Infections Flashcards
CNS infections are medical emergencies. True/False? Why?
True
Untreated infection can lead to brain herniation and death, and cord compression with paralysis
Brain and spinal cord do not regenerate once injured
List the main differential diagnoses for CNS infections causing fever and/or altered mental state
Meningitis (inflammation of the meninges)
Encephalitis (inflammation of brain)
Meningoencephalitis (inflammation of brain and meninges)
Encephalomyelitis (inflammation of brain and spinal cord)
Severe sepsis syndrome
Abscess
When is the typical onset of viral meningitis?
Late summer/autumn
Which viruses are typically responsible for viral meningitis?
Enteroviruses most common e.g. ECHO, coxsacchie
HSV and other microbes also
List investigations/diagnostic tools for viral meningitis
Viral stool culture
Throat swab
Lumbar puncture for CSF
PCR
Outline treatment for viral meningitis
Supportive - paracetamol, fluids, rest, dark room
Which part of the brain does viral encephalitis affect?
Infection of brain parenchyma
List the main causes of viral encephalitis
Herpes simplex Varicella zoster CMV, HIV, measles Travel-viruses Rabies Non-infectious (autoimmune)
Which viruses are the only treatable causes of viral encephalitis?
HSV
Varicella zoster
List clinical features of viral encephalitis
Insidious onset
Meningismus (rigidity, photophobia, headache)
Altered consciousness (comatose, seizures, paralysis)
Confusion, psychosis
Speech and memory deficit
List investigations for viral encephalitis
Lumbar puncture
Electroencephalography (EEG)
MRI
What is the main treatment for viral encephalitis?
IV aciclovir
List the main causes of bacterial meningitis in neonates
Listeria monocytogenes
Group B Strep. (pneumococcus)
E. coli
Which antibiotic combats Listeria monocytogenes?
Ampicillin/amoxicillin
Which organism is the main causes of bacterial meningitis in children?
H. influenzae (type b)
Which organism is the main cause of bacterial meningitis in 10-21 year olds?
Neisseria meningitides from the throats of healthy carriers
List the main causes of bacterial meningitis in adults
Strep. pneumoniae
Neisseria meningitides
A fracture of the cribriform plate increases the risk of which bacterial meningitis?
Pneumococcal (Strep. pneumoniae)
List the main causes of bacterial meningitis in the immunocompromised
Strep. pneumonia Neisseria meningitides Staph aureus Listeria Aerobic Gram -ves Mycobacterium Cryptococcus neoformans
List clinical features of bacterial meningitis
Meningismus (rigidity, photophobia, headache) Nausea/ Vomiting Pyrexia Stiffness/ pain (particularly in neck) Confusion (GCS <14) Rash
Signs of bacterial meningitis are often absent in the very young, very old and immunocompromised. True/False?
True