CNS Infections Lecture Powerpoint Flashcards
Meningitis
Inflammation of the meninges any part or all 3 layers, most often the arachnoid mater and CSF in the subarachnoid space initially, caused by bacterial or viral exposure most often, common in newborn in elderly
3 vaccines that have drastically decreased rate of meningitis
- HIB
- meningococcal
- pneumococcal
Pathogenesis of meningitis
-Infection enters body, invades bloodstream, crosses BBB, invades meninges, and multiplies in the CSF
Most common ways meningitis can spread (3)
- Mother to child during birth
- cough or sneezing
- food prep
Neisseria meningitis characteristic appearance
Rash (bleeding under skin), poor prognosis
Bacterial vs viral meningitis
Bacterial is much more severe and fatal than viral
When a patient has suspected bacterial meningitis, need…
….immediate antibiotic treatment ASAP to improve prognosis
Most common organisms that cause bacterial meningitis (5) and what is the leading cause?
- Neisseria meningitidis
- strep pneumonia (leading cause in US)
- Listeria monocytogenes (in children and elderly)
- Group B streptococcus (children)
- E coli (children)
Clinical presentation of bacterial meningitis (3)
-Fever
-nuchal rigidity
-mental status change
(sudden acute onset of this)
Kernigs sign
Place patient supine with hip flexed at 90 degrees, attempt to extend leg at knee, positive when there is resistance to extension or pain in lower back or posterior thigh
Brudzinski sign
Place patient in supine and passively flex the head toward the chest, positive when there is flexion of the knees and hips in response
Viral meningitis usually preceded by a ___. It is usually ___
URI, self limiting
1 cause of acute viral meningitis
-Enterovirus
Symptoms of viral meningitis vs bacterial
Viral is same as bacterial but much less severe except sometimes in immunocompromised patients
How to differentiate between viral vs bacterial meningitis? (3)
- Blood cultures (start antibiotics after empirically and don’t take them after giving medication otherwise false neg)
- Lumbar puncture with CSF analysis
- Polymerase chain reaction viral testing
How many tubes of CSF are typically sent for analysis? What about in suspected subarachnoid hemorrhage with blood tinge?
3 tubes, 4 tubes
CSF findings in bacterial vs viral meningitis
Bacterial: cloudy appearance, leukocyte count is high, glucose low, protein high
Viral: CSF is clear, wbc count lower predominant lymphocytes, glucose normal range
Before getting Lumbar puncture with any concern of increased intracranial pressure, need to get…
….CT
Examethasone in meningitis treatment
Used in viral and bacterial, reduces cerebral edema, increases ICP, and decreases neurological complications and mortality
