What’s the difference between ALS and MND?

What’s the difference between ALS and MND?

With the ice bucket challenge currently replicating like a virus through social media to raise much needed awareness of ALS (amyotrophic lateral scelrosis), a few patients have started to ask what is the condition and is it another name for MND (motor neuron disease)?

If you don’t make it to the end of this explanation, please do remember that the important thing is to donate money rather than just dowsing yourself in ice cold water. Better still, if you can, do both – raise awareness and much needed funds.

The term Motor Neuron Disease (MND) encompasses several different conditions whose common feature is the premature degeneration of motor nerves (known as neurons or sometimes neurones). There are two groups of motor neurons – upper motor neurons travelling from the brain down the spinal cord, and lower motor neurons branching outwards to supply muscles in the face, throat, arms, chest and legs. Both groups of neurons tend to be involved in MND but to varying extents, which is one of the many reasons why each patient’s disease is subtly unique.

MND was first described in the mid-late 1800s, and the French Neurologist Jean-Martin Charcot is widely credited with the first detailed descriptions. He noticed that a common feature of most cases was muscle wasting, the medical term for which is amyotrophy (literally “lack of muscle growth”). This is a feature of degeneration of lower motor neurons. The resulting muscle wasting can be thought of as a wilting leaf when the water supply from a damaged branch fails – there is nothing intrinsically wrong with the muscle but it wastes when there is no electrical or ‘nutritional’ input from the lower motor neuron.

When Charcot went on to look at the spinal cords of patients with MND, he also noticed scarring of the descending upper motor neuron pathways from the brain. The medical term for this is lateral sclerosis (literally scarring of the outermost pathways of the cord). Damage to these pathways produces the stiffness that some patients notice (this is called spasticity), and results in exaggerated reflexes that the neurologist can detect on examination.

On their own, both amyotrophy and lateral sclerosis are processes that can occur as part of several other neurological conditions. Charcot’s genius was to recognise that in MND both processes were occurring simultaneously. He called it Amyotrophic Lateral Sclerosis (ALS). There are virtually no other neurological conditions in which both these processes occur simultaneously.

Nearly 90% of patients with MND have the mixed ALS form of the disease, so that the terms MND and ALS are commonly used to mean the same thing. Within this large ALS group there is still a huge variation in the way the disease presents and progresses. With further study it is apparent that the other 10% of patients tend to show either predominantly lower motor neuron damage with prominent muscle wasting, or solely upper motor neuron degeneration with relatively little muscle wasting but prominent stiffness. The former group are termed Progressive Muscular Atrophy (PMA) and the latter group Primary Lateral Sclerosis (PLS), to reflect each end of a spectrum. Some of these cases, particularly those with PLS, seem to have a much slower rate of progression.

So the terms MND and ALS effectively mean the same thing. An analogy would be to refer to the Canary Islands in general, or choosing to be more specific and refer to Tenerife as the most commonly visited of them.

Finally, there are other ways that neurologists sometimes categorise MND cases. One method is by the site where the disease symptoms being – for example if it is in the speech and swallowing motor nerves (which arise from the ‘bulb’ of the brain stem) then it is termed bulbar-onset MND. Another group of MND patients have a disease that predominantly affects the shoulder regions, and is termed the ‘flail arm’ variant. These so-called ‘regional phenotypes’ follow some common trends in their patterns of progression, but no system of categorisation to date can predict with certainty the course of the disease for an individual patient.

The content for this post was taken from the Oxford MND Centre www.oxfordmnd.net 

About the Author

Robin is the editor of theactivehealthclinic.com and is the principle Chiropractor of Active Health Chiropractic and Physiotherapy in Bath. Visit Robin’s team page to learn more.

Comments (2)

  1. Caroline Faulkner :

    I have just been diagnosed with bulbs mnd and be gratefull for you advice as I would like to be able to manage this natural if possible

    • Robin Marshall :

      Hi Caroline, I am very sorry to hear of your recent diagnosis. Whilst conservative care may be, at times, supportive in your management there are no reliable studies suggesting it has ever been curative or been found to significantly change the course of the disease. The degree to which you may or may not find conservative care helpful is unknown and would depend on a much better knowledge of all your symptoms and what variables of your health you have addressed, such as your immune health and any systemic inflammatory challenges you face. In the first instance, you should always be managed by a neurologist not a neuromuscularskeletal specialist, even though you may experience neuromuscularskeletal complaints at times. I am in no way dismissing the useful role lifestyle advice such as exercise and nutrition can have in supporting an individual’s management of MND, nor the usefulness of hands-on care in palliatively helping in the short term to reduce some of the consequences of some symptoms, but it is certainly not something we would be a primary point of care for here at Active Health and your first point of call should always be your neurologist. I am more than happy to discuss your needs on the phone and find you an expert consultant neurologist in your area to have manage your diagnosis if this is not underway already. If you are already being well managed under specialist care then I am happy to consult with you on whether additional supportive or adjunctive conservative therapies and lifestyle advice may be perceived to be of benefit in your personal circumstances. Sorry I cannot be of greater help. Best wishes and thank you for reaching out to us.

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