I kept loosing the feeling in my thumb and first 2 fingers on my left hand THIS MEANT NO CLUTCH CONTROL

A wrist operation for Carpal Tunnel later and it was cured!
I'd had the right wrist operated on about 8 years earlier. My right had kept going numb at night, not good when you get a shout and have to drive the fire truck!
Carpal tunnel syndrome effect the thumb and first 2 fingers. If it's these that keep going numb, go see your doctor!
Mine always played up when filtering in London traffic.