09.3 Pathology of the Brain

Question 1

How can an infection gain entry to the CNS?

Answer 1

Directly - middle ear infection/basal skull fracture
Blood - sepsis/endocarditis
Iatrogenic - VP shunt/surgery/LP

Question 2

What are some signs/symptoms of meningitis?

Answer 2

Headache
Neck stiffness
Fever
Photophobia
Vomiting
Rigors

Question 3

What can cause meninigitis?

Answer 3

Neonate- E coli
2-5 H influenzae
15-30 N meningitidis
30+ S pneuominae

Question 4

In encephalitis what is the usual infective agent?

Answer 4

A virus

Question 5

Name some prion diseases

Answer 5

Kuru

Creutzfeld Jakob disease

Question 6

During raised intracranial pressure what herniations can occur?

Answer 6

Subfalcine
Tentorial
Tonsillar

Question 7

What occurs in a subfalcine herniation?

Answer 7

Brain herniates to the opposite side of the SOL
Singulate gyrus is fushed under the falx cerebri
Ischaemia of the middle parts of the parietal and frontal lobes due to compression of anterior cerebral artery

Question 8

What occurs in tentorial herniation?

Answer 8

Uncus herniates through tentorial notch
Damage to CNIII
Occlusion of cerebellar arteries

Question 9

What occurs in tonsillar herniation?

Answer 9

Cerebellar tonsils pushed through the foramen magnum

Compression of the brainstem leads to coma, apnoea and/or cardiac arrest

Question 10

What is a benign and malignant cause of a primary brain tumour?

Answer 10

Benign - meningioma

Malignant - astrocytoma

Question 11

What is the main tumour type in the brain?

Answer 11

Metastasis from elsewhere