Lecture 13– Introduction to neuropathology Flashcards
types of neuropathology
infections
dementia
increased intracranial pressure
stroke
the CNS is usually sterile. name 3 routes of entry of microorganisms
- Direct spread e.g. middle ear infection, base of the skull
- Blood borne e.g. sepsis, infective endocarditis (bacterial emboli)
- Iatrogenic e.g. Ventricular-Peritoneum (hydrocephalus) shunt, surgery, lumbar puncture
Cerebral abscess cause by middle ear infections
Acute Meningitis
- Inflammation of the leptomeninges (pia/arachnoid )
- With or without septicaemia
why is prompt diagnosis life saving in people with acute meninigits
disease process moves very quickly
- Oedema in the brain due to acute inflammation (very quick decline)
- Inflammatory cell influx
- Raises ICP = death
Causative organism (various in immunocompromised individuals): neonates
E.Coli, L. monocytogenes
Causative organism (various in immunocompromised individuals): 2-5 yrs
H. influenza type B (HiB)
Causative organism (various in immunocompromised individuals): 5-30 yrs
N. Meningitides
Causative organism (various in immunocompromised individuals): over 30
S. Pneumonia
Chronic meningitis
- Chronic clinical course
- Rare
- Causative agent: Tuberculosis
- Granulomatous inflammation
- Fibrosis of the meninges
- Nerve entrapment
Complication of meningitis
- Local
- Death (swelling –> Raised intracranial pressurte (RICP))
- Cerebral infarction –> neurological deficit
- Cerebral abscess
- Subdural empyema (pus within a potential space)
- Epilepsy
- Systemic (if associated with septicaemia)
differenc e between encephalitis and meningitis
- Parenchyma not meninges
- Neuronal cell death by virus
- Inclusion bodies
- Temporal lobe
- Herpes virus
- Spinal cord motor neurones
- Polio
- Brainstem
- Rabies
- Neuronal cell death by virus
encephalitis is usuallly
viral and self-limiting (viral flu like illness/ headaches)
ecephalitis brain
damage caused lymphocytic inflammatory reaction
what is a prion
a proteion (PrP)
- A normal constituent of synapse
- Problems when this protein mutates
ways Prions mutate
- Sporadic mutation
- Familial mutation
- Ingested mutation
how do mutated Prions (PrPs) cause disease
- Mutated PrP interacts with normal PrP to undergo a post translation conformation changeà PrPs start to aggregate
- Extremely stable structure
- Insoluble
- Causes cell death
vCJD
Variant Creutzfeldt-Jakob Disease (vCJD)
Variant Creutzfeldt-Jakob Disease (vCJD)
Variant Creutzfeldt-Jakob disease (vCJD) is a prion disease that was first described in 1996 in the United Kingdom. There is now strong scientific evidence that the agent responsible for the outbreak of prion disease in cows, bovine spongiform encephalopathy (BSE or ‘mad cow’ disease), is the same agent responsible for the outbreak of vCJD in humans.
vCJD is different fro
classical CJD (e.g. a form of dementia)
- Each has a unique genetic prion
characteristics of vCJD infection which make it different to classic CJD
- Prolonged incubation period of 15+ year
- Prions not eradicated by traditional sterilisation
- More symptoms and effects patients at younger age
comparison table comparing classical CJD and variant CJD
is vCJD an infection? Think about Kochs postulates
debatable
define dementia
“Acquired global impairment of intellect, reason and personality without impairment of consciousness”