Neurology: meningitis

Question 1

What is meningitis?
What can it lead to?

Answer 1

Rare infection, affects delicate membranes (meninges) that cover the brain + spinal cord.
 Bacteria, fungi, viruses but also injury, cancer, certain types of drugs can cause meningitis
 Can lead to brain damage, loss of hearing, kidney failure

Question 2

What do the meninges do?

Answer 2

• Meninges: protect and provide structural support for the brain (between brain and skull)

Question 3

What three main types of meningitis are there?

Answer 3

Bacterial, viral, chronic

Question 4

Bacterial: most common bacteria, when does it start, where do they travel?

Answer 4

• Neisseria meningitides, streptococcus pneumoniae and listeria monocytogenes = most common bacteria
• Starts mostly when bacteria get into bloodstream from sinuses, ears, throat.
• Bacteria travel upstream to brain

Question 5

Viral meningitis: two characteristics?

Answer 5

• More common than bacterial form
• Generally less serious

Question 6

3. Chronic meningitis: symptoms? How is it cuased?

Answer 6

• Similar symptoms as acute meningitis, but develops over couple of weeks
• Results from infection with fungus or mycobacteria (That causes TBC)

Question 7

Most common symptoms of meningitis? + other? + more severe symptoms?

Answer 7

Often confused with the flu. Fever, severe headache, neck stiffness. Others:

• Nausea and vomiting
• Confusion and disorientation (acting “goofy”)
• Drowsiness or sluggishness
• Sensitivity to bright light
• Poor appetite
• More severe symptoms include seizure and coma

The more severe symptoms occur bc of inflammatory response, which leads to swelling and compression of nerves -> impaired vision/hearing + seizures

Question 8

Risk factors meningitis?

Answer 8

• Children <5
• Teenagers/young adults 16-25
• Adults >55
• People with certain conditions, such as damaged/missing spleen, long-term disease, immune system disorders
• Outbreaks most likely happen where people live close to each other

Question 9

Diagnosis meningitis?

Answer 9

• Physical exam (neck stiffness, skin rash)
• Blood tests to find bacteria
• CT/MRI for swelling/inflammation
• Cerebrospinal fluid collection

Question 10

Treatment meningitis?

Answer 10

Depends on type of meningitis

Bacterial:
- antibiotics right away
-> when exact bacteria is found, more specific drugs
Corticosteroids (to ease inflammation)
Viral:
- goes away on its own. Stay in bed, drink plenty of fluids.
- Might have to take antiviral medication
Fungal:
- Anti fungal medication

Question 11

describe how bacterial meningitis can happen and how the infection can lead to edema in the brain

Answer 11

When a pathogen enters the cerebrospinal fluid, immune response happens, inflammation.
- Blood-brain barrier is now more permeable. Causes influx of white blood cells and plasma, contributes inflammation and increases volume + viscosity of cerebrospinal fluid
- These changes contribute to development of cerebral edema: accumulation of fluid in the brain
- Also, increased pressure can disrupt blood flow and result in damage to brain tissue

Question 12

Explain why antibiotics for meningitis are usually started before diagnosis

Answer 12

-bacterial meningitis is most severe but viral meningitis is more common. Because of the severity of bacterial meningitis, antibiotics are started immediately without waiting for lab results.