Brain herniations Flashcards Preview

Neurology Week 4 2018/19 > Brain herniations > Flashcards

Flashcards in Brain herniations Deck (24)
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1
Q

What is a herniation?

A

Abnormal movement of an organ through an opening

2
Q

What causes brain herniation?

A

Increased intracranial pressure

secondary to tumours, bleeding, hydrocephalus, infection, cerebral oedema…

3
Q

What are the four important types of brain herniation?

A

Cingulate / Subfalcine

Central

Uncal

Tonsilar

4
Q

Which lobe is involved in a cingulate herination?

A

Most of them

Cingulate gyrus runs along the midline

5
Q

What does the cingulate gyrus herniate underneath?

Does it move medially or laterally?

A

Falx cerebri (lining of dura running down the midline)

Medially

6
Q

What structure may be damaged by a cingulate/subfalcine herniation?

A

Anterior cerebral artery

7
Q

Which artery is most at risk of damage in a subfalcine herniation?

A

Anterior cerebral artery

8
Q

Which part of the brain does the anterior cerebral artery supply?

A

Medial cerebral hemispheres - from frontal to parietal lobes

Corpus callosum

Caudate nucleus

9
Q

Which symptoms are caused by a cingulate / subfalcine herniation?

A

Contralateral leg weakness

legs map to areas of motor strip supplied by anterior cerebral artery, and remember motor pathways cross over so damage affects the opposite side

10
Q

Which lobe shifts in an uncal herniation?

A

Temporal lobe

11
Q

In an uncal herniation, the temporal lobe passes through an opening in which structure?

A

Tentorium cerebelli

12
Q

Which structures does the brain herniate through in

a) cingulate
b) uncal herniations?

A

a) Falx cerebri

b) Tentorium cerebelli

13
Q

Which symptoms are caused by uncal herniation?

A

Dilation of ipsilateral pupil (compression of CN III)

Contralateral hemiparesis (compression of medullary pyramids, where motor fibres cross over, causes muscle weakness)

14
Q

Which symptoms are seen in

a) cingulate
b) uncal herniations?

A

a) Contralateral leg weakness
b) Ipsilateral dilation, contralateral hemiparesis

15
Q

In which herniation does the cerebellum pass through the foramen magnum?

A

Tonsilar herniation

16
Q

Which

a) part of the brain
b) bony structure

is involved in tonsilar herniation?

A

a) Cerebellum
b) Foramen magnum

17
Q

Which symptoms are caused by tonsilar herniation?

A

Cushing’s triad

Hypertension

Bradycardia

Irregular breathing

caused by compression of centres in the medulla

18
Q

What congenital malformation, causing narrowing of the spinal cord, may tonsilar herniation be caused by?

A

Chiari malformation

Narrowing of the spinal cord which causes CSF blockage > increased ICP

19
Q

What is a central herniation of the brain?

A

Downwards movement of brainstem towards the tentorium cerebelli

20
Q

Which important space, containing venous blood, the internal carotid artery and a cranial nerve, is compressed in central herniation?

A

Cavernous sinus

21
Q

Which cranial nerve travels in the cavernous sinus?

A

CN VI

Abducent nerve

22
Q

What symptom is caused by compression of CN VI in a central herniation?

A

Diplopia

23
Q

Which symptoms are caused by

a) tonsilar
b) central

herniations?

A

a) Cushing’s triad (hypertension, bradycardia, irregular breathing)

b) Diplopia

24
Q

Which symptoms are caused by

a) tonsilar
b) subfalcine
c) uncal
d) central

herniations?

A

a) Cushing’s triad (hypertension, bradycardia, irregular breathing)

b) Contralateral leg weakness

c) Ipsilateral dilation, contralateral hemiparesis

d) Diplopia