A new study carried out by scientists from Maastricht University Medical Center in the Netherlands has suggested that an increase in the permeability of the blood-brain barrier may have an important role to play in the early stages of Alzheimer’s disease. The blood-brain barrier stops the circulating blood from entering the brain and is essential for keeping the brain tissue healthy. Via a collection of cells and subcellular structures, the blood-brain barrier helps to both regulate the delivery of vital nutrients, while blocking neurotoxins. It’s also involved with the removal of excess substances from the brain.
By using MRI scans the researchers have been able to identify leakages in the blood-brain barrier of people who have been diagnosed with early Alzheimer’s disease. So far, the results of this research have suggested that an increase in the permeability of the blood-brain barrier may be a key mechanism at the beginning of the disease. The researchers used the MRI to compare the brain tissue of 16 early Alzheimer’s patients with that from 17 healthy controls. All the participants in the study were of a similar age. They also measured leakage rates of the blood-brain barrier and used this data to generate a histogram in order to assist in determining the extent of the leakage.
From the histogram the researchers found that the leakage rate observed in the Alzheimer’s patients was significantly higher than that observed in the control group. Furthermore, while the leakage was distributed throughout the cerebrum, those patients with Alzheimer’s showed a significantly higher amount of leakage in the grey matter, including the cortex. The researchers also found a small amount of blood-brain barrier impairment in the white matter of the brain too.
When the blood-brain barrier is impaired in this way it means that the brain is no longer protected, causing disruption to the stability of the brain cells and changes to the environment where the nerve cells interact. This could eventually lead to the brain being unable to function properly. In fact, this was found to be the case, as the researchers were able to make a connection between the extent of the impairment of the blood-brain barrier and the patients’ decline in cognitive performance. This suggests that the early pathology of Alzheimer’s is linked to a faulty blood-brain barrier, and that it could lead to cognitive decline and dementia.
The study was published recently in the online journal Radiology.