What Is ALS? The Ice Bucket Challenge Explained

If you hadn’t heard of the condition ‘ALS’ before, then you probably have by now. Head over to Facebook and you’ll find that just about everyone you know has uploaded a video of themselves getting drenched in water. In fact, you may have even been nominated too and thus found yourself tipping a bucket of water over your head.

This is the ‘ALS Ice Bucket Challenge’ and after pouring water on your own head, and probably donated your money, you might be wondering what it’s actually all about.

What actually is ALS? What have you just donated money to? And what is the significance of the bucket of water? If you’re asking those questions, then the bucket has worked and generated something much more important than cash: awareness.

What Is ALS?

ALS stands for Amyotrophic Lateral Sclerosis, also sometimes known as Lou Gehrig’s Disease and Motor Neurone Disease (MND – more common in the UK).

The condition is a ‘neurodegenerative disease’, meaning that it causes the gradual loss of neurons. Other neurodegenerative diseases include Parkinson’s, Alzheimer’s and Huntington’s disease. While the others were more commonly heard of prior to the ice-bucket challenge, ALS is actually the most common of motor neuron diseases affecting 30,000 Americans at the time of writing. 5,600 new cases are diagnosed each year.


ALS is characterised by spasticity of the muscles and progressive weakness through muscle atrophy. This also leads to difficulty in speaking (called dysarthria), breathing (dyspnea) and swallowing (dysphagia).

The earliest symptoms are often weakness along with cramping, stiffness and dysphagia. Often cramping and stiffness will affect the legs and arms first (‘limb onset ALS’) which is the case for around 75% of sufferers. This can lead to difficulty walking and running and common stumbling. Those whose arms are affected first may struggle with tasks like buttoning shirts, writing or opening locks. In some cases the symptoms never progress and can remain in one or both arms, though this is uncommon.

This can also result in a feeling of ‘numbness’ in the limbs and torso, which is where the ice-bucket challenge comes in – it is intended to simulate the sensation so that those who take part can experience one of the symptoms (to a much milder and very temporary extent).

Those with ‘bulbar onset’ (accounting for around 25% of cases) experience the symptoms first in speaking and swallowing. This can also lead to loss of tongue mobility. Less common still is ‘respiratory onset’ which first affects the intercostal muscles (between the ribs) and thus makes breathing difficult. Others can experience frontotemporal dementia-like symptoms first, which then progress into ALS.

Just under half of patients can also experience an effect known as the ‘pseudobulbar effect’ or ’emotional lability’ which results in random laughter, smiling and crying. This is related to degeneration of the upper motor neurons causing the exaggeration of emotional expression.

As the condition progresses, it can eventually lead to a complete lack of movement in the limbs, as well as the loss of speech and the ability to swallow. In most cases patients will eventually become dependent on a ventilator. The precise order and rate of symptoms however varies to a large degree from person to person. It tends to progress more slowly in those who are less than 40 years old at onset, who are mildly obese or whose symptoms begin in a single limb. Progression is faster meanwhile in those with bulbar-onset, respiratory-onset or symptoms of frontotemporal dementia.

Ultimately most ALS patients will die within three to five years from respiratory failure. On average the survival time is around 39 months, with only 4% surviving over 10 years. One of the most famous cases of motor neurone disease is that of Stephen Hawking who has lived for over 50 years with the condition – though this is a very exceptional and rare case.

Other risks come from difficulty in chewing and swallowing which can lead to choking. Aspiration pneumonia is also a common and dangerous complication.


ALS has a strong genetic element and runs in families. Defects on chromosome 21 (which is related to superoxide dismutase) have been identified in around 20% of familial cases. Another 6% of cases appear to be related to a genetic abnormality known as a ‘hexanucleotide repeat’ in a region called C9orf72.

In 90% of cases however there is no family history of the disease and in these scenarios the cause is often unknown. There are some theories suggesting that head trauma, drug use, exposure to electromagnetic fields or contact sports could increase the likelihood of developing the condition. The neurotransmitter glutamate is also thought to potentially play a role. ALS patients have unusually high amounts of glutamate in their spinal fluid which could play a role in motor neuron degeneration. Lesions can also lead to ALS when they affect the frontotemporal lobes or other areas related to motor control.


There is no cure for ALS, and thus treatment is focussed on management. Riluzole (Rilutek) is the only form of treatment shown to be effective, but will only extend lifespan by a few months. Riluzole cannot reverse damage already done to motor neurons and may cause some liver damage (in around 10% of cases).

Otherwise, treatments include medications that aim to reduce fatigue and muscular discomfort. They can also be used to treat depression, sleep programs, dysphagia and other issues. Physical and occupational therapy can also be useful for rehabilitation and delaying the loss of strength and control. As breathing becomes more difficult, breathing can be assisted by ventilators.

As you can see then, ALS is a very serious condition and one that truly deserves all the attention that it’s been getting. If you get nominated, then you don’t have to throw a bucket of water over yourself… but you should definitely consider a donation.

1 Comment

  1. The article is very informative. Would you be able to tell me the year this article is written? I intend to cite this article in order to substantiate of one of the claims I made in my school report. Thank you very much!

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