ammonia is nuro toxin,,it allters brain chemistry,,,if a horses can get tn from breathing in ammonia,,why then can we not,,,,vets gave horses nerve blocks in the mouth,,same way a dentist does,,,tn gone,,,,they could ride the horses,,,then tn comes back,,,,,,if you alter brain chemistry,,you allter signaling process,,,,sailors drinking sea water which alltered brain chemistry with salt,,,,tn was the result,short lived though,,.tn one cause only,,,it is perhaps a desease of the elderly,,,because with age,liver and kidneys are no longer filtering as they used to,,,that is a big clue to this illness,,there are not a multitude of cures for the same illness,,or any illness,,,ther is but one