In the case of epilepsy, severing nerves in the brain can help restore mental health.  To solve most nervous system ailments, cutting nerves is the exception, not the norm for regaining function.

Recent advances in nano-material science have made significant strides in reconnecting nerves in the peripheral nervous system. Until now the standard approach to repairing damaged nerves as been to take a nerve from one part of the body and move it to the damaged section.  The downside here is obvious; there is one less nerve somewhere else in your body.

The new approach uses tube-like polymer substrates structures that act as a bridge to guide the nerve growth.  These structures, made of biodegradable polymer films have nano-patterned grooves that guide neurons so they grow in the right direction. This technique is similar in spirit to how viticulturists guide the grape vine growth that makes all the fine wine.  Perhaps in time, similiar techniques might be used to help regrow damaged tissue in our brains.