Unless you've been living under a rock, you're probably well aware of the ALS Ice Bucket Challenge. This social media campaign has stormed the internet, flooding newsfeeds from Facebook to Twitter. In this challenge, a person "challenges" their friends to the ice bucket challenge (pouring ice water over your head) or they have to donate $100 to the ALS Association. If you scour the internet hard enough, you may even be able to find my attempt...

As silly as this may seem, you can't deny that it has definitely sparked conversation and has raised more than 79.7 million dollars since July 29. Incredible!

But what exactly is ALS, and why is it so devastating? Join me as we explore the biology behind Lou Gehrig's disease!

Part 1: The Basics: What is ALS?

Amyotrophic Lateral Sclerosis, or ALS, is a progressive neurodegenerative disorder that affects the motor neurons in your brain and spinal cord. Essentially, motor neurons are cells in your nervous system that control your muscles. These are the same neurons that allow you to chew your food and shove your way into metro cars during rush hour! Below is a little schematic of what they look like:

The structure on the left hand side of this picture is known as the soma, or the cell body. In neurons, electrical signals originate at this point and travel down the axon in the center of the neuron! When the impulse reaches the end of the neuron, it causes the muscles that it's associated with to contract. In ALS patients, these axons begin to contract, causing the muscles to lose their association with the motor neuron.

When muscles aren't stimulated, they tend to waste away. This process is called atrophy. You may have heard of atrophy ocurring in the legs of patients who have been in a wheelchair for an extended amount of time. In cases like these, the idea is the same: If you don't lose it, you'll lose it! This leads to eventual paralysis of several parts of the body.

About 25% of ALS cases are what is known as bulbar onset. These patients begin to lose control over their voluntary muscles their head and torso, leading to difficulty breathing and speaking. The remaining 75% of patients are known to have limb onset ALS. These patients begin to notice symptoms in their arms and legs before the disease spreads to other parts of their body. It's estimated that 30,000 people in the United States at any given time suffer from ALS, which is why attention to this terrible disease is so important.

ALS is fatal - after disease onset (which normally happens after the fourth decade of life), most patients succumb within 3-5 years.

What causes ALS? Is it genetic, or does it happen spontaneously?

Unfortunately, we don't know a lot right now about what causes ALS. Of all ALS cases, 10% are related to a genetic mutation and are known as familial ALS (fALS). The remaining 90% of cases are sporadic cases of ALS (sALS). It's very possible that some patients who fall into the sporadic ALS category have a previously unidentified genetic mutation, or a genetic mutation that those with fALS have that spontaneously occurred.

How close are we to a cure?

This is always a tough question to answer! Organizations such as the ALS Association and the Northeast ALS Consortium are sponsoring a wide variety of clinical trials with potential ALS treatments. The process by which treatments pass through the usual hurdles to come to market is long and arduous (I may write about this in the future), so even these treatments have the possibility of failing and going back to square one. It’s really easy for small successes in the clinic to be overblown in the media, so I’m always conservative on estimates for this. While I can’t put a timeline as to when we’ll have a viable treatment for ALS, what I can say is the rate at which we are learning more about ALS is greatly increasing! At the risk of making this post overly heavy, if you wish to discuss these particular discoveries, just shoot me a message!

So remember, always hope. Know that there are hundreds of brilliant minds all around the globe working towards a cure, and that one day, we will live in a world where treating ALS is as routine as getting over the common cold.

"Hope lies in dreams, in imagination, and in the courage of those who dare to make dreams into reality." - Jonas Salk