Progressive Muscular Atrophy vs. Amyotrophic Lateral Sclerosis: What’s the Difference?

 

Receiving a diagnosis of Motor Neuron Disease can be extremely challenging for both the patient and their family. It is therefore all the more important to understand which subtype of Motor Neuron Disease the patient has, how it will affect their body, and what the treatment options are. Progressive Muscular Atrophy (PMA) and Amyotrophic Lateral Sclerosis (ALS) are two disease subtypes that are often confused for one another. Here’s a quick guide to distinguishing between the two.

Understanding Progressive Muscular Atrophy and Amyotrophic Lateral Sclerosis

Both PMA and ALS belong to a category of diseases known as Motor Neuron Diseases. Motor Neuron Diseases are a group of neurodegenerative disorders that selectively affect motor neurons — the cells which control all the voluntary muscles of the body, in turn affecting voluntary movements.

Progressive Muscular Atrophy, also known as Duchenne-Aran muscular atrophy, affects the lower motor neurons and leads to muscular weakness and atrophy in the arms, legs, or both. Patients lose control over their motor skills and ultimately lose the ability to walk, use their hands, or position themselves.

Amyotrophic Lateral Sclerosis, also known as Lou Gehrig’s disease, leads to the degeneration of both lower and upper neurons and causes rapid muscular weakness and atrophy, culminating in paralysis. The British physicist Stephen Hawking had ALS and was famous for having survived decades past the initial diagnosis. 

Differences between PMA and ALS

There has been a certain amount of ongoing debate about how to distinguish PMA from ALS. Some physicians even maintain that PMA is just an earlier stage of ALS, which has been recorded to happen in certain cases. Others consider PMA and ALS to merely be part of a spectrum for which the blanket term is Motor Neuron Disease. However, the consensus so far is that PMA is a ‘sibling condition’ to ALS and a much rarer subtype of Motor Neuron Disease. Here’s how to tell the two conditions apart.

• PMA only affects the lower motor neurons, while ALS affects both upper and lower motor neurons.

• PMA largely affects men, while ALS affects both men and women with the occurrence only slightly higher among men.

• PMA affects younger adults, while ALS most commonly occurs among patients between 40 and 60 years of age.

• PMA typically manifests first with weakness in the hands, while ALS typically first shows up as intermittent muscle twitches. 

• PMA is a very rare Motor Neuron Disease, accounting for only about 4% of cases, while ALS is the most common one.

• The duration between the initial symptoms showing up and the time of diagnosis is usually longer for PMA than for ALS.

How to diagnose PMA and ALS

There is no specific test for any Motor Neuron Disease, and they are usually diagnosed with the help of a physical test followed by a neurological test. For PMA, diagnosis is usually done by exclusion, when other conditions like spinal muscular atrophy or multifocal motor neuropathy have been ruled out. 

For ALS, diagnosis requires the presence of both upper and lower motor neuron degeneration as well as the progressive spread of symptoms to other parts of the body as determined by an examination. Treatment for Motor Neuron Diseases, whether PMA or ALS, is largely for symptomatic relief. Physiotherapy, the use of electronic wheelchairs, respiratory aids, occupational therapy, and psychological support are all important components of a patient’s treatment plan. 

Apart from this, Stem Cell Therapy has emerged as a promising treatment over the last few years for people affected with PMA and ALS.  It is a potential new approach for treating Motor Neuron Disease, and clinical studies have shown that patients have become much better as compared to their early status — after they received it.

Both Progressive Muscular Atrophy (PMA) and Amyotrophic Lateral Sclerosis (ALS) require a timely diagnosis and careful treatment to prolong the patient’s lifespan and enhance their quality of life. Stem Cell Therapy, Physiotherapy, and motor aids as part of the best treatment for Motor Neuron Diseases can go a long way in improving the patient’s mobility, while emotional support and a steady network of caregivers can help them make the most of each day.