Most people with multiple sclerosis who have difficulty walking say it is the most challenging part of the debilitating disease, U.S. researchers say. However, a survey by Harris Interactive on behalf of the National Multiple Sclerosis Society and Acorda Therapeutics indicated 40 percent of people with MS rarely or never discuss walking problems with their doctor. The June 10-17 survey of more than 1,200 adults living with MS indicated 65 percent reported having trouble walking, the inability to walk or difficulty maintaining balance at least twice per week. Seventy percent of those with walking issues say that\'s the toughest symptom to deal with. In addition, a majority of people living with MS reported they experienced walking problems within the first few years after diagnosis, while among people diagnosed with MS within the past five years, 58 percent reported experiencing a mobility issue at least twice a week. On average, people with MS ages 41 or younger who do discuss trouble walking with their doctor initiate the conversation only 46 percent of the time. An estimated 78 percent of these women and 62 percent of these men report that trouble walking makes getting around dangerous, the survey indicated.