Treating multiple sclerosis in the natalizumab era: risks, benefits, clinical decision making, and a comparison between North American and European Union practices.

Multiple sclerosis (MS) is the most common cause of nontraumatic severe neurological disability in young adults. If left untreated, most individuals with MS will accumulate significant physical and/or cognitive disability as the consequence of demyelination and axonal injury. Treatment has focused on disease-modifying therapies (DMTs) and questions remain about timing and indications for their use. Natalizumab is a humanized monoclonal antibody directed against alpha4-integrin that prevents migration of leukocytes into the brain parenchyma. The clinical and radiological efficacy of natalizumab has been shown in several randomized trials; however, adverse events associated with natalizumab have limited its use as a first-line agent. In this review we compare current recommendations for the use of first-line DMTs, adverse events associated with MS therapies, and differences between the practices in North American and the European Union.

High-resolution anatomic, diffusion tensor, and magnetization transfer magnetic resonance imaging of the optic chiasm at 3T.

PURPOSE: To evaluate techniques for anatomical and physiological imaging of the intracranial optic nerve (ON), optic chiasm (OC), and optic tract (OT) at 3T with the aim of visualizing axonal damage in multiple sclerosis (MS). MATERIALS AND METHODS: Imaging was performed on a 3T scanner employing a custom-designed head coil that consisted of a coil array with four coils (30 x 30 cm(2)). Oblique fast spin echo (FSE) images, magnetization transfer (MT)-enhanced 3D gradient-echo (GRE) time-of-flight (TOF) images, and line scan diffusion images (LSDI) were obtained. Full diffusion tensor (DT) analysis was performed, and apparent diffusion coefficient (ADC), fractional anisotropy (FA), and fiber direction maps were obtained. RESULTS: FSE anatomic images were obtained with an in-plane resolution of 0.39 x 0.52 mm(2). The in-plane resolution of the MT and LSDI images was 0.78 x 0.78 mm(2). The OC, intracranial ON, and OT can be seen on these images. The dominant fiber orientations in the OC, ON, and OT, as derived from the DT images, are displayed. CONCLUSION: This study shows that by using 3T and a custom-designed, four-channel head coil, it is possible to acquire high-resolution anatomical and physiological images of the OC, ON, and OT. The pilot results presented here pave the way for imaging the anterior visual pathway in patients with MS.