What began as a competitive quest in college--to run the Boston Marathon--has evolved into something far more life affirming for Ben Beach.

Running, and running well, was always the easy part for Beach (58), from Bethesda, MD. In 1967, Beach ran his first Boston Marathon as a freshman at Harvard. He has traveled back to Boston every Patriots Day since, and now, preparing for his 41st consecutive Boston on Monday, Beach owns the second longest such streak, behind Neil Weygandt, who started his streak in 1966.

Back in the day, say 25 years ago, Beach regularly placed among the leaders at Boston, where he has a personal best of 2:27. But over the last several years, a neurological disorder called dystonia has made going 26.2 miles more difficult than Beach ever bargained for.

The problem, an involuntary muscle movement in Beach's left leg, began five years ago and has gotten progressively worse. When conventional treatments failed to provide relief, Beach sought help at the National Institutes of Health, where botox injections have quieted somewhat the misfiring signals from his brain to his leg. Still, Beach's left leg flails outward at an odd angle and leaves him off-balance at every stride; he admits, with a touch of understatement and good cheer, that "my gait is less than ideal."

Beach's finishing time has slid dramatically over the last five years, although cross-training on a bike and work with weights has helped him maintain a runner's physique and general fitness. Last year, throughout an emotional 40th anniversary run with support and pacing help from his two adult children, Carter and Emily, Beach finished the marathon in 4:11.

"Some people could say I'm nuts, and I can appreciate that," Beach said. "But Boston and the streak are a part of me, and I'm bound and determined to keep it going."

Beach has another streak at the Cherry Blossom Ten Mile run in Washington, where he is the only runner to have finished every one of the event's 36 years. On April 6, Beach ran 1:33:43, an enviable time for most of the finishers that day but 15 minutes slower than he had run a year earlier. So this year at Boston is likely to be difficult as well.

"I miss the competitive aspect of racing," Beach said. "These days it's more a question of whether I can make it to the end. But running a marathon is always a challenge. It's now more of a challenge, in a different way."

Learn more about Dystonia