CVA Flashcards
Discuss the most common areas for HTN intracranial haemorrage
1) Basal ganglia (putamen especially) 44$
2) thalamic 13%
3) Cerebellum 9%
4) Pons 9%
Describe the penumbra
THe area of the brain surrounding the pirmary injury which is preserved by a tenuous supply of blood from collateral vessels.
Briefly describe the blood supply to the brain
Blood is supplied to the brain by the anterior and posterior circulation. The anterior ciruclation orginates from the carotid system and perfuses 80% of the brain including the optic nerve.
The ACA supplies the basal and medial aspects fo the cerebral hemispheres and extends to the anterior two thirds of the parietal lobel.
The MCA feeds the lenticulostriate branches that supply the putamen part of the anterior limb of the internal capsule the lentiform nucleus and the external capsule
Posterior syuplies the brainstem - dereived from the two vertebral arteries that ascend through the transvere processes of the cervical vertebrae.
Discuss ACA strokes
Mainly affects the frontal lobe function. The patient has altered mentation coupled with impaired judgment and insight as well as the presence of primitive grasp and suck reflexes
Bowel and bladder incontinence may be features of ACA
Paralysis and hypesthesia of the lower limb opposite the side of the lesion are characteristic. Leg weakness greater than arm weakness is classic of ACA
Describe MCA stroke
Motor and sensory disturbances are the hallmakrs of the occlusions of the MCA
Arm > leg
may involve only a distal portion or part of the face but almost always has both motor and sensory deficit
Hemianopsia or blindness in one half of the visal field occurs ipsilateral to the lesion. Agnosia and aphasia are common especially if the lesion occurs in the dominant hemishere.
Aphasia is common in dominant hemisphere strokes. Aphasia may be expressive receptive or bot.
Dysarthria is difficulty forming words due to muscle deficit they understand verbal communication and uses word choices appropriately
Define dominant cerebral hemisphere
the hemisphere that controls language usually left (95%)
Describe posterior stroke
Causes the widest variety of symptoms and as a result may be the most difficult to diagnose
The symptoms reflect CN deficits, cerebellar involvement and involvement of the neurosensory tracts.
The brainstem also contains the reticular activating system which is responsible for consciousness and emesis control
Unlike anterior strokes those with posterior may have ALOC and nausea and vomiting. Visual agnosia (inability to recognize objects seen)
3rd nerve palsy can occur as can homonymous hemianopsia. Visual neglect also seen
Vertigo syncope diplopia, visual field defects wekaness paralysis dysarthria dysphagia, spasticity ataixa or nystagmus may be present.
Posterior circulation strokes can also have crossed deficits with more deficits on one side and sensory loss on the other
Discuss components of the NIHSS score
1) LOC - GCS
2) Best gaze - horizontal EOM by voluntary or doll’s eye maneuver
3) visual field
4) facial palsy
5) motor arms
6) motor leg
7) limb ataxia
8) sensory
9) best language (describe a cookie jar picture or name objects)
10) dysarthria (read list of words)
11) extinction or neglect
Describe haemorrhagic stroke
Sudden onset of headache, vomiting severly elevated BP and focal neurologic deficits that progress over minutes.
Poor prognostic indicators for patients with ICH include a decreased level of consciouness on arrival, IVH and large volue ICH
Discuss the ICH score
Intracerebral haemorrahge score prediciting mortality after acute ICH
GCS
3-4 =2
5-12 =1
13-15 = 0
ICH volume
>30mls =1
<30mls =0
Intraventricular haemorrhage
Present =1
Abscent = 0
Age
>80 1
< 80 0
30 day mortality 0=0 1=13% 2=26 3=72 4= 97 5= 100%
Define TIA
Time based – originally defined as a sudden onset of a focal neurolgoical symptoms and or sign lasting less than 24 hours brought on by a transiet decrease in blood flow which renders the brain ischemic in the area producing symptoms. LImited as infarction can occur in this time
Tissue based - TIA is a transient episode of neurological dysfunction caused by focal brain or spinal cord or retinal ischemia without acute infarction
Discuss ABCD2 score
Age >60 =1
BP >140/90 when first assessed post TIA = 1
Clinical features
- Motor =2
- sensation =1
- other =0
Duration of symptoms
->60minutes =2
-10-60 =1
<10 =0
T2DM = 1
Score
6-7 high risk 7 day stroke
4-5 moderate risk 4 percent -
>4 low risk 1 percent –> aspirin and OPD
ABCD 31
-adds if recurrent in the last week or imaging suggestive of infarct or icnrease risk +ve carotid doppler or MRI
Discuss early signs of ischaemic stroke on CT
1) Visualisation of the clot - immediately
- Dense artery sign
2) Early parenchymal signs
- sulcal effacement
- loss of insular ribbon
- loss of grey-white interface
- mass effect
- acute hypodensity
What are the national institute of neurological disorders and stroke reccomended stroke evaluation targets for potential lytic candidates
Door to doctor –>10minutes
Door to CT completion –> 25 minutes
Door to CT reading –> 45 minutes
Door to treatment –> 60 minutes
Access to neurological expertise –> 15 minutes
access to neurosurigcal expertise –> 2 hours
Discuss management of ischemic stroke
Neuroprotective measures -30 degrees head -normal bsl -normal sodium -maintain appropriate MAP >80 -
A: as needed although most ischemic strokes have a normal GCS and do not require intubation
B: maintain o2 >94% nil need for hyperoxia
C: Unless eligible for thrombolytic therapy blood pressure lowering is not indicated in acute ischaemic stroke unless severe >220/120 or if the patient has active ischaemic coronary disease heart failure aortic dissection hypertensive encephalopathy or pre-eclampsia
If parenteral agents are used labetalol 10-20mg or a calcium channel blocker (nicardipine) can be used.
If eligible for lysis blood pressure most be below 185/110
- labetablol 10-20 mg IV over 1-2 minutes
- hydralazine can be consided
- measure BP every 15 minutes during treatment and 2 hours post and than 30 minutly for 6 hours
- may require infusion of labetalol or nicardipine to maintain BP >180
Discuss inclusions criteria for lysis
Inclusion criteria
- clinical diagnosis of ischaemic stroke causing measurable neurological deficit
- Onset of symptoms <4.5 hours before beginning treatemtn - if exact time not known taken as the last time the patient was seen well
- Age> 18 years
- No ICH on initial CT
Discuss exclusion criteria for lysis
Patient history
- ischaemic stroke or severe head trauma in the previous three months
- previous intracranial haemorrhage
- intra-axial intracranial neopalsm
- GIT malignancy
- GIT haemorrhage in the previous 21 days
- intracranial or intraspinal surgery wihtin the prior three months
Clinical
- Persistent Bp >185/110
- symptoms suggestive of SAH
- active internal bleeding
- presentation consistent with IE
- stroke known or suspected to be associted with dissection
- acute bleeding diathesis
Haem -platelets <100 current anticoagulation INR >1.7 Therapeutic doses of clexane received wihtin the past 24 hours -current use of DOAC
CT
- evidence of haemorrahge
- extensive regions of obvious hypodensity consistent with irreversible injury
Discuss warning criteria (careful consideration and weighting of risk to benefit)
Only minor neuro signs or radpidly improving
- serum glucose <2.8
- serious trauma in the previous 14 days
- major surgery in the previous 14 days
- history of GIT or GUT bleeding
- seizure at the onset of stroke
- pregnancy
- art punction at a noncompressible site in the previous 7 days
- large untreated unruptured intracranial aneurysms
Additional for treatment at 3-4.5 hour (exclusion criteria for ECASS 3)
>80 years of age
oral anticoagulant use reguardless of INR
sever stroke (NIHSS >25)
Combination of both previous stroke and diabetes mellitus
Discuss dose of alteplase
0.9mg/kg IV up to 90mg (10% of dose as bolus with the rest as an infusion over 60 minutes)
Discuss option for mechanical thrombectomy
4.5 0 24 hours otherwise either lyse or standard care
If stroke is due to posterior circulation LAO consider MTA
Stroke is due to anterior circulation LAO and <6 hours MT indicated if
- treatment can be started within 6 hours of stroke symptom
- neuroimaging with small infarct core and no haemorrahge
- there is persistent potentionally disabling neurological deficit
Stroke is due to anterior ciruclation LAO 6-24hours
- treatment can be started within 6-24 hours of the time last known to be well and there is clinical core mismatch as defined by the DAWN trial
- treatment can be started within 6 -16 hours of time last known ot be well and there is an imaging target mismatch as defined by the DEFUSE 3 trial
Discuss DAWN trial eligibility
- Treatment can start withi 6 -24 hours of time last known well
- failed or contracindiated IV TPA
- A deficit on the NIHSS of >10
- No signfiaicnt prestroke disability
- Baseline infarct involving <1/3 of MCA territory
- A clinical core mismatch according to age
1) >80 years - NIHSSS >10 and infarct volume <21,;
2) <80 years - NIHSS 10-19 and infarct volume <31
3) <80 NIHSS >20 and infarct volume <51ml
Discuss DEFUSE 3 trial eligibility
Treatemtent can started within 6-16 hours
- a defciti of the NIHSS of >6
- Only slight prestroke disability: baseline mRS score <2
- Occlusions of the cervical or intracranial ICA or the M1 segment of the MCA
- age 18-90
- A target mismatch profile on CT perfusion or mRI defeined as
1) ischaemic core volume <70 ml
2) a mismatch ratio (the volume of the perfusion lesion divided by the volume of the ischemic core) >1.8
3) a mismatch volume (volume of perfusion lesion minus volume of the ishcaemic core) >15mls
Discuss management of ICH
Supportive care
-Intubation often needed – consideration for short acting sedation for neurological evaluation
BP control is commonly performed after ICH. Controversial as dropping a normally hypertensive patient BP may reduced CPP
-consensus target is between 140-180 and a MAP <130 - INTERACT study, Atach 2- nil benifit in more strict BP control <140
Reverse anticoagulants
Nil evidence to suggest the use of platelets in ICH in those on antiplatelet therapy (PATCH trial) – still used if there is a new thrombocytopenia
For patients with clinical or radiographic evidence of raised ICP therapies aimed at lowering ICP should be considered
-discussion with neurosurgery in regards to the benefits of an extraventricular drain (EVD)
Discuss stroke mimics
Hypoglycaemia -Mass lession -Seizures (todds paresis) -Hemiplegic migraine -Functional factitious -Encpehalopathies/metabolic MS BElls
