Stroke & anoxia Flashcards
(100 cards)
1
Q
Binswanger disease
A
Subcortical ateriosclerotic encephalopathy; small vessel vascular dementia caused by damage to white matter
2
Q
CADASIL
A
Cerebral autosomal dominant arteriopathy with subcortical infarcts & leukoencephalopathy
3
Q
At what level of decreased arterial oxygen is cognitive affected? When does unconsciousness occur? Death?
A
75% arterial oxygen, 50%, 30-40%, respectively
4
Q
Ischemia
A
Reduced blood flow due to interruption or reduction of blood delivery to the brain
5
Q
Hypoxia
A
Tissue oxygen deprivation
6
Q
Anoxia
A
Complete lack of O2 in the arterial blood or tissues
7
Q
Hypoxemia
A
Reduced oxygenation of the blood
8
Q
What is the most common cause of hypoxia/anoxia?
A
Cardiac arrest
9
Q
What are some other causes of hypoxia/anoxia?
A
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
Q
Why are some areas of the brain more vulnerable to anoxia/hypoxia?
A
Attributed to vascular or hemodynamic specificity, increased regional metabolism of glucose, and/or proximity to structures with high levels of excitatory amino acids
11
Q
Brain regions most vulnerable to anoxia/hypoxia
A
Watershed regions, neocortex, hippocampus, BG, cerebellar Purkinje cells, primary visual cortex, frontal regions, thalamus
12
Q
NP deficits associated with anoxia
A
Impaired memory, executive dysfx, apperceptive agnosia, visuospatial deficits, overall cognitive decline, extrapyramidal signs, cerebellar ataxia, intention or action myoclonus
13
Q
Definition of stroke
A
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
Q
Ischemic stroke
A
Blood flow is insufficient to maintain neurologic function; infarction occurs when ischemia reaches threshold to produce cell death
15
Q
Transient ischemic attack (TIA)
A
Acute transient neurological deficit that typically lasts <1 hr & is w/o persistent neuro abnormality or evidence of acute infarction on imaging
16
Q
What is the risk of clinical stroke after TIA?
A
1/3 within 5 years
17
Q
Lacunar infarct
A
Small cavity caused by a small deep cerebral infarct, most often associated with arterial HTN
18
Q
What is the window for t-PA?
A
3 hours of onset
19
Q
Risk factors for stroke
A
75+, AA/Hispanic, male, HTN, AFib, diabetes, high cholesterol, smoking, abdominal obesity, metabolic syndrome
20
Q
How does smoking increase stroke risk?
A
Contributes to atherosclerosis, alters coagulation systems by increasing fibrinogen, platelet aggregation, & hematocrit level, reduces blood vessel distensibility
21
Q
Thrombosis
A
Obstruction of blood flow due to blood clot formed locally with a blood vessel
22
Q
Embolism
A
Material is formed elsewhere in the vascular system & travels to lodge in a vessel
23
Q
What areas of the CNS are vulnerable to global cerebral ischemia?
A
Purkinje cells in cerebellum
Ca1 region of hippocampus
Watershed zones
Cerebral cortical layers
24
Q
Brief global cerebral ischemia
A
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
