First off I am a complete newbie and first time owner. I have never owned nor handled a spider so take this with a grain of salt.. as far as ethics are concerned I feel I have an opinion on the matter tho.. I would ask myself this question. Is there a chance that the neurological problem bothers, causes pain, or otherwise negatively affects the snakes? If the answer is yes, then I would be opposed. They could be completely unaffected but if you answer yes then you believe there is a chance it could lead to a poor quality of life, why do it? Again just my opinion and I am new to this so take from it what you will.
Essentially i I think it comes down to the individual and there beliefs on the issue.