The US Food and Drug Administration has approved an experiment on a group of volunteers that could lead to significant improvements in the early diagnosis of multiple sclerosis. Neurologists from Case Western University, in Cleveland have developed a new marker for PET (positron emission tomography) imaging, known as Myeliviz, that could enable this “machine” to highlight the condition of myelin (the sheathing that protects nerve fibers and is damaged by the disease) with a high degree of accuracy, thus providing a detailed and early picture of possible lesions. The study has been funded by the National Institutes of Health (NIH).
Multiple sclerosis is an auto-immune disease that – according to some estimates – affects 2.3 million people worldwide. With this disease the body’s defence system targets myelin by mistake, thus “ruining” the axons of the nerve cells to varying degrees (axons are the projections that conduct nerve impulses). Lesions are formed long before the first symptoms appear, but up until now no examination was able to highlight them at such an early stage, and this explains why diagnosis is often made late. Furthermore, MRIs are the current standard-of-care imaging examination for MS, which – as accurate as they may be – only provide anatomical information (i.e. they show up the areas of the brain where there is no myelin). PET imaging, on the other hand, shows where the specific substances (tracers) injected into the blood of patients by radiologists is “captured” and also provides a picture of what happens to cells metabolically, hence showing the live biochemical “behaviour” of cells, and as a result helps us to understand to what extent a certain organ or tissue is compromised compared to its normal state.
For years researchers have tried in vain to develop a specific PET scan for MS, but all attempts have failed due to the lack of adequate tracers: the one developed by Case Western University, which causes lesions to appear as dark spots in the clear image of healthy myelin, could finally offer early and reliable results. If the success of the first tests is repeated, existing drugs, which are much are more effective than those of the past, could be used to intervene before nerve fibers get too damaged. In addition, the entire process could be managed better by supplementing PET imaging with magnetic resonance imaging.
Finally, if the potential of Myeliviz is proven, experts are suggesting that it could also be used for other illnesses of the nervous system that affect myelin, such as strokes, epilepsy, trauma, several types of tumors and neurodegenerative diseases.