Central Nervous System Infections Flashcards
Three Layers of the Cranial meninges
Dura mater
Arachnoid mater
Pia mater
Where is the cerebrospinal fluid?
Sits between the arachnoid mater and Pia mater, this space is called the subarachnoid spaces
Damage to brain and spinal cord can cause
Deafness, blindness, learning disabilities, paralysis, and death.
What does the blood brain barrier (BBB) do?
Protects the Nervous System (spinal cord and brain) from infection from bone and other structures. Protects it from pathogens.
What is meningitis?
Inflammation of the meninges
What is Encephalitis?
Inflammation of the brain
What is Meningococcal disease caused by?
Neisseria meningitidis
How many groups of N.meningitidis are that have been identified?
12
What groups of meningitis are most likely to cause disease? And what one in NZ is most likely to cause disease?
A, B, C, X, Y, and W
In NZ group B is most likely to cause disease, although group W is on the rise.
Where is the meningococcal bacteria commonly carried?
In the nose and throat, although the do not commonly cause disease.
In what age group are carriage rates higher?
Older teenagers and young adults
How is meningococcal disease transferred?
contact with saliva.
What increases the risk of getting meningococcal disease?
Exposure to tobacco smoke, binge drinking, another respiratory illness, living in close proximity to others, being in close contact with someone who carries the disease, age and ethnicity, or a decreased immune system.
Symptoms in infants
more gradual onset, fever, cry, appear unsettled, feed poorly, vomit, sleepy or hard to wake, rash or spots.
Symptoms in adults
Fever, malaise, nausea, vomiting, muscle aches and pains, drowsiness, headache, dislike of bright lights, neck stiffness, or rash
What sort of rash appears in meningococcal disease?
Petechial rash, red or purple spots on the skin.
How is a petechial rash caused?
Caused by a minor bleed from broken capillary blood vessels. The bacteria releases endotoxin when it lyses that activates the Hageman factor (clotting factor) causes disseminated intravascular coagulation (DIC), DIC is what appears as a rash.
What test can distinguish a petechial rash from other rashes?
Glass test
How to test for Meningitis?
Lumbar puncture
How is a lumbar puncture procedure done?
a needle is inserted between 2 vertebrae in the lower spine, it shouldn’t been forced out it should drip out.
Normal vs. Abnormal CSF
Normal: clear to slightly yellowish
Abnormal: Cloudy and or blood- this indicates sign of a pathogen.
Excess polymorphonuclear cells (neutrophils) in CSF analysis indicate what?
A bacteria infection.
In bacterial meningitis what would the levels of CSF glucose and protein levels show in a CSF analysis, and why?
Decrease in CSF glucose and increase in protein levels from normal. The infecting bacteria use up glucose for energy and excrete protein.
What do lymphocytes or monocytes indicate?
viral or chronic inflammation.
What does a gram stain of N. meningitidis bacteria show?
Gram negative (pink) diplococci (pairs of dots).
What treatment is used for meningitis?
Antibiotic therapy.
What are the complications of Meningococcal disease?
- Meningitis (inflammation of the membranes around the brain)
- Septicaemia (blood infection)
- Pneumonia (lung infection)
- Long-term damage (skin scarring, limb amputation, hearing loss, and brain damage).
- Death (1-2 out of 10 people die)
What preventative treatment would you give to people in contact with the cases?
Rifampicin, Ciprofloxacin or Ceftriaxone +/- vaccine if suitable
Where in their body are the contacts likely to be carrying N. meningitidis?
Nasopharynx
