Elder,
Was there a penalty to actions that goes along with the critical?
markc and Marc R, I'd normally agree with you, but here's my thinking...
Unparalysis is a 15th lvl spell for Paladins. It cures one (1) paralysis problem. It's not the same spell on Nerve Law at 10th lvl, because the Nerve Law has a duration of 10 min/lvl and the Paladin spell is Permanent (assuming no typos).
The 18th lvl Paralysis Cures (Nerve Law) has a recovery time of 1-10 days and is ONLY for spells and diseases, not poisons. (and possibly, not wounds from crits..)
It sounds like all of the Nerve Repair spells are for repairing a penalty that resulted from a crit, or when the injury says "nerve damage".
But Unparalysis (Nerve Law) is a temporary fix until you get something better.
A Paladin can't cure any kind of Nerve Damage resulting from injury, crits, whatever (Unless he learns other spell Lists). But he can permanently cure one paralysis problem.
It's up to the GM, Elder, but I think this might be "one paralysis problem".