Vascular and Traumatic Brain Injury

Question 1

1. name the two reflections of the dura mater
2. What is the significance of this for brain injury?
3. Which cranial nerve lies on the base of the skull on the floor of the tentorium?

Answer 1

1. tentorium cerebelli - separates cerebellum and brainstem from occipital lobes
   falx cerebri - separates the two cerebral hemispheres
2. The brain can be compressed against these relatively tough projections
3. Occulomotor (III)

Question 2

Name three consequences of brain injury that can be revealed by CT scan

Answer 2

1. intracranial haemorrhage
2. midline shift
3. effacement of ventricles

Question 3

Define the following intracranial haemorrhages and what they can be caused by

1. Extradural
2. Subdural
3. Subarachnoid
4. Intracerebral

Answer 3

1. between skull and dura mater; presents as lentiform bleed on CT scan; Caused by tear of menningeal arteries
2. between dura mater and arachnoid mater. Caused by tearing of bridging veins
3. between arachnoid mater and pia mater. often result of secular aneurism of the cerebral artery
4. haemorrhage within the brain tissue. Caused by haemorrhagic stroke.

Question 4

Name symptoms associated with brain injury. Which of these are associated with increased risk of intracranial haemorrhage

Answer 4

altered conscious level

• loss of consciousness*
• post-traumatic amnesia
• pre-traumatic amnesia*

vomiting*
pain
dizziness

*associated with intracranial haemorrhage

Question 5

1. What is focal injury?
2. What is diffuse injury?
3. Give examples of diffuse injury

Answer 5

1. localised injury, such as contusion or haemorrhage
2. widespread injury
3. diffuse axonal injury, hypoxic brain injury, diffuse swelling

Question 6

1. Describe the mechanism of progressive damage following brain injury
2. What is progressive damage worsened by? (2)

Answer 6

1. mechanoporation - holes form in the bilayer that makes up the BBB
   calcium flux through porous bilayer
   formation of oxygen free radicals, and lipid peroxidation
   cytokine mediated inflammation
   axotomy
2. reduced perfusion and increased intracranial pressure

Question 7

Name 5 examples of secondary brain injury

Answer 7

1. raised ICP
2. hypoxia
3. ischaemic brain injury
4. seizures
5. infection

Question 8

MONROE-KELLY DOCTRINE

1. what is there a pressure volume relationship between?
2. How does the body compensate for raised ICP?
3. What is the clinical relevance of this?

Answer 8

1. intracranial pressure, volume of CSF, blood and brain tissue, and the cerebral perfusion pressure
2. decrease in venous volume and CSF in the brain
3. Once compensatory equilibrium has been reached, any further increase in mass will lead to a rise in ICP. Point of decompensation - onset of symptoms

Question 9

1. Name 2 consequences of raised ICP

2. Why is important to maintain blood pressure in patients with brain injury? (2)

Answer 9

1. pupillary dilation (due to compression of occulomotor nerve; parasympathetic fibres found superficially)

herniation of uncus - pushes uncus against brainstem

2. higher systemic pressures are required to maintain cerebral perfusion pressure with raised ICP
   poor perfusion can lead to secondary brain injury

Question 10

Define the following:

1. Stroke

2. TIA

Answer 10

1. a sudden focal neurological deficit, due to a vascular lesion, lasting longer than 24 hours
2. a focal deficit lasting a few seconds to 24 hours. Complete clinical recovery

Question 11

1. Which artery suppies the brainstem?
2. What does the anterior cerebral artery supply?
3. What does the middle cerebral artery supply?
4. What does the posterior cerebral artery supply?

Answer 11

1. basilar
2. medial cerebral hemisphere (lower limbs), including the frontal lobe
3. lateral cerebral hemisphere (upper limbs); speech areas
4. occipital lobe

Question 12

What are the effects of disruption to the:

1. anterior cerebral artery
2. middle cerebral artery
3. posterior cerebral artery
4. end arteries

Answer 12

1. contralateral lower limb weakness/hemiplegia and/or sensory loss; frontal lobe abnormalities
2. contralateral upper limb weakness/hemiplegia and/or sensory loss; global aphasia/dysphasia
3. visual disturbances; contralateral hemianaesthesia and hemiparesis if internal capsule is affected.
4. lacunar stroke

Question 13

1. Which sites are particularly vulnerable to large artery atheroma which can embolise?
2. name cardiac causes of embolism which can cause a stroke
3. Name three other causes of ischamic stroke other than large artery atheroma

Answer 13

1. arterial branch points such as the origin of the great vessels, proximal internal carotid etc
2. AF, valvular problems, endocarditis, paient foramen ovale
3. small vessel disease
   vasculitis
   carotid dissection

Question 14

Name 5 causes of haemorrhagic stroke

Answer 14

1. hypertension
2. arterio-venous malformation
3. aneurism
4. cerebral amhloid antipathy
5. coagulation disorders/iatrogenic blood thinning

Question 15

1. Describe symptoms of carotid artery occlusion
2. describe symptoms of perforating vessel occlusion
3. describe symptoms of the posterior circulation

Answer 15

1. contalateral hemiplegia and hemisensory disturbance
   homonymous hemianopia
   deterioration of consciousness
   gaze palsy - deviation of eyes towards side of lesion
   global aphasia
2. pure motor or pure sensory deficits
3. vertigo, ataxia, isolated hemianopia

Question 16

What is the treatment of

1. Occlusive Stroke
2. Haemorrhagic Stroke

Answer 16

1. thrombolysis with tissue plasminogen activator or surgical thrombectomy (if can treat within 4.5 hours)
   long term aspirin and statins
2. lower BP to <160/90
   reverse any anticoagulation

Question 17

Name 5 risk factors for ischaemic stroke in young people

Answer 17

1. arterial dissection (Marfan’s syndrome)
2. cardioembolism due to patient foramen ovale
3. vasculitis
4. genetic condition
5. ilicit drug use - cocaine and amphetamines

Question 18

1. How is hypertension associated with increased risk of stroke? (4)
2. How can BP be lowered to reduce risk of stroke
3. What are the effects of reducing hypertension in reducing stroke risk

Answer 18

1. accelerated atherosclerosis
   increased shear on vessel walls
   increased risk of wall rupture and aneurism, leading to haemorrhage
   small vessel disease > lacunar stroke
2. exercise, diet, BP medications
3. for every 7.5mmHg drop in BP, there is a risk of stroke by 50%

Question 19

1. How is AF associated with increased risk of stroke?
2. What is the risk of stroke in those with AF?
3. What is the risk of stroke in those with untreated AF?

Answer 19

1. blood pools in atrial leading to clotting
2. 16%
3. 35%

Question 20

1. How does smoking increase risk of stroke (2)

2. What percentage of stroke deaths are attributable to smoking?

Answer 20

1. accelerated atherosclerosis; increased platelet adhesion

2. 10%

Question 21

1. What is secondary stroke prevention?
2. How common is recurrent stroke?
3. name 5 methods of secondary stroke prevention

Answer 21

1. prevention of stroke in people who have already had strokes
2. 10% in the first year
3. treating blood pressure, AF treatment, antiplatelet therapy (clopidogrel), smoking, lipids

Question 22

1. Name 2 ways in which internal carotid artery emboli can lead to stroke
2. How is this treated?

Answer 22

1. embolise distally
   decrease the diameter of the vessel lumen; combined with low blood pressure, due to anti-hypertensives, can cause insufficient flow
2. carotide endocardectomy