Flashcards in CNS infections Deck (65)
What, technically, is meningitis?
Inflammation of the pia or arachnoid mater
What are the three major, noninfectious causes of meningitis?
What is encephalitis?
Inflammation of the brain parenchyma
What is meningoencephalitis?
Inflammation of meninges and the brain
What is myelitis?
Inflammation of the spinal cord
What is the classic triad for meningitis?
Rash + meningitis = ?
What is Kernig's sign?
Resistance to passive extension at the knee
What is Brudzinski's sign?
Spontaneous flexion of the knees and hips when the neck is passively flexed
What are the age ranges for Neisseria meningitidis caused meningitis?
What are the age ranges for Strep pneumo caused meningitis?
Adults over 18
What are the four conditions where imaging should precede LP?
-New onset sz
Where is the needle inserted with an LP?
What is the normal value for opening pressure with an LP?
What is the normal value of glucose in CSF?
What is the normal protein in CSF?
What is the normal WBC count in CSF?
Less than 5
What is the definition of hypoglycorrhachia?
CSF [glucose] is less than 60% of blood
What happens to the following with bacterial meningitis:
-Opening pressure = more than 180
-WBCs More than 10 (PMNs)
-CSF:BG ratio Less than 0.31
-Protein More than 50
What is the treatment for strep pneumonia caused meningitis?
Third or fourth generation cephalosporin
Why are steroids used in the treatment of meningitis?
To relieve the side effects of the inflammation on the brain
What is the steroid of choice for meningitis?
What is the most common cause of meningitis: bacterial, fungal, viral, or parasitic?
Unless (___) occurs, viral meningitis is usually self limited.
What are the CSF findings of aseptic meningitis?
What are the usual viral causes of aseptic meningitis?
What is the treatment for aseptic meningitis?
How does meningitis lead to seizures in the long term?
Scarring in the brain leads to an epileptic focus
What are the two bugs that more commonly cause meningitis in immunosuppressed patients?
Are PCRs done with aseptic meningitis? Why or why not?
No--does not change treatment plan
Treatment for viral meningitis is supportive except for infections with which virus?
What usually causes HSV encephalitis?
Reactivation from a trigeminal ganglion
What is the presentation of HSV encephalitis?
-Changes in LOC
-Bizzare CNS s/sx
Why can there be RBCs in the CSF of pts with HSV encephalitis?
Hemorrhagic changes in the brain 2/2 infx
What are the CT/MRI findings of HSV encephalitis?
Focal area of high attenuation
What is the treatment for HSV encephalitis?
What are the CSF findings of HSV encephalitis?
How are the s/sx of HIV caused meningitis, as opposed to other viral causes of meningitis?
No real difference, but may progress to dementia
What are the two focuses of lyme disease?
What is the classic neurological findings of lyme disease?
What is chronic lyme disease?
Nonspecific s/sx of unknown cause
What is the definition of acute meningitis?
Less than a 4 week duration
What are the protein findings of aseptic, septic, and chronic meningitis?
Aseptic = mild increase
Septic = High protein
Chronic = High protein
What are the WBCs that characterize chronic meningitis?
Moderate monocytic pleocytosis
What are the usual causes of chronic meningitis?
How does the clinical presentation of chronic meningitis compare to acute?
Usually more subtle
How do you diagnose chronic meningitis?
MRI with contrast
Why is gadolinium used with MRIs in diagnosing meningitis?
Breakdown of the BBB leads to uptake of the Gd by the meninges
What causes TB meningitis?
Discharge of bacilli from tubercles within the brain or meninges into the subarachnoid space
True or false: TB encephalitis is usually caused by hematogenous spread of bacilli
False--Discharge of bacilli from tubercles within the brain or meninges into the subarachnoid space
What causes CN involvement with TB meningitis?
Thick, gelatinous exudate
What causes hydrocephalus with CNS TB?
Blockage of CSF flow from exudate
How does TB meningitis usually present, relative to usual meningitis?
Slower onset, with cranial neuropathies, and hemiparesis
What are the CSF findings of TB, in terms of:
What is the treatment for TB meningitis? Duration?
What is the major challenge in treating TB meningitis?
What is the prognosis of TB meningitis?
25%, with worse outcomes at age extremes
Who usually gets Progressive multifocal leukoencephalopathy?
What is the infectious agent that causes PML?
What is the presentation of PML?
Insidious progression of dementia with focal findings
What are the MRI findings of PML?
Non-enhancing multifocal white matter lesions
What are the CSF findings of PML?
What is the presentation of Prion diseases?
Who gets Kuru?
South sea islanders who participate in eating the dead