Difference Between ALS and MS

The main difference between ALS and MS is that ALS only affects the motor functions of the body, whereas MS affects both motor functions and sensory functions.

ALS (Amyotrophic Lateral Sclerosis) and MS (Multiple Sclerosis) are two neurodegenerative diseases that have a negative impact on our central nervous system, including the brain and spinal cord, thus creating a disruption in the functioning of muscles and nerves. 

Key Areas Covered

1. What is MS (Multiple Sclerosis)
     – Definition, Types, Signs and symptoms, Causes, Treatment
2. What is ALS (Amyotrophic Lateral Sclerosis) 
     – Definition, Types, Signs and symptoms, Causes, Management
3. Difference Between ALS and MS
     – Comparison of Key Differences

Key Terms

ALS, Amyotrophic Lateral Sclerosis, MS, Multiple Sclerosis

What is Multiple Sclerosis (MS)

MS is an autoimmune neurodegenerative disorder, which affects the brain and spinal cord, resulting in a broad range of signs and symptoms associated with visual disturbances, dysfunction of limb movements, balance, and sensation. Being a lifelong condition with several debilitating features, some affected individuals might experience mild-moderate features, possibly reducing their quality of life.

As far as the pathophysiology of this condition is considered, some abnormality in the function of our immunity system would act in a way that damages the myelin sheath – the protective layer covering nerves. The damage and scar formation taking place over a long period of time will ultimately slow down the transmission of nerve impulses or completely halt them. Although the exact etiology for the immune system to act this way is not clear, some scientists suggest that genetics and environmental factors play a major role in initiating the autoimmune process.

MS owns a significant female predominance with a female: male of 3:1; most diagnosed individuals are of 20-30 years of age.

Types of MS

There are two major types of MS:

• Relapsing-remitting MS – Patients with this type of MS will experience completely new episodes or worsening symptoms (relapses), which usually last for a few days and slowly improve within a similar duration. The period between these attacks is known as Remission, which can last as long as for a few years.

• Primary progressive MS – Patients with this type of MS will experience gradually worsening symptoms over years without any remission periods.

Signs and Symptoms

Signs and symptoms of MS usually vary from one person to another. The commonest presentation of MS can affect any part of the body and include:

• Easy fatigability
• Difficulty in walking and limb movements
• Disturbances of vision, including visual blurriness
• Bladder incontinence
• Numbness and tingling sensation in the body
• Muscle stiffness and spasms
• Difficulty in maintaining balance and coordination
• Disturbances related to cognitive functions such as thinking, learning, and planning

Treatment

There is no permanent cure for MS, but early interventions can definitely slow down the progress and limit disabilities. Treating relapses with steroids, symptom-specific treatment, and disease-modifying therapy play main roles in the therapeutic management of MS.

What is Amyotrophic Lateral Sclerosis (ALS)

ALS is a progressive neurodegenerative disorder that has a significant negative impact on neurons in the brain and spinal cord. ‘A-MY0-TROHPIC’ is a Greek term that means no muscle nourishment resulting in the wasting of muscles. The lateral side of the spinal cord is responsible for sending nerve impulses to control and signal muscular movements, and this condition itself will ultimately lead to damage and scarring of this area, causing sclerosis.

Types

There are two types of ALS:

• Sporadic ALS – The commonest form of ALS, accounting for 90-95% of affected individuals.
• Familial ALS – An inherited form of ALS with an incidence of around 5% of affected individuals.

Signs and Symptoms

The onset of signs, symptoms, and their progression will vary from one person to another and usually starts with the group of muscles responsible for limb movements and swallowing. Other typical features of ALS include,

• Gradual, painless, and progressive muscle weakness and paralysis – the key feature
• Tripping and dropping things
• Unusual fatigability of upper and lower limbs
• Slurred speech
• Muscle cramping and twitching
• Uncontrollable episodes of laughing or crying
• Shortness of breath (due to respiratory muscle paralysis at later stages)

ALS only impairs the motor functions in our body; sensory parts such as vision, hearing, tasting, and touch are completely intact.

Diagnosis

A complete clinical history and neurological examination, along with a comprehensive series of diagnostic studies, are mandatory in establishing an accurate diagnosis of ALS. Major modalities of diagnosis include,

• Electrodiagnostic tests (Electromyography (EMG) and nerve conduction velocity (NCV))
• Blood tests (high-resolution serum protein electrophoresis)
• Hormonal analysis (thyroid and parathyroid hormone levels)
• 24-hour urine collection for heavy metals
• Spinal tap
• X-rays, including magnetic resonance imaging (MRI)
• Myelogram of the cervical spine
• Nerve biopsy

Management

There is no permanent cure for ALS, but symptomatic management plays an important role in limiting disabilities.

Difference Between ALS and MS

Definition

MS is an autoimmune neurodegenerative disorder that affects the brain and spinal cord by disrupting the myelin sheath (protective sheet which covers neurons). ALS is a progressive and fatal neurodegenerative disorder that has a significant negative impact on neurons in the brain and spinal cord.

Impact

MS mainly causes sensory disturbances and can show temporary impairment of muscle movements and temperature sensitivity. However, ALS will only impair muscle movements where sensations are completely intact.

Functions Affected

ALS only affects the motor functions of the body, whereas MS affects both motor functions and sensory functions.

Symptoms 

Patients suffering from MS will experience easy fatigability, difficulty in walking and limb movements, disturbances of vision including visual blurriness, bladder incontinence, numbness, tingling sensation of the body, muscle stiffness, and spasms. Meanwhile, patients with ALS will usually show progressive muscle weakness, ultimately ending up with paralysis, muscle cramping, twitching, and slurred speech.

Conclusion

The main difference between ALS and MS is that ALS only affects the motor functions of the body, whereas MS affects both motor functions and sensory functions. Both MS and ALS do not have a permanent cure, but symptomatic management can have a significant role to be played in reducing the rate of mortality and morbidity.

Image Courtesy:

1. “Multiple Sclerosis” By BruceBlaus – Own work (CC BY-SA 4.0) via Commons Wikimedia 

2. “ALS Cross” by Frank Gaillard – (CC BY-SA 3.0) via Commons Wikimedia