Ch 80 Stroke Flashcards
(28 cards)
What % of patients with a TIA have a stroke?
10% at 3 months; most occur within 48 hours
What is the normal CBF?
>50 ml/100g/min; (GM = 75 and WM 25)
How does pC02 affect CBF?
Through changes in CVR by vasodilation / vasoconstriction
What is the CMRO2 of normal brain?
3.5 ml/100g/min
How is cerebrovascular reserve measured?
1g Acetazolamide challenge: Change is CBF is measured using MR perfusion before and after. 3 types of response: 1 - baseline CBF increases (normal) 2 - baseline CBF unchanged (no reserve) 3 - baseline CBF falls (steal phenomenon)
What are the sites the ECA can supply blood to the ICA?
Facial A > opthalmic A Middle meningeal A > Lacrimal / vidian A / caroticotympanic A Supfl. temporal A > Supraorbital A
What are the sites the ECA can supply blood to the VA?
Occipital A > muscular VA branches Spinal radicular A > VA
Why does PCA stroke cause macula sparing?
As dual supply from MCA
What is Balint syndrome?
Classically seen with bilateral parietal lobe lesions: Optic ataxia (inaccuracy of visually guided movements), Simulatagnosia (cannot identify objects presented simultaneously but can individually) and Oculomotor apraxia (defect of voluntary eye movements).
What are the features of a Heubner infarct?
Expressive aphasia, hemiparesis (UE>LE and prox>distal)
Which artery causes an infarct in the posterior limb of the internal capsule?
Anterior choroidal A - causes hemianopia, hemisensory loss and hemiplegia
What is the cause of bilateral thalamic infarcts?
Artery of percheron occlusion
What is lateral pontine syndrome?
Marie-Foix syndrome = ipsilateral ataxia, contralateral weakness and contralateral sensory loss of pain and temperature due to infarction of the middle cerebellar peduncle.
Label the structures in the medulla
CST
Medial lemniscus
Inferior olivary nucleus
Hypoglossal nucleus
MLF
Spinothalamic and spinocerebellar tracts
CN 10 from solitary nucleus
Spinal trigeminal tract
Vestibular nuclei
Inferior cerebellar peduncle
Gracile and cuneate nuclei
What structures are affected in Wallenberg’s syndrome?
CN10 - dysphagia and hoarse voice
Spinothalamic tract -impaired pain and temperature sensation
Spinocerebellar tract - ataxia
Spinal trigeminal tract - facial paraesthesia
Inferior cerebellar peduncle - ataxia
Inferior vestibular nucleus - vertigo
Sympathetics - Horner’s syndrome
What is Dejerine-Roussy syndrome?
Thalamic pain due to stroke
What is top of the basilar syndrome?
Mesencephalothalamic syndrome = Parinaud’s with CN3 palsy and abulia
What is caused by a stroke effecting the STN?
Hemiballismus
What are the main risk factors for stroke?
Diabetes
HTN
Smoking
High cholesterol / obesity
What are the treatment option for symptomatic carotid artery stenosis?
Best medical therapy with aspirin / clopidogrel, statin and BP management. Stop smoking.
Endarterectomy
Endovascular stenting
When should you treat asymptomatic carotid artery stenosis?
>60% stenosis and if patient fit for surgery as this carries a 10% risk of stroke in 10 years. Risk of surgery is 2-3%.
(Note: Treat >50% if symptomatic)
What is the evidence for Carotid endarterectomy?
North Americal Symptomatic Carotid Endarterectomy Trial (NASCET)
&
Asymptomatic Carotid atherosclerosis study (ACAS)
What is the risk of stroke recurrence after first stroke?
3% at 30 days
26% at 5 years
Which patients do no benefit from carotid endarterectomy?
<50% stenosis or near occlusion
