasing dependence and premature death.
In most cases Alzheimer’s disease occurs in later life. 1 in 6 people over the age of 80 will have dementia, the majority of whom will have Alzheimer’s disease. In my clinic, I often seen patients with early-onset Alzheimer's disease, where symptoms – often memory loss but sometimes problems with vision, speech or behaviour – start before the age of 65. In the UK there are over 40,000 people under the age of 65 with dementia. Current treatments for Alzheimer's disease can help boost the levels of some of these chemicals which can help with some of the symptoms, but there are no treatments yet available to prevent or get rid of the plaques or tangles.
Q.3 Do we have a reliable means of early detection?
In current clinical practice, a diagnosis of Alzheimer’s disease is only possible when patients present with symptoms – usually failing memory. A diagnosis of Alzheimer’s disease is made following a clinical evaluation which includes assessments of memory, other aspects of thinking, and a cognitive examination. Blood tests are done to exclude other causes of memory impairment, and it is recommended that all patients have some form of brain scan, usually an MRI. This is useful both to exclude other brain diseases that can cause cognitive problems, but also to look for shrinkage particularly in the memory areas of the brain (hippocampi) which is a feature of Alzheimer’s disease. New technologies, including certain forms of positron emission tomography (PET) scans and spinal fluid assessments allow for some of the proteins that cause Alzheimer plaques (amyloid) and tangles (tau) to be measured during life. Whilst not widely available, these have great utility in helping establish that an individual’s cognitive symptoms are due to Alzheimer’s disease.
From a research perspective, there is considerable interest in identifying individuals with either very mild memory or cognitive symptoms, or who are asymptomatic. It is hoped that these individuals might benefit from new approaches being developed to target the plaques and tangles rather than just boosting the chemical messengers, the aim being to prevent or delay the onset of symptoms. Again, amyloid PET scans and spinal fluid assessments are showing great promise in being able to identify Alzheimer’s pathology very early, as is the advent of new genetic technologies that may help predict who is at risk. In due course, we hope that blood tests may also prove useful in detecting Alzheimer’s disease early.
Q.4 Are there specific scientific developments and/or technologies that have made your research possible?
There have been huge advances in our understanding of biomarkers – tests that can demonstrate aspects of Alzheimer pathology – in the last few years. MRI scans are becoming more sensitive; we now have a range of PET tracers which can help show up different proteins involved in Alzheimer’s disease; and new techniques mean we can measure proteins in spinal fluid and blood at ever smaller concentrations. New genetic technologies also allow us to analyse and assess many different genetic factors that may help us determine who is at risk of developing Alzheimer’s disease. Finally, there are a number of very promising drugs targeting both plaques and tangle which are currently in clinical trials, and will hopefully produce positive results in near future.
Q.5 How can patients and the public help researchers discover more about Alzheimer’s?
There are many ways that the public can help researchers discover more about Alzheimer’s disease. It is vitally important that we continue to promote awareness that Alzheimer’s disease is a brain disease and not simply part of the ageing process. Research in Alzheimer’s and other forms of dementia is hugely underfunded compared to diseases with comparable impacts, and whilst funds available for dementia research have increased considerably in the last few years, there is much more to be done. Finally, individuals – both patients with Alzheimer’s disease and healthy people – can get involved in research, for example by signing up to take part in dementia studies. For more information about how you can help visit Join Dementia Research. Clinical trials for dementia and Alzheimer’s disease currently recruiting at UCLH are also listed on the ‘Find a Study’ database, where visitors can search by condition using a drop down list or enter key words.
