Paediatric encephalitis

Question 1

What is encephalitis?

Answer 1

Inflammation of the brain

Question 2

What are the causes of encephalitis?

Answer 2

This can be the result of infective or non-infective causes.

Non-infective causes are autoimmune, meaning antibodies are created that target brain tissue.

Question 3

What is the most common cause of encephalitis?

Answer 3

The most common cause is infection with a virus. Bacterial and fungal encephalitis is also possible although much more rare in the UK.

Question 4

What is the most common cause of encephalitis in children?

Answer 4

In children, the most common cause is herpes simplex type 1 (HSV-1) from cold sores.

Question 5

What is the most common cause of encephalitis in neonates?

Answer 5

In neonates, it is herpes simplex type 2 (HSV-2) from genital herpes, contracted during birth.

Question 6

What are other viral causes of encephalitis?

Answer 6

1. Varicella zoster virus (VZV) associated with chickenpox
2. Cytomegalovirus associated with immunodeficiency
3. Epstein-Barr virus associated with infectious mononucleosis
4. Enterovirus
5. Adenovirus
6. Influenza virus

It is important to ask about vaccinations, as the polio, mumps, rubella and measles viruses can cause encephalitis as well.

Question 7

What are the presentations of encephalitis?

Answer 7

1. Altered consciousness
2. Altered cognition
3. Unusual behaviour
4. Acute onset of focal neurological symptoms
5. Acute onset of focal seizures
6. Fever

Question 8

What are the investigations for encephalitis?

Answer 8

1. Lumbar puncture, sending cerebrospinal fluid for viral PCR testing
2. CT scan if a lumbar puncture is contraindicated
3. MRI scan after the lumbar puncture to visualise the brain in detail
4. EEG recording can be helpful in mild or ambiguous symptoms but is not always routinely required
5. Swabs of other areas can help establish the causative organism, such as throat and vesicle swabs
6. HIV testing is recommended in all patients with encephalitis.

Question 9

What are the contraindications to lumbar puncture?

Answer 9

1. GCS below 9
2. Haemodynamically unstable
3. Active seizures or post-ictal

Question 10

What is the management for encephalitis?

Answer 10

Intravenous antiviral medications are used to treat the suspected or confirmed underlying cause:
1. Aciclovir treats herpes simplex virus (HSV) and varicella zoster virus (VZV)
2. Ganciclovir treats cytomegalovirus (CMV)

• Repeat lumbar puncture is usually performed to ensure successful treatment prior to stopping antivirals.
• IV Aciclovir is usually started empirically in suspected encephalitis until results are available. Other viral causes have no effective treatment and management is supportive.
• Followup, support and rehabilitation is required after encephalitis, with help managing the complications.

Question 11

What are the complications of encephalitis?

Answer 11

1. Lasting fatigue and prolonged recovery
2. Change in personality or mood
3. Changes to memory and cognition
4. Learning disability
5. Headaches
6. Chronic pain
7. Movement disorders
8. Sensory disturbance
9. Seizures
10. Hormonal imbalance