Infections of CNS Flashcards
what is meningitis?
inflammation of the meninges
meninges= lining of brain + spinal cord
what is more serious- bacterial or viral meningitis?
usually bacterial
most common cause of bacterial meningitis?
NEISSERIA MENINGITIS= most common
what type of bacteria is neisseria meningitis?
gram negative diplococcus
Most common cause of bacterial meningitis- neonates?
-Listeria monocytogenes
-Group B strep
-E.Coli
LEG- neonates do not use their legs
Most common cause of bacterial meningitis- infants + children ?
H. influenza
Most common cause of bacterial meningitis- 10-21 years?
neisseria meningitis
Most common cause of bacterial meningitis- >21?
Strep pneuomoniae
Neisseria meningitis
More exposed to pneumonia
Neisseria meningitis= most common and >21s are probs going to hospital if something is wrong
Most common cause of bacterial meningitis- >65?
Strep pneumonia
Listeria monocytogenes
Lost at this age
They all die of pneumonia
presentation meningitis?
Triad of:
-headache
-neck stiffness
-fever
photophobia + vomiting are often present
how may meningococcal septicaemia present?
-a non-blanching rash
-Red or purple
-Initially small spots in groups anywhere on body, become blotchy, little bruises
invstigations bacterial meningitis?
Lumbar puncture
what is seen on LP in bacterial meningitis?
-CSF
-Protein
-Glucose
-WCC
Within the hour and treatment commended immediately after
-CSF cloudy
-Protein high (>220)
-Glucose low (<34)
-WCC high (neutrophilia)
-Culture: bacteria
Treatment- Bacterial meningitis in adults?
-Dexamethasone ( give steroids with or before Abs for 4 days)
-Ceftriaxone (IV)
Penicillin allergy= chloramphenicol
Add Amoxicillin IV 2g 4 hourly if:
Penicillin allergy= co-trimoxazole
≥ 60 years
Immunocompromised
Neonatal
Alcoholic
DM
if in community e,.g. GP= benzylpenicillin
Treatment- bacterial meningitis in children?
<3 months Cefotaxime + Amoxicillin
3 months 1st dose Cefotaxime followed 6 hours later with once daily Ceftriaxone
+/- Dexamethasone IV starting before or with first dose of antibiotic
Chloramphenicol if penicillin allergic
who gets additional amoxicillin (or co trimoxazole if penicillin allergic) with bacterial meningitis?
≥ 60 years
Immunocompromised
Neonatal
Alcoholic
DM
LP- viral meningitis?
opening pressure
WBC
gram stain
protein
CSF appearance
Opening pressure= normal/elevated
Cells= lymphocytes (WBC elevates)
Gram stain= -ve
Bacterial antigen detection= -ve
Protein= normal/ slightly raised
CSF= clear
treatment- viral meningitis?
supportive and self limiting (4-10 days)
LP aseptic meningitis?
low WBC
minimal protein elevation
Normal glucose
infectious causes of aseptic meningitis?
HSV1/2
Lyme’s
Enterovirus
Malaria
Mumps
Measles
non infectious causes of aseptic meningitis?
Carcinomatous
Sarcoidosis
Vasculitis
Drugs
what suggests that meningitis is more likely to be viral?
Recent flu-like illness.
Lack of vaccination.
Travel hx, insect bites etc.
Typically more focal neuro. changes than
bacterial (seizures, behavioural changes etc).
common causes of viral meningitis?
-enteroviruses (echovirus, Coxsackievirus) MOST COMMON
-Mumps
-HSV and herpes zoster virus
-HIV
-Measles
-Influenza
arboviruses
LP for TB meninigitis?
Opening pressure
WBC
Gram stain
Protein
Blood glucose
opening pressure= elevates
WBC= lymphocytes
Gram stain= +ve or -ve
Protein high/very high
<60% blood glucose
what is encephalitis?
inflammation of the brain
causes- encephalitis?
most commonly caused by viral infection
CAUSES:
HIV
Viral- HSV 1 (most common
Bacterial
Fungal, parasitic
presentation- encephalitis?
-insidious onset (sometimes sudden)
-meningismus
-stupar, coma
-seizures, partial paralysis
-confusion, psychosis
-speech, memory symptoms
MRI- encephalitis?
-bilateral medial temporal involvement
-temporal lobe and adjacent parahippocampal gyrus will look brightest white
LP- encephalitis?
LP
Viral - elevated lymphocytes, viral detection by CSF PCR
Limbic - antibodies may be identifiable
treatment- encephalitis?
aciclovir (give before you even do tests)
what is Kernigs sign?
Pain on resistance on passive knee extension with hips fully flexed
for diagnosing meningitis
KErnigs= Knee Extension painful
what is Brudzinkis sign?
Knees and hips flex on bending the head forwards
-test for meningitis
brudziNKis= Neck flexion leads to Knee flexion
CI for lumbar puncture?
-GCS <13
-Seizures
-Papilloedema
-Focal neurological signs
-Severe/ rapidly developing illness (rapidly evolving rash)
if any of these do a CT first
management if LP cannot be done in <1 hour?
give antibiotics immediately
prophylaxis for family of someone with meningitis?
ciprofloxin or rifampicin
do you contact public health- meningitis
yes contact public health
-and make sure contacts receive oral ciprofloxin or rifampicin as prophylaxis
Most common complicaion of meningitis?
sensorineural hearing loss
Most common complicaion of meningitis?
sensorineural hearing loss
