Multiple sclerosis and aging.

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system, whose incidental peak occurs around 30 years. This review focuses on epidemiologic, physiopathological, clinical and therapeutic characteristics of MS in elderly patients in two different situations: 1) late-onset MS (after 50 years), 2) aging in MS with young adult-onset. Epidemiologic studies established that MS occurs after 50 years in 5% of cases. As opposed to young adult-onset MS, late-onset MS is characterized by a predominant progressive course, a longer diagnosis delay, a higher prevalence of motor disability, while cognitive impairment is similar in terms of frequency and affected cognitive domains. Improvement of MS patients' global healthcare together with life expectancy increase has led to an increased number of elderly patients with MS, regardless of age at onset. Care providers must take into account the potential more frequent comorbidities in this specific population and pharmacological differences with younger subjects to adapt and optimize the risk/balance benefit of disease-modifying therapies.