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Flashcards in Stroke & anoxia Deck (100):
1

Binswanger disease

Subcortical ateriosclerotic encephalopathy; small vessel vascular dementia caused by damage to white matter

2

CADASIL

Cerebral autosomal dominant arteriopathy with subcortical infarcts & leukoencephalopathy

3

At what level of decreased arterial oxygen is cognitive affected? When does unconsciousness occur? Death?

75% arterial oxygen, 50%, 30-40%, respectively

4

Ischemia

Reduced blood flow due to interruption or reduction of blood delivery to the brain

5

Hypoxia

Tissue oxygen deprivation

6

Anoxia

Complete lack of O2 in the arterial blood or tissues

7

Hypoxemia

Reduced oxygenation of the blood

8

What is the most common cause of hypoxia/anoxia?

Cardiac arrest

9

What are some other causes of hypoxia/anoxia?

reduced arterial pressure due to lung disease, reduced hemoglobin due to anemia or blood loss, biochemical block of cerebral utilization of O2 due to cyanide poisoning

10

Why are some areas of the brain more vulnerable to anoxia/hypoxia?

Attributed to vascular or hemodynamic specificity, increased regional metabolism of glucose, and/or proximity to structures with high levels of excitatory amino acids

11

Brain regions most vulnerable to anoxia/hypoxia

Watershed regions, neocortex, hippocampus, BG, cerebellar Purkinje cells, primary visual cortex, frontal regions, thalamus

12

NP deficits associated with anoxia

Impaired memory, executive dysfx, apperceptive agnosia, visuospatial deficits, overall cognitive decline, extrapyramidal signs, cerebellar ataxia, intention or action myoclonus

13

Definition of stroke

Abrupt onset of a focal neurologic deficit that is consistent with a vascular distribution & lasts >24 hrs with or without an image positive for stroke OR <24 hours with a positive image

14

Ischemic stroke

Blood flow is insufficient to maintain neurologic function; infarction occurs when ischemia reaches threshold to produce cell death

15

Transient ischemic attack (TIA)

Acute transient neurological deficit that typically lasts <1 hr & is w/o persistent neuro abnormality or evidence of acute infarction on imaging

16

What is the risk of clinical stroke after TIA?

1/3 within 5 years

17

Lacunar infarct

Small cavity caused by a small deep cerebral infarct, most often associated with arterial HTN

18

What is the window for t-PA?

3 hours of onset

19

Risk factors for stroke

75+, AA/Hispanic, male, HTN, AFib, diabetes, high cholesterol, smoking, abdominal obesity, metabolic syndrome

20

How does smoking increase stroke risk?

Contributes to atherosclerosis, alters coagulation systems by increasing fibrinogen, platelet aggregation, & hematocrit level, reduces blood vessel distensibility

21

Thrombosis

Obstruction of blood flow due to blood clot formed locally with a blood vessel

22

Embolism

Material is formed elsewhere in the vascular system & travels to lodge in a vessel

23

What areas of the CNS are vulnerable to global cerebral ischemia?

Purkinje cells in cerebellum
Ca1 region of hippocampus
Watershed zones
Cerebral cortical layers

24

Brief global cerebral ischemia

Coma that persists <12 hrs, transient confusion or amnesia

25

Prolonged global cerebral ischemia

Comas that persist at least 12 hrs with lasting focal or multifocal motor, sensory, & cognitive deficits

26

Arteriovenous malformation

Tangle of dilated blood vessels; forms an abnormal connection between arteries & veins & can cause damage by compression of neighboring structures or shunting of blood away from the site leading to hypoperfusion of surrounding tissue

27

Cavernous malformation

Large vascular lumen with collagenous walls lined by a single layer of endothelial cells; affects veins with no arterial connections

Most common manifestation is recurrent seizures, but often clinically silent

28

Capillary telangiectasias

Small regions of abnormally dilated capillaries, rarely give rise to ICH

29

Venous angioma

Dilated veins visible on MRI scans as single flow void extending to brain surface; not known to cause any clinical symptoms themselves

30

4 major types of aneurysms

Saccular (most common)
Giant (>1 in across)
Fusiform (bulges from all sides & has no neck)
Mycotic (results from infection in artery wall)

31

Increased risk for aneurysm rupture is associated with

Size >10 mm in diameter, age, chronic HTN, cigarette smoking, alcohol use, atherosclerosis

32

Common symptoms of aneurysm rupture

Abrupt onset of severe HA, nausea & vomiting, stiff neck, loss or alteration of consciousness, confusion or slowed thinking, motor problems, visual disturbance

33

How are aneurysms treated?

Clipping, coiling

34

Where are aneurysms most likely to occur?

AComm, start of MCA, PComm

35

Stroke risk in sickle cell anemia

Sickled red blood cells adhere more readily to surface of blood vessels; increased CBF to compensate for decreased oxygenation of red blood cells reduces cerebrovascular reserve; stroke is usually large vessel, but chronic insufficiency leads to watershed infarcts

36

What are the signs of an incomplete (watershed) L ICA infarct?

Aphasia (mostly mixed transcortical or transcortical motor)
R motor & sensory impairments
Gerstmann's syndrome
Agnosias
Memory deficits possible

37

What are the signs of an incomplete (watershed) R ICA infarct?

Aprosody
L motor & sensory impairment
Anosognosia, L neglect, ideational apraxia, constructional apraxia
Memory deficits possible

38

What are the signs of a complete L ICA infarct?

R HP including lower face
R hemianesthesia
Aphasia (global or Broca's)
Gerstmann's syndrome
Apraxias
Acute IL monocular blindness, right HH
Frontal lobe behaviors
Memory, particularly verbal, may be impaired

39

What are the signs of a complete R ICA infarct?

L HP including lower face
L hemianesthesia
Receptive & expressive aprosody
Acute IL monocular blindess, left HH
Frontal lobe behaviors
Memory, particularly nonverbal, may be impaired

40

What are the signs of a left ACA infarct?

R leg motor & sensory loss
Akinesia, mutism, abulia, frontal release signs
Transcortical motor aphasia
Memory deficits possible, particularly poor retrieval
Alien hand syndrome (R)

41

What are the signs of a right ACA infarct?

L leg sensory & motor loss
L arm weakness
Apathy, stimulus-bound behaviors, jocularity, hypomania, frontal release signs
Left inattention
Alien hand syndrome (L)

42

What are the signs of a left MCA stem infarct?

R HP & hemianesthesia
R HH possible, left gaze preference
Global aphasia
Motor apraxias & visuoconstructional deficits
Acalculia & memory loss
Mood changes, particularly depression

43

What are the signs of a right MCA stem infarct?

L HP & hemianesthesia
Left HH possible, right gaze preference
Profound hemineglect
Visuoconstructional deficits
Motor apraxia
Memory impairments
Anosognosia, mood changes, aprosody

44

What are the signs of a L MCA deep territory infarct?

R pure motor HP
Mild aphasia syndromes
Deficits in mvmt w/ BG involvement
Mood changes w/ depression

45

What are the signs of a R MCA deep territory infarct?

L pure motor HP
L hemineglect
Visuoconstructional deficits

46

What are the signs of a L MCA inferior division infarct?

Fluent aphasia
R face & arm sensory loss
R visual field defect
R face & hand motor loss possible (mild)
Gerstmann's syndrome
Visuoconstructional/visuospatial deficits
Mood changes w/ depression

47

What are the signs of a R MCA inferior division infarct?

L face & arm sensory loss
L visual field defect
L face & hand motor loss possible (mild)
L hemineglect
Visuoconstructional/visuospatial deficits
Mood changes, w/ hypomania or affective flattening
Receptive aprosody

48

What are the signs of a L MCA superior division infarct?

R face & arm motor loss
Some face & arm sensory loss
Nonfluent aphasia
Mood changes w/ depression

49

What are the signs of a R MCA superior division infarct?

L face & arm motor weakness
Some face & arm sensory loss
Variable L inattention
Expressive aprosody
Dorsolateral syndrome (poor problem-solving, impaired sequencing, perseveration, poor reasoning)
Mood changes w/ hypomania & hollow jocularity

50

What are the signs of a L PCA infarct?

R HH or some kind of visual field defect
Visual agnosia
Alexia w/o agraphia
Transcortical sensory aphasia
Motor & sensory loss of hand & face
Mood changes w/ depression

51

What are the signs of a right PCA infarct?

L HH or some kind of visual defect
Visual agnosias
Receptive aprosody
Motor & sensory loss of hand & face
Mood changes w/ anxiety or depression

52

What are the signs of a left ACA-MCA watershed infarct?

Transcortical motor aphasia
R motor & sensory impairment of trunk, hips, & proximal extremities

53

What are the signs of a right ACA-MCA watershed infarct?

L motor & sensory impairment of trunk, hips, & proximal extremities
Visuoconstructional deficits

54

What are the signs of a left MCA-PCA watershed infarct?

Transcortical sensory aphasia
Gerstmann's syndrome
Agnosias
Memory deficits possible, particularly verbal

55

What are the signs of a right MCA-PCA watershed infarct?

Visuoconstructional & visuoperceptual deficits
Visual agnosias
Memory deficits possible, particularly nonverbal

56

Pure sensory stroke

Taste may be impaired, no vision loss, motor deficits, or NP impairment

57

Vasculature involved in pure sensory stroke

Inferiolateral (thalamo-geniculate) artery

58

Localization of pure sensory stroke

VPL nuclei of thalamus, taste impaired if VPM is affected

59

Pure sensorimotor stroke

Hemisensory loss of hand, face, leg; taste may be impaired; HP of face, hand, leg; no NP impairments

60

Vasculature involved in pure sensorimotor stroke

Thalamogeniculate & lenticulostriate arteries

61

Localization of pure sensorimotor stroke

Ventrolateral & VPL, thalamic somato-sensory projections, corticospinal & corticobulbar pathways, VPM involvement = loss of taste

62

Vasculature involved in pure motor HP

lenticulostriate arteries, perforating branches of PCA, anterior choroidal artery

63

Localization of pure motor HP

posterior limb of IC, pons (anterior portion), cerebral peduncle, corona radiata

64

Vaculature involved in pure motor HP with dysarthria

Penetrating branches of the basilar artery, lenticulostriate arteries

65

Localization of pure motor HP with dysarthria

Medial pons, cerebral peduncle, genu of IC

66

Vasculature involved in pure motor HP with ataxia (ataxic hemiparesis)

Penetrating branches of the basilar artery, lenticulostraite arteries

67

Localization of ataxic hemiparesis

medial pons, less often due to IC including corona radiata

68

Hemi-dystonic lacunar stroke

may be asymptomatic, may see mvmt disorders, rarely NP deficits, OC symptoms reported

69

Vasculature involved in hemi-dystonic lacunar stroke

lenticulostriate arteries, anterior choroidal artery, recurrent artery of Heubner

70

Localization of hemi-dystonic lacunar stroke

putamen and/or globus pallidus

71

Hemiballism/chorea lacunar stroke

Hemiballismus of extremity due to infarct in the subthalamic nucleus (thalamogeniculate artery)

72

Clinical features of a thalamogeniculate artery stroke

Hemisensory loss
Hemiataxia
Possible thalamic pain syndrome
HP (mild) & loss of taste
No NP deficits

73

Clinical features of stroke of the paramedian arteries

Impairment of declarative memory (retrieval deficits & inefficient consolidation)
Behavioral apathy w/ somnolescence
Vertical gaze palsy
Confabulation may be present

74

Clinical features of a stroke of the tuberothalamic artery

Dominant hemisphere: aphasia symptoms, verbal memory w/ impaired encoding & consolidation

Nondominant hemisphere: nonverbal memory impairment, hemineglect, visuoconstructional & visuospatial deficits

Bilateral: apathy, lethargy, anterograde amnesia

75

Dejerine-Roussy syndrome (thalamic pain syndrome)

Severe burning pain CL to lesion w/ allodynia (conversion of benign pain to unbearable pain) & hyperapthia (testing for Babinski produces severe pain)

76

Top-of-the-basilar syndrome

CL ataxia, HP or tetraparesis
IL CN III palsy
Somnolence
Visual hallucinations (poorly formed), memory impairment (anterograde), apathy & abulia, akinetic mutism in some cases

77

Watershed zones

Border zone of anastomoses that lies between territories of 2 major cerebral arteries

Anastomose: to unite by contact, e.g., 2 vessels at their extremities

78

What is the main clinical significance of watershed zones?

A significant drop in blood pressure will lead to drop in oxygenated blood supply where 2 arterial distributions overlap - become infarcted

79

Where do thrombi usually occur?

At the site of a pre-existing stenosis of an artery

80

What is the most common embolic source?

Heart

81

Embolization

Method used to close vessels feeding AVMs

82

Common conditions that require embolization

-Reduce size of AVM before resection
-Treat aneurysms & cavernous fistulas that cannot be resected
-Stop uncontrollable bleeding of an artery following head or neck injury

83

Anterior communicating artery syndrome

Dense anterograde amnesia, disorientation, & confabulation combined with disturbances of attention & behavior

84

Arteriosclerosis

Thickening & hardening of smaller arteries; assoc. w/ chronic HTN

85

Atherosclerosis

Build-up of fatty deposits in arterial walls, assoc. w/ MI

Most often affect MCA, ACA, ophthalmic artery

86

Cerebral amyloid angiopathy

Dementia through multifocal recurrent hemorrhages & WM ischemic disease; often familial

87

Chronic obstructive pulmonary disease (COPD)

Disease with poor expiratory airflow, may cause chronic hypoxia resulting in cognitive decline

88

Hemosiderin

Protein residual of the breakdown of blood

Can cause nervous system dysfunction

89

Temporal arteritis (giant cell arteritis)

Vasculitis affecting temporal arteries, including those supplying the eye

HA in temporal lobes, may have jaw pain when chewing, malaise, fever, weight loss; may lose vision

90

Vasculitis

Inflammation or vasospasm causing narrowing of vessels

91

Weber's syndrome

Midbrain arterial thrombosis damaging CN III and corticospinal tract

92

Neuroimaging correlates of anoxia/hypoxia

Focal & diffuse neuropathologic lesions & atrophy, lesions in hippocampus, BG, cerebellum, WM changes; significant hippocampal atrophy

93

Neurologic syndromes/symptoms associated with anoxia/hypoxia

Persistent coma or stupor, dementia w/ or w/o extrapyramidal signs, extrapyramidal syndrome w/ cognitive impairment, choreoathetosis, cerebellar ataxia, intention or action myoclonus

94

Prolonged periods of hypotension affect when structures?

Watershed zones, cerebellum, BG, spinal cord

95

Global cerebral ischemia is associated with what conditions?

Cardiac arrest, respiratory failure, hyperglycemia, status epilepticus

96

Wallenberg's syndrome

Lateral medullary syndrome (PICA)

Ipsilateral cerebellar ataxia, Horner's syndrome, facial sensory deficit, CL impaired pain & temp sensation, nystagmus, vertigo, nausea, dysphagia & dysarthria, hiccup, sparing of motor system

97

Most common sites of primary hypertensive hemorrhage

Putamen, thalamus, cerebellum, pons, caudate, lobar subcortical

98

Symptoms of primary hypertensive hemorrhage

Severe HA, vomiting, oculomotor disturbance, nuchal rigidity, altered consciousness

99

Lobar hemorrhage in the elderly is most often related to

Amyloid angiopathy

100

Children with sickle cell anemia tend to have _____ strokes, adults usually have _____ strokes

Ischemic, hemorrhagic

This is the reversal of the usual trend