Cerebrovascular Dz Lecture Flashcards
(103 cards)
1
Q
Sudden or rapid onset of a neurologic deficit in the distribution of a vascular territory lasting over 24 hours
A
Stroke
2
Q
The sudden onset of a neurologic deficit in the distribution of a vascular territory lasting less than 24 hours
**most last less than 30 mins
A
TIA
3
Q
REVERSIBLE ischemic insult to brain cells that recover, but increases risk of subsequent stroke
A
TIA
**increase in frequency of TIAs is a bad sign!!!
4
Q
worsening signs or symptoms over time ..describes what type of stroke?
A
Stroke-in-evolution (progressive stroke)
5
Q
What percentage of strokes are ischemia/infarct?
What percentage are hemorrhagic?
A
Ischemic/infarct: 85%
Hemorrhagic: 15%
6
Q
3rd leading cause of death in US
over 200,000 deaths per year
Men 1.3x more common
Blacks 1.3x more common
A
Strokes
7
Q
MC cause of death in patients with cebrovascular disease
A
MI
8
Q
Most powerful risk factor for developing a stroke?
A
HTN!
..esp systolic BP
9
Q
What is the goal BP to keep under for preventing strokes?
A
under 140/90
10
Q
Smoking increases risk of by 2-4x
A
Stroke
11
Q
Diabetes Mellitus increases risk by 3x
A
Stroke
12
Q
HTN
Smoking
Atherosclerosis
Diabetes Mellitus
Atrial fibrillation
others: male gender, OCPs, excess ETOH, hyperlipidemia
A
Risk factors for stroke
13
Q
Atherosclerosis: large vessels often involved *involved in ____% of all ischemic strokes (infarct)
A
50%
14
Q
- Adequacy of collateral circulation
- Development of Circle of Willis
- Duration of insult/restoration of blood flow.
A
Pathological outcomes depend on these
15
Q
SMALL vessel disease- deep penetrating arterioles occlude/thrombose
A
Lacunar infarcts (aka lipohyalinosis)
16
Q
Small vessel disease (Lacunar infarcts) account for ___% of ischemic strokes
A
20%
17
Q
Major risk factor of Lacunar infarcts (small vessel disease)
A
HTN!
..lipids and DM also contribute
18
Q
The defect on CT or MRI of a very small stroke or TIA (lacunar infarct) is less than…
A
1.5 cm (most are under 5 mm)
19
Q
May be without symptoms..detected by CT scan as incidental finding
A
Lacunar (aka lopohyalinosis), or small vessel disease
20
Q
Atherosclerosis of: base of aorta carotid bifurcation origin of internal carotid external carotid vertebral/basilar arteries
A
increase risk of ischemic stroke!!!
21
Q
Embolism from heart or artery to brain
*blood clot breaks off, occludes more distant/distal vessel
A
Cerebral emboli
22
Q
Why is a well developed Circle of Willis important?
A
This can be protective against stroke!
23
Q
Cardiac emboli often lodge in _____ sized vessels (MCA, ACA)
A
MEDIUM
24
Q
Artery to artery emboli often cause _____ or ___________
A
TIAs or small neuro deficits
*lodge, then break up
25
Frequent source:
Carotid bifurcation or internal carotid
\*often small emboli: Platelets/fibrin/RBCs
Artery to artery emboli
26
~20% of ischemic strokes
\*OFTEN CAUSED BY A FIB
Cardioembolism
27
MI with mural thrombus (35% incidence post large anterior wall MI) can lead to....
Cardioembolism
28
**A fib\*\*\***
MI with mural thrombus
Dilated cardiomyopathy
VHD
can all cause...
Cardioembolism
29
ABRUPT onset of non-convulsive focal defect in a vascular territory
Stroke
30
80-90% have NO warning symptoms
(10-20% have warning, TIA)
Stroke
31
- Contralateral hemiparesis or hemisensory loss
- Hemianopsia (visual field defect)
- If **dominant** hemisphere..Aphasia
- If **non dominant.**.speech and comprehension preserved. may develop anosognosia (denial/neglect of deficit) or a confusional state
MIDDLE CEREBRAL ARTERY (MCA) involvement
32
Less common..
\*Sx more pronounced in leg, associated language, gait disturbance
ANTERIOR CEREBRAL ARTERY (ACA) involvement
33
Least common..
Crossed contralateral dysfunction (motor/sensory) plus ipsilateral bulbar/cerebellar signs: vertigo, dizziness, gait disturbance, diplopia, facial palsy, dysarthria, etc
Posterior circulation (ie Vertebral artery off subclavian) involvement
34
HTN Deep penetrating arterioles
Small infarcts up to 1.5 cm on CT/MRI
\*clinical syndrome depending on where infarct is; may also present as TIA
Lacunar strokes/infarcts
35
Transient monocular blindness
Embolism to ophthalmic artery (off carotid)
Amaurosis fugax (carotid disease present)
36
Image of choice for stroke within the first 48 hours?
CT scan!
(CTs are better than MRIs the first 48 hours after intracranial hemorrhage)
37
Detection of infarcts on CT limited to _____ and \_\_\_\_\_\_
SIZE and TIMING
38
only 5% of strokes are visible in 1st 12 hours, but more than \_\_\_\_% are visible at one week
90%
39
More readily available
Less expensive
No contrast required
Benefits of CT (over MRI)
40
Changes of infarct may be seen as early as one hour- usually not available or needed emergently
MRI/MRA
41
True or False...
MRI/MRA provide better detail than CT for small lesions and other pathology.
\*Better for imaging of **POSTERIOR FOSSA**
TRUE
42
Non invasive with excellent resolution of large vessels
\*Replaces need for arteriogram in some patients
\*May be difficult to differentiate complete vs near complete occlusions.
Magnetic resource angiogram (MRA)
43
3 to 4.5 hours is the window for...
giving tPA!!
44
DO NOT CORRECT ISCHEMIC STROKE PATIENT'S HYPERTENSION UNTIL IT REACHES...
over 200 systolic over 100 diastolic
\*body regulates itself! so don't mess with it
45
When do you start to correct an ischemic stroke patient's HTN?
2 weeks after they come to the ER
46
What type of stroke patient is it OK to lower BP in?
(but must do cautiously)
Hemorrhagic stroke
47
Screening tool for evaluating **COMMON CAROTID** and **ORIGIN OF INTERNAL CAROTID ARTERY**
limitations: may be difficult to differentiate between complete vs near complete occlusions
Carotid doppler ultrasound (duplex)
\*\*non invasive but limited capability
48
**MOST ACCURATE
\*\*GOLD STANDARD\*\* for extra and intracranial disease**
Arteriography
\*also most invasive!
49
**Gold standard for strokes!! most accurate (but invasive)**
Complications: contrast reaction, kidney failure, plaque rupture, stroke
(\*non ionic contrast has reduced complications)
Arteriography
50
Risk factor modification:
**Aggressive control of... BP, Lipids, Diabetes**
\*smoking cessation, exercise, diet
Prevention of Stroke
51
Full anticoagulation for A fib pts!
\*Warfarin (Coumadin) therapy long term
..this is essential for?
Prevention of strokes
52
Abrubt onset of symptoms with transient focal neuro deficit dependent on involved anatomy (anterior, posterior circulation).
\*Sx may vary during episodes.
\*Exam between episodes is normal.
\*Warning for subsequent stroke.
TIAs
53
* *-Embolic from carotid stenosis/plaque\*\*\***
- Embolic from cardiac source
- Severe carotid stenosis with transient hypotension
- Small vessel occlusion: Lacunar infarcts may mimic
TIA causes!
54
How can you possibly predict/pick up an emboli from carotid stenosis/plaque?
By listening for bruits in carotid arteries!
55
Surgical tx of a carotid TIA which removes plaque
Carotid endarterectomy
56
Best results if **SYMPTOMATIC blockage** and **greater than 70% stenosis**
\*significantly reduces risk of subsequent ipsilateral stroke
Carotid endarterectomy
57
Can be done in select\* pts with symptoms and 50-70% stenosis
Carotid endarterectomy
| (this has MAJOR complications)
58
These drugs are indicated for all patients with:
less than 70% stenosis and TIA symptoms
diffuse cerebrovascular dz
pts who are poor surgical candidates
patients with asymptomatic carotid disease
Anti-platelet agents
59
These agents prevent platelet aggregation and release of vasoactive substances like thromboxane A2
Anti platelet agents
60
Inhibits cyclooxygenase Inhibits synthesis of thromboxane A2,
increasing both platelet aggregation and vasoconstriction
Aspirin
61
lasts permanently for life of platelet (about 8 days)
\*325 mg/daily
Aspirin
(SE= GI side effects and bleeding)
62
Decreases frequency of TIA’s and risk of subsequent stroke
Also applies to patient with prior stroke- ↓incidence of recurrence.
Aspirin
63
75mg/day
Inhibits platelet aggregation and prevents activation of glycoprotein IIb/IIIa (a fibrinogen binder)
\*Decreases atherosclerotic events
Clopidogrel (Plavix)
64
Slightly better outcomes compared to ASA alone but expensive!
\*alternative to ASA in patients with recurrent TIA’s or ASA intolerance/allergy.
Clopidogrel (Plavix)
(SE= diarrhea, rash)
65
Usually good prognosis for recovery over ~4-6 weeks
Tx= supportive measures plus ASA or Clopidogrel.
**\*AGGRESSIVE LONG TERM TX OF BP AND LIPIDS!!\*\*\*\*\***
Lacunar infarct tx
66
What is essential to control long term in pts with lacunar infarct?
BP and Lipids!
67
True or false...
You should hospitalize ALL stroke patients and most TIA patients (esp if first TIA episode)
TRUE
68
Cerebral infarct= thrombotic or embolic occlusion of major vessel.
Treatment dependent on timing!
What image must you obtain first to rule out hemorrhage?
head CT scan!
69
If onset of cerebral infarct (NO HEMORRHAGE) is within 4.5 hours, what can you give?
thrombolytic therapy with tPA (bolus infusion up to 90 mgs) over 1 hour
70
If within 4.5 hours, can give bolus infusion up to 90 mgs over 1 hour
tPA (thrombolytic therapy)
71
Thrombolytic therapy increases the chances of a favorable outcome by about .....
50%
72
True or false..
Thrombolytics cause neurologic outcome improved at 3 mos and 1 yr with decrease in expected deficit and reduction of initial deficit.
True
73
Cerebral hemorrhage in 6 to 7% (half will die)
. ..risk of?
tPA
74
Recent bleeding
Prior stroke
BP over 185/110
Recent major stroke
**Contraindications** of tPA
75
Loose mesh stent placed in thrombus obstructing cerebral vessel
\*removes thrombus and restores blood flow.
Solitaire device
76
What did the SWIFT-PRIME trial show?
that tPA plus Solitare device works better than tPA alone!
3 months later.. tPA alone, 35% functioning
tPA+solitare, 60% functioning
77
Which study showed...
tPA alone, 3 months later 35% of pts function independently
tPA plus Solitare, 3 months later 60% of pts function independently
SWIFT-PRIME
78
True or False..
Heparin preparations are used for immediate and short term anticoagulation (days)
TRUE
79
Is Warfarin used for short or long term oral anticoagulation?
LONG! (works by inhibiting production of clotting factors in liver)
80
Best diagnostic for detecting or ruling out a hemorrhage?
**CT scan!!**
81
If CT scan is negative, what can you do to rule out a subarachnoid hemorrhage?
Spinal tap
82
Major risk factor of intracerebral hemorrhage?
HTN
83
HTN
Heme and bleeding disorders
Trauma
Anticoagulant therapy
Liver dz
..all risk factors of?
Intracerebral hemorrhage
84
Rapid evolution of neuro deficit often progressing to hemiparesis, hemiplegia or hemisensory loss; 50% mortality \*Loss of or impaired consciousness develops in 50%. \*Vomiting and headache are common.
Intracerebral hemorrhage
85
Most due to bleeding from saccular aneurysms
\*highest risk if greater than 6 mm
Subarachnoid bleed
86
Sudden onset of severe headache followed by:
N/V
impaired or loss of consciousness
+/- neuro deficit.
\*Meningeal signs often present: **Kernigs and Brudzinski signs**
Subarachnoid bleed
87
If suspected and CT is negative...
do CSF tap and look for blood or xanthochromia
Subarachnoid bleed
88
Treatment: If patient is conscious.. bed rest, symptomatic and supportive care with **cautious reduction of B.P.**
\*Angiography once patient stable
\*Surgery or coil placement to prevent re-bleeding where applicable.
Subarachnoid bleed
89
Most common vascular malformation of CNS often involving MCA and branches.
\*Tangled web of arteries connected directly to veins- congenital
up to 70% bleed
often by age 40
Males\>Females
some familial trends
2-3% risk bleed per year
Arterial Venous Malformations (AVM)
90
S/S: hemorrhage (30-60%), headache (5-25%), recurrent seizure (20-40%), focal deficits
CT may confirm hemorrhage;
angiography necessary for diagnosis.
Treatment: surgery if lesion is accessible.
Arterial Venous Malformations (AVM)
91
Carotid bifurcation
Internal carotid
..common sources of?
Artery to artery emboli
92
Strokes involving **anterior circulation** (ie anterior choroidal, anterior cerebral, middle cerebral arteries)
are associated with what type of symptoms?
**Hemispheric:**
aphasia
apraxia (difficulty with skilled movements)
hemiparesis
hemisensory losses
visual field defects
93
Strokes involving **posterior circulation** (vertebral and basilar arteries)
are associated with what symptoms?
**Brainstem dysfunction**:
Coma
Drop attacks
Vertigo
N/V
Ataxia
94
\_\_\_\_\_\_ strokes are often preceded by TIAs
\_\_\_\_\_\_ strokes occur abruptly without warning
(choices: embolic, thrombotic)
**Thrombotic** strokes usually preceded by TIAs (**T**hrombotic have **T**IAs)
**Embolic** strokes usually abrupt without warning
(thrombotic strokes are when a clot forms in one of the arteries that supplies the brain)
95
Usually caused by embolus from carotid or left ventricle
Sxs:
Contralateral hemiplegia (arm/face \> legs)
Hemianesthesia
**dominant hemisphere:** global aphasia (receptive and motor)
**non-dominant hemisphere**: anosognosia (denial/neglect of deficit), contructional apraxia
Middle cerebral artery (MCA)
96
What happens if there is an occlusion in the anterior cerebral artery (ACA) **proximal** to anterior communicating artery and the circle of willis is intact?
NO symptoms!
97
If distal occlusion....
Paralysis of opposite foot/leg
Sensory loss to toes, foot and leg
Urinary incontinence
Grap reflex
Suck reflex
Abulia (slowness to respond)
Impaired gait/stance
Behavioral changes
Memory disturbances
Anterior cerebral arery (ACA)
98
Contralateral hemiparesis or hemisensory loss
Hemianopsia (visual field defect)
## Footnote
**dominant hemisphere: aphasia
non dominant hemisphere: anosognosia (denial) or a confused state**
Middle cerebral artery (MCA)
99
Less common
Sx more pronounced in leg, associated language, gait disturbance
Anterior cerbral artery (ACA)
100
HTN, deep penetrating arterioles
**small infarcts up to 1.5 cm on MRI/CT**
clinical syndrome depends on location
may present as TIA
Lacunar infarct
101
AKA multi-infarct dementia
Classically hypertensive patients
+/- history of TIA or stroke
Usually manifests as forgetfulness in absence of depression and inattentiveness
**\***typically occurs in stepwise fashion, related to area of CNA affected
Vascular dementias
102
DO NOT CONFUSE THIS WITH A STROKE
Classic triad:
Cannot close 1 eye
Cannot raise eyebrow
Periauricular pain
Bell's Palsy
103
What nerve is involved in Bell's Palsy?
Facial nerve
