Meningitis

Question 1

What is meningitis?

Answer 1

Inflammation of the meninges, usually due to infection.

Question 2

What are the causes of bacterial meningitis?

Answer 2

• Neisseria meningitidis (most common cause)
• Streptococcus pneumoniae
• Haemophilus influenzae,
• Group B strep (most common cause in neonates neonates as bacteria colonises the vagina)
• Listeria monocytogenes (seen in immunosupressed)

Question 3

What are the viral causes of meningitis

Answer 3

Viral meningitis is more common but less severe.
- Enterovirus (coxsackie)
- HSV
- VZV
- Investigated by PCR of sample and treated with aciclovir if you suspect HSV.

Question 4

What are the fungal causes of meningitis?

Answer 4

Cryptococcus neoformans - mainly affects immunosupressed. Causes a SOL

Question 5

What are the parasitic causes of Meningitis?

Answer 5

Amoebea or toxoplasma gondii (occurs in immunocompromised)

Question 6

What are the non infective causes on meningitis?

Answer 6

• Malignancy
• Chemical meningitis
• Drugs such as NSAIDs or trimethorprim
• Systemic inflammatory diseases

Question 7

What are the signs and symptoms of meningitis?

Answer 7

• Headache,
• Fever,
• Neck stiffness,
• Photophobia,
• Nausea and vomiting,
• Seziures (less common in viral),
• Reduced consciousness
• Features of meningocccocal septicaemia such as a non-blanching petechial rash

Question 8

What are signs of meningeal irritation?

Answer 8

1. Kernig’s sign - Knee and hip flexed at 90 degrees. Patient experiences pain with knee extension
2. Brudzinski’s sign - Passive flexion of the neck causes involuntary flexion of hips and knees

Question 9

What are the differential diagnosis of meningitis?

Answer 9

• Enchephalitis (headaches, fever, altered consciousness, seziures, focal neurological signs and behavioral changes)
• SAH
• Brain abscess (headache, fever, N&V, focal neuro deficites, seziures)
• Sinusitis
• Migraine

Question 10

What are the investigations for meningitis?

Answer 10

1. Bloods (FBC, U&Es, Clotting and Glucose)
2. ABG
3. Blood cultures,
4. Head CT
5. Lumbar puncture for bacterial culture, viral PCR, cell count, protein and glucose (with paired blood glucose) (within 1 hour of arriving at hospital)

Question 11

What are the contraindications for doing a lumbar puncture?

Answer 11

• Brain shift on CT,
• Rapid GCS reduction,
• Respiratory or cardiac compromise
• Rapidly evolving rash,
• Infection at the LP sight
• Coagulopathy

Question 12

When do you need to CT BEFORE LP?

Answer 12

Signs of raised ICP, however do not delay giving antibiotics:
- Focal neurological signs/ CNS signs,
- GCS < 12 (DO CT FIRST),
- Immunocompromised
- Papilloedema,
- Buldging of fontanelle (children)
- DIC
- Seziures

Question 13

What are the differences in a LP in a bacterial and viral infection

Answer 13

Bacterial - Cloudy, raised proteins, reduced glucose and neutrophils.
Viral - Clear, raised protein (not as high as in bacterial), normal glucose and lymphocytes

Question 14

What are the risk factors for pneumococcal and listeria

Answer 14

Pneumococcal - Middle ear disease, head injury, neurosurgery, alcohol and immunosupression.
Listeria - Immunosupression and pregnancy

Question 15

What are signs of pneumococcal meningitis

Answer 15

Focal signs, seziures and VIII palsy.
May have signs of pneumococcal infection elsewhere such as endocarditis
Pneumococcal meningitis has a higher mortality than meningococcal

Question 16

What is the treatment of suspected bacterial meningitis in the community/hospital

Answer 16

• If there will be a delay of more than 1 hour of transferring patient to hospital then give urgent Benzylpenicillin or ceftriaxone/cefotaxime
• In hospital give 2g IV of ceftriaxone very 12hours. If over 50years then add amoxicillin
• Can also give IV Dexamethasone especially in high ICP

Question 17

What is the definitive antibiotic therapy for the different bacterial meningitis?

Answer 17

Meningococcal - IV ceftriaxone/benzyl penicillin for 5 days.
Pneumococcal - IV ceftriaxone/benzyl penicillin for 10-14 days.
Listeria - IV amocixillin for 21 days
Add IV dex especially in pneumococcal.

Question 18

Explain the prophylaxis measures for contacts of bacterial meningitis?

Answer 18

• Anyone who has been in close contact with the patient 7 days before onset.
• Single dose of ciprofloxacin

Question 19

What are the complications of meningitis?

Answer 19

• Septic shock,
• DIC,
• Coma,
• Subdural effusions,
• SIADH,
• Seizures,
• Intracerebral abscess
• Brain herniation
• Hydrocephalus
• Delayed complications eg, hearing loss, CN dysfunction, hydrocephalus, intellectual deficits, ataxia, blindness
• Death
• Waterhouse-Friderichsen syndrome

Question 20

What is progressive focal multifocal leucoencephalopathy?

Answer 20

Progressive motor dysfunction that occurs due to JC virus. Seen in immunocompromised patients.
- No specific treatment but can give ARVs if HIV positive

Question 21

What are the features of encephalitis, the investigations and treatment?

Answer 21

Presents with confusion, fever +/- seizures. Most common is HSV encephalitis
Investigations are LP which shows lymphocytic CSF, temporal lobe changes on EEG and MRI scanning can be done.
Treat with IV aciclovir for 2-3 weeks

Question 22

What is Waterhouse-Friderichsen syndrome?

Answer 22

This is where severe bacterial infections causes the blood vessels in the adrenal glands to rupture. It causes an adrenal crisis due to acute adrenal insufficiency