Meningitis and Encephalitis

Question 1

What is the definition of meningitis?

Answer 1

Inflammation of the meninges

Question 2

What is the definition of encephalitis?

Answer 2

Inflammation of the brain

Question 3

What are the symptoms and signs of a case of meningococcal meningitis caused by neisseria meningitidis (Bacterial)

Answer 3

Symptoms 
12 hour gradual onset headache 
Severe + generalised 
Feverish 
Photophobic 
Nuchal rigidity – not moving neck

Signs 
Temp – 38.9 
HR – 110 bpm 
BP – 100/60
No rash

Question 4

Describe the carriage and transmission of meningococcal meningitis

Answer 4

Throat carriage in approx. 10% population
25% of 15 to 19 year olds
Person-person spread
Inhalation of respiratory secretions
Close prolonged contact, e.g. household members
Direct contact (kissing)
Disease in minority

Question 5

What can meningococcal disease cause? What are the differentiations?

Answer 5

Can either cause septicaemia or meningitis:
Septicaemia – non-blanching rash (starts off as pinpoint purple dots on hands/feet)
Meningitis without septicaemia – no rash
25% just septicaemia
60% both
15% just meningitis

Question 6

What is the prognosis of meningococcal meningitis

Answer 6

Fatal in approx. 10% with disease:
Up to 50% with septicaemia
Approaching 100% if untreated
1 in 8 suffer long term morbidity e.g. headache, joint stiffness, epilepsy, hearing loss, learning difficulties

Question 7

What is the treatment for meningococcal meningitis?

Answer 7

Early antibiotics improve prospect of recovery
IV ceftriaxone or cefotaxime – must be after blood cultures, should in theory be after lumbar puncture but normally is due to lack of funding.
Can start antibiotics before set diagnosis just in case
No evidence for corticosteroids for meningococcal meningitis

Question 8

When are vaccines given for meningococcal meningitis?

Answer 8

Men C vaccine – given to 1-3 y.o. since 1999
Men B vaccine – given to 2-4 month olds since 2015
Men ACWY vaccine – given to teenagers since 2015

Question 9

What are the symptoms and signs of a meningitis caused by streptococcus pneumoniae?

Answer 9

Symptoms
24 hour history of gradual onset headache 
Feverish 
Confused in last 12 hours 
No travel 
Hypertension 
Allergic Rhinitis 

Signs
Temp – 38 
HR – 64 bpm 
BP 105/90 
GCS 14/15 
Photophobia 
Nuchal rigidity 
No rash 
No focal neurological signs

Question 10

How would the CSF results and gram stain of a pneumococcal meningitis look?

Answer 10

CSF Results:
CSF glucose is lower than blood
Increased proteins
Cloudy

Gram stain:
Gram positive – purple colour
Streptococcus pneumoniae – paired

Question 11

Which type of meningitis is corticosteroids treatment for? What is the treatment?

Answer 11

Dexamethasone for 4 days if streptococcus pneumoniae is confirmed
Significantly reduced mortality and neurological disability at 8 weeks if GCS< 11

Question 12

What are the signs and symptoms of meningitis due to listeria monocytogenes?

Answer 12

Symptoms 
Unwell for 4 days 
Vomiting and diarrhoea 
Fever 
Muscle aching 
2 days gradual onset severe global headache 
No rash  

Signs 
Temp 38.8 
HR 100bpm 
BP 110/70 
GCS 14/15 (disoriented in time and place) 
Photophobia 
Nuchal rigidity 
No rash present
No focal neurological signs

Question 13

What are the CSF results of meningitis due to listeria

Answer 13

Lymphocytes not polymorphs

No organisms seen on gram stain – similar to fungal

Question 14

How does listeria cause meningitis, who is at risk? What is the mortality?

Answer 14

Blood cultures
3rd common cause of bacterial meningitis in adults (rarer than meningococcal or pneumococcal)
Eat listeria – shouldn’t cause a problem unless immunocompromised/pregnant or neonates
If gets into blood such as with those who are immunosuppressed it causes meningitis in 55-70%
Mortality approx. 25%

Question 15

How would you treat listeria meningitis?

Answer 15

treat with amoxicillin 2g every 4 hours aswell as normal antibiotics (ceftriaxone or cefotaxime) until know for sure the cause from lumbar puncture

Question 16

What are the signs and symptoms of viral meningitis due to enterovirus

Answer 16

Symptoms
2 day history gradual onset severe headache
Preceding 3 days muscle aching + lethargy
Feeling hot and cold
Photophobia
Neck stiffness

Signs 
Temperature 38.6°C
Heart rate 110 bpm
BP 100/60
Alert, orientated
Photophobia
Nuchal rigidity
No rash present

Question 17

What are the csf results of a enteroviral meningitis

Answer 17

Protein is only a little up and not significant blood glucose to CSF glucose – suggests viral
Clear colourless – viral

Question 18

What are some common causes of viral meningitis

Answer 18

Enteroviruses
Herpes Simplex Virus (Mollaret’s)
Mumps
Measles
Adenovirus
HIV 
Non viral: Lyme disease, syphilis, drugs
Often have other symptoms too e.g. measles has rash

Question 19

What is the treatment for viral meningitis?

Answer 19

Self limiting

Doesn’t need specific treatment- just treat symptoms

Question 20

What are the symptoms of TB meningitis?

Answer 20

Symptoms

Unwell for 2 months
2 stone weight loss 
Fever
Drenching night sweats
1 month gradual onset worsening headache

Question 21

What are the risk factors of TB meningitis?

Answer 21

HIV, alcoholism, diabetes, steroids, anti-TNF agents, immigration from area of high prevalence

Question 22

What is the treatment for TB meningitis?

Answer 22

Start treatment without waiting for results
12 months treatment:
rifampicin, isoniazid, pyrazinamide, ethambutol
Dexamethasone (Thwaites regimen)
Acetazolamide + frusemide, or repeated LP for communicating hydrocephalus
Consider early ventriculo-peritoneal shunting for non-communicating hydrocephalus

Question 23

What are the symptoms of cryptococcal menigitis due to fungal cryptococcus neoformans?

Answer 23

3 stone weight loss in 6 months
Gradual onset headache + fever for 2 weeks
No photophobia
No neck stiffness
No rash
Received antibiotics for chest infection 6 weeks ago

Question 24

What is treatment for cryptococcal meningitis

Answer 24

AmBisome (liposomal amphotericin B) and flucytosine for 2 weeks (anti-fungal)
Serial lumbar punctures

8 weeks fluconazole – 400mg daily

Question 25

Who is at risk of cryptococcal meningitis?

Answer 25

Immunocompromised, rare immunocompetant have cryptococcal meningitis

Question 26

What are the symptoms of viral encephalitis?

Answer 26

Normally fit and well
2 days progressive headache + fever
Preceding “flu-like” symptoms
24 hours acute confusion, behavioural change
Insomnia
No regular medications
No unwell contacts

Question 27

What would CSF results of viral encephalitis look

Answer 27

Viral – clear CSF (bacterial, fungal would be cloudy), same as viral meningitis
Not significant increase in protein
Not significant difference between blood glucose and CSF glucose

Question 28

How do you distinguish between encephalitis and meningitis?

Answer 28

Altered mental status
Motor or sensory deficits
Altered behaviour / personality
Speech or movement disorder

Question 29

What are the infectious causes of encephalitis?

Answer 29

Viruses
Direct invasion of the CNS:
Herpes viruses (Most common one)
Arboviruses (arthropod-borne viruses e.g. mosquitos when birds ar reservoirs and take virus to US)
Immune-mediated post infection/vaccination:
ADEM (acute disseminated encephalomyelitis)
Mumps, measles, rubella, influenza
Bacteria
Listeria, mycoplasma, Lyme, syphilis
TB
Parasites
Cerebral malaria, toxoplasmosis, Parastrongylus
Fungi

Question 30

What are the types of viruses that can cause encephalitis?

Answer 30

Herpes viruses:
Herpes simplex 1 & 2
Varicella zoster virus
Epstein-Barr virus
Cytomegalovirus
Human herpes virus 6, Human herpes virus  7
Enteroviruses:
Coxsackie, echoviruses, enteroviruses 70 & 71, parechovirus
Poliovirus
Paramyxoviruses
Measles, mumps
Others (rarer)
Influenza, adenovirus, parvovirus, rubella

Question 31

What is the clinical presentation of HSV encephalitis?

Answer 31

Acute presentation
Flu-like prodrome
Fever (90%)
Headache
Altered consciousness 
Disorientation (76%)
Seizures in 1/3 of patients with HSV-1 encephalitis
Focal neurological signs common
Speech disturbance (59%)
Behavioural change, e.g. hypomania, irritability (41%)
Memory impairment

Question 32

What is the prognosis of HSV encephalitis

Answer 32

Mortality 70% if untreated
2/3 survivors have significant neuropsychiatric sequelae:
69% Memory impairment 
45% Personality / behavioural change 
41% Dysphasia 
25% Seizures

Question 33

What is the treatment for enecephalitis?

Answer 33

Aciclovir: sooner given the better, if suspected encephalitis perform urgent LP and commence acyclovir +/- antibiotics. If LP delayed start treatment ASAP
Reduces mortality from 70% to 28%
Limits severity of postencephalitic impairment
Poor outcome if delay >2 days between hospitalisation and commencing treatment

Question 34

What is the advice on when to stop acyclovir?

Answer 34

14-21 days in confirmed HSV encephalitis
If clinical suspicion of HSV encephalitis is high but initial CSF PCR negative, continue aciclovir and repeat LP after 48 hrs
If repeat PCR negative but clinical suspicion persists then continue IV aciclovir for at least 10 days
If clinical suspicion low or alternative diagnosis apparent then stop aciclovir after 2nd negative PCR

Question 35

What was the dexenceph study investigating?

Answer 35

Retrospective non-randomised data – corticosteroid administration improved outcome in 22 of 45 patients with HSV encephalitis given steroids at the same time as aciclovir was initiated
Efficacy not yet proven
Optimal timing unclear
Often used if significant brain oedema or if deterioration despite appropriate antiviral treatment

Question 36

How can a teratoma cause encephalitis?

Answer 36

Body produces antibodies against NMDAR in the teratome, they then attack other areas
Young female patients with psychiatric symptoms, amnesia, seizures, frequent dyskinesias, autonomic dysfunction and decreased GCS
All had ovarian or other teratomas
Immediate removal of teratoma lead to removal of antibody-mediated response
Rapid recovery