CNS Infections Flashcards
Protozoal infections of the CNS is most commonly caused by…?
Toxoplasmosis
What type of microorganisms can cause acute meningitis?
Bacteria
Virus
What type fo microorganism can cause subacute meningitis?
Bacteria
What are the signs and symptoms of meningitis?
Headache Neck stiffness Reduced GCS Fever Confusion Rash (purpuric)
What underlying disorders can result in pnuemonoccocal infection of the meninges?
Middle ear disease Head injury Neurosurgery Alcohol Immunosuppresion
What factors are. associated with an adverse outcome in patients with bacterial meningitis?
Pneumococcal infections Reduced GCS CNS signs Older age >60 years CN palsy Bleeding
What investigations and examinations should be conducted in suspected meningitis?
Throat examination Blood cultures Throat culture Viral gargle FBC U&Es LFTs CRP Lumbar puncture
In suspected meningitis when should a CT be conducted before a lumbar puncture is done?
CNS <12 CNS signs Papilloedema Immunocompromised Seizure
In suspected meningitis, when is a lumbar puncture contraindicated?
Brain shift Rapid GCS reduction Severe sepsis Rapidly evolving rash Infection at lumbar puncture site Respiratory/cardiac compromise Coagulopathy
Meningococcal and pneumococcal infections of the meninges should be treated with which antibiotics?
IV Ceftriaone
Listeria infections of the meninges should be treated with which antibiotics?
IV amoxicillin
What are the concerns with pre-hospital antibiotic therapy?
Microbe lysis pre-hospital leading to a cytokine storm
Exacerbation of sepsis
Lack of supportive measures
Viral meningitis is usually only diagnosed after exclusion of bacterial meningitis. How is this treated?
Supportive treatments
Aciclovir only if the patient is immunocompromised
What are the symptoms of viral encephalitis?
Confusion
Fever
Seizures
How is viral encephalitis treated?
IV acyclovir for 2-3 weeks
How is viral encephalitis investigated?
EEG
MRI
Lumbar puncture - lymphocytic CSF
Intra-cerebral TB may be unmasked during treatment for other TB infection. T/F?
True
Which cranial nerves are commonly affected by intracerebral TB?
CN 3, 4, 6 and 9
How is intracerebral TB treated?
Steroids for one year
What are the possible complications of HIV brain disease?
Encephalitis
Dementia
Neurological-syphillis
Opportunistic infections such as TB, cryptococcus, toxoplasmosis and JVC
What is progressive focal multifocal leucoencephalopathy?
A progressive motor dysfunction which typically affects immunocompromised individuals.
What organism causes intra-cerebral toxoplasmosis?
Toxoplasma gondii
What are the signs and symptoms of intra-cerebral toxoplasmosis?
Headache
Seziures
Focal CNS signs
How is intra-cerebral toxoplasmosis treated?
Sulphadiazine
Pyrimethamine
How is crytococcal meningitis treated?
Amphotericin B
Flucytosine
Cryptococcal meningitis can cause a raised ICP. How can this be treated?
Shunt
What is the classic train of symptoms which defined meningitis?
Fever
Nuchal rigidity
Change in mental status
What type fo headache typically occurs in meningitis?
Severe and generalised meningitis
What. is the Brudzzinski sign?
Spontaneous flexion of the hips during attempted flexion of the neck. illustrates meningism; used to examine for neck stiffness/nuchal rigidity
What is the Kernig sign?
The inability or reluctance to allow full extension fo the knee, when the hip is flexed 90 degrees. Indicates meningitis
What three important contraindication may delay/defer perfuming a lumbar puncture?
Evidence of raised intracranial pressure (mass effect on CT, clinical. signs of impending herniation)
Spinal epidural abscess
Thrombocytopenia
What are the common causative organisms of meningitis in developed countries?
Strep.pneumoniae
N.meningitidis
H.influenzae
Group B strep
What are the CSF findings that would be suggestive of bacterial meningitis?
High white blood cell count with a polymorph predominance
High protein >200mg/dL
Low glucose <40 mg/dL
What are the CSF findings typical of asceptic (viral) meningitis?
WBC elevated (but generally less than seen in bacterial meningitis) with lymphocyte predominance Slightly raised protein Normal glucose
What characterises Purpura fulminant (a possible complications of meningococcal septicaemia)?
Cutaneous haemorrhage and necrosis due to DIC
What is the long-term consequence of bacterial meningitis?
Sensorineural hearing loss
What are the four common causes of community acquired bacterial meningitis in adults in developed countries?
Streptococcus penumoniae
Neisseria pneumoniae
H. influenzae
Group B streptococcus
Listeria monocytogenes is an important bacterial cause of meningoencephalitis in which patients?
Neonates
Pregnancy
Immunosuppressed
Elderly
A small proportion of patients may be hypothermic with meningitis. T/F?
True
What is Brudzinski sign in meningitis?
Spontaneous flexion of the hips during attempted passive flexion of the neck used to examine for neck stiffness
What is Kernig’s sign in meningitis?
The inability or reluctance to allow full extension of the knee when the hip is flexed to 90 degrees
What CSF findings are suggestive of bacterial meningitis?
High wight blood cell count with polymorph predominance
High protein
Low glucose
What CSF findings would you expect in viral meningitis?
WBC elevated (but not as much as in bacterial meningitis) with a lymphocyte predominance
Slightly high protein
Glucose normal
Purpura fulminans is a complication of meningococcal septicaemia What is it characterised by?
Cutaneous haemorrhage and necrosis due to DIC.
