Random Stuff

Question 1

In the internal capsule, where would fibres representing the lower limbs be found?

Answer 1

Posterior limb - contains UMNs that supply most of the body.

Question 2

In the internal capsule, where would fibres representing the face be found?

Answer 2

The genu

Question 3

Parkinson’s disease is classified by which triplet of signs?

Answer 3

Tremor
Rigidity
Bradykinesia

Question 4

A patient has suffered a stroke affecting the internal capsule near the genu, will his facial weakness by of the contralateral upper or lower face?

Answer 4

Contralateral lower face - because upper face has a bilateral UMN innervation, hence is spared in strokes. The lower face receives a contralateral UMN innervation.

Question 5

What is the normal function of the basal ganglia?

Answer 5

Determines the most appropriate set of movements needed to carry out a task.

Question 6

What is hemiballismus?

Answer 6

Damage to subthalamic nucleus, which leads to decreased inhibition of thalamus and therefore increased movement.

Question 7

What is the pathology behind Huntingtons Disease?

Answer 7

Loss of inhibition of GPe, leads to less inhibition on thalamus and increased movement (hyperkinetic movement).

Question 8

What is a subfalcine herniation?

Answer 8

When the brain herniated under the falx cerebrii, often caused by a tumour in cerebral hemisphere.

Question 9

What is an uncal herniation?

Answer 9

Herniation of the uncus down through the tentorial notch of the tentorium cerebelli.

Question 10

Are you more likely to get altered conscious level with a subfalcine or uncal herniation?

Answer 10

More likely to get reduced consciousness in an uncal herniation as the reticular formation in the brainstem is compressed.

Question 11

What can be compressed in a subfalcine herniation? What is the consequence?

Answer 11

Anterior cerebral artery

Can lead to contralateral muscle weakness

Question 12

What can get compressed in an uncal herniation?

Answer 12

Midbrain - can lead to CN III palsy
Cerebral peduncle - contralateral weakness due to compression of motor structures
Reticular formation - leads to decreased consciousness.

Question 13

What is tonsillar herniation?

Answer 13

When the cerebellar tonsils herniate through the foramen magnum.

Question 14

What is the triad of Cushing’s reflex?

Answer 14

High BP
Bradycardia
Low respiratory rate

Question 15

When does Cushing’s reflex occur?

Answer 15

When raised ICP is not treated and continues to rise - has quite a bad prognosis.

Question 16

What is a lacunar infarct?

Answer 16

Blockage of one of the lenticulostriate arteries that supplies the internal capsule.

Question 17

What is myogenic autoregulation? Name 2 organs that do it.

Answer 17

Constriction and dilation of blood vessels to maintain perfusion to organs. Done by the kidney and the brain - if BP decreases, afferent arteriole dilates to maintain GFR and cerebral arteries vasodilate to maintain cerebral perfusion.

Question 18

What is the effect of adenosine on the cerebral arterioles?

Answer 18

Powerful vasodilator - adenosine is a metabolite, hence brain produces lots of it and therefore has a high blood supply.

Question 19

What is metabolic hyperaemia?

Answer 19

Increase in metabolites in highly metabolically active tissues e.g. K+, adenosine etc.
Metabolites act as vasodilators, increasing blood flow to tissue.

Question 20

Where are the main barorceptors found?

Answer 20

Carotid bodies - carotid sinus

Aortic bodies - arch of aorta

Question 21

What is prion related disease?

Answer 21

When mutated prions interact with normal prions to undergo a post-translational conformational change and form prion aggregates.
Prion aggregates cause neuronal death and lead to a group of conditions called spongiform encephalopathies.