Over time, diabetes mellitus can damage various organs such as the eyes, kidneys, cardiovascular system and the peripheral nervous system as well as the central nervous system, the brain. This “brain damage” can lead to things such as memory problems. These memory problems are especially pronounced in older diabetes patients; they also seem to be at a greater risk of dementia. Because not enough is currently known about what causes diabetes’ harmful effects on the brain, Sanne Manschot attempted to identify more clearly what the brain damage consists of. She also looked for risk factors to make it possible to prevent this in the future.
In diabetic rats, Manschot first studied the role of blood vessel damage in causing brain damage. These rats were treated with a medicine (enalapril) commonly used in diabetes to protect vascular walls and to lower high blood pressure. In the rats this led to improved learning and memory, blood circulation in the brain, synaptic plasticity (a cellular form of learning), and the speed with which impulses are transferred in the brain. So, in the rats, the damage to the blood vessels and the circulation in the brain seems to make a significant contribution to the brain damage.
In addition, Manschot studied how “brain damage” manifests itself in patients with diabetes and what the risk factors are for its development. In this study (the Utrecht Diabetic Encephalopathy Study or UDES), patients with type II diabetes were compared with contemporaries in the same age group. In order to get an impression of learning ability and memory, they were given neuropsychological tests and the brain was also examined using a brain scan (MRI). The blood vessels in the head and eyes were also examined extensively in all patients. In addition, other possible complications of diabetes (in the kidneys and nerves) were identified.
Manschot did in fact find changes in the cognitive functions of the diabetes patients, both in the tests and in the MRI scans. There seems to be a relationship between arteriosclerosis and the severity of the cognitive function disorders and changes in the MRI. For the first time, Manschot describes the nature of the changes in the MRI related to changes in cognition. The indications that point to a role for the vascular system are also important because possible preventive measures can then focus on this. A follow-up study is already underway.
Sanne Manschot
Diabetic encephalopathy: a cerebrovascular disorder?
PhD advisor 1: Prof. L.J. Kappelle
PhD advisor 2: Prof. W.H. Gispen
Co-advisor: Dr. G.J. Biessels