ALS / Lou Gehrig’s Disease

Since we are all enjoying watching our favorite celebrities get doused with ice water on TV to support the Ice Bucket Challenge, I thought I would give you guys a primer on amyotrophic lateral sclerosis (ALS) and what happens to the body when someone suffers from it. If you don’t know what I’m talking about, Google ”Ice Bucket Challenge” or check for #IceBucketChallenge on Twitter and watch the fun.

ALS is also known as Motor Neurone Disease (MND) and Lou Gehrigs Disease in the United States (after the famous Yankees first baseman who suffered from and raised awareness about the disease).

What is ALS?

In simple terms, ALS can be described as a degenerative disease of motor neurons in the spinal cord and brain. So before we go any further, let’s talk about what a motor neuron is.

Your brain is in charge of sending electrical signals to your muscles when you want to move them. The signals are sent through a series of nerves which carry and pass off the information through a complex pathway called the motor neuron system. If these nerve pathways don’t work and no information gets to the muscle, that muscle becomes paralyzed.

The term ‘amyotrophic’ is doctor speak for muscles dying off due to lack of nutrition and stimulation (when they lose stimulation, the body automatically diverts nutrition away from them to save energy).

The ‘Lateral Sclerosis’ part of the name refers to what you would see if you looked at the spinal cord of a patient suffering from advanced stages of the disease. The motor neuron system that I mentioned earlier is present on the lateral aspect (the outer edges) of the spinal cord. In advanced ALS, you would see that those pathways have shrunken and scarred over. The word sclerosis is more fancy-pants for scarring.  

In ALS, for reasons we still don’t understand, the nerve pathways in the motor neuron system start dying off. Most of the time, the disease starts with weakness of the peripheral muscles in the arms or legs and becomes progressive. Unfortunately there is still no cure for the disease and the average patient who is untreated passes away within 3 years of diagnosis.

Who gets it?

Worldwide the disease seems to favor people of European heritage, with Finland having one of the highest rates of the disease worldwide. The interesting thing about Finland is that is where they have isolated a specific genetic mutation that leads to the disease (for those of you who are interested in genetics, it’s called the Hexanucleotide repeat expansion in C9orf72). Now that doesn’t mean that all cases of ALS are genetic. The data just isn’t there yet to confirm that. But the growing evidence seems to be leaning that way.

The best data on the epidemiology of this disease is available in the USA. It shows that ALS is the most common neurodegenerative disease of the motor neuron system. The incidence of ALS is about equal to that of MS (Multiple Sclerosis) and 5 times more common than Huntington’s Disease.

How is it Diagnosed?

ALS should be suspected in any patient who develops a slowly progressive and painless loss of muscle function in one or more functional muscle groups. The clincher here is that there shouldn’t be any change in the patient’s ability to feel sensations from those affected muscle groups.

ALS is always worked up clinically. There is no special blood test or scan that can screen for it yet. ElectroNeuroMyography (ENMG) testing is a very helpful tool in testing specific muscle groups and the test is used to confirm motor neuron damage in patients who are being tested for the disease. ALS is always a diagnosis where everything else is ruled out first.

A good neurologist would examine and send a patient for imaging, blood work and ENMG before settling on a diagnosis of ALS.

Treatment

Treatment is broadly divided into 3 aspects:

1. Education: The patient needs to know what to expect and what precautions to take. The ALS association’s “Living with ALS” manuals are some of the best reading you can find on this disease. I would suggest that anyone who suffers from or has a loved one who suffers from ALS head on over to //www.alsa.org/resources/manuals.cfm and read them as soon as they can.
2. Medication: So far, the US FDA has approved one medication called Riluzole for the treatment of ALS. It works by decreasing the concentration of a chemical called glutamate in the neurons. Glutamate is a neurotransmitter that naturally decreases the activity in the neuron. Now, under normal circumstances, glutamate is important. But in ALS, when the nerves are already losing their ability to stimulate the muscles, Riluzole can slow the progress of the disease considerably.
3. Supportive treatment: Physical and rehab therapy is very important here. Anything that can keep the muscles active helps.