The preservation of a protein found in particular synapses in the brain plays a key role in protecting against vascular dementia after a stroke, say researchers at King's College London.
The study, funded by the Dunhill Medical Trust, is published today in the 9 November issue of Neurology, the medical journal of the American Academy of Neurology. Researchers say the study findings increase understanding of vascular dementia, and highlight a possible target for future diagnoses and treatment of the condition.
Professor Paul Francis, King's College London, said: 'Vascular dementia accounts for 15 to 20 per cent of the 25 million people worldwide with dementia, yet there is currently no effective treatment. It is common for people to develop vascular dementia after suffering a stroke, which can be devastating for patients and their carers.
'Understanding the chemical processes that affect the brain when people develop vascular dementia is a vital step towards identifying potential treatments for this common condition. The findings of this study take us that little bit closer towards achieving this goal.'
Vascular dementia, the second most common form of the condition, is caused by problems in the supply of blood to the brain, such as a stroke, and can affect memory, thinking, behaviour and the ability to perform everyday activities. One in three older people who have a stroke develop dementia within three months, with a 10-fold increased risk of dementia over five years.
The team, led by Professor Paul Francis at King's in collaboration with Newcastle University, studied differences in nerves and synapses in the brain tissue of individuals with and without dementia, over half of which had also suffered a stroke previously.
A synapse is a tiny gap between two neurones (nerve cells) in the brain, and information is transported across this gap by a neurotransmitter. Synapses that use glutamate (an amino acid) as a neurotransmitter are known to be related to memory and cognition, and contain a protein called VGLUT1.
The autopsy study specifically looked at the levels of VGLUT1 by analysing brain tissue from 73 individuals, obtained from the Brains for Dementia Research programme. Forty-seven individuals had a form of cerebrovascular disease, triggered when the blood supply to the brain is disturbed in some way, such as a stroke. Twenty-seven of these people had undergone an annual cognition test in the years before their death as part of the Cambridge Assessment of Mental Health for the Elderly (CAMCOG) evaluation.
The findings show a correlation between levels of VGLUT1 and cognition scores – the higher the concentration of VGLUT1, the better they did in the CAMCOG cognition assessment.
Crucially, the study also showed that in those individuals who did not develop dementia after a stroke, the levels of VGLUT1 were significantly higher.
These findings suggest that if levels of VGLUT1 can be preserved artificially after a stroke, the chances of developing vascular dementia could be significantly reduced.
Notes to editors
King's College London
King's College London is one of the top 25 universities in the world (2010 QS international world rankings), The Sunday Times 'University of the Year 2010/11' and the fourth oldest in England. A research-led university based in the heart of London, King's has nearly 23,000 students (of whom more than 8,600 are graduate students) from nearly 140 countries, and some 5,500 employees. King's is in the second phase of a £1 billion redevelopment programme which is transforming its estate.
King's has an outstanding reputation for providing world-class teaching and cutting-edge research. In the 2008 Research Assessment Exercise for British universities, 23 departments were ranked in the top quartile of British universities; over half of our academic staff work in departments that are in the top 10 per cent in the UK in their field and can thus be classed as world leading. The College is in the top seven UK universities for research earnings and has an overall annual income of nearly £450 million.
King's has a particularly distinguished reputation in the humanities, law, the sciences (including a wide range of health areas such as psychiatry, medicine, nursing and dentistry) and social sciences including international affairs. It has played a major role in many of the advances that have shaped modern life, such as the discovery of the structure of DNA and research that led to the development of radio, television, mobile phones and radar. It is the largest centre for the education of healthcare professionals in Europe; no university has more Medical Research Council Centres.
King's College London and Guy's and St Thomas', King's College Hospital and South London and Maudsley NHS Foundation Trusts are part of King's Health Partners. King's Health Partners Academic Health Sciences Centre (AHSC) is a pioneering global collaboration between one of the world's leading research-led universities and three of London's most successful NHS Foundation Trusts, including leading teaching hospitals and comprehensive mental health services. For more information, visit: www.kingshealthpartners.org.
Brains for Dementia Research
Brains for Dementia Research is an initiative funded jointly by the Alzheimer's Socity and the Alzheimer's Research Trust to address the shortage of brain tissue from individuals that have been assessed regularly during life that is so essential for research into dementia. All brain tissue used in the study was obtained from the Brains for Dementia Research programme. All individuals, or their next of kin, had given consent for their brain tissue to be used for research into dementia after their death. http://www.brainsfordementiaresearch.org.uk
The Dunhill Medical Trust is a grant-making charitable trust which supports research into the causes and treatment of disease, disability and frailty related to ageing. For further information visit www.dunhillmedical.org.uk. E-mail: admin@dunhillmedical.org.uk."
Journal
Neurology