Functional improvement and symptom management in multiple sclerosis: clinical efficacy of current therapies

Disease-modifying treatments (DMTs), which are the foundation of multiple sclerosis (MS) care, reduce clinical exacerbations (relapses) and slow disease progression; however, improving quality of life (QOL) is an unmet need for many individuals with MS. DMTs, including interferon-beta, glatiramer acetate, natalizumab, mitoxantrone, and fingolimod, reduce the rate and severity of relapses, the accumulation of brain and spinal cord lesions as shown on magnetic resonance imaging (MRI), and disability progression. Many studies link diminished QOL with specific MS symptoms (fatigue, impaired mobility, spasticity, etc). Even in patients already receiving DMTs, symptoms and QOL may improve with additional agents that treat specific symptoms, thereby improving patient function and ability to perform activities of daily living (ADLs). Patients have reported that mobility impairment is one of the worst aspects of MS. Almost half of patients treated with DMTs reported no improvement in mobility. However, blocking the voltage-dependent potassium channels on the surface of demyelinated nerve fibers may improve signal conduction. Dalfampridine, a potassium channel blocker, received Food and Drug Administration (FDA) approval for all forms of MS specifically to improve walking, which was demonstrated by increased walking speed. By improving walking in some patients with MS, the effects of dalfampridine may complement those of DMTs and address the stated priorities of many patients.