Neuropathology 3- raised ICP, SOL and trauma

Question 1

Normal value of intercranial pressure

Answer 1

5-13mmHg

Question 2

Five potential causes of raised ICP

Answer 2

SOL
Diffuse lesion (e.g. oedema)
Hydrocephalus
Increased venous volume (e.g. obstructed airway, obstructed neck veins)
Hypoxia/hypercapnia

Question 3

How do hypoxia and hypercapnia lead to raised ICP?

Answer 3

Arteriolar vasodilatation- increases arterial blood volume within brain

Question 4

Normal volume and turnover of CSF

Answer 4

120-150ml; turnover of 3-5x per day

Question 5

Where is CSF produced?

Answer 5

Choroid plexus in the lateral and fourth ventricles

Question 6

Where is CSF reabsorped?

Answer 6

Into the dural venous sinuses, via arachnoid granulations

Question 7

Foramen between lateral and third ventricle

Answer 7

Foramen of Monro

Question 8

How does CSF enter the subarachnoid space?

Answer 8

Via the exit foraminae of Luschka and Magendie

Question 9

Obstruction to flow of CSF occurring within the ventricular system

Answer 9

Non-communicating hydrocephalus

Question 10

Communicating hydrocephalus

Answer 10

Obstruction to flow of CSF occurring outwith the ventricular system (e.g. in subarachnoid space or arachnoid granulations)

Question 11

Neurological features associated with raised ICP

Answer 11

Reduction in consciousness level
Ipsilateral fixed and dilated pupil
Papilloedema
Signs of shift/herniation

Question 12

Three most common types of herniation in raised ICP

Answer 12

Subfalcine ( cingulate gyrus under the falx celebri)
Tentorial (temporal lobe herniates through tentorium)
Tonsillar (cerebellar tonsils herniate into the foramen magnum)

Question 13

Manifestations of subfalcine herniation

Answer 13

Sensory/motor loss in leg due to ischaemia of the sensory/motor cortexes

Question 14

Manifestations of a tentorial herniation

Answer 14

Ipsilateral dilated pupil, defective eye movements due to third nerve compression

Question 15

Signs of a tonsillar hernia

Answer 15

Apnoea by compression of respiratory centres

Question 16

Most common type of malignant primary intercranial tumour

Answer 16

Astrocytoma

Question 17

Cancers which commonly metastasize to brain

Answer 17

Bronchus, breast, kidney

Question 18

Astrocystomas often develop into…

Answer 18

Glioblastoma

Question 19

Glioblastoma can be identified by immunohistochemistry against…?

Answer 19

GFAP

Question 20

Which has the worst prognosis, primary or secondary glioblastoma?

Answer 20

Primary- mean survival around 5 months

Question 21

Common symptoms of brain malignancy

Answer 21

Focal symptoms
Headache
Vomiting
Seizures

Question 22

Potential causes of a single brain abscess

Answer 22

Usually focal cause- e.g. otitis media, sinusitis, skull fracture, penetrating injury

Question 23

Potential causes of multiple brain abscesses

Answer 23

Usually result from septicaemia

Question 24

Five aetiologies of cerebral oedema

Answer 24

Vasogenic (blood-brain barrier defect)
Cytotoxic (ischaemic)
Interstitial (hydrocephalus)
Hypo-osmotic (reduced plasma osmolality)
Hydrostatic (increased perfusion pressure)