Histopathology and serial, multimodal magnetic resonance imaging in a multiple sclerosis variant.

Defining tools in magnetic resonance imaging (MRI) representing specific pathological processes is needed to understand the complex relationship between inflammation, myelin breakdown, axonal injury and clinical symptoms in multiple sclerosis (MS) and its variants. Here, we describe a case of histologically-defined MS, in which the radiological appearance of the lesion and clinical course support the diagnosis of Balo's concentric sclerosis. Serial magnetization transfer, diffusion tensor imaging and 1H-magnetic resonance spectroscopy, from 14 days to 13 months after biopsy, allow the contextual interpretation of specific pathological changes. In our case, acute inflammation was sensitively traced by fractional anisotropy and increased lactate in spectroscopy. In contrast, magnetization transfer ratio and the apparent diffusion coefficient monitor the sequential loss of tissue in selected rings of the lesion. The delay from the peak of symptoms in a dramatic clinical course to the maximum tissue destruction indicated through MRI suggests that compromise of axonal function may be decisive for the acute clinical situation. This is the first report comparing 1H-magnetic resonance spectroscopy, magnetization transfer and diffusion tensor imaging with histopathology in a patient with Balo's concentric sclerosis.