Why is it so hard to cure ALS? - Fernando Vieira
-
0:07 - 0:12In 1963, a 21-year-old physicist
named Stephen Hawking -
0:12 - 0:15was diagnosed with a rare
neuromuscular disorder -
0:15 - 0:20called amyotrophic lateral sclerosis,
or ALS. -
0:20 - 0:22Gradually, he lost the ability to walk,
-
0:22 - 0:23use his hands,
-
0:23 - 0:25move his face,
-
0:25 - 0:27and even swallow.
-
0:27 - 0:30But throughout it all,
he retained his incredible intellect, -
0:30 - 0:32and in the more
than 50 years that followed, -
0:32 - 0:37Hawking became one of history’s most
accomplished and famous physicists. -
0:37 - 0:39However, his condition went uncured
-
0:39 - 0:44and he passed away in 2018
at the age of 76. -
0:44 - 0:46Decades after his diagnosis,
-
0:46 - 0:49ALS still ranks as one
of the most complex, -
0:49 - 0:50mysterious,
-
0:50 - 0:54and devastating
diseases to affect humankind. -
0:54 - 0:58Also called motor neuron disease
and Lou Gehrig’s Disease, -
0:58 - 1:03ALS affects about two out of every
100,000 people worldwide. -
1:03 - 1:05When a person has ALS,
-
1:05 - 1:07their motor neurons,
-
1:07 - 1:11the cells responsible for all voluntary
muscle control in the body, -
1:11 - 1:13lose function and die.
-
1:13 - 1:17No one knows exactly why
or how these cells die -
1:17 - 1:20and that’s part of what
makes ALS so hard to treat. -
1:20 - 1:22In about 90% of cases,
-
1:22 - 1:27the disease arises suddenly,
with no apparent cause. -
1:27 - 1:29The remaining 10% of cases are hereditary,
-
1:29 - 1:35where a mother or father with ALS passes
on a mutated gene to their child. -
1:35 - 1:39The symptoms typically first appear
after age 40. -
1:39 - 1:44But in some rare cases, like Hawking’s,
ALS starts earlier in life. -
1:44 - 1:50Hawking’s case was also a medical marvel
because of how long he lived with ALS. -
1:50 - 1:55After diagnosis, most people with
the disease live between 2 to 5 years -
1:55 - 2:00before ALS leads to respiratory problems
that usually cause death. -
2:00 - 2:04What wasn’t unusual in Hawking’s case
was that his ability to learn, -
2:04 - 2:05think,
-
2:05 - 2:08and perceive with his senses
remained intact. -
2:08 - 2:12Most people with ALS do not experience
impaired cognition. -
2:12 - 2:16With so much at stake
for the 120,000 people -
2:16 - 2:18who are diagnosed with ALS annually,
-
2:18 - 2:22curing the disease has become one of
our most important scientific -
2:22 - 2:24and medical challenges.
-
2:24 - 2:26Despite the many unknowns,
-
2:26 - 2:31we do have some insight into how ALS
impacts the neuromuscular system. -
2:31 - 2:36ALS affects two types of nerve cells
called the upper and lower motor neurons. -
2:36 - 2:39In a healthy body,
the upper motor neurons, -
2:39 - 2:41which sit in the brain’s cortex,
-
2:41 - 2:44transmit messages
from the brain to the lower motor neurons, -
2:44 - 2:46situated in the spinal cord.
-
2:46 - 2:50Those neurons then transmit
the message into muscle fibers, -
2:50 - 2:53which contract or relax in response,
-
2:53 - 2:55resulting in motion.
-
2:55 - 2:57Every voluntary move we make occurs
-
2:57 - 3:01because of messages transmitted
along this pathway. -
3:01 - 3:04But when motor neurons degenerate in ALS,
-
3:04 - 3:07their ability to transfer
messages is disrupted, -
3:07 - 3:11and that vital signaling system
is thrown into chaos. -
3:11 - 3:14Without their regular cues,
the muscles waste away. -
3:14 - 3:17Precisely what makes
the motor neurons degenerate -
3:17 - 3:20is the prevailing
mystery of ALS. -
3:20 - 3:25In hereditary cases, parents pass genetic
mutations on to their children. -
3:25 - 3:28Even then, ALS involves multiple genes
-
3:28 - 3:31with multiple possible impacts
on motor neurons, -
3:31 - 3:34making the precise triggers
hard to pinpoint. -
3:34 - 3:39When ALS arises sporadically,
the list of possible causes grows: -
3:39 - 3:40toxins,
-
3:40 - 3:40viruses,
-
3:40 - 3:41lifestyle,
-
3:41 - 3:45or other environmental factors
may all play roles. -
3:45 - 3:48And because there are
so many elements involved, -
3:48 - 3:53there’s currently no single test that
can determine whether someone has ALS. -
3:53 - 3:57Nevertheless, our hypotheses
on the causes are developing. -
3:57 - 4:02One prevailing idea is that certain
proteins inside the motor neurons -
4:02 - 4:04aren’t folding correctly,
-
4:04 - 4:06and are instead forming clumps.
-
4:06 - 4:10The misfolded proteins and clumps
may spread from cell to cell. -
4:10 - 4:13This could be clogging up normal
cellular processes, -
4:13 - 4:18like energy and protein production,
which keep cells alive. -
4:18 - 4:21We’ve also learned that along with
motor neurons and muscle fibers, -
4:21 - 4:24ALS could involve other
cell types. -
4:24 - 4:29ALS patients typically have inflammation
in their brains and spinal cords. -
4:29 - 4:34Defective immune cells may also play
a role in killing motor neurons. -
4:34 - 4:38And ALS seems to change the
behavior of specific cells -
4:38 - 4:41that provide support for neurons.
-
4:41 - 4:44These factors highlight
the disease’s complexity, -
4:44 - 4:48but they may also give us a fuller
understanding of how it works, -
4:48 - 4:50opening up new avenues for treatment.
-
4:50 - 4:54And while that may be gradual,
we’re making progress all the time. -
4:54 - 4:56We’re currently developing new drugs,
-
4:56 - 4:59new stem cell therapies
to repair damaged cells, -
4:59 - 5:04and new gene therapies
to slow the advancement of the disease. -
5:04 - 5:06With our growing arsenal of knowledge,
-
5:06 - 5:09we look forward to discoveries
that can change the future -
5:09 - 5:11for people living with ALS.
- Title:
- Why is it so hard to cure ALS? - Fernando Vieira
- Description:
-
View full lesson: https://ed.ted.com/lessons/why-is-it-so-hard-to-cure-als-fernando-vieira
Amyotrophic Lateral Sclerosis (ALS), also called motor neuron disease and Lou Gehrig’s Disease, affects about two out of every 100,000 people worldwide. When a person has ALS, their motor neurons - the cells responsible for all voluntary muscle control in the body - lose function and die. Fernando G. Vieira shares what we know (and don't know) about ALS.
Lesson by Fernando G. Vieira, animation by Artrake Studio.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TED-Ed
- Duration:
- 05:22
Michelle Mehrtens edited English subtitles for Why is it so hard to cure ALS? - Fernando Vieira | ||
Michelle Mehrtens edited English subtitles for Why is it so hard to cure ALS? - Fernando Vieira | ||
Bethany Cutmore-Scott approved English subtitles for Why is it so hard to cure ALS? - Fernando Vieira | ||
Bethany Cutmore-Scott accepted English subtitles for Why is it so hard to cure ALS? - Fernando Vieira | ||
Michelle Mehrtens edited English subtitles for Why is it so hard to cure ALS? - Fernando Vieira |