Diagnosis of Meningitis and Encephalitis

Question 1

meninges

Answer 1

layers of tissue that protect the CNS.

Question 2

cerebrospinal fluid

Answer 2

cushions and protects the CNS. flows in ventricles and along the spinal cord

Question 3

viral meningitis

Answer 3

aseptic meningitis. most common form of meningitis in the US. usually mild to moderate in severity and will usually resolve without treatment. enterovirus is the most common cause.

Question 4

less common causes of viral meningitis

Answer 4

HSV, EBV, VZV, influenza, measules, mumps, arboviruses

Question 5

bacterial meningitis

Answer 5

usually a medical emergency. untreated is usually fatal. caused by many types of bacteria

Question 6

Streptococcus pneumoniae

Answer 6

currently most common form of bacterial meningitis in US. infants under 2 and immunocompromised people are at greatest risk

Question 7

neisseria meningitidis

Answer 7

seen in college students, infants, children, international travelers, immunocompromised. leading cause of bacterial meningitis in children and young adults. highly contagious

Question 8

haemophilus influenzae type B

Answer 8

incidence has decreased in US due to vaccination of kids

Question 9

group B streptococcus, E. coli, listeria

Answer 9

most common causes of meningitis in neonates and can be passed from mother to baby

Question 10

what can cause chronic meningitis?

Answer 10

mycobacterium tuberculosis, terponema pallidum, and fungi

Question 11

fungal meningitis

Answer 11

rare, commonly seen in immunocompromised. cryptococcus neoformans is most common cause. not contagious.

Question 12

parasitic meningitis

Answer 12

rare. naegleria fowleri found in warm water lakes and rivers. parasite enters respiratory system through nose. common in africa, south america, south china

Question 13

encephalitis

Answer 13

acute infection of the brain characterized by fever, headache, and an altered state of consciousness, with or without seizures. mostly caused by viruses.

Question 14

causes of viral enceph

Answer 14

HSV, enteroviruses, rabies virus, arboviruses

Question 15

characteristic signs and symptoms of encephalitis and meningitis

Answer 15

fever, severe persistent headache, a stiff neck, sensitivity to light, mental changes, lethargy

Question 16

complications of meningitis and enceph

Answer 16

15-25% who survive may have neurological sequelae including hydrocephalus, deafness, blindness, periodic seizures, and/or some degree of impaired thinking processes. newborns at highest risk

Question 17

reasons you perform lab tests

Answer 17

distinguish infections from other conditions with similar symptoms. determine cause as rapidly as possible to guide treatment. evaluate affected person’s general state of health, immune status, etc to minimize inflammation and brain damage. determine infection’s source

Question 18

Cerebrospinal fluid analysis

Answer 18

done through a spinal tap. CSF usually clear, small amount of protein, 2/3 concentration of blood glucose. cloudy, lots of protein, and less glucose can be seen in meningitis/enceph. usually small number of WBC. neutrophils increased in bacterial infection, lymphocytes increased in parasitic infection. CSF gram stain for direct observation of microorganisms. CSF culture for bacteria, fungi, viruses

Question 19

other less common CSF tests

Answer 19

CSF AFB smear and culture (positive with TB and mycobacteria). CSF Molecular tests (TB). CSF Syphilis testing (negative does not rule out syphilis)

Question 20

CSF tests used to distinguish between bacterial and viral meningitis

Answer 20

CSF lactic acid (levels usually increased with bacterial and fungal meningitis.) CSF lactate dehydrogenase. CSF C-reactive protein (sensitive for bacterial meningitis)

Question 21

what are there vaccines for?

Answer 21

haemophilus influenzae type B. streptococcus pneumoniae. neisseria meningitidis

Question 22

treatment for bacterial causes

Answer 22

broad spectrum antibiotic. modify once you know cause. antibiotics must pass through BBB. treatment may continue for weeks, months, even years. drain abscesses

Question 23

treatment for viral causes

Answer 23

monitoring, rest, relief of symptoms. can give acyclovir for HSV or VZV. if you have HIV, may need highly active antiretroviral therapy

Question 24

treatment for fungal causes

Answer 24

IV anti-fungal drugs. long time. immunocompromised may have to continue oral therapy indefinitely to prevent recurrence

Question 25

treatment for parasitic causes

Answer 25

no antimicrobial agents for naegleria fowleri. anti-parasitic drugs can be used for toxoplasma and other bugs