Nervous system´s infections Flashcards
The most common cause of bacterial meningitis and sepsis in neonates aged ≤ 72 hours
Group B Streptococci
Main cause of meningitis in newborns
1- Group B Streptococci
2- E. coli
3- Lysteria monocytogenes
Main cause of meningitis in children 1 month - 2 years
1- Streptococcus pneumoniae
2- Neisseria meningitidis
3- Group B Streptococci
4- Haemophilus influenzae B (if not immunized)
Main cause of meningitis 2-50 years
Streptococcus pneumoniae (except 11-17 Neisseria meningitidis)
Main cause of meningitis at over 50 years of age
1- Streptococcus pneumoniae
2- E. coli
3- Listeria monocytogenes
4- Haemophilus influenzae b
5- N
Inflammatory disease of the meninges
Meningitis
Inflamation of the cerebral parenchyma
Encephalitis
Encapsulated concentration of pus inside of the brain. Tends to be pluribacterial.
Brain abcess
Most common bacterial causes of meningitis in HIV
Mycobacterium tuberculosis
Listeria monocytogenes
Most common viral causes of meningitis in HIV
CMV
VZV
HSV-2
EBV
HSV-6
JCV (leukoencephalopathy)
Most common fungal causes of meningitis in HIV
Cryptococcus
Bacterial pathogens most related to brain abcess post-sinusitis
Streptococcus viridans
Streptococcus milleri
Staphylococcus aureus
Most common parasitical cause of meningitis in HIV
Toxoplasma gondii
Clinical triad of meningitis
Fever
Headache
Neck stifness (rigidez nuca)
(Bacterial meningitis symptoms, in only 50% of cases)
Most common agent of meningitis post a basilar skull fracture
S. pneumoniae
Most common agent of meningitis post a penetrating trauma
Staphylococcus aureus
Clinical signs of meningitis IN NEONATES
Lethargy
Muscle hypotonia
Vomiting
Hypo/hyperthermia
¡¡¡Fontanelle bulging!!!
Clinical triad of acute encephalitis
- Focal neurological deficiencies (related to medial temporal lobe)
- Seizures
- Altered mental status
Prodromal symptoms of encephalitis
Fever
Headache
Nausea/vomiting
Most common pathways on infection meningitis
1- Previous colonization of the nasopharynx or uppar airways before entering the CNS through:
* hematogenous dissemination
* contiguous tissue spread
2- Direct infection due to head trauma or surgery
Incubation period bacterial meningitis
3-7 days
Treatment for bacterial meningitis for children under 1 month
Ampicilin + an aminoglicoside (gentamicine) +/ 3° gen cephalosporin (cefotaxime / ceftazidime)
NOT ceftriaxone (contraindicated for high risk of billiary sludging uner
Treatment for bacterial meningitis in children over 1 month to adults under 50 years
Vancomycin + 3° gen cephalosporin (ceftriaxone/ cefotaxime)
Treatment for bacterial meningitis in adults over 50 years
Vancomycin + ampicilin + 3° gen cephalosporin (ceftriaxone/ cefotaxime)
Treatment for bacterial meningitis in immunocompromised patients
Vancomycin + ampicilin +
cefepime / meropenem
- cefepime (4° gen cef)
- meropenem (carbapenem)
tx viral meningitis (enterovirus)
Supportively (symptoms)
Tx viral meningitis (VZV / HSV-1 / HSV-2)
Acyclovir
Tx viral meningitis CMV
Ganciclovir / Valganciclovir
If meningitis due to S. pneumoniae or H. influenzae is suspected or proven, include ———— to tx
Corticosteroids (dexamethasone)
If meningitis due to L. monocytogenes is suspected or proven, include ——– to tx
Ampicilin
Syndrome commonly associated with meningococcal meningitis
Waterhouse-Friderichsen syndrome
(adenal insufficiency caused by an adenal hemorrage)
With a petechial rash, fever, hypotension, shock, IV coagulation
- Coagulopathy —– Icutus —– Necrosis
- Coagulopathy —– Embolus —– Hemorrage
Bacteria most commonly related to brain abcesses
Streptococcus milleri
Viridans streptococci (sinusitis)
Streptococcus aureus
Most common cause of bacterial meningitis in a basilar cranial fracture
S. pneumoniae
Most common cause of bacterial meningitis from a external cranial fracture
Streptococcus aureus
Infiltration of neutrophils and cerebral edema in the first 3-5 days of infection
Early cerebritis
Necrosis, liquefaction, and infiltration of macrophages that eventually results in the formation of a fibrotic capsule around the lesion and happens after 2-3 weeks of infection
Late cerebritis
Multiple brain abcesses is related to a ———- spread
Hematogenous
Single brain abcesses are related to a ———- spread.
Contiguous
