Intercranial Tumours

Question 1

How are intracranial tumours classified?

Answer 1

• Malignant (likely infiltrative)

- Benign (typically non-infiltrative)

Question 2

What is the difference between a malignant and benign tumour?

Answer 2

Malignant more likely to regrow after surgical removal

**

Question 3

What is metastasis?

Answer 3

Malignant travel through bloodstream to other parts of the body (commonly breast /lung)

Question 4

Name 3 infiltrative tumours

Answer 4

1. Astrocytoma (astrocyte cells - star-shaped glial cells found throughout the brain)
   Gliomas of brain stem & cranial nerves (prognosis v low)
2. Oligodendroglioma (oligodendrocyte cells)
   - cells form myelin sheath around axons of nerve cells
   - rare + slow
3. Glioblastoma Multiforme
   - as early as childhood, 3-6mnths prognosis
   - destructive + fatal

Question 5

Name 3 non-infiltrative tumours

Answer 5

Meningiomas
Acoustic neuroma
Pituitary tumours

Question 6

What are gliomas?

Answer 6

Collection of growths (relatively fast-growing) which arise from supporting glial cells
40-50% of all brain tumours

Question 7

Meningiomas?

Answer 7

Most common (15%) + best prognosis for complete recovery
Benign (commonly arachnoid layer)
Older + women
Slow growing; tissue not destroyed but fx affected

Question 8

Acoustic neuroma?

Answer 8

Benign (auditory canal)
Schwann cells
Tinnitus, (partial) deafness, one-sided loss of taste

Question 9

2 types of Pituitary Tumours:

Answer 9

• Non-functioning pituitary adenomas (benign) pressure caused headaches + possible visual field deficits
• Functioning pituitary adenomas: acidophilic (gigantism); chromophobic (hyper/hypo-pituitarism); basophilic (excessive ACTH secretion - growth hormone; Cushing’s Syndrome - dwarfism)

Question 10

Metastatic tumours?

Answer 10

Fast growing, cancer cells travel through bloodstream to secondary site (lung, breast & skin commonly)
Early detection is NB *rarely operate when there are multiple sites

Question 11

What are common types of childhood tumours?

Answer 11

• Medullablastoma:
• malignent
• inferior vermis close to exit of CSF from 4th ventricle (obstructive hydrocephalus = increased intracranial pressure)
• vomiting+headache
• Cerebellar astrocytoma
• Gliomas of brainstem & optic nerve
• Pineloma

Question 12

Diagnosis and treatment of brain tumours

Answer 12

Headaches, nausea, vomiting, papilledema, loss in cog. fx, seizures

• surgical removal
• chemotherapy
• radiation therapy

Question 13

4 infections in the brain:

Answer 13

Brain abscess: pocket of puss

Meningitis (bacterial or virus):

• NB test: LP
• blood tests: WBC higher
• treated with benzylpenicillin

Encephalitis (many causes like Herpes Simplex)

• inflammation
• medial temporal & oribtal frontal areas (through olfactory bulbs)
• limbic system esp hippocampus
• anterograde amnesia

Neurotoxins
-somatization, hysterical features & depression

Question 14

What is Korsokoff Syndrome and how is it treated?

Answer 14

Alcohol abuse -> thiamine (B12) deficiency + ethanol effects -> limbic thalamus + mammillary bodies
Treatment: thiamine replacement, hydration, nutrution (occasionally drug therapy) 2 years