L7 - Infective Disorders of the Meninges and Brain Flashcards
1. Learn about different types of meningitis - viral, bacterial, fungal and (non infective) 2. Understand acute intracranial infections - bacterial meningitis, viral encephalitis and brain abscess 3. Understand chronic infections of the nervous system - chronic meningeal infections, HIV, JC virus and measles reactiviation, prion diseases
Briefly describe Meningitis
summarise key symptoms
- Inflammation of meninges
- Headache, vomiting, photophobia, neck stiffness, Kernig’s signs
What is Kernig’s sign?
Physically demonstrable symptoms of meningitis.
- Severe stiffness of the hamstrings causes an inability to straighten the leg when the hip is flexed to 90 degrees.
Briefly describe encephalitis?
- Viral invasion / inflammation of brain tissue.
- Behavioural change, ‘psychiatric illness’, confusion, coma, focal signs and convulsions.
What is a brain abscess?
- Inflammation and collection of infected material.
- Space occupying legion
What is myelitis?
- Inflammation of spinal cord.
- Can cause myelin and axon to be damaged
- resulting in symptoms such paralysis and sensory loss.
What is a prion?
Protein that can trigger normal proteins in brain to fold abnormally.
Describe bacterial meningitis?
- Very serious, death can occur.
- Tissues around brain swell.
- Interferes with blood flow
- can result in paralysis or stroke.
Describe viral meningitis?
common cause?
- Inflammation of lining of brain and spinal cord.
- Common cause: non-polio enteroviruses
Recap routes of spread that pathogens use to get into the body
Respiratory, Gastrointestinal, Mucosal, Insect-borne, injections, congenital and sexually transmitted
Example of a disease that enters into peripheral nerves
Rabies
- brain swells
- madness and convulsions
- death
Disease Herpes simplex virus?
- Enters via olfactory mucosa.
- Infection of the skin.
Herpes simplex virus: Two types.
- -> Affects temporal lobe
- -> Leads to memory loss.
1. HSV1 - oral to oral (cold sores)
2. HSV2 - sexually transmitted
Disease that enters through sinuses
Pneumococcus - common cause of blood stream infections
Disease that crosses the blood brain barrier
Japanese encephalitis virus
- Spreads through mosquito bites
- symptoms: fever, headache, vomiting, confusion and difficulty moving
Describe fungal meningitis?
Cryptococcus!
- Not transmitted person to person, fungi are usually inhaled.
- Headache, stiff neck, fever and nausea are potential symptoms.
- Blood and CSF are culted and examined during diagnosis.
State examples of bacteria which cause Bacterial meningitis? (3)
- Pneumococcus
- Meningococcus
- Tuberculosis
