8.3 Intro to neuropathology Flashcards
What are the possible routes that a microorganism can gain entry to the CNS? How many are there? Examples of each
Direct spread - middle ear infection, base of skull fracture
Blood-borne e.g. sepsis, infective endocarditis
Iatorgenic- VP shunt, surgery, lumbar puncture
What is meningitis?
Inflammation of leptomeninges
What are the leptomeninges?
Pia and dura
What 2 types of meningitis are there?
With or without septicaemia
What is a symptom of meningitis with septicaemia?
Non blanching rashes
What are the causative organisms of meningitis and what age groups do they effect?
Neonates- E.coli, L. Monocytogenes
2-5: H. influenza b
5-30: N. meningitides ( 3 types)
>30: s.pneumoniae
What does chronic meningitis lead to/resemble?
TB
What are some of the features of TB induced by chronic meningitis?
Granulomatous inflammation
Fibrosis of meninges
Nerve entrapment e.g. of facial nerve
What are some local complications of meningitis?
Death (swelling --> Raised ICP) Cerebral infarction--> neurological deficit Cerebral abscess Subdural empyema Epilepsy
What are the systemic complications of meningitis?
Septicaemia
What is encephalitis? Viral or bacterial?
Viral
Which part of the brain does encephalitis affect?
Parenchyma not meninges
Which parts of the brain do different viruses affect the brain in encephalitis?
Neuroneal cell death by virus - inclusion bodies Temporal lobe- Herpes Spinal cord motor neurons- polio Brain stem- rabies Lymphocytic inflammatory reaction
Name another virus that can affect the brain?
Cytomegalovirus
What is a prion?
A normal constituent of a synapse (PrP)
