Ch22 Other non-bacterial infections

Question 1

A haemorrhagic viral encephalitis with a prediliction for the temporal lobes

Answer 1

Herpes Simplex 1

Question 2

What are the MRI findings in Herpes Simplex Encephalitis?

Answer 2

Increase signal on T2WI MRI. Particularly in temporal lobe and spanning sylvian fissure (“transsylvian sign”)

bilateral more suggestive of HSE

Question 3

What are the EEG findings in HSE?

Answer 3

PLEDs (periodic lateralising epileptiform discharges) coming from temporal lobe. Can vary a lot over a few days

Question 4

What is the definitive investigation to confirm HSE?

Answer 4

Brain biopsy, however Aciclovir should be started as soon as HSE suspected.

Brain biopsy reserved for cases with inconclusive investigations.

Question 5

What are the different forms of CJD?

Answer 5

1. Transmissible (possibly via prions)
2. Inherited (AD)
3. Sporadic

Question 6

What are the EEG findings in CJD?

Answer 6

Bilateral sharp waves (0.5-2/sec)

Question 7

What are the forms of transmissible spongiform encephalopathy?

Answer 7

CJD
Kuru
Gerstmann-Straussler-Scheinker disease
Fatal Familial Insomnia

Question 8

What gene is affected in the familial form of CJD?

Answer 8

Amyloid gene on Chromosome 20

Question 9

Commonest parasitic infection in CNS?

Answer 9

Tinea solium (causes neurocystericosis)

Question 10

What is Brun syndrome?

Answer 10

Intraventricular neurocystericosis causing hydrocephalus

Question 11

What is the difference between cysticercus cellulosae and cysticercus racemosus?

Answer 11

Cysticercus racemosus tend to form larger cysts around the basal cisterns and produce more inflammation

Question 12

What is Bartonella Hensae better known as?

Answer 12

Cat-scratch disease

Question 13

What caused primary amoebic meningoencephalitis?

Answer 13

Naegleria Fowleri. Found in freshwater, gets in through the cribiform plate and almost always fatal