Small vessel disease often affects entire brain Nijmegen researchers present new framework for serious disease

13 June 2018

Radboud university medical center researchers state that damage to the smallest cerebral vessels can have effects throughout the brain. Small vessel disease (SVD) should therefore no longer be regarded as a local but as a generalized brain disorder. This approach has consequences for research, diagnostics and treatment

As the general population gets older, the incidence of age-related diseases such as dementia is increasing. About forty million people around the world currently have this disease. A remarkable feature of dementia is that small vessel disease is the main cause.
 
Not so innocent
For a long time, microhemorrhages and other minute injuries were thought to be harmless phenomena. It has now become clear that they are the most important vascular cause of dementia and are also responsible for about one-fifth of all cerebral infarctions. Small vessel disease is often associated with gait problems too and could ultimately lead to parkinsonism.
 
New framework
A team of Nijmegen researchers headed by Frank Erik de Leeuw will present a new framework to describe the often highly divergent symptoms of SVD in Nature Reviews Neurology. De Leeuw: “Nearly everyone of age sixty and over has some degree of SVD. This does not affect some people, while in others this will lead to dementia or parkinsonism, with admission to a nursing home as the inevitable outcome. Because the damage to the smallest cerebral vessels can occur anywhere in the brain, highly diverse symptoms can be expected.”
 
Vessels and nerves
The microhemorrhages and other minimal injuries to blood vessels may lead to damage to the surrounding nerves. De Leeuw: “These effects are often easier to image than the blood vessel damage itself. This allows identification of the disease sites, which can then be linked to the symptoms. It seems obvious, for example, that damage to the motor cortex is the cause of the gait problems seen in some patients.”
 
Local cause, widespread symptoms
This review article presents SVD research from an entirely new perspective as new imaging tests show that local manifestations of SVD may affect the entire brain, causing highly diverse symptoms. De Leeuw: “It appears that SVD not only causes structural damage but also functional problems. Depending on its role in the functional network, damage at one site may lead to loss of function – and thus other symptoms – at other sites. In other words, local SVD-related damage leads to generalized cerebral defects.
 
Perspective
The idea to approach SVD not as a local but as a general problem manifested all over the brain is not entirely new. It is consistent with the way in which researchers look at some other neurological disorders such as multiple sclerosis. De Leeuw: “This change in perspective changes the way in which we do research, diagnose patients and develop treatments. Obviously, the main question is whether this new framework will lead to a more precise characterization of the disease. The better we know the disease, the better we can help the patient.”
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Paper in Nature Reviews Neurology: Cerebral small vessel disease: from a focal to a global perspective - Annemieke ter Telgte, Esther M. C. van Leijsen, Kim Wiegertjes, Catharina J. M. Klijn, Anil M. Tuladhar & Frank-Erik de Leeuw
www.nature.com/articles/s41582-018-0014-y