Oxford University researchers funded by Parkinson's UK have developed a simple and quick MRI technique that offers promise for early diagnosis of Parkinson's disease.
The team demonstrated that their new MRI approach can detect people who have early-stage Parkinson's disease with 85% accuracy, according to research published in Neurology, the medical journal of the American Academy of Neurology.
'At the moment we have no way to predict who is at risk of Parkinson's disease in the vast majority of cases,' says Dr Clare Mackay of the Department of Psychiatry at Oxford University, one of the joint lead researchers. 'We are excited that this MRI technique might prove to be a good marker for the earliest signs of Parkinson's. The results are very promising.'
Claire Bale, Research Communications Manager at Parkinson's UK, explains: 'This new research takes us one step closer to diagnosing Parkinson's at a much earlier stage – one of the biggest challenges facing research into the condition. By using a new, simple scanning technique the team at Oxford University have been able to study levels of activity in the brain which may suggest that Parkinson's is present. One person every hour is diagnosed with Parkinson's in the UK, and we hope that the researchers are able to continue to refine their test so that it can one day be part of clinical practice.'
The researchers from the Oxford Parkinson's Disease Centre also received support from the National Institute for Health Research (NIHR) Oxford Biomedical Research Centre and the NIHR Clinical Research Network: Dementias and neurodegeneration (DeNDRoN).
Parkinson's disease is characterised by tremor, slow movement, and stiff and inflexible muscles. It's thought to affect around 1 in 500 people, meaning there are an estimated 127,000 people in the UK with the condition. There is currently no cure for the disease, although there are treatments that can reduce symptoms and maintain quality of life for as long as possible.
Parkinson's disease is caused by the progressive loss of a particular set of nerve cells in the brain, but this damage to nerve cells will have been going on for a long time before symptoms become apparent.
If treatments are to be developed that can slow or halt the progression of the disease before it affects people significantly, the researchers say, we need methods to be able to identify people at risk before symptoms take hold.
Conventional MRI cannot detect early signs of Parkinson's, so the Oxford researchers used an MRI technique, called resting-state fMRI, in which people are simply required to stay still in the scanner. They used the MRI data to look at the 'connectivity', or strength of brain networks, in the basal ganglia – part of the brain known to be involved in Parkinson's disease.
The team compared 19 people with early-stage Parkinson's disease while not on medication with 19 healthy people, matched for age and gender. They found that the Parkinson's patients had much lower connectivity in the basal ganglia.
The researchers were able to define a cut-off or threshold level of connectivity. Falling below this level was able to predict who had Parkinson's disease with 100% sensitivity (it picked up everyone with Parkinson's) and 89.5% specificity (it picked up few people without Parkinson's – there were few false positives).
Dr Mackay explains: 'Our MRI approach showed a very strong difference in connectivity between those who had Parkinson's disease and those that did not. So much so, that we wondered if it was too good to be true and carried out a validation test in a second group of patients. We got a similar result the second time.'
The scientists applied their MRI test to a second group of 13 early-stage Parkinson's patients as a validation of the approach. They correctly identified 11 out of the 13 patients (85% accuracy).
'We think that our MRI test will be relevant for diagnosis of Parkinson's,' says joint lead researcher Dr Michele Hu of the Nuffield Department of Clinical Neurosciences at Oxford University and the Oxford University Hospitals NHS Trust. 'We tested it in people with early-stage Parkinson's. But because it is so sensitive in these patients, we hope it will be able to predict who is at risk of disease before any symptoms have developed. However, this is something that we still have to show in further research.'
To see if this is the case, the Oxford University researchers are now carrying out further studies of their MRI technique with people who are at increased risk of Parkinson's.
Notes to Editors
- Parkinson's disease is most often diagnosed from observing people's symptoms over time. Parkinson's doesn't show up at all with existing MRI techniques. Instead, MRI scans may be used to exclude other brain and neurological conditions if a doctor is worried some other damage might have occurred. The new MRI approach pioneered by the Oxford University researchers, which takes just an additional 6 minutes, could be added onto these routine MRI scans to give more diagnostic information.
- The figures on accuracy, sensitivity and specificity are good for a non-invasive test like an MRI scan, say the researchers. However, they're not of a level that would make sense as a population-wide screening programme for Parkinson's, like those seen for breast or bowel cancer, for example. Instead, the researchers suggest the MRI scan could in future be used where people might be considered to be at higher risk of Parkinson's, or for other reasons.
- Current treatments for Parkinson's help in managing symptoms. Some have questioned what value early diagnosis would be in this situation. But Dr Mackay says: 'If we are to develop treatments to slow or halt progression to Parkinson's disease before symptoms arise, we will also need to develop ways of identifying people who would benefit from them. They are two sides of the same coin. We need both. We are hopeful we have made progress on the second part of this challenge.
She adds: 'Unless you can find people who are at increased risk of Parkinson's, you can't even do clinical trials of new drugs well. We need to develop early diagnosis alongside new treatments. They go hand-in-hand.'
- There is another imaging technique for diagnosing Parkinson's disease called SPECT that is used in some cases. But this is invasive, expensive and involves some exposure to radiation. A simple and quick MRI diagnostic approach would be preferable.
- In another part of the study, the researchers used their MRI approach to compare brain connectivity in the 19 patients with early-stage Parkinson's when they were off and when they were on medication. When they were on medication, they showed the same connectivity as people without Parkinson's.
- The paper 'Functional connectivity in the Basal Ganglia network differentiates PD patients from Controls' is to be published in the journal Neurology with an embargo of 21:00 UK time / 16:00 US Eastern time on Wednesday 11 June 2014.
- Oxford University's Medical Sciences Division is one of the largest biomedical research centres in Europe, with over 2,500 people involved in research and more than 2,800 students. The University is rated the best in the world for medicine, and it is home to the UK's top-ranked medical school.
From the genetic and molecular basis of disease to the latest advances in neuroscience, Oxford is at the forefront of medical research. It has one of the largest clinical trial portfolios in the UK and great expertise in taking discoveries from the lab into the clinic. Partnerships with the local NHS Trusts enable patients to benefit from close links between medical research and healthcare delivery.
A great strength of Oxford medicine is its long-standing network of clinical research units in Asia and Africa, enabling world-leading research on the most pressing global health challenges such as malaria, TB, HIV/AIDS and flu. Oxford is also renowned for its large-scale studies which examine the role of factors such as smoking, alcohol and diet on cancer, heart disease and other conditions.
- About Parkinson's UK
Every hour, someone in the UK is told they have Parkinson's.
It affects 127,000 people in the UK - which is around one in 500 of the population.
One in 20 people are under 40 when they are diagnosed.
Parkinson's is a degenerative neurological condition, for which there currently is no cure. The main symptoms of the condition are tremor, slowness of movement and rigidity.
Parkinson's UK is the UK's leading charity supporting those with the condition. Its mission is to find a cure and improve life for everyone affected by Parkinson's through cutting edge research, information, support and campaigning.
For advice, information and support, visit http://www.parkinsons.org.uk or call our free, confidential helpline on 0808 800 0303.
Our work is totally dependent on donations. Help us to find a cure and improve life for everyone affected by Parkinson's.
- The National Institute for Health Research (NIHR) is funded by the Department of Health to improve the health and wealth of the nation through research. Since its establishment in April 2006, the NIHR has transformed research in the NHS. It has increased the volume of applied health research for the benefit of patients and the public, driven faster translation of basic science discoveries into tangible benefits for patients and the economy, and developed and supported the people who conduct and contribute to applied health research. The NIHR plays a key role in the Government's strategy for economic growth, attracting investment by the life-sciences industries through its world-class infrastructure for health research. Together, the NIHR people, programmes, centres of excellence and systems represent the most integrated health research system in the world. For further information, visit the NIHR website.
Journal
Neurology