Infections of CNS Flashcards
What is meningitis?
Inflammation of the layers of tissue that cover the brain and spinal cord (meninges) and of the fluid-filled space between the meninges (subarachnoid) space
Who can meningitis effect?
- Anyone but most common in babies, young children, teenagers and young adults
What is the most common type of meningitis?
- Viral meningitis
Least common and least serious type
What is the least common type of meningitis?
- Bacterial meningitis
Can be very serious if not treated
What are the 12 symptoms of meningitis?
- High temperature above 38C
- Vomiting
- Headache
- Rash that does not fade
- A stiff neck
- Dislike for bright lights
- Drowsiness or unresponsiveness
- Seizures
- Confusion
- Breathing quickly
- Muscle/joint pain
- Cold hands and feet
What are 6 additional symptoms of meningitis in babies?
- Refuse feeds
- Be irritable and unusual fussiness (particularly when held)
- High-pitched cry
- Stiff body/floppy/unresponsive
- Bulging soft spot on top of head (25%)
What is the prevalence of seizures in newborns and children in meningitis?
- 1/3 of newborns
2. 1/5 infants and children
What is the aetiology of bacterial meningitis in newborns? (2)
- Usually from an infection of the blood stream (sepsis)
2. Typically bacteria is acquired from birth canal
What are the most common types of bacteria causing meningitis in newborns?
Group B streptococci
Escherichia coli
Listeria monocytogenes
What is the aetiology of bacterial meningitis in older infants and children?
- Infection through contact with respiratory secretions containing bacteria
What are the most common type of bacteria causing meningitis in children? (3)
- Steptococcus pneumonia and neiserria meningitidis
- Haemophilus influeza type b was the most common type
- Current vaccines are making these rare causes of childhood meningitis
Give 3 types of bacteria causing meningitis
- Meningococcal bacteria (several types A, B, C, W, X, Y and Z)
- Pneumoccal bacteria
- Haemophilus infuenzae type b bacteria
Give 3 types of viruses causing meningitis
- Enteroviruses
- Mumps
- Herpes simplex
How can viral and bacterial meningitis be spread? (4)
- Sneezing
- Coughing
- Kissing
- Sharing utensils/toothbrushes
How is meningitis diagnosed? (4)
- Physical exam of symptoms
- Lumbar puncture
- Blood tests
- Sometimes imaging tests
Why are imaging tests sometimes used in diagnosis of meningitis? What imaging tests can be used?
- Ultrasonography and CT
2. Determine the degree of pressure on the brain and whether an abccess is present
What is the prognosis of bacterial meningitis?
- 1/10 cases is fatal
2. Even with timely treatment 5-25% of newborns die
Give the mortality rates for older children according to bacterial time
- Haemophilus influenzae
- Neisseria meningitidis
- Streptococcus pneuomoniae
- Haemophilis 2-5%
- Neisseria 5-10%
- Streptococcus 10-20%
In newborns who survive, what is the prognosis of meningitis? (2)
- 20-50% = serious brain and nerve problems (eg. hydrocephalus), hearing loss and intellectual disability
- 30% have mild residual problems eg. learning disorders, mild hearing loss or occassional seizures
In children who survive, what is the prognosis of meningitis?
15-25% develop brain and nerve problems such as hearing loss, intellectual disability and seizures
What are 6 other complications associated with meningitis?
- Memory/concentration difficulties
- Co-ordination/movement/balance
- Vision loss
- Amputation (prevent spread)
- Bone/joint problems eg. arthirits
- Kidney problems
What is the treatment for meningitis? (5)
- Antibiotics intravenously
- Some corticosteroids (reduce risk of hearing loss)
- Fluid to prevent dehydration
- Oxygen if breathing difficulties
- Steroids to reduce swelling around brain
What is encephalitis? (3)
- Inflammation of the brain when a virus directly infects the brain
- Or when a virus, vaccine or something else triggers inflammation
- The spinal cord may also be involved (encephalomyelitis)
What is the classification of encephalitis? (2)
- Primary: virus directly infects brain and spinal cord
2. Secondary: infection starts elsewhere and spreads to the brain
What are 5 early symptoms of encephalitis?
Similar to flu
- High temp above 38C
- Head ache
- Vomiting
- Aching muscles and joints
- Some - spotty/blistery rash
What 5 additional symptoms may be seen in infants/young children?
- Vomiting
- Bulging fontanel (soft spot in scalp)
- Constant crying
- Body stiffness
- Poor appetite
What are 13 serious symptoms of encephalitis?
- Confusion or disorientation
- Drowsiness
- Seizures
- Personality and behaviour changes eg. agitated
- Difficulty speaking
- Weakness or loss of movement
- Hallucinations
- Loss of sensation in body parts
- Involuntary eye movements eg. side to side
- Vision problems
- Loss of consciousness
- Coma
- Sensitivity to light
What is the aetiology of encephalitis? (5)
- Cause is sometimes unclear, usually infection or problem with immune system
- Virus that directly infections brain
- Virus that caused a previous infection becomes reactivated and directly damages brain
- Virus or vaccine triggers an autoimmune reaction (attacks brain tissue)
- Mosquitos and ticks that carry viruses
Give 4 viruses which can spread to the brain to cause encephalitis
- Herpes simple
- Varicella sozter (chickenpox and shingles)
- Measles, mumps and rubella
- Spread by animals
Where in the brain does herpes simplex usually affect?
- Temporal lobe and frontal lobe
2. Can be dangerous and lead to severe brain damage and death
Give 4 types of viruses spread by animals to cause encephalitis
- Tick-born encephalitis
- Japanese encephalitis
- Rabies
- Possibly Zika
Give 4 triggers which can cause a problem with the immune system to cause encephalitis
- Previous infection in another part of the body (few weeks earlier) - post infectious encephalitis
- A tumour - autoimmune encephalitis
- A vaccination (very rare)
- Unknown cause - autoimmune encephalitis
Give 5 investigations to diagnose encephalitis
- CT
- MRI (most common)
- Lumbar puncture
- EEG
- Blood/urine tests (test for antibodies to the virus)
Why is a lumbar puncture used to diagnose encephalitis?
- Number of white blood cells is increased in CSF when brain and meninges are inflamed
Summarise the prognosis of encephalitis
- Outlook depends on severity
2. Most people with severe encephalitis will experience complications
Give 13 complications of encephalitis
- Loss of memory
- Behavioural/personality changes
- Epilepsy
- Fatigue
- Physical weakness
- Intellectual disability
- Lack of muscle co-ordination
- Vision problems
- Hearing problems
- Speech problems
- Coma
- Difficulty breathing
- Death
What is the prognosis for mild and severe cases of encephalitis?
Mild: inflammation likely to resolve in a few days
Severe: may require weeks or months to recover and may cause permanent brain damage/death
How is encephalitis treated? (3)
- Depends on cause: anti-viral drug, antibiotic, corticosteroids
- Measures to relieve symptoms and provide life support
- Plasma exchange
Give 4 examples of drugs used to treat encephalitis
- Acyclovir (herpes simplex and herpes sozter)
- Ganciclovir (cytomegalovirus)
- Anticonvulsants (prevent/stop seizurs)
- Sedatives (restlessness, aggressiveness and irritability)
Give 2 treatments of auto-immune encephalitis
- Corticosteroids to reduce brain inflammation
2. Plasma exchange (remove abnormal antibodies or immune globulin)
