Medical Q&A : find your quiz answers here !

1. Which of the following is the primary treatment for Guillain-Barré syndrome?

A- Corticosteroids
B- Plasmapheresis or IVIG
C- Antivirals
D- Antibiotics
The correct answer is:

Plasmapheresis or IVIG

Explanation:
Guillain-Barré syndrome (GBS) is an acute autoimmune disorder in which the immune system mistakenly attacks the peripheral nerves, leading to rapid-onset muscle weakness and paralysis. The condition is often triggered by infections, such as Campylobacter jejuni, or other immune-stimulating events.

Primary Treatment:

1. Intravenous Immunoglobulin (IVIG):
   
   • IVIG provides passive immunity by modulating the immune response, reducing nerve damage caused by autoantibodies.
   • It is given over 5 days and is generally well tolerated.
2. Plasmapheresis (Plasma Exchange):
   
   • This procedure removes harmful autoantibodies and immune complexes from the blood.
   • It is typically done over 4-6 exchanges within two weeks and is most effective when started early.

Both treatments are equally effective and are used within the first two weeks of symptom onset to reduce severity and accelerate recovery.

Why Not the Other Options?

• Corticosteroids:
  
  • Not effective for GBS and may even prolong recovery.
  • They are not recommended as standard treatment.
• Antivirals:
  
  • GBS is an autoimmune-mediated condition, not a direct viral infection.
  • Antivirals do not target the underlying pathophysiology.
• Antibiotics:
  
  • While Campylobacter jejuni is a common trigger, treating the infection does not prevent or stop GBS progression.
  • Antibiotics do not affect the autoimmune process causing nerve damage.

Summary:
For Guillain-Barré syndrome, the primary treatment is plasmapheresis or IVIG, which helps reduce the immune-mediated nerve damage and speeds up recovery.

 

What is the most common cause of meningitis in neonates?

A- Streptococcus pneumoniae
B- Escherichia coli
C- Group B Streptococcus
D- Listeria monocytogenes

The correct answer is:

Group B Streptococcus (GBS)

Explanation:
Meningitis in neonates (infants ≤28 days old) is primarily caused by bacterial infections acquired during birth or shortly after. Among the listed pathogens, Group B Streptococcus (GBS) is the most common cause of neonatal meningitisworldwide.

Why is Group B Streptococcus the Most Common Cause?

• Vertical Transmission: GBS is a part of the normal vaginal and gastrointestinal flora in many pregnant women. Neonates are exposed to it during delivery if the mother is colonized.
• Early-Onset Disease (EOD): Occurs within the first week of life, often presenting as sepsis, pneumonia, or meningitis.
• Late-Onset Disease (LOD): Develops between 1 week and 3 months of age, primarily presenting as meningitis.

Why Not the Other Options?

• Streptococcus pneumoniae:
  
  • Common in older children and adults, but rare in neonates.
  • Typically associated with community-acquired meningitis after the neonatal period.
• Escherichia coli (especially K1 strain):
  
  • A significant cause of neonatal meningitis, but less common than GBS.
  • More frequently seen in preterm infants and neonates with prolonged rupture of membranes.
• Listeria monocytogenes:
  
  • Can cause neonatal meningitis, but is much rarer than GBS and E. coli.
  • More commonly seen in cases of maternal infection during pregnancy due to contaminated food, leading to intrauterine infection.

 

What is the most common cause of meningitis in neonates?

A- Streptococcus pneumoniae
B- Escherichia coli
C- Group B Streptococcus
D- Listeria monocytogenes

The most common cause of meningitis in neonates is:

Group B Streptococcus (GBS)
Explanation:

• Group B Streptococcus (GBS) (also known as Streptococcus agalactiae) is the leading cause of bacterial meningitis in neonates, particularly in the first month of life.
• GBS is transmitted from the mother to the baby during birth, especially if the mother is colonized in the genital or gastrointestinal tract.
• Early-onset GBS disease (within the first 7 days of life) often presents with sepsis, pneumonia, and meningitis.
• Late-onset GBS disease (7 days to 3 months) is more commonly associated with meningitis.

Why Not the Other Options?

1. Streptococcus pneumoniae – A leading cause of meningitis in older infants and children but is not the most common cause in neonates.
2. Escherichia coli – While E. coli, especially K1 strain, is a common cause of neonatal meningitis, GBS is more frequent.
3. Listeria monocytogenes – Can cause neonatal meningitis, particularly in preterm infants and immunocompromised newborns, but it is less common than GBS.

 

Which of the following is the most common cause of aortic stenosis in elderly patients?
A- Bicuspid aortic valve
B- Rheumatic heart disease
C- Degenerative calcification
D- Infective endocarditis

Answer: Degenerative calcification
Explanation:
In elderly patients, the most common cause of aortic stenosis is degenerative (senile) calcification of the aortic valve. This process occurs due to long-term wear and tear on the valve, leading to progressive calcification and thickening of the valve leaflets, which restricts blood flow from the left ventricle to the aorta.

Why not the other options?

1. Bicuspid Aortic Valve (BAV) – While BAV is a common congenital abnormality and can lead to aortic stenosis, it typically causes symptoms earlier in life (before the age of 65). In contrast, degenerative calcification affects patients in their 70s and 80s.
   
   
2. Rheumatic heart disease – Although a significant cause of aortic stenosis in developing countries, rheumatic heart disease has declined in prevalence in developed nations. It typically affects the mitral valve first and is often associated with a history of rheumatic fever.
   
   
3. Infective Endocarditis – While infective endocarditis can damage the aortic valve and cause regurgitation or stenosis, it is not the most common cause of aortic stenosis in elderly patients. Instead, it is more often associated with acute valve dysfunction rather than the chronic narrowing seen in degenerative calcification.
   

Summary:

• Most common cause in the elderly: Degenerative calcification
• Pathophysiology: Progressive calcification and fibrosis of the aortic valve due to aging and mechanical stress
• Risk factors: Aging, hypertension, hyperlipidemia, smoking, and chronic kidney disease

Thus, in elderly patients, degenerative calcification is the leading cause of aortic stenosis.

 

Which of the following is the primary treatment for myasthenia gravis?

A- Pyridostigmine
B- Corticosteroids
C- Azathioprine
D- Plasmapheresis

The correct answer is: Pyridostigmine

Explanation:
Myasthenia Gravis Overview:

• Myasthenia Gravis (MG) is an autoimmune neuromuscular disorder where antibodies attack the acetylcholine receptors (AChR) at the neuromuscular junction.
• This leads to muscle weakness that typically worsens with activity and improves with rest.

Primary Treatment: Pyridostigmine

• Pyridostigmine is an acetylcholinesterase inhibitor.
• It prevents the breakdown of acetylcholine, increasing its availability at the neuromuscular junction.
• This enhances communication between nerves and muscles, improving muscle strength.
• It is the first-line symptomatic treatment because it directly improves the hallmark symptom: muscle weakness.
• Dosage is usually adjusted based on patient response.

Other Options Explained:

• Corticosteroids (e.g., Prednisone):
  • Used in moderate to severe cases or if symptoms are not controlled by pyridostigmine.
  • Helps reduce autoimmune activity but not the first-line initial therapy due to side effects.
• Azathioprine:
  • An immunosuppressant used as a steroid-sparing agent in long-term management.
  • Slow onset of action (may take months), so it is not a primary or immediate treatment.
• Plasmapheresis:
  • Short-term treatment used during myasthenic crises or preoperatively.
  • Removes circulating antibodies but not used as routine primary therapy.