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ALS - Amyotrophic lateral sclerosis

Sal explains the disease ALS, amyotrophic lateral sclerosis, and takes the "ice bucket challenge.". Created by Sal Khan.

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Video transcript

- ALS or Amyotrophic Lateral Sclerosis is an extremely debilitating and usually fatal disease and it's a horrible disease. You have your motor neurons, the neurons that are essentially activating your muscles, telling your muscles when to twitch or when to contract and that these neurons, these cells that traverse, that go from your brain all the way to your muscles, so there's these unusually long cells. They go through your spinal cord, they degenerate. They degenerate and as they degenerate, there's no way for your brain to send the signals to your muscles to do the things that your muscles need to do and so your muscles atrophy and so that's actually where the first part of ALS comes from, the "A" in ALS, Amyotrophic. "A" means no or not or kind of the opposite. "Myo" means, is referring to muscle and 'trophic" is nourishment, so this is one way to think about it is "no muscle nourishment", but what's really happening is that the muscles start to die away because they're no longer to be-- They can no longer be activated because, I guess you could say, the wires or motor neurons that would normally activate them, they degenerate and what's especially horrible about this is, obviously, it causes paralysis, people lose control over basic things including their speech, is the whole time that this is happening and this is degenerating, the individual in question has full mental awareness, so they're fully aware of what's going on in their body so you could imagine it's a fairly horrible thing for people to go through and there have been many famous cases of people with ALS, most famously probably Lou Gehrig. In fact, ALS in the U.S., at least, is often called Lou Gehrig's disease, one of the most famous baseball players of all time for the New York Yankees. He died of ALS, really, when he was about my age in his late 30s. Stephen Hawking, he is one of the small percentage of ALS sufferers who have been able to live several decades past his diagnosis. It effects one to two out of 100,000 individuals each year. So if you were to imagine kind of a large stadium of people, in a given year you would expect to-- If you say there's roughly 100,000 people here, you would expect one to two of them to get afflicted with ALS. The reason why it's important to have research behind this is it's a very, a very not so well understood disease. People know what happens. They know that the motor neurons degenerate, but they don't know why it's happening. There is-- Scientists have identified some genetic component to ALS for some of the sufferers, but for the majority, they can't identify a genetic component and it's unclear what environmental components are causing it, although people think there must be some environmental components, but as far as most people can tell it just randomly afflicts people once they kind of get into their early middle age, so it's a really, really horrible disease and it's really important that people have awareness for it and that there is an appropriate level of funding and in case you're wondering, yes, I did take the ice bucket challenge as well. I have been challenged by Shawn O'Sullivan to do the ice bucket challenge, so I'm about to do it. Y'all ready? - Girl: Yeah - Boy: Yeah - [Voiceover] : (giggling) - Ah. - [Voiceover] : (laughing) - I'd now like to issue the challenge to three other people. The other Salman Khan, famous Bollywood actor. Esther Cho, who works with me at Khan Academy and my kids, who seemed too happy to see myself get doused with cold water.