Dough, there may be some unusual anatomical issue at the root of your hand numbness but most likely the litany of causes and cures experienced by you will be much the same as for everyone else including myself. You might singly or in combination try to:

move your hands every few minutes to a different location;
ride in the drops for a few minutes;
rotate the bar up a degree or two;
rotate the bar down a degree or two;
raise the bar a bit with with a shim to put you in a slightly more upright position;
shorten the stem to the next size down;
move the saddle aft a good bit. (This is what worked for me and I may try a new
setback seat post.)

Basically, keep trying ideas.