Q 2.28. Amyotrophic lateral sclerosis


Mr. Sunak, a 50-year-old male, presents to the hospital with a six-month history of progressive muscle weakness, accompanied by persistent muscle twitching and difficulty in grasping objects. His initial symptoms manifested in the right hand, with subsequent spreading to the arms and legs. 


Neurological examination reveals evident muscle atrophy, fasciculations, and heightened reflexes. Further evaluation through electromyography (EMG) confirms widespread motor neuron dysfunction, strongly indicative of Amyotrophic Lateral Sclerosis (ALS). Mr. Sunak’s medical history rules out other potential causes, supporting the diagnosis.


 Given the nature of ALS, a multidisciplinary treatment plan is initiated. The team includes neurologists for ongoing assessment, physical therapists to address mobility challenges, respiratory therapists to monitor pulmonary function, and speech-language pathologists to manage potential speech and swallowing difficulties.

 *This case underscores the importance of early recognition, a collaborative approach to care for patients and their families dealing with ALS



Overview of ALS:

  • ALS is a progressive neurodegenerative disorder affecting motor neurons in the brain and spinal cord.
  • It leads to the gradual loss of voluntary muscle control and eventually results in paralysis.
  • Both upper and lower motor neurons are affected, causing muscle weakness, atrophy, and difficulty in speaking, swallowing, and breathing.


2. Clinical Presentation:

    • Symptoms: Initial signs may include muscle weakness, twitching, and cramping, often starting in the limbs.


    • Typical Amyotrophic Lateral Sclerosis (ALS) Neurological Status:

      • Mental Status: Initially normal, but cognitive changes may occur later.
      • Cranial Nerves: Facial weakness, dysarthria, and dysphagia.
      • Motor Examination:
        • Upper Motor Neuron Signs: Hyperreflexia, spasticity, and weakness.
        • Lower Motor Neuron Signs: Fasciculations, muscle atrophy, and weakness.
      • Sensory Examination: Typically normal.
      • Reflexes: Hyperactive deep tendon reflexes.
      • Gait and Balance: May develop spastic gait or weakness.

Remember that these descriptions provide a simplified overview, and actual clinical assessments involve a comprehensive evaluation of various neurological functions. ALS, in particular, presents with a distinct combination of upper and lower motor neuron signs.


  • Progression: As ALS advances, patients may experience difficulty walking, speaking, and breathing.
  • Variable Manifestations: ALS can present as limb-onset (most common) or bulbar-onset, affecting speech and swallowing first.


3. Diagnosis:

  • Clinical Assessment: Based on the patient’s medical history, symptoms, and neurological examination.


  • Electromyography (EMG): Confirms motor neuron dysfunction and helps rule out other conditions.

Let’s break down the electromyography (EMG) findings in amyotrophic lateral sclerosis (ALS) in a simple way:

1. Spontaneous Electrical Activity:

    • In ALS, muscles may show spontaneous electrical activity even at rest.
    • This includes fasciculations (small muscle twitches) and fibrillations (tiny muscle contractions).
    • Imagine your muscles having little parties without your permission!

2. Motor Neuron Damage Clues:

      • EMG helps us see if the motor neurons (nerve cells controlling muscles) are affected.
      • We look for signs of lower motor neuron (LMN) involvement, common in ALS.
      • These clues include positive sharp wave potentialsfibrillations, and fasciculation ppotentials

3. Peripheral Nerve Velocity:

        • ALS primarily affects motor neurons, not peripheral nerves.
        • The peripheral nerve conduction velocity (how fast signals travel along nerves) remains preserved in ALS.
        • So, while the muscles misbehave, the nerves’ speed remains intact!


  • MRI and other tests: Done to exclude other potential causes of symptoms.


4. Treatment:

  • No Cure: ALS is incurable; treatment focuses on managing symptoms and improving quality of life.
  • Medications: Riluzole and Edaravone are FDA-approved drugs that may slow disease progression. People with ALS often die within 5 years of diagnosis. approved treatments extends life expectancy by just a few months.
  • Supportive Care: Physical therapy, occupational therapy, and assistive devices help maintain function and independence. Respiratory support is life-saving in advanced stages.
  • Multidisciplinary Approach: Involving neurologists, respiratory therapists, and speech-language pathologists for comprehensive care.



Although both are neurological disorders that affect the peripheral nervous system they differ in terms of etiology, clinical presentation and prognosis.



Amyotrophic Lateral Sclerosis (ALS)

Guillain-Barré Syndrome (GBS)


Often sporadic or linked to genetics

Typically triggered by infections, autoimmune response

Onset and Progression

Gradual onset, steady progression

Rapid onset, peaks in weeks, potential for gradual recovery

Affected Nervous System Components

Primarily motor neurons in brain and spinal cord

Primarily peripheral nerves, causing demyelination

Symptom Distribution

Both upper and lower motor neuron signs; affects limbs and bulbar region

Typically starts in lower limbs and ascends symmetrically


Progressive and fatal, life expectancy 2-5 years

Many individuals experience good recovery with proper intervention

Primary Symptoms

Muscle weakness, atrophy, speech and swallowing difficulties

Weakness, tingling, numbness, often starting in legs

EMG Results

Shows widespread motor neuron dysfunction and denervation

Typically reveals slowing of nerve conduction velocity due to demyelination

CSF Results

Normal in ALS, may be used to rule out other conditions

Elevated protein levels due to immune response and demyelination in GBS


Verified by Dr. Petya Stefanova