Inflammatory Demyelinating Diseases

The spinal cord is commonly affected in inflammatory demyelinating diseases (IDD) of the central nervous system. In the most common IDD, multiple sclerosis (MS), the importance of spinal cord involvement is highlighted by the inclusion of characteristic cord lesions in its current diagnostic criteria. In neuromyelitis optica, longitudinally extensive spinal cord lesions over three or more segments are considered almost pathognomonic for the disease. In general, spinal cord lesion load shows a strong correlation with disability, and spinal cord-derived magnetic resonance imaging (MRI) measures are some of the strongest biomarkers of a disabling disease course. In progressive forms of MS, the clinical phenotype is consistent with a progressive myelopathy in most cases. These forms of MS, especially primary progressive MS, represent a major challenge for disease activity monitoring. Novel quantitative MRI metrics characterizing spinal cord involvement in MS are expected to find their way into routine clinical monitoring as they provide unique insight into tissue abnormalities, allowing for monitoring of disease progression and assessment of response to treatment. These techniques include magnetization transfer MRI, diffusion-weighted imaging, atrophy measurement techniques, T1 and T2 relaxometry, and magnetic resonance spectroscopy.