CNS infections Flashcards
Common organisms causing meningitis in neonates
Listeria
Group B strep
E coli
What is the commonest organism causing meningitis in young children?
Haemophilus influenza
What is the commonest organism causing meningitis in adolescents (10-21y/o)
Neisseria Meningitidis
What are some early clinical symptoms of meningitis?
Headache
Leg Pain
Cold hands
Abnormal skin colour
List some later symptoms of meningitis
Neck stiffness Photophobia Kernig's sign Decreased consciousness Seizures Petechial rash
What is significant about a meningitis rash?
Non-blanching
Petechia
List the main investigations done for bacterial meningitis:
Blood cultures FBC Us and E's CT imaging PCR Lumbar puncture (if appropriate)
Bacterial meningitis can be culture negative. True or False
True
10-15%
What three symptoms make up meningism?
Neck stiffness
Photophobia
Headache
What is the most common causative organism of meningitis in >65y/o
Strep Pneumoniae
What is the most common causative organism of meningitis in pregnant women?
Listeria Monocytogenes
What is Kernig’s sign?
When the patient’s hip is flexed, their knee resists extension.
What is Brudzinski’s sign?
This is when forced flexion of the neck elicits a flexion reflex in the hip
Why would you do a CT before a Lumbar puncture in suspecting meningitis?
If patient is showing any signs of raised ICP
If patient has raised ICP it is not appropriate to do an LP as this could lead to coning.
What would a lumbar puncture show in bacterial meningitis?
Cloudy turbid CSF
Increased cell count with polymorphs present
Decreased glucose
increased protein
What is the treatment for bacterial meningitis?
Ceftriaxone IV
Dexamethasone
If listeria suspected –> amoxicillin
What prophylactic antibiotics are given to those in contact with bacterial meningitis?
Ciprofloxacin
OR
if contraindicated - rifampicin
What other medication can be given alongside antibiotics to improve patient outcome in bacterial meningitis?
Steroids
When should you not give steroids in bacterial meningitis?
If patient has developed meningitis post surgery or is in septic shock
Immunocompromised patients
Viral meningitis is more severe than bacterial. True/false?
False
It is usually self limiting and lasts roughly 4-10 days
What group of viruses are mainly responsible for viral meningitis?
Enteroviruses
e.g. ECHO
What virus can cause a more severe viral meningitis that leads to encephalitis?
Herpes Simplex Virus
HSV
What symptoms are seen in viral meningitis?
Similar to bacterial
Meningism
Fever may be less pronounced
What would be seen on a lumbar puncture in viral meningitis?
Normal opening pressure Clear CSF Raised cell count Glucose normal/low Protein high/normal
Other than an LP what other investigations might you do for viral meningitis?
Viral Stool culture
CSF PCR
Throat swab
What is the treatment for viral meningitis?
Supportive therapy
Can give IV acyclovir in extreme cases
What is the characteristics of CSF in TB meningitis?
Opaque fluid which settles to form fibrin webs
Lymphocytes present
Decreased glucose
Increased protein
Define encephalitis:
Acute inflammation of the brain parenchyma which can commonly occur following a viral infection
What is the most common causative virus in encephalitis?
HSV
List some other viruses which can cause encephalitis?
EBV
CMV
Mumps
Varicella Zoster
What virus is most likely to cause focal neurological deficits e.g. aphasia in encephalitis
HSV
What virus would you suspect in a patient who has not been vaccinated, with parotitis?
Mumps
List some symptoms of encephalitis:
Fever Stupor and confusion Acute onset headache Vomiting Photophobia Neurological defects Altered consciousness
What are the main investigations for encephalitis, and what would they show?
CT –> cerebral oedema
MRI –> Temporal oedema in HSV
Treatment for encephalitis?
IV acyclovir
What is an uncommon but serious outcome from having the measles, which can occur years after the initial infection?
Subacute Sclerosing Panencephalitis
What symptoms are demonstrated in subacute sclerosing panencephalitis
Personality changes
Cognitive decline
Myoclonus
What might be seen in CSF in Subacute Sclerosing Panencephalitis?
Increased IgG anti-measles antibodies
