Stroke

Front 1

What are some general risk factors for atheroma?

Back 1

Smoking
Adverse family Hx
Diabetes
Hypertension

Front 2

What are some general risk factors for intra-cranial bleed?

Back 2

Hypertension (dominant)
Anticoagulation
Thrombolysis

Front 3

What are some general risk factors for an in-situ thrombosis?

Back 3

Atheroma RF
Polycythemia or hyperviscosity
Vasculitis
High alcohol intake
Thrombophilia, e.g. Factor V Leiden
OCP

Front 4

What are the major causes of thromboembolic strokes?

Back 4

Emboli from the heart (20%)
Atheromatous plaques in the aorta, extra- or intra- cranial circulation (80%)

Front 5

How long do TIAs last?

Back 5

By definition, up to 24 hours, but normally they last less than a few minutes.

Front 6

What causes amaurosis fugax?

Back 6

Embolic atherogenic debris from the carotid artery travels to the opthalmic branch of the internal carotid, causing unilateral blindness lasting less than a few minutes.

Front 7

What is the significance of a TIA?

Back 7

They imply an active intravascular plaque, i.e. one in which thrombosis is actively occurring and embolising distally.

Hint 7

They are a major risk factor for subsequent disabling stroke.

Front 8

What investigations should be done in a suspected TIA?

Back 8

Urgent ECHO/MRI to determine whether a high-grade lesion (>70% stenosis in ICA) is present.

Hint 8

Surgical resection (i.e. carotid endarterectomy) significantly decreases the rate of disabling stroke.

Front 9

What are the symptoms associated with a vertebrobasilar circulation stroke?

Back 9

Diplopia
Dysphagia
Dysarthria
Unsteadiness
Unilateral weakness with contralateral facial weakness
Bilateral visual loss
Amnesia

Front 10

How does a carotid territory stroke in the dominant hemisphere present?

Back 10

Hemiplegia + dyspraxia + language dysfunction.

Front 11

How does a carotid territory stroke in the non-dominant hemisphere present?

Back 11

Hemiplegia + neglect.

Front 12

What are the additional characteristics seen in a MCA stroke?

Back 12

Hemianaesthesia and hemianopia.

Front 13

What are the symptoms of a pontine stroke?

Back 13

Pinpoint pupils
Coma
Pyrexia
Paresis

Hint 13

Frequently cause death.

Front 14

What are the characteristics of lacunar stroke syndromes?

Back 14

Lacunar infarcts are small (<1.5cm) and usually either pure motor or pure sensory, without affecting the vision.

Front 15

What does the anterior cerebral artery supply?

Back 15

The parasagittal cerebral cortex, which includes portions of motor and sensory cortex related to the contralateral leg and micturition centre.

Front 16

Are anterior cerebral artery strokes common? If not, why not?

Back 16

Not common, because emboli from extracranial vessels or the heart are more apt to enter the larger-caliber MCA which receives more blood flow.

Front 17

What does the clinical syndrome resulting from and ACA stroke look like?

Back 17

Contralateral paralysis and sensory loss affecting the leg.
Voluntary control of micturition impaired.

Front 18

What does the MCA supply?

Back 18

Most of the cerebral hemisphere.
Deep subcortical structures.

Front 19

What are the division of the MCA?

Back 19

Superior division.
Inferior division.
Lenticulostriate branches.

Front 20

What does the superior division of the MCA supply?

Back 20

Entire motor and sensory cortical representation of hand, arm, face.
Expressive language (Broca) area of the dominant hemisphere.

Front 21

What does the inferior division of the MCA supply?

Back 21

Visual radiations.
Macular vision region.
Comprehension language (Wernecke) area of the dominant hemisphere.

Front 22

What do the lenticulostriate branches supply?

Back 22

Basal ganglia.
Motor fibres related to face, hand, arm, leg in the internal capsule.

Front 23

What happens to the gaze in an MCA stroke?

Back 23

Gaze preference towards affected hemisphere, due to frontal eye field involvement.

Front 24

What happens in a superior division of the MCA stroke?

Back 24

Contralateral hemiparesis and hemisensory loss affecting, face, arm, hand. Spares leg.
NO homonymous hemianopia.
If dominant: Broca's involvement produces an expressive aphasia.

Front 25

What happens in an inferior division of the MCA stroke?

Back 25

Less common.
Contralateral homonymous hemianopia.
Impaired cortical sensory functions (e.g. graphesthesia and stereognosis).
Disorders of spatial thought (e.g. neglect).
Wernicke's involvement: Receptive aphasia. Happy babblers.

Front 26

What happens in an occlusion at the bifur-/trifur- cation of the MCA?

Back 26

Severe.
Combines features of superior and inferior divisions.
Contralateral hemiparesis and hemisensory deficit involve face, arm > leg.
Homonymous heminaopia.
Global aphasia.

Front 27

What happns in an occlusion of the stem of the MCA?

Back 27

Devestating.
Occurs proximal to the origin of the lenticulostriate artery.
Infarction of motor fibres in capsule affects leg.
Conralateral hemiplegia and sensory loss in face, hand, arm, leg.

Front 28

What is the basic anatomy of the ICA?

Back 28

Arises where the common carotid artery divides into ICA and ECA.
Gives rise to ACA, MCA, opthalmic artery which supplies retina.

Front 29

What does symptomatic occlusion of the ICA look like?

Back 29

Resembles MCA stroke.
Contralateral hemiplegia, hemisensory deficit, homonymous hemianopia, aphasia.

Front 30

What is the clinical pictures in progressive atherosclerotic occlusion of the ICA?

Back 30

Premonitory TIAs.
Transient monocular blindness caused by ipsilateral retinal artery ischeamia.

Front 31

What do the paired posterior cerebral arteries arise from?

Back 31

The tip of the basilar artery.

Front 32

What do the paired posterior cerebral arteries supply?

Back 32

Occipital cerebral cortex, medial temporal lobes, thalamus, rostral midbrian.

Front 33

What does the clinical syndrome from a posterior cerebral artery stroke look like?

Back 33

Homonymous hemianopia affecting the contralateral visual field.

Front 34

How does the homonymous hemianopia caused by a PCA stroke differ to an MCA stroke involving the inferior division?

Back 34

PCA stroke: the visual field defects are more dense superiorly.

Front 35

What may occlusions of the posterior cerebral artery at the level of the midbrain cause?

Back 35

Ocular abnormalities: vertical gaze palsy, oculomotor nerve palsy, vertical skew deviation.

Front 36

What happens when PCA occlusion affects the occipital lobe of the dominant hemisphere?

Back 36

Anomic aphasia: difficulty naming objects.
Alexia without agraphia: inability to read, no impairment of writing.
Visual agnosia.

Front 37

What can bilateral PCA infarction cause?

Back 37

Cortical blindness.
Memory impairment (temporal lobe).
Inability to recognise faces.

Front 38

What is the course of the basilar artery?

Back 38

Arises from the junction of the paired vertebral arteries. Courses over the ventral surface of the brainstem to terminate at the level of the midbrain where it bifurcates to form the MCA.

Front 39

What does the basilar artery supply?

Back 39

Occipital and medial temporal lobes.
Medial thalamis.
Posterior limb of internal capsule.
Entire brainstem and cerebellum.