Ah, it can be called Lou Gehrig Disease, named after an American basketball player. Or even Charcot's Disease, after the doctor who identified it in 1869. Still, I've not heard of it.
Here we go. It is what I know as Motor Neuron Disease, a rather descriptive name given the symptoms.
I thought the challenge was either to donate, or have iced water tipped over you. Apparently you do both and then show the world. This will raise peoples curiosity about the disease and raise funds. Well, it certainly raised my curiosity and I have given the cause publicity.
(insert You Tube video of Highriser taking the challenge here)
Sorry, problem with the link. Here is a link to people who have been very affected by ALS and took the challenge. Thanks John.