55 msfocusmagazine.org the past several years, our understanding of strategies to minimize the risk of PML with Tysabri have increased dramatically. The primary risk factors for the development of PML in patients on Tysabri are JC virus anti- body index status, length of time on the drug, and whether the patient has had any prior immunosuppressant exposure. Manypatients are felt to be in a risk group for PML that would makeTysabri unappealing forlong-term use. This new study may give some of these patients the option of remaining on what could be a very effective drug for them. Two questions were answered by this most recent study. Does extending the time between Tysabri doses lessen the effectiveness of the drug? Second, does extending the time between Tysabri doses improve thesafetyofthedrug?Fortunately, the study would suggest that patients can continue to do very well in terms of controlling their MS with the extended intervals between Tysabri doses. Furthermore, the risk of PML appears to be significantly reduced by extending these intervals. Deep brain stimulation may offer new fatigue treatment Up to 90 percent of people living with MS report experiencing severe fatigue. Treatment options are scarce, and no licensed pharma- ceutical treatments are available. In contrast, deep transcranial magnetic stimulation has been used in the diagnosis and treatment of a range of neurological and psychiatric disorders. Researchers at NeuroCure Clinical Research Center, Charité–Universitätsmedizin Berlin, Germany, found that dTMS can produce significant improvements in fatigue symptoms. The findings were published in the journal Neurology Neuroimmunology & Neuroinflammation Dr.Thrower: Fatigue remains one of the most common symptoms seen with multiple sclerosis. Many individuals with MS list fatigue as their most bothersome symptom. Fatigue is also one of the leading causes of vocational disability for the MS community. Currently, there is no FDA-approved treatment option for managing fatigue in MS. Many medications are used off label, however. These include amantadine, modafinil, armodafinil, and stimulant medications such as methylphenidate. Sleep hygiene and regular exercise are also important tools in managing MS- related fatigue. This new study sheds light on what may be a new tool in the battle against MS-related fatigue. Transcranial magnetic stimulation may prove to be a safe and convenient treatment option for people with MS suffering from fatigue. The results of a larger study will be anxiously anticipated. Two new studies examine natalizumab and pregnancy risks Twonewstudieslookattheeffectsofstopping the newer, stronger drug natalizumab for multiple sclerosis during pregnancy. The researchers found that women who take natalizumab forMS mayexperience increased disease activity if they stop taking the drug prior to pregnancy, however the risk may be reduced if they take the drug up until conception. The second, related study says taking natalizumab during the first trimester may increase the risk of miscarriage, but the risk is small and within the risk range of Many individuals with MS list fatigue as their most bothersome symptom.