Multiple sclerosis and later entertainment career
In 1977, Rhue was diagnosed with multiple sclerosis. She continued to work, including a role in Days of Our Lives, but by 1985, Rhue's legs had become so weak that she could only get around by wheelchair. Rhue described her fear and anxiety after being unable to land on-screen work in the entertainment industry for a period of 11 months. She said, "It became apparent that I would have to invent a giant accident to explain the wheelchair or start telling the truth."
Rhue managed to resume her career and was praised by media outlets for not allowing her health issues to hold her back. She played intermittent roles that did not require her to walk or stand, sometimes incorporating the wheelchair as part of the character. For example, she played a wheelchair-using ballistics expert on the CBS police-based legal drama, Houston Knights. She also played a judge in the scripted court show, Trial by Jury, lasting only the 1989–90 television season. She performed the role in a wheelchair, unseen by viewers behind the judge's bench. Her casting was uncharacteristic for court shows, a genre dominated by male actors previously. She also performed a recurring role in Murder, She Wrote, said to be her last television role. Angela Lansbury created a role for her when she heard that Rhue was at risk of losing her health insurance because she could no longer work enough hours.
Contrary to rumors, her illness had nothing to do with her not reprising the Star Trek role of Lt. Marla McGivers in the film Star Trek II: The Wrath of Khan (1982). At the time of the film's production start in late 1981, Rhue was still mobile and appearing in television roles, but hiding her diagnosis for fear of it impacting her career. Director Nicholas Meyer stated that he wrote McGivers out of his drafts of the film (with a line referencing the character's death) in order to give the Khan character additional motivation for seeking vengeance.
In 1991, she played a wheelchair-using character in her last film role, the made for television thriller A Mother's Justice.
