Encephalitis

Question 1

What is encephalitis?

Answer 1

Encephalitis is the acute inflammation of the brain parenchyma and usually has a viral cause.

Question 2

What causes encephalitis?

Answer 2

Most commonly herpes simplex, VZV and other herpes group viruses, enteroviruses and adenovirus

Question 3

What is the clinical presentation for encephalitis?

Answer 3

Physical Symptoms:

• Fever
• Seizures
• Headache
• Movement disorders
• Sensitivity to light
• Sensitivity to sound
• Neck stiffness
• Loss of consciousness

Cognitive Symptoms:

• Excessive sleepiness
• Confusion and disorientation
• Irritability
• Anxiety
• Psychosis
• Hallucinations
• Memory loss
• Other behavioral changes
• Cognitive impairment

Question 4

What may severe cases of encephalitis lead to?

Answer 4

• Weakness or partial paralysis in the arms and legs
• Double vision
• Impairment of speech or hearing
• Coma

Question 5

How would you diagnose encephalitis?

Answer 5

There are different investigations that can be done to confirm encephalitis:

1. MR imaging shows areas of inflammation and swelling, generally in the temporal lobes in HSV encephalitis. Raised intracranial pressure and midline shift may occur leading to coning.
2. EEG shows periodic sharp and slow wave complexes.
3. CSF puncture shows an elevated lymphocyte count (95%).
4. Viral detection by CSF PCR is highly sensitive for several viruses such as HSV and VZV

Question 6

How would you manage encephalitis?

Answer 6

Suspected HSV and VZV encephalitis is treated immediately with i.v. aciclovir (10 mg/kg 3 times a day for 14–21 days), even before investigation results are available.

• Early treatment significantly reduces both mortality and long-term neurological damage in survivors
• Seizures are treated with anticonvulsants

Long-term complications are common including memory impairment, personality change and epilepsy.