Brain imaging may help identify sleep disorder patients at greatest risk for neurodegenerative diseases such as dementia and Parkinson’s disease, an international team of researchers has found.
Their study of people with rapid-eye-movement sleep behavior disorder (IRBD) found that brain imaging tests can detect neurodegenerative disease-related brain abnormalities before a person develops noticeable symptoms.
Previous research has shown that IRBD of unknown cause may be an early predictor of neurodegenerative diseases in more than half of patients, but it hasn’t been possible to identify which patients will develop these diseases.
Brain scan
Being able to identify IRBD patients at increased risk would lead to earlier treatment and improve understanding of the early stages of neurodegenerative diseases, according to Alex Iranzo de Riquer, of the Hospital Clinic of Barcelona, and colleagues.
At the start of the study, 43 patients with IRBD underwent two brain imaging tests — dopamine transporter imaging and transcranial sonography.
Of the 27 patients whose imaging tests showed brain abnormalities associated with Parkinson’s and a brain disease known as dementia with Lewy bodies, eight (30 percent) had developed a neurodegenerative disease when assessed 2-1/2 years later. Five had Parkinson’s disease; two had dementia with Lewy bodies; and one had multiple system atrophy, a rare condition that affects movement, balance and other bodily functions.
The patients without brain abnormalities (and 70 percent of those with such abnormalities) remained disease-free at the end of the study.
The study findings were released online Sept. 14 in advance of publication in the November print issue of The Lancet Neurology.
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Researchers have shed new light on Parkinson’s disease, which could help with the development of cures or treatments in the future.
The collaboration, led by Professor Peter Redgrave from the University of Sheffield´s Department of Psychology, suggests that many of the problems suffered by patients with Parkinson´s disease can be understood in terms of damage to control circuits in the brain responsible for habits.
An important processing unit in the brain (the basal ganglia) is part of two behavioural control circuits – habitual control, which directs our fast, stimulus-driven automatic, largely unconscious movements; and voluntary goal-directed control, which is driven by a conscious appreciation of the action´s outcome.
An important proposal in the article is that Parkinson´s disease is linked to a preferential loss of the neurotransmitter dopamine from the regions involved in habitual control.
The proposed analysis offers a further important insight into the symptoms of Parkinson´s disease. At the level of the basal ganglia, the goal-directed and habitual control circuits are physically separated, but down-stream, they converge on shared motor systems (that is, we can do the same action either under goal-directed or habitual control).
Numerous experiments show that the loss of dopamine from the basal ganglia increases inhibitory output from the habitual control circuits.
Therefore, for a patient with Parkinson´s disease to express goal-directed behaviour, they have to overcome the distorting inhibitory signals from the malfunctioning habitual control system.
This provides a further reason for why patients find it so difficult to initiate and maintain actions and why their behaviour is so effortful and slow.
These ideas also offer a potential resolution of a continuing paradox in Parkinson´s disease research – why destruction of the parts of the basal ganglia responsible for habits can have such a beneficial effect on Parkinson´s disease.
Professor Redgrave and his team propose that removal of the distorting inhibitory output from habitual control circuits could make it easier for goal-directed behaviour to be expressed.
It is hoped this new interpretation of Parkinson´s disease will help in the discovery of new cures and treatment in the future for the 120,000 people in the UK suffering with the disease.
The analysis is published online and will appear in the November issue of Nature Reviews Neuroscience.
The term Alzheimer’s disease refers to a condition first recognized in 1907. In that year Alois Alzheimer reported in the medical textbooks that a woman of 51 had died of ‘dementia’. It wasn’t the ‘dementia’ that caused the interest but the fact that this woman’s brain had been examined under the microscope and it showed changes not seen before.
In certain parts the brain fibres were tangled up and there were areas of clumping together of brain matter. As time went by, some more quite young people who had died of ‘dementia’ were found to have brains that showed the same abnormalities. The condition was then called Alzheimer’s disease. At that time it was only described in younger people (before retirement age) and the dementia was called ‘pre-senile dementia’.
It was then noted that the same type of dementia (with the same symptoms) occurred much more frequently in older people. Their brains when examined under the microscope showed the same abnormalities. Because Alzheimer had described his condition in younger people, the elderly were described as having senile dementia of the Alzheimer type or SDAT This tended to make things rather complicated, and as dementia in younger people is quite rare it is becoming increasingly common to call the whole group Alzheimer’s disease.
The two words Alzheimer’s disease can’t convey the complicated set of symptoms that make up the condition, unless you personally know a suffer. A quick description often used is the slow onset of memory loss with a gradual progression to loss of judgment and changes in behaviour and temperament. A more complicated definition has been issued by the Royal College of Physicians:
Dementia is the global impairment of higher functions, including memory, the capacity to solve the problems of day to day living, the performance of learned perceptuo-motor skills, the correct use of social skills and the control of emotional reactions, in the absence of gross clouding of consciousness.
These definitions are only guides to the whole complicated condition called Alzheimer’s disease, so we need to work through some of the more common problem areas. The condition starts very slowly, so much so that close relatives and carers often do not notice that anything is wrong for a long time, then when certain things are pointed out they can often think back and realize that the dementia began a few years previously.
It has been calculated that someone needs to lose about 80 per cent of their working brain cells before mild symptoms develop, i.e. problems occur late and the brain must adapt very well for a long time. It is useful to think of the condition having three phases: mild, moderate and severe -a sufferer does not always move on to the worst phase. A sudden deterioration usually means that an acute condition (such as a chest or urine infection) has occurred. A small group of sufferers do seem to have a more rapid and downwards course (like a malignant cancerous disease) and death can occur within a few years. For most however the decline is quite slow, especially if the person is well cared for and any other medical problems are tackled early and effectively. Many people with Alzheimer’s die of something else (heart attack, stroke and even old age).
The most common problems are those of memory loss, disorientation, loss of judgment, changes in personality, difficulty in communicating, loss of practical skills and changes in behaviour. Thus, it can be understood that Alzheimer’s disease is far more than just memory loss (as some of the definitions try to show) -eventually the condition affects all of the parts that make us an individual who relates and responds to other people. Even in the very late stages, however, a sufferer is able to show responses to kindness and gentleness, but early on part of the personality, the person’s individuality, is affected.
Portable devices with painless laser beams could soon replace X-rays as a non-invasive way to diagnose disease.
Researchers say that the technique could become widely available in about five years.
The method, called Raman spectroscopy, could help spot the early signs of breast cancer, tooth decay and osteoporosis.
Scientists believe that the technology would make the diagnosis of illnesses faster, cheaper and more accurate.
Raman spectroscopy is the measurement of the intensity and wavelength of scattered light from molecules.
It is already being used in the chemical and pharmaceutical industries. For instance, Raman lasers are used to measure flame characteristics. By studying how fuels burn, pollution from the products of combustion can be minimised.
Michael Morris, a chemistry professor at the University of Michigan, US, has been using Raman for the past few years to study human bones.
So far, he has been working on cadavers, but he says that Raman could prove effective in living patients.
“You can replace a lot of procedures, a lot of diagnostics that are out there right now. The big advantage is that it’s non-invasive, pretty fast – much faster than classical procedures – and more accurate,” he told BBC News.
When a person is sick, or about to become sick, the chemical mix in the tissue is quite different from that in healthy tissue, scientists say. So the Raman spectrum changes depending on the tissue it analyses, Professor Morris explained.
“Raman gives you a molecular fingerprint, a composition of whatever it is you’re measuring,” he said.
“In diseased states, the chemical composition is either slightly abnormal or very markedly abnormal, depending upon the diseases.”
http://www.bbc.co.uk/news/science-environment-11390951
The costs associated with dementia will amount to more than 1% of the world’s gross domestic product this year at $604bn (£388bn), a report says.
The World Alzheimer Report says this is more than the revenue of retail giant Wal-Mart or oil firm Exxon Mobil.
The authors say dementia poses the most significant health and social crisis of the century as its global financial burden continues to escalate.
They want the World Health Organization to make dementia a world priority.
Campaigners say more investment in dementia care and research into new treatments is needed. Spending more money now would save nations more money in the future by decreasing the disease burden, they say.
A large part of the problem is people living longer – as life expectancy goes up around the world there will be more people who will develop dementia.
http://www.bbc.co.uk/news/health-11373018
Russian scientists claimed to have successfully tested a medicine which could be a breakthrough in treating patients of Parkinson’s disease.
“We have synthesised a compound which completely removes all symptoms of Parkinson’s disease in animals,” said Konstantin Volcho, a spokesman of Vorozhtsov Institute of Organic Chemistry in the southwestern Siberian city of Novosibirsk.
He said the tests conducted on animals with Parkinson’s disease “demonstrated that the medicine returns all parameters back to normal and does not require additional medication”.
“It has also been proven by long-term experiments,” he added.
The scientists believe the clinical trials of the drug could take at least two years, after which it will be tested on humans.
Researchers have already filed a patent application for the compound.
Though the medicine will not cure the patients completely but it allows patients to live a normal, healthy life for a longer period, the institute spokesman said.
“Currently there is no cure for Parkinson’s disease, the main target of PD treatment is to give patients the maximum quality of life for as long as possible,” he said.