Blood Supply and Stroke Flashcards
1
Q
What is the main anterior circulation of the brain?
A
- Internal carotid arteries
2
Q
What do the internal carotid arteries supply?
A
- Anterior 3/5 of the cerebrum
- Diencephalon
3
Q
What are the main branches of the internal carotid arteries?
A
- Middle cerebral artery (MCA)
- Anterior cerebral artery (ACA)
- Perforating branches (striate, lenticulochoridal arteries)
4
Q
What are the main arteries of the posterior circulation of the brain?
A
vestobasilar arteries
5
Q
What do the vestibasilar arteries supply?
A
- Brainstem
- Cerebellum
- Posterior 2/5 of cerebrum
- Diencephalon
6
Q
What are the main branches of the vestibasilar arteries?
A
- Cerebellar (PICA, AICA, SCA)
- Pontine
- Posterior cerebral arteries
- Striate & thalamic
7
Q
What is autoregulation of the arteries of the brain?
A
- Brain is well-adapted to keep cerebral blood flow in an optimal range
- Blood vessels respond to changes in blood pressure top maintain and steady and safe flow rate
8
Q
What are the 3 main questions when someone presents with stroke like symptoms?
A
- What is the problem?
- Where is the problem?
- What are you going to do?
9
Q
What are the main signs of a stroke?
A
- Sudden onset
- Facial asymmetry
- Speech disturbance (dysphasia)
- Asymmetrical weakness in muscles
10
Q
What is the definition of a stroke?
A
- Interruption of the blood supply to a focal part of the brain causing loss of neurological function
- Symptoms last >24 hours or lead to death with no apparent cause other than that of vascular origin
11
Q
What is the definintion of a transient ischaemic attack?
A
- Same cause as stroke
- Symptoms lasting <24 hours
12
Q
What are the 5 main causes of a haemorrhagic stroke?
A
- Hypertension
- Amyloid angiopathy
- Tumour
- Vascular malform (AVM)
- Bleeding disorders
13
Q
What are the three different types of stroke and what is the prevalence?
A
- Ischaemic – 80-85%
- Haemorrhagic – 15%
- Subarachnoid haemorrhage – 5%
14
Q
What is primary brain damage?
A
- Mechanical damage associated with the mass effect
- Within minutes to hours from the onset of bleeding
15
Q
What is secondary brain damage?
A
- Surrounding oedema
- Oxidative stress and inflammation
16
Q
What are the main causes of ischaemic stroke?
A
- large vessel atheroma
- small vessel disease
- hypoperfusion
- cardio-embolism
17
Q
What is a lacunar stroke?
A
- type of ischaemic stroke that occurs in deep areas of the brain when the small perforating branches are obstructed by microatheroma
18
Q
Describe the progression of an ischameic stroke
A
- Core = where permanent damage occurs in ischaemic stroke **Nothing can be done to save these neurons
- Penumbra = surrounds the core **these are neurons that can be saved with fast and appropraite management
19
Q
What is the “watershed” area?
A
most vulnerable to hypoperfusion because they are furthest away from the source of blood
**Can occur if BP is reduced too rapidly in patients who present with hypertension
20
Q
What is the prevelance of stroke in each artery of the brain in ischamic stroke?
A
- 51% MCA
- 13% small vessels
- 7% ACA
- 5% PCA
21
Q
What are the main areas of assessment when a patient presents with a stroke?
A
- Airway
- Breathing
- Circulation
- Clarify the history!
- Clarify the history!!
- Past medical history: Conditions, Medications
- Check the signs
- Level 1 investigations
22
Q
Outline the main aspects and signs to look for in an examinatio of vascular neurology
A
- BP and pulse measurements in 2 arms
- Level of consciousness (Glasgow Coma Score; document progress)
- Cardiac and carotid bruits
- Blood glucose level
- Neck stiffness/meningism (Kernig’s/Brudzinski signs)
- Abnormal or involuntary movements
- Any seizure-like activity
- Skin rash/infarcts e.g. vasculitis, popular rash
- Specific neurological
- Eye movements (gaze preference, fixed deviation)
- Speech, visual fields, inattention, motor & sensory
- Gait assessment
23
Q
What are the main classification systems for stroke?
A
- Oxford Community Stroke Project (OCSP)
- Clinical
- TOAST classification
- Mechanism (e.g. large vessel, small vessel, cardioembolic)
- Carotid or vertebrobasilar territory
24
Q
What should you check in the OCSP classification of stroke
A
- motor/sensory pathways (muscle power, sensation)
- Visual pathways (field of vision)
- Higher cortical functions (speech, spatial awareness)
- Brainstem functions (swallowing, eye movements)
25
Features of lacunar syndrome (LACS)
* Pure motor, pure sensory, sensorimotor, ataxic hemisphere
26
What are the 4 classifications in the OCSP?
* TACS - Total anterior circulation syndrome
* PACS - Partial anterior circulation syndrome
* LACS - lacunar syndrome
* POCS - posterior circulation syndrome
27
What are the features of posterior circulation syndrome (POCS)?
* Brainstem, cerebellar and/or isolated homonymous hemianopia
28
What are the features of total anterior circulation syndrome (TACS)?
* Triad of hemiparesis (or hemisensory loss), dysphasia (or other higher cortical function) and homonymous hemianopia
29
What are the features of partial anterior circulation syndrome (PACS)?
* 2 of the features of TACS or isolated dysphasia or parietal lobe signs (e.g. inattention, agnosia, apraxia, agraphesthesia, alexia
30
What are the 5 S's that mimic stroke?
* Seizures
* Sepsis
* Syncope
* SOL (tumour, subdural)
* Somatisation
31
what things are regularly overlooked when diagnosing stroke?
* Evolution of symptoms
* Maximum deficit
* Drugs
* Newly prescribed
* OCP
* Recreational
* Visuo-spatial or perceptual disorder
* Truncal ataxia
* Apraxia
32
What are the main investigations that should be carried out when stroke is suspected?
* Good history and examination
* ECG/Holter (24hr ECG), ECHO
* Cholesterol/autoimmune & thrombophilia screen
* Carotid doppler
* CT brain/MRI brain
* Cerebral angiography
33
What are the common risk factors of stroke?
* Hypertension
* Ischaemic heart disease
* smoker
* peripheral vascular disease
* TIA
* diabetes mellitus
34
What are the main indications for urgent head imaging?
* Depressed level of consciousness
* Unexplained progressive or fluctuating symptoms
* Papilledema, neck stiffness or fever
* Severe headache at onset
* History of trauma prior to onset
* Indication of thrombolysis or anticoagulation
* History of anticoagulant treatment or known bleeding tendency
35
Reasons for a head CT (1st option)?
* Fast image acquisition
* Widely available
* Good at showing blood and bone
36
What can a head CT show?
* Cerebellar haemorrhage
* Another cause (tumour; SDH)
* Early ischaemia
37
What are the main types of MRI
* T1-weighted MRI
* T2-weighted MRI
* Perfusion MRI
* Diffusion Weighted Imaging
* Apparent Diffusion Coef. Imaging
* Flair
38
What are the contraindications for MRI?
* metal implants
* children/agitated patients
* body weight limitations
* claustrophobia
39
Give the treatment option in the following stage of stroke identification:
BEfore or ideally after scanning
Aspirin (300mg/day)
40
Give the treatment option in the following stage of stroke identification:
* Haemorrhage excluded
* Considered suitable treatment
* Onset \< 4.5 hours
Thrombolytic treatment with IV r-tPA administed in specialist centre
41
Give the treatment option in the following stage of stroke identification:
* Patients with AF
* Haemorrhage excluded
* Usually after 10-14 days of stroke
Anticoagulation
42
Give the treatment option in the following stage of stroke identification:
* patients with IHS
Aggressive early BP treatment
43
Give the treatment option in the following stage of stroke identification:
Patients with cerebellar stroke
Consulation with neurosurgery for secondary hydrocephalus
44
What is the management of a subarchnoid haemorrhage?
* CT brain/lumbar puncture if CT normal looked for bilirubin and xanthochromia. Cerebral angiogram
* Management:
* Airway: intubate if severe hypoxaemia
* Fluid: 3L of 0.9% NaCl per 24hours
* BP: keep MAP \< 130mmHg. If higher; IV labetalol or esmolol or enalapril
* Nimodipine 60mg 6X/day (for three weeks)
* Codeine or tramadol for pain (avoid NSAID)
* Phenytoin if seizures have occurred
45
What is the secondary drug treatment - anti-thrombotic
* Clopidogrel or Aspirin + Dipyridamole. In atrial fibrillation: Warfarin or NOAC (dabigatran, rivaroxaban, apixaban)
46
what is the secondary drug treatment - blood pressure
* Target BP \< 130/80 with calcium channel blocker, thiazide diuretic (Bendroflumethiazide or indapamide), ACE inhibitor (perindopril)
47
What is the secondary drug treatment - anti-lipids
* If total cholesterol \> 4.0mmol/L (or LDL-C \> 2.5 mmol/L [100mg/dl]) treat with statin (simvastatin – but caution in ICH or history of cerebral haemorrhage)
48
