27 Clinical: CNS Infections

Question 1

Label Each color as either

• Pia Mater
• Arachnoid Mater
• Dura Mater

Answer 1

Question 2

Fill in the Boxes

Answer 2

Question 3

Fill in the Boxes

Answer 3

Question 4

What are the 2 main/basic ways that someone can get meningitis?

Answer 4

Question 5

Blood Brain Barrier

• How do can bacteria that have pneumococcal proteins pass the blood-brain-barrier?

Answer 5

Question 6

Blood Brain Barrier

• What bacterial protein interacts with CD46 in order to cross the blood-brain-barrier?
• What does this attach to on the outside of cerebrovascular endothelial cells?

Answer 6

Question 7

Blood Brain Barrier

• How do Group B Strep and E. coli facilitate CNS infection?

Answer 7

Question 8

Blood Brain Barrier

• What 2 things are absent in the CNS, allowing bacteria to multiply rapidly?

Answer 8

Question 9

Bacterial (Pyogenic) Meningitis

• What is the most important thing to know when you encounter this condition?
• How common is this among infectious deaths?
• What type of bacterial meningitis has a fatality rate of up to 30%?
• How common do patients present with seizures?
• What are the top 3 etiologic agents that causes this condition in adults?
  
  • Which one is especially common in immunosuppressed individuals and people over 55 years old?

Answer 9

Question 10

Bacterial (Pyogenic) Meningitis

• How common do patients present with neurologic sequelae?
  
  • What 5 conditions make up this sequela?
• What are the 4 major risk factors for this condition?

Answer 10

Question 11

Bacterial (Pyogenic) Meningitis

• Classic Triad
  
  • What 3 things make up this triad?
  • How common is each individual condition?
    
    • How does this change when considering patients who have all 3 conditions?

Answer 11

Question 12

Complications of Meningitis

• What meningitis-related pathology causes hydrocephalus?
• What meningitis-related pathology causes cerebral herniation?
• Besides the answers to the above questions, what are the other 2 common complications of meningitis?

Answer 12

Question 13

Physical Exam Findings w/ Meningitis

• A patient is lying supine with their thigh flexed onto the abdomen, and can not completely extend the leg.

What sign is this?

Answer 13

Question 14

Physical Exam Findings w/ Meningitis

• A patient is lying supine and flexes their neck forward. When this happens, their knees/hips go into flexion involuntarily. Further, when one side of the lower extremity is passively flexed by a physician, the opposite extremity does the same movement.

What sign is this?

Answer 14

Question 15

Dx of Meningitis

• What procedure is needed?
  
  • What individuals need a head CT before the above is performed? Why?

Answer 15

Question 16

Bacterial Agents

• 80% of bacterial meningitis is caused by just 3 bacteria. Other types of bacteria can affect pregnant women, infants, and/or the elderly. Of the listed bacteria assign each of the following.

A. Most Common Cause of bacterial meningitis

B. 2nd Common Cause of bacterial meningitis

C. 3rd Common Cause of bacterial meningitis

D. Common in pregnant women, infants and the elderly

E. Common in only infants and the elderly

F. Common only in infants

Answer 16

Question 17

Dexamethasone

• What is the ONLY type of meningitis that this drug been shown to decrease mortality and hearing loss in?
• This drug decreases the CSF concentrations of which 2 cytokines?
• This drug must be used in a certain timeframe, otherwise, it won’t have any benefit for a patient. What is this timeframe?
• Why does this drug impair vancomycin use?
• What other antibiotic would consider if the strain the bacteria that is causing the meningitis is penicillin-resistant or cephalosporin-resistant?

Answer 17

Question 18

CSF Findings in Meningitis

• For the following tests, indicate what result would (+) for bacterial meningitis.

Answer 18

Question 19

CSF Findings in Meningitis

• For the following tests, indicate what result would (+) for viral meningitis.

Answer 19

Question 20

Encephalitis

• This has mostly viral etiology. However, what occurs in about 60% of all encephalitis cases?
• What virus is both the most common pathologic agent, especially in the 20 to 40 age range, as well as the most important cause of fatal encephalitis in the US?
  
  • What do these patients present like?
  • What lobes are most commonly damaged?
  • Is this virus considered a primary or secondary infection?
  • What do you use to treat it?

Answer 20

Question 21

Encephalitis

• HSV’s are the most common cause of encephalitis.
  
  • What type of virus is the second most common cause of encephalitis?
  • How are these viruses transmitted to humans?
  • What is special about the time of year that the infection rate is particularly high?

Answer 21

Question 22

Meningoencephalitis

• This is a mixture of both meningitis and encephalitis.
  
  • What is extremely critical to initiating presumptive treatment for meningoencephalitis?
  • What is notable about the mortality rate for it?

Answer 22