CNS Infections Flashcards
What is meningitis?
Inflammation of the meninges
What are the causes of meningitis? (3)
- Bacterial
- Viral
- Fungal
What bacteria commonly cause meningitis in newborns? (3)
- Group B strep
- E.Coli
- Listeria monocytogenes
What bacteria commonly cause meningitis in children & teens? (2)
- Neisseria meningitidis
- Strep pneumoniae
What bacteria commonly cause meningitis in adults & the elderly? (2)
- Strep pneumoniae
- Listeria monocytogenes
What are the symptoms of meningitis? (5)
- Meningism: acute headache, fever, neck stiffness
- Photophobia
- Phonophobia
- Altered consciousness
- Nausea + vomiting
What are the signs of meningitis? (3)
- Non-blanching petechial rash
- Kernnig’s sign
- Brudzinski’s sign
How would you manage meningitis? (7)
- IM benzylpenicillin 1200mg + admit pt
- Stabilise: A, B, C
- Assess GCS
- Blood cultures w/in the hour
- Broad spec ab = cephalosporins (ceftriaxone, cefotaxime)
- Steroids (IV dexamethasone)
- Prophylaxis to close contacts of pt
If you suspect fungal meningitis, what test would you do?
Test blood for beta-D-glucan
What prophylaxis do you give to the patient’s close contacts? (3)
- Ceftriaxone
- Rifampin
- Ciprofloxacin
When would you do a lumbar puncture in meningitis?
If pt has no shock/ raised ICP/ convulsions
Where should you do a lumbar puncture?
L3/4
When would you do an MRI in meningitis?
If focal neurological signs, papilloedema, continuous/ uncontrolled seizures, GCS = 12
What would the CSF results be for bacterial meningitis? (4)
- Raised opening pressure due to cerebral oedema
- High neutrophils
- Low glucose
- High protein
What would the CSF results be for viral meningitis? (4)
- Normal opening pressure
- High lymphocytes
- Normal glucose
- Normal proteins
What would the CSF results be for fungal meningitis?
Elevated opening pressure
What viruses cause meningitis? (5)
- Enterococcus (coxsackie)
- HIV
- Herpes simplex
- Mumps
- Varicella zoster
What fungi cause meningitis? (2)
- Cryptococcal
- Coccidioides
What is encephalitis?
Inflammation of the brain parenchyma
What are the causes of encephalitis? (6)
- Viral
- Bacterial
- Fungal
- Parasitic
- Non-infective (autoimmune & paraneoplastic)
- Other causes: tropical - rabies; tick-borne encephalitis
What is the most common viral cause of encephalitis?
HSV (herpes zoster virus)
What should you ask a pt suspected of encephalitis?
History of travel/ animal bite
What are the investigations for encephalitis? (3)
- Contrast-enhanced CT head/ MRI head (do before LP)
- LP (CSF, viral PCR)
- Other tests (blood tests, urine tests, swabs)
What are the treatments for encephalitis? (3)
- IV acyclovir if HSV/VZV
- Supportive therapy
- Symptomatic treatment
What would be the CSF results for encephalitis? (3)
- Moderately increased lymphocytes
- Moderately increased protein
- Reduced glucose
What are the early symptoms of encephalitis? (2)
- Flu-like symptoms (headaches, fever, confusion, N&V)
- (+/- meningism)
What are the late symptoms of encephalitis? (2)
- Decreased GCS/ coma
- Seizures
How does the initial infection of herpes zoster present?
As chickenpox
How does the reactivation of herpes zoster present?
As shingles
What are the risk factors for herpes reactivation? (3)
- Old age
- Poor immune system
- Chickenpox < 18 months age
How does herpes present?
Dermatomal distribution of rash + pain
How do you treat herpes?
Oral acyclovir
