postherpetic neuralgia
"Prescribed for nerve pain following shingles after crippling left hand side pain that did not respond to standard analgesia.
two unexpected beneficial side effects have occurred.  
My long term and almost permanent anxiety ( we are talking 35 years   ) has been greatly reduced. 
The problem that I had following a transient ischamic attack some five years prior where my bodies idea of the spacial position of my left leg via external stimulus did not agree with my visual perception and viewing my leg caused a strange spacial readjustment where the leg shifted four inches to the left but in reality stayed still. My visual acuity also improved as if everything was lit by stage lighting."