Has your wife ever mentioned seeing you moving or making soft vocalizations prior to striking out? I ask because if there is any warning that can be seen or heard, and your wife happens to be awake, she might be able to gently awaken you before it escalates into unconsciously striking out.

When I sleep on my back, i always have nightmares, some of which lead to paralysis and attempts to scream on the way up. My dog comes over and noses me, which breaks the hold. Perhaps your wife nudging you would do the same.

Its not a cure, and your wife won't be awake every time, but when she is, it might cut down on the number of episodes.

Sam