MS is related to an immune system attack on nerve coverings.
ALS weakens muscles and its cause is unknown.
MS and ALS share some similar symptoms.
Ellen Lindner / Verywell
This article looks at symptoms, causes, diagnosis, and treatment options in MS vs. ALS.
Symptoms of MS vs. ALS
Neurological symptoms are the hallmark of both MS and ALS.
Still, while there are a few overlaps in symptoms, there are major differences.
Muscle Weakness in Arms and Legs
ALS always advances to cause muscle paralysis (complete weakness).
The muscles eventually atrophy (shrink and deteriorate).
Many people with MS experience mild or moderate muscle weakness, but only rarely experience paralysis.
Your speech may be hard to understand, and you might also drool, especially when speaking.
This can be intermittent or can progress throughout the disease course.
Mood or Personality Changes
MS may producemoodand personality changes due to its direct effect on the brain.
This will often progress to the point that afeeding tubeor othermeans of nutritionis needed.
They later progress to mechanical ventilation, which uses a powered machine to support lung function.
Breathing problems rarely occur in MS and are usually mild.
Likewise, it is rare forMS-related respiratory problemsto require breathing assistance.
Vision Changes
In MS, vision can be affected byoptic neuritisornystagmus.
Some people with ALS report tingling sensations.
However, this is not common and it usually goes away.
Tingling and sensory discomfort are symptoms of MS that are due to the disease itself.
In ALS, these symptoms are triggered by pressure and prolonged immobility.
MS and ALS are both commonly associated withconstipation.
Causes
Both of these conditions affect the brain and the spine.
MS, but not ALS, can also involve the optic nerves (the nerves that control vision).
MS is three times more common in women, while ALS tends to affect men and women equally.
In addition, the disease pathophysiology (biological changes) of the two conditions is completely different.
Why Do People Develop MS?
MS is a disease caused bydemyelinationof nerves in the brain, spine, and optic nerves.
Myelin is a fatty coating that insulates nerves, allowing them to function efficiently.
There may be hereditary and environmental components to MS, but the cause remains a mystery.
Why Do People Develop ALS?
Diagnosis of MS vs. ALS
A physical examination can show some overlapping features in MS and ALS.
With MS, you might have muscle spasms, which are noticeable, involuntary muscle jerks.
Spasms may develop late in the course of ALS.
Because of this, testing is needed.
Testing and Imaging
Diagnostic testing and imaging can help distinguish these two conditions.
Alumbar puncture (spinal tap)will show a characteristic pattern with MS that is not seen with ALS.
This medication is believed to prevent neurotoxic damage, preventing disease progression.
The impact on people with ALS is not yet known.
For example, you may benefit from physical therapy to optimize your swallowing and motor control.
A supportive brace can help you walk or use your hands and arms.
Summary
MS and ALS are both neurological diseases and share some similar symptoms.
They also have some distinct differences.
One very significant difference is the prognosis: MS is rarely fatal, while ALS is a terminal illness.
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