Pressure points are real and do have an effect, but it seems that those effects are grossly overestimed by many traditional martial artists, and to a lesser degree, underestimated by grapplers and MMAers, who occaisionally use them, whether they are even aware of it (e.g. framing someone's windpipe with your forearm to create space to get an underhook, such as when escaping sidemount, etc.)
It seems to me that there is a big opportunity to integrate pressure point awareness with positional awareness (without which pressure points are nullified.) In mma, there is also room to integrate pressue point strking with general striking offense and defense. The obvious pressure points such as the eyes and groin would still need to be prohibited (although they were alowed in the early UFCs, none of the people knew both how to grapple and how to use pressure points.)
Pressuring or striking (in mma) the nerve suggested by the original poster may be effective, if the person doing it were an experienced wrestler and took into account weather they were in a position to get thrown before they could escape, and adjusted their body to buy time to do so, and had other ways of getting out to fall back on if adrenaline caused the other person not to feel it.
Few people who are knowlegable about pressure points are otherwise good mixed martial artists, and few good mma'ers know much about pressure points. I think as mma'ers look to get an edge and more traditional martial arts schools incorporate grappling and mma training, we will see more use of pressure points in mma. I realize they are now illegal in the UFC, but they aren't in a lot of other oranizations and I immagine they would be reallowed if they were shown to be safe and effective.
