one of the uses of neurontin is for neuropathic pain which is a fancy way of saying you get pain because a nerve is being physically irritated for one reason or another and that is how it is reacting--by your brain perceiving pain. i like to think of neurontin being used this way as a kind of tranquilizer for the nerve.
my own history with it, however, is that i had a lot of finger and muscle twitching as they increased my dose of neurontin. it was affecting my ability to hold a pen or pencil and write. i took it for a pinched nerve in my back that causes muscle spasms. since, i have been switched to zonegran, gabatril and now to topamax. these are all anti-epileptic drugs, but they affect the nerves by tranquilizing or soothing them. hard to explain this concept. anyway, i like the topamax a lot. it has greatly reduced by muscle spasms which are the real cause of the pain and my finger twitching is practically nil.
the conservative treatment for cts, as another poster mentioned, is to wear wrist splints. the splints keep the arm, wrist and hand in a neutral position that minimizes irritation to the radial vein which is the culprit here. they can be purchased at any drug store where they have the first aid supplied, like ace wraps. the pain in your mom's hands as well as the sensation of them "falling asleep" which is called paresthesia is due to the radial nerve being pinched where is passes through a hole in the bone of the wrist called the carpal tunnel. there is a progression of symptoms that occur when a nerve is squeezed like that. it includes tingling, numbness, and pain. the amount of squeezing (or compression) of the nerve that is going on determines the extent of these symptoms a person will have.
here are links to information about carpal tunnel syndrome:
these are links to information about neurontin. i'll admit that it is very hard to find information as to why neurontin works for neuropathic pain: