Today I've got Heidi's character on the couch. She wrote in with this question:
I'm not sure if this is plausible: I have a injured character who can walk, but when stressed, he exhibits psychosomatic-type symptoms, where he becomes temporarily partially paralyzed and is in a wheelchair. I looked up somatoform disorder, and I think that is what he has, maybe that combined with a bit of post-traumatic stress disorder.
Well, Heidi, it looks like the situation you're describing actually fits more of a Conversion Disorder (which is a Somatoform disorder--that's just the overarching category, if you will).
Here's the criteria for a Conversion Disorder (with your character's symptoms in red), which is a little-tapped educational tidbit for authors. In fact, I've never read a book featuring it, though there might be some out there.
A. One or more symptoms or deficits affecting voluntary motor or sensory function (temporary paralysis of legs) that suggest a neurological or other general medical condition.
B. Psychological factors are judged to be associated with the symptom or deficit because the initiation or exacerbation of the symptom or deficit is preceded by conflicts or other stressors (when he's stressed, he becomes partially paralyzed).
C. The symptom or deficit is not intentionally produced or feigned (he doesn't have a secondary gain, like receiving disability services, etc.).
D. The symptom or deficit cannot, after appropriate investigation, be fully explained by a general medical condition, or by the direct effects of a substance, or as a culturally sanctioned behavior or experience (the doctors tell him it's not a medical issue).
E. The symptom or deficit causes clinically significant distress or impairment in social, occupational, or other important areas of functioning or warrants medical evaluation (I assume this is the case).
His paralysis is really a psychological issue, not medical. He doesn't fit criteria for Somatization Disorder because you didn't mention that he had more than the one physical issue...and people with that disorder present with tons of physical maladies. (Click here for a list.)
So yes, in short, I believe the scenario you've described is feasible. Kudos for checking with a professional before jumping knee-deep in your manuscript. Hopefully you'll avoid major rewrites this way.
Thanks for writing in!