Random Stuff Flashcards
In the internal capsule, where would fibres representing the lower limbs be found?
Posterior limb - contains UMNs that supply most of the body.
In the internal capsule, where would fibres representing the face be found?
The genu
Parkinson’s disease is classified by which triplet of signs?
Tremor
Rigidity
Bradykinesia
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?
Contralateral lower face - because upper face has a bilateral UMN innervation, hence is spared in strokes. The lower face receives a contralateral UMN innervation.
What is the normal function of the basal ganglia?
Determines the most appropriate set of movements needed to carry out a task.
What is hemiballismus?
Damage to subthalamic nucleus, which leads to decreased inhibition of thalamus and therefore increased movement.
What is the pathology behind Huntingtons Disease?
Loss of inhibition of GPe, leads to less inhibition on thalamus and increased movement (hyperkinetic movement).
What is a subfalcine herniation?
When the brain herniated under the falx cerebrii, often caused by a tumour in cerebral hemisphere.
What is an uncal herniation?
Herniation of the uncus down through the tentorial notch of the tentorium cerebelli.
Are you more likely to get altered conscious level with a subfalcine or uncal herniation?
More likely to get reduced consciousness in an uncal herniation as the reticular formation in the brainstem is compressed.
What can be compressed in a subfalcine herniation? What is the consequence?
Anterior cerebral artery
Can lead to contralateral muscle weakness
What can get compressed in an uncal herniation?
Midbrain - can lead to CN III palsy
Cerebral peduncle - contralateral weakness due to compression of motor structures
Reticular formation - leads to decreased consciousness.
What is tonsillar herniation?
When the cerebellar tonsils herniate through the foramen magnum.
What is the triad of Cushing’s reflex?
High BP
Bradycardia
Low respiratory rate
When does Cushing’s reflex occur?
When raised ICP is not treated and continues to rise - has quite a bad prognosis.
What is a lacunar infarct?
Blockage of one of the lenticulostriate arteries that supplies the internal capsule.
What is myogenic autoregulation? Name 2 organs that do it.
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.
What is the effect of adenosine on the cerebral arterioles?
Powerful vasodilator - adenosine is a metabolite, hence brain produces lots of it and therefore has a high blood supply.
What is metabolic hyperaemia?
Increase in metabolites in highly metabolically active tissues e.g. K+, adenosine etc.
Metabolites act as vasodilators, increasing blood flow to tissue.
Where are the main barorceptors found?
Carotid bodies - carotid sinus
Aortic bodies - arch of aorta
What is prion related disease?
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.
