I don't know your handlebar set-up but simply getting drop bars and riding on the hoods solved all of my hand numbness issues. I like oversized 31.8 diameter bars with flat tops. I use gel pads and Cinelli cork/gel tape to the give the bars a cushy feel. Works great.The advantage to drop bars isn't the ability to ride on the hoods, it's the ability to have several hand placements so the nerves aren't subject to pressure all in one place. You can ride with your hands on the hoods, on the tops or on the drops and give your hands a variety of pressure points.
The real "cure" for handlebar palsy is not to get it in the first place. Move your hands to various positions as you ride.