Session 10 - Group Work Flashcards
1) A patient has a magnetic resonance angiogram of their brain which is reported as normal.
a) Which elements of the cerebral vasculature can you identify? Add some labels
Anterior communicating artery
2) A 73 year old man presents to the emergency department with weakness in his right upper limb and expressive dysphasia. He admits to being a smoker and to not taking his ‘blood pressure pills’. He is seen by the stroke team who perform an MRI scan, shown below.
a) Which lobe of the brain has been predominantly affected? Give three reasons for your answer
- Weakness in the right upper limb suggests weakness in the left brain
- Expressive dysphagia would be a problem in Broca’s area which would be that kind of region (frontotemporal region)
- Side - weakness in the homunculus suggests this
2) A 73 year old man presents to the emergency department with weakness in his right upper limb and expressive dysphasia. He admits to being a smoker and to not taking his ‘blood pressure pills’. He is seen by the stroke team who perform an MRI scan, shown below.
b) A branch of which vessel is most likely to have been occluded?
Middle cerebral artery
2) A 73 year old man presents to the emergency department with weakness in his right upper limb and expressive dysphasia. He admits to being a smoker and to not taking his ‘blood pressure pills’. He is seen by the stroke team who perform an MRI scan, shown below.
c) Would you predict any visual field defect in this patient? Explain your answer.
One of the branches of the MCA is occluded, as shown by the scan. But that doesn’t mean the entire MCA supply is going to be affected. As we can see on the scan it is limited to the left frontal lobe so none of our optic tract travels throough our area, so NO, we will not have any visual field defects.
3) A 53 year old woman was admitted to the emergency department with right leg weakness, incontinence of urine. Neurological examination reveals 2/5 power in the right lower limb and 4/5 power in the right upper limb with no facial asymmetry. Whilst being catheterised the woman described altered sensation in her perineum. Her MRI scan is shown below. In MRI scans, early ischaemic strokes typically appear as high signal areas.
a) In the absence of a scan, could this be easily placed in an Oxford stroke class? Which specific vessel is involved?
We can’t classify it yet because we don’t have enough information - we need information about her higher cortical function e.g. is her speech affected? So it could be but we don’t know which one it is because we need a better history to classify it.
Anterior cerebral artery
3) A 53 year old woman was admitted to the emergency department with right leg weakness, incontinence of urine. Neurological examination reveals 2/5 power in the right lower limb and 4/5 power in the right upper limb with no facial asymmetry. Whilst being catheterised the woman described altered sensation in her perineum. Her MRI scan is shown below. In MRI scans, early ischaemic strokes typically appear as high signal areas.
b) Assuming the stroke was caused by an embolus, do you think it has lodged proximally or distally to the anterior communicating artery? Explain your answer. Hint: think about the role of communicating arteries
A proximal occlusion would be accounted for by the rest of the Circle of Willis, therefore the embolus must be at the distal end of the communicating artery, where there is no other collateral supply.
3) A 53 year old woman was admitted to the emergency department with right leg weakness, incontinence of urine. Neurological examination reveals 2/5 power in the right lower limb and 4/5 power in the right upper limb with no facial asymmetry. Whilst being catheterised the woman described altered sensation in her perineum. Her MRI scan is shown below. In MRI scans, early ischaemic strokes typically appear as high signal areas.
c) Why is she incontinent, with altered perineal sensation?
So the ACA affects the frontal lobe, and in the frontal lobe you have the paracentral lobules that affect voluntary micturition. If this is affected then you get incontinence.
The ACA supplies this area of the sensory homunculus in the midline, where the genitalia is found, so there is altered sensation in her perineum.
3) A 53 year old woman was admitted to the emergency department with right leg weakness, incontinence of urine. Neurological examination reveals 2/5 power in the right lower limb and 4/5 power in the right upper limb with no facial asymmetry. Whilst being catheterised the woman described altered sensation in her perineum. Her MRI scan is shown below. In MRI scans, early ischaemic strokes typically appear as high signal areas.
d) Are any major white matter pathways vulnerable in a stroke to this region? How might damage to these pathways manifest?
ACA also has an important white matter distribution which is to the corpus callosum – as it loops over the superior surface of CC it sends lots of little branches into white matter pathway supplying that CC – so a big stroke affecting the ACA could technically result in damage to the corpus callosum and the effects you might be familiar with in disconnecting two hemispheres e.g. alien hand syndrome.
3) A 53 year old woman was admitted to the emergency department with right leg weakness, incontinence of urine. Neurological examination reveals 2/5 power in the right lower limb and 4/5 power in the right upper limb with no facial asymmetry. Whilst being catheterised the woman described altered sensation in her perineum. Her MRI scan is shown below. In MRI scans, early ischaemic strokes typically appear as high signal areas.
e) There is slight midline shift. If the brain swells further, which cortical region is at risk of herniation?
Subfalcine herniation (underneath falx but cingulate gyrus)
4) A 53 year old man is brought to the stroke unit. He has no memory of what happened to him and is unsure of where he is. His daughter reports that she found her dad on the floor in his flat, complaining of a feeling of ‘numbness all down on side’. His MRI is shown below.
a) Which parts of the brain have been affected by the stroke? Look carefully, comparing both sides, and use information from the history!
Symptoms - lost his memory
- numbness all down one side
Scan - stroke towards the medial right side. It is the medial temporal artery that has been affected.
So the occipital and thalamus has been affected.
4) A 53 year old man is brought to the stroke unit. He has no memory of what happened to him and is unsure of where he is. His daughter reports that she found her dad on the floor in his flat, complaining of a feeling of ‘numbness all down on side’. His MRI is shown below.
b) Which side is the sensory change likely to be on?
Left side of the body (right side of the brain)
Posterior cerebral artery affected
4) A 53 year old man is brought to the stroke unit. He has no memory of what happened to him and is unsure of where he is. His daughter reports that she found her dad on the floor in his flat, complaining of a feeling of ‘numbness all down on side’. His MRI is shown below.
c) Is the visual system likely to have been affected? If so, how?
Yes as the occipital lobe has been affected - this is the visual cortex where visual processing occurs. This is likely to produce unilateral hemianopia - left homonymous hemianopia bc left visual field is affected - optic chiasm is covered bitemporal.
4) A 53 year old man is brought to the stroke unit. He has no memory of what happened to him and is unsure of where he is. His daughter reports that she found her dad on the floor in his flat, complaining of a feeling of ‘numbness all down on side’. His MRI is shown below.
d) Can you explain his disorientation and lack of recall for the
event?
Temporal lobe involvement - this is involved in memory and orientation.
(Although whole brain is involved in memory, he only has a temporary memory loss and disorientation which is primarily supplied by the inferior part of temporal lobe.)
5) A post-mortem examination is performed on a patient who died following a collapse. A cardiac cause of death is found, but the brain is found to have the following lesion.
The lesion is consistent with the appearance of a previous stroke.
a) To which of the Oxford classes does this stroke belong? Occlusion of which vessels can lead to this pattern?
LACs (Lacunar syndrome) - the lenticulostriate arteries (branch of MCA) giving you what’s called a lacunar stroke.
5) A post-mortem examination is performed on a patient who died following a collapse. A cardiac cause of death is found, but the brain is found to have the following lesion.
The lesion is consistent with the appearance of a previous stroke.
b) Precisely, which region of grey matter has been damaged? Make sure you are happy with the plane and level of the section!
Coronal section under the lateral ventricles - so it is the globus pallidus.
5) A post-mortem examination is performed on a patient who died following a collapse. A cardiac cause of death is found, but the brain is found to have the following lesion.
The lesion is consistent with the appearance of a previous stroke.
c) With reference to the grey matter lesion, speculate about the clinical features the patient may have displayed (would there have been excess movement or paucity of movement?). Use the following diagram to help you.
Loss of GPi leads to decreased inhibition on the thalamus. Decreased inhibition means that more glutamate is produced, acting on the cortex, so there is an excess of movement.
5) A post-mortem examination is performed on a patient who died following a collapse. A cardiac cause of death is found, but the brain is found to have the following lesion.
The lesion is consistent with the appearance of a previous stroke.
d) The stroke affected the internal capsule. Which parts of the body might show an upper motor neurone lesion? Give reasons for your answer
Face and possibly hand/arm depending on how far down the internal capsule it went.
6) A patient was seen in the stroke unit with left sided cerebellar signs. A series of MRI scans are shown below.
a) Which vascular territory is the lesion in?
Left superior cerebellum
6) A patient was seen in the stroke unit with left sided cerebellar signs. A series of MRI scans are shown below.
b) Assuming that the patient only displayed cerebellar signs and no other neurology, was the vessel occluded near its origin or more distally? Give reasons for your answer.
More distally bc if you only get cerebellar signs it hasn’t affected the pons. If it was more proximal you would have contralateral hemiparesis due to cerebral peduncle involvement (where the motor tract falls).
7) A patient presented with severe vertigo and nausea and subtle cerebellar signs on the left side, including nystagmus. A CT scan performed soon after presentation is shown below. Note that in CTs at this stage, strokes appear as hypodense.
a) How has the scan been done? I.e. in which plane and at which level approximately?
Sagittal plane and in the midline? Slightly off-centre on the left?
7) A patient presented with severe vertigo and nausea and subtle cerebellar signs on the left side, including nystagmus. A CT scan performed soon after presentation is shown below. Note that in CTs at this stage, strokes appear as hypodense.
b) Which vascular territory has the stroke occurred in?
Posterior inferior cerebellar artery, but also anterior cerebral artery
7) A patient presented with severe vertigo and nausea and subtle cerebellar signs on the left side, including nystagmus. A CT scan performed soon after presentation is shown below. Note that in CTs at this stage, strokes appear as hypodense.
c) Why can cerebellar strokes lead to the feeling of vertigo? Ask your CTF to demonstrate the ‘spinning chair trick’.
Cerebellum is responsible for motor coordination so loss can cause nystagmus due to malcoordination.
7) A patient presented with severe vertigo and nausea and subtle cerebellar signs on the left side, including nystagmus. A CT scan performed soon after presentation is shown below. Note that in CTs at this stage, strokes appear as hypodense.
d) Is the brainstem vulnerable? If so, speculate how this might manifest (think about arterial supply to the brainstem as well as effects of swelling in the posterior fossa).
Yes, posterior inferior cerebellar arteries supplies the brainstem from the vertebral arteries.
8) During a rugby match, a 13 year old boy receives a severe blow to the head which led to transient loss of consciousness on the pitch. He is taken to be seen by the school nurse and reports that he feels fine and would like to return to the match. The nurse decides to observe him for 30 minutes before making any further decisions.
After 20 minutes the boy starts complaining of headache and the nurse notices that he seems drowsy. After a further 2 minutes the boy has completely lost consciousness. The nurse puts him into the recovery position and calls for an ambulance.
At hospital the boy receives a CT scan of his head, showing the following.
a) What is your diagnosis? Which vessel has ruptured?
Extradural haemorrhage - middle meningeal artery.
