A doctor says Lyle Alzado, the football star-turned-actor, is suffering from side effects of brain cancer that would have made impossible for him to assault a woman process server last week in Marina del Rey, Calif. Alzado, 42, once a fierce defensive end for the Los Angeles Raiders and Denver Broncos, was diagnosed three weeks ago and has been troubled by "progressive dizziness over several weeks culminating in a loss of right arm, right hand and right leg coordination," his doctor, Dr. Robert Huizenga, said. "He is quite unsteady when he walks." Alzado was arrested Tuesday after he allegedly assaulted a 5-foot-5 woman who was trying to serve legal papers pertaining to a business deal. The woman was not hurt but sprayed Alzado with Mace because she felt he was getting ready to push her off the balcony of his 10th-floor apartment. Alzado, who was treated at a hospital for the effects of the Mace, is to appear in court May 21.