n the past two decades the diagnosis of MS has been revolutionised by the availability of magnetic resonance imaging (MRI) techniques that enable the diagnosis to be made more accurately and more quickly than was previously possible, for example by identifying sub-clinical lesions and using Gadolinium-enhancement to identify active lesions. In people who present with one clinical event suggestive of MS, just one scan is enough to be able to make a positive diagnosis of MS, if it satisfies the 2010 revised McDonald criteria.
More recently powerful MRI techniques including magnetization transfer-MRI, diffusion tensor-MRI, and proton MR spectroscopy, have been used to study inflammation and tissue damage in regions of the brain such as the cerebral cortex, for which conventional MRI techniques are insufficiently sensitive. Several of these non-conventional MRI techniques are being developed for use in the diagnosis of MS, especially for primary progressive MS and cases of relapsing-remitting MS where more conventional MRI is inconclusive.
These studies have also demonstrated that MS is not just a disease of the myelin-rich white matter, but that in addition to focal inflammatory lesions, the pathophysiology of MS involves diffuse damage spread through the grey and white matter.
These studies have also highlighted the importance of neurodegeneration and tissue repair and reorganisation in response to damage in the cortex.
In addition research has indicated that several MRI measurements of grey matter damage and central nervous system atrophy may be useful in predicting progression in MS.
To complement the development of more powerful MRI techniques, scientists are also identifying biomarkers – cytokines, antibodies or antigens – in the blood or cerebrospinal fluid that can assist with diagnosis and prognosis in MS, which can be objectively measured and used as indicators for particular inflammatory or neurodegenerative processes, or responses to pharmacological treatments.