Cerebral Inflammation Flashcards
Define meningitis and describe where there’s infiltration of lymphocytes
inflammation of the meninges caused by viral or bacterial infection
inflitration in between arachnoid and pia mater (sub-arachnoid space)
Define encephalitis adn give a histological feature of it?
inflammation of the brain caused by infection or autoimmune mechanisms.
there is vascular cuffing. (around blood vessels)
describe the nature (density) of the vascularisation of the CNS; explain
very dense.
No neurone is more than 100um from a capillary
What forms theblood brain barrier and extensively describe and draw it
Capillaries form it; the BBB capillaries have tight junctions at endotheilal cell-cell contacts.
This massively reduces solute and fluid leak across the capillary wall
what froms the perivascular glial in the BBB
Astrocytes- they help to maintain the BBB
Explain the consequences of the nature oif the BBB
Solutes cannot cross the BBB due to the tightness of the BBB
This allows the BBB to control exchange of substances using specific transopters (influx and efflux transporters)
Blood- borne infections agents have reduced entry into the CNS tissue
What defines the vasculatrue of the BBB (at the end)
Astrocyte endfeet
Describe and explain what happens in the BBB when it is disrupted either by truama , infection etc
Firstyl there’s endothelial layer disruption.
This leads to fibrinogen leakage from vessel intop parenchyma
Astrocyte then gather together around fibrinogen and breakdown BBB
Collagen is disrupted as the ECM grows too much (over thickens)
Astrocyte end-feet changes
what are the initial symptoms fo encephalitis
flu-like symptoms wiht pyrexia
Headache
N.B. initial symptoms are generally benign
What are the subsequent symptoms of encephalitis
- Confusion or disorientation
- Seizures or fits
- Changes in personality and behaviour
- Difficulty speaking
- Weakness or loss of movement
- Loss of consciousness- due to brain swelling
These symptoms depends on the cause of encephalitis and the pt. it can come in hours. days or weeks
What are the commonest causes of encephalitis
viral infection like:
- Herpes Simplex
- Measles
- Varicella (chickenpox)
- Rubella (German measles)
what are the other less common causes of encephalitis
- Mosquito, tick and other insect bites
- Bacterial and fungal infections
- Trauma
- Autoimmune
What are the treatments for encephalitis
treatment depends on the cause of it:
- Antivirals e.g. acyclovir
- Steroids- reduce swelling and inflammation
- Antibiotics/antifungals
- Analgesics
- Anti-convulsants- risk of seizures
- Ventilation- if breathing becomes too difficult
what are the feature sof multiple sclerosis
Autoimmune demyelinating disease of the CNS
Relapsing remitting disease at first
Relapses linked to inflammatoru activity
There’s secondaray progression which is linked to neurofengeneration
what is the cellular pathology of MS
Inflammation
Demyelination
Axonal loss
Neurodegeneration.
This is characterised by perivascular and leptomeningeal inflammation
why do symptoms of MS vary among pts
Symptoms vary because the amount and location of damage to the central nervous system is different in each person with MS
i.e. randomly affect any white matter tract
Describe the inflammatory markers of MS in histology
What cells are affected?
Perviscular cuffing and immune cell infiltration
Particularly CD3 T-Cells and CD20 B cells
Describe the epidmeiology of meningitis
- Irritation, inflammation and swelling of the meninges
- 6th most common infectious disease killer
- Affects more than 5 million people per annum worldwide
- Leaves 1 in 5 of the infected people with an impairment of some sort
what are the bacterial causes of meningitis
- Meningococcal – the most common cause of bacterial meningitis in UK
- Pneumococcal
- Haemophilus Influenzae type b (Hib)
- Streptococccal – the main cause in newborn babies
what are the other causes of meningitis
- Viral - very rarely life-threatening
- Fungal
Define Cerebral vasculits
inflammation of blood vessel walls (sometimes called angiitis)
whats the infection of the spinal cord and causes
vertebral osteomyelitis
causes: bacteria, fungal, viral, granuloma
Outline the different CSF results for bacterial, virus, SAH etc
what investigations can you use to discern encephalitis
MRI
Lumbar puncture
bloods?
