I am sorry to say that I do not understand what do you mean by the knots in the nervous system on hands. If you mean little swellings along the course of nerves, then 3 possibilities come to mind:
1. Swellings due to benign tumours of nerves called neurofibroma. They can occur in any part of body. Commonly associated with dark leaf shaped brownish pigmentations on body.
2. Swellings due to fatty benign tumours called lipomas.
3. Swellings due to a parasite in the muscle called cysticercus.
It will be worthwhile to seek a medical opinion.