L2: Cerebrovascular Disorders Flashcards
(166 cards)
1
Q
Notes in Cerebral Arterial Circulation
A
2
Q
Blood Supply of the Brain
A
- The carotid system.
- The vertebrobasilar system.
3
Q
The Carotid System
A
4
Q
Course of MCA
A
Lateral surface of cerebral hemisphere
(in sylvian sulcus).
5
Q
What does MCA supply?
A
Lateral aspect of anterior 3/5th of
cerebral hemisphere.
6
Q
Course of ACA
A
Medial surface of cerebral hemisphere (around corpus callosum) to parieto-occipital sulcus
7
Q
What does ACA supply?
A
Medial aspect of anterior 3/5th of cerebral hemisphere & upper edge of lateral surface.
8
Q
Vertebrobasilar System
A
9
Q
What does PCA supply?
A
Supply posterior 2/5th of the cerebral hemisphere (Whole occipital lobe and the Posterior part of the temporal lobe).
10
Q
The 3 major cerebral arteries (ACA &MCA &PCA) give off 2 types of branches: ………
A
- Superficial or Cortical branches: supply pia matter & the cortex.
- Basal or Central branches: supply its central part (white matter & basal ganglia).
11
Q
Circle of Willis
A
12
Q
Diseases of the Nervous brain vessels include:
A
- Stroke
- TIA
13
Q
Def of Stroke
A
- Rapidly developing clinical symptoms and/or signs of focal loss of brain function lasting more than 24 hours or leading to death with no apparent cause other than that of vascular origin.
14
Q
Incidence of Stroke
A
- Stroke is the commonest cerebrovascular disease.
- Sometimes called a “brain attack”.
15
Q
Types of Stroke
A
16
Q
Incidence of Cerebral Venous Thrombosis
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- < 2% of all strokes.
- Predominantly affects young adults and children.
- Accounts for up to 50% of strokes during pregnancy and Puerperium
17
Q
Pathogenesis of Ischemic Stroke
A
Sudden Thrombotic or Embolic occlusion of a cerebral artery.
18
Q
Causes of Ischemic Stroke
A
19
Q
Thrombotic Causes of Ischemic Stroke
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20
Q
Embolic Causes of Ischemic Stroke
A
21
Q
Hematological Causes of Ischemic Stroke
A
22
Q
Risk Factors for Ischemic Stroke
A
Non Modifiable & Modifiable
23
Q
Non-Modifiable RF for Ischemic Stroke
A
24
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Modifiable RF for Ischemic Stroke
A
25
Prognosis of **Ischemic Stroke**
Depends upon:
1. Site & size of the infarction.
2. Age.
3. Other comorbidities.
26
Clinical Features of **Ischemic Stroke**
- Focal loss of neurological function
- Negative in quality
- Rapidly developing
- Maximal at onset
27
Clinical Features of **Ischemic Stroke**
- Focal Loss of neurological Function
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Clinical Features of **Ischemic Stroke**
- Focal Loss of neurological Function (In Carotid System)
Unilateral signs e.g.
a. Hemiplegia,
b. Hemi-hypoesthesia,
c. Hemianopia
d. Aphasia (if the left hemisphere is involved).
29
Clinical Features of **Ischemic Stroke**
- Focal Loss of neurological Function (In Veretbrobasilar System)
Bilateral signs
a. Motor and sensory signs (hemiplegia may also be found)
b. Disturbance of cranial nerves and cerebellum.
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The commonest involved artery is the ....... which supply the internal capsule
MCA & its central branches
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The MCA supplies: .......
- Lateral portions of frontal and parietal lobes
- Superior part of the temporal lobe
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So, its blockage May damage the following structures: .......
So, its blockage May damage the following structures:
1) Primary Motor Cortex
2) Primary somatosensory cortex
3) Broca’s area
4) Optic radiations
33
Occlusion of PICA →
Lateral medullary syndrome
34
Clinical Features of **Ischemic Stroke**
- Negative in Quality
35
Clinical Features of **Ischemic Stroke**
- Rapidly Developing
The onset of the focal neurological symptoms and signs is sudden or acute
36
Clinical Features of **Ischemic Stroke**
- Maximal at Onset
- The focal neurological symptoms and signs are maximal at onset (i.e. evolving over minutes to hours in all of the affected body parts) rather than progressive (evolving over days to weeks and migrating from one body part to another).
37
INVx in **Ischemic Stroke**
- 1st Line INVx
- Urgent Plain CT
- Duplex Carotid US
- ECG & Echo
- Specialized INVx
38
INVx in **Ischemic Stroke**
- 1st Line INVx
1. Full blood count & ESR
2. PT, INR and PTT
3. Plasma glucose
4. Plasma urea & electrolytes
5. Plasma cholesterol
6. Urine analysis
39
INVx in **Ischemic Stroke**
- 1st Line INVx (Significance)
- These investigations may reveal important modifiable risk factors & may suggest the cause of stroke (e.g. polycythemia, thrombocythemia, infective endocarditis
40
INVx in **Ischemic Stroke**
- Urgent plain CT
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INVx in **Ischemic Stroke**
- Duplex Carotid US
When a carotid ischemic event is suspected.
42
INVx in **Ischemic Stroke**
- ECG & Echo
When a potential Cardioembolic source is suspected
43
INVx in **Ischemic Stroke**
- Specialized INVx
When the cause of stroke remains uncertain e.g.:
1. MRI and MRA of the brain.
2. Transcranial Doppler.
3. Tests for collagen vascular disease.
4. Angiography, etc.
44
Acute TTT of **Ischemic Stroke**
- Emergency Care
- Throbolytic TTT
- Neuroprotective TTT
- Prevention of Complications
44
Def of **Ischemic Penumbra**
- Zone of reversible ischemia around core of irreversible infarction
- Salvageable in first few hours after ischemic stroke onset.
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**Penumbra** is damaged by ......
1. Hypoperfusion
2. Hyperglycemia
3. Fever
4. Seizure
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TTT of **Ischemic Stroke**
Modern therapy for ischemic stroke includes:
1. Acute treatment: to reduce morbidity and mortality.
2. Rehabilitation: to reduce disability and dependence.
3. Prevention: to reduce stroke recurrence.
47
Emergency Care of **Ischemic Stroke**
- Airway
- Breating
- Circulation
48
Emergency Care of **Ischemic Stroke**
- Airway
To protect against air way obstruction
- Suction of Nasal and pharyngeal secretions may be needed.
- Endotracheal intubation may be needed.
49
Emergency Care of **Ischemic Stroke**
- Breathing
To protect against air way hypoventilation, and aspiration.
- Pulse oximetry or arterial blood gases
- Supplemental oxygen & ventilatory assistance.
- A feeding tube is placed if there is oropharyngeal dysfunction
50
- Mild hypothermia ...... the brain
- Mild hyperthermia ...... the outcome.
- protects
- Worsens
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Emergency Care of **Ischemic Stroke**
- Circulation
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Emergency Care of **Ischemic Stroke**
- Circulation (Blood Pressure Monitoring)
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Emergency Care of **Ischemic Stroke**
- Circulation (cardiac Monitoring)
To guard against MI & arrhythmia.
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- If the patient was taking hypotensive drugs before the stroke → .......
- If BP does not fall after a 1-2w → ......
- Continue them in the same dose.
- use ACE inhibitors. (gradual & permanent lowering to <140/85 (target))
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- If systolic BP was >220 mmHg or diastolic BP was >120 mmHg → ......
use LV. labetalol or sodium nitroprusside (urgent but slow lowering of BP is indicated)
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Thrombolytic Therapy of **Ischemic Stroke**
Recombinant Tissue Plasminogen Activator (Actilyse)
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Thrombolytic Therapy of **Ischemic Stroke**
- Aim
To recanalize the occluded artery and re-perfuse the ischemic brain tissue
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Thrombolytic Therapy of **Ischemic Stroke**
- Dose
0.9 mg/kg I.V.
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Thrombolytic Therapy of **Ischemic Stroke**
- Precautions
- It carries the risk of major bleeding, hence should be used carefully and only in the presence of facilities to handle bleeding complication
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Thrombolytic Therapy of **Ischemic Stroke**
- Indications
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Thrombolytic Therapy of **Ischemic Stroke**
- CI
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Neuroprotective Therapy of **Ischemic Stroke**
- Aim
Preventing or limiting the brain tissue damage that occurs in the area of reduced cerebral blood flow.
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Neuroprotective Therapy of **Ischemic Stroke**
- Examples
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Prevention of Complications in **Ischemic Stroke**
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Prevention of Complications in **Ischemic Stroke**
- Brain Edema
1. Fluid restriction for 24-48 hours.
2. Mannitol 20% solution 0.25 - 1 gm / kg over 30-60 minutes
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Prevention of Complications in **Ischemic Stroke**
- Pneumonia
1. Prevention of aspiration.
2. Chest exercise & early mobilization.
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Prevention of Complications in **Ischemic Stroke**
- DVT
Low doses of unfractionated or LMW heparin for Bed ridden patients.
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Prevention of Complications in **Ischemic Stroke**
- depression
Antidepressants
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Prevention of Complications in **Ischemic Stroke**
- Electrolyte Disturbance & Nutritional Deficiency
1. Adequate LV. fluids.
2. Tube feeding (after 3 days).
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Prevention of Complications in **Ischemic Stroke**
- Prssurte Sores
1. Skin cleaning.
2. Frequent positional changes.
3. Frequent change of bed sheets.
4. Special mattress.
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Prevention of Complications in **Ischemic Stroke**
- Seizures
Anticonvulsant medications
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Prevention of Complications in **Ischemic Stroke**
- Urosepsis
Indwelling catheters are used only when absolutely indicated and for the shortest possible time
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Rehab in **Ischemic Stroke**
Should start as soon as the diagnosis of stroke is established and includes:
1. Physiotherapy.
2. Speech therapy.
3. Occupational therapy.
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Prevention of 2ry **Ischemic Stroke**
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Prevention of 2ry **Ischemic Stroke**
- Aggresive Control of RF
Avoid smoking.
Lipid lowering.
Control of diabetes.
Treatment of hypertension.
75
Prevention of 2ry **Ischemic Stroke**
- Antiplatlet Therapy
For thromboembolic ischemic strokes. e.g.
Aspirin 75-150 mg daily
Clopidogrel 75 mg daily.
76
Prevention of 2ry **Ischemic Stroke**
- Anticoagulant Therapy
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Prevention of 2ry **Ischemic Stroke**
- Carotid endarterectomy
For patients with severe carotid stenosis (>70%) and non-disabling ischemic symptoms
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Types of **Hemorrhagic Stroke**
- ICH
- SAH
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Causes of **Intracerebral Hemorrhage**
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Most common Causes of **Intracerebral Hemorrhage**
Hypertension
81
Hematological Disorders Causing **Intracerebral Hemorrhage**
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Vascular Malformations Causing **Intracerebral Hemorrhage**
Saccular or Mycotic aneurysms.
Arteriovenous malformations.
Cavernous angiomas.
83
Inflammatory Vessel Diseases Causing **Intracerebral Hemorrhage**
Granulomatous Angitis.
Polyarteritis Nodosa.
84
Incidence of **1ry (Hypertensive) Intracerebral Hemorrhage**
This is the commonest spontaneous intracerebral hemorrhage.
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Pathogenesis of **1ry (Hypertensive) Intracerebral Hemorrhage**
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It is due to ....... in the cerebral arteries
chronic hypertension & degenerative changes
87
- Extravasated blood forms a mass (hematoma) → disrupts and **compresses the adjacent brain tissue.**
- If the hemorrhage is large, → **displacement of the midline structures to the opposite side** → compression the reticular activating system and respiratory centers → coma & death.
- In the first hours and days following the hemorrhage, edema accumulates around the clot and **adds to the mass effect.**
..
88
Sites of ****1ry (Hypertensive) Intracerebral Hemorrhage****
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Most common Site of **1ry (Hypertensive) Intracerebral Hemorrhage**
Putamen
“The most common type of ICH” lenticulostriate artery"
90
Most Dangerous Site for **1ry (Hypertensive) Intracerebral Hemorrhage**
Thalamus
91
CP of **ICH**
..
92
CP of **ICH**
- Time of Symptoms
In the majority of cases, the hemorrhage has its onset while the patient is up and active.
93
CP of **ICH**
- Onset
Abrupt onset of symptoms over minutes, hours or a day or Depending on the size of the ruptured artery
94
CP of **ICH**
- General
- Specific
95
General CP of **ICH**
Clinical manifestations of increased intracranial pressure
- Headache
- Vomiting
- Depressed level of consciousness and
- Seizures (in some cases)
96
Specifc CP of **ICH**
clinical manifestations which are related to the site of the hematoma
- Putaminal
- Lobar
- Thalamus
- Cerebellar
- Pontine
97
CP of **Putaminal Hemorrhage**
98
CP of **Lobar Hemorrhage**
99
CP of **Thalamic Hemorrhage**
100
CP of **Cerebellar Hemorrhage**
101
CP of **Pontine Hemorrhage**
102
Dx of **ICH**
103
Dx of **ICH**
- Clinically
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Dx of **ICH**
- Brain CT
- CT is reliable and superior to MRI in early detection of intracerebral hemorrhage (white mass).
- The surrounding edema is hypodense.
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Dx of **ICH**
- Brain MRI
MRI is particularly useful for brainstem hemorrhages.
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Dx of **ICH**
- Others
As PT, PPT, Platelet count, Liver functions etc.
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Prognosis of **ICH**
108
TTT of **ICH**
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TTT of **ICH**
- Emergency Care
to protect against Airway obstruction, Hypoventilation, & Aspiration (ABC)
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TTT of **ICH**
- Control of BP
Carried out cautiously & slowly (see before).
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TTT of **ICH**
- Control of ICP
**Rapid treatment of intracranial HTN improves the outcome of patients with ICH.**
- Controlled hyperventilation to PCO2 (25-30 mmHg).
- IV mannitol (0.25-1 gm/kg).
- Dexamethasone.
112
TTT of **ICH**
- Prevention & TTT of Comp
as seizures, pneumonia etc. (see before).
113
TTT of **ICH**
- Surgical Evacuation
Especially in patients with superficial (lobar hematomas or with cerebellar hemorrhage
113
Def of ****SAH****
Sudden flooding of the subarachnoid space with arterial blood.
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Etiology of **SAH**
115
CP of **SAH**
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CP of **SAH**
- Sex
Both sexes might be affected.
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CP of **SAH**
- Age
Aneurysmal group: usually in the 4th and 5th decades.
Angiomatous group: usually in the 2nd and 3rd decades.
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CP of **SAH**
- Premonitoring Symptoms
usually absent but it can be in the form of:
- Periodic headache.
- Recurrent ophthalmoplegia
- Seizures.
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CP of **SAH**
- Onset
- Sudden, usually during periods of activity Spontaneous but occasionally precipitated by: Physical strain. Straining.
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CP of **SAH**
121
CP of **SAH**
- Rapidly Increasing ICP
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CP of **SAH**
- Headache
Severe, worst headache (thunderclap) “felt first in the suboccipital & cervical region”
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CP of **SAH**
- Consciousness
Change in the state of consciousness varying from drowsiness to semi-coma and even coma.
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CP of **SAH**
- Fundus Ex
Fundus examination may show slight Papilledema and Retinal hemorrhage
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CP of **SAH**
- Meningeal Irritation
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CP of **SAH**
- Focal Manifestations
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INVx for **SAH**
- Brain CT
- CSF Examination (If CT Unavailable)
- Angiography (4 Vessels Angiography)
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INVx for **SAH**
- Brain CT
Blood appears in the subarachnoid space.
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INVx for **SAH**
- CSF
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INVx for **SAH**
- Angiography (4 Vessels Angiography)
To localize the site of the aneurysm or angiomatous malformation.
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Prognosis of **SAH**
- Immediate
- 1/2 the cases recover from the acute attack.
- Better prognosis in younger patients & when the coma is neither deep nor prolonged.
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Prognosis of **SAH**
- Late
There is usually no residual disability, but 1/3 of the survivors are liable to suffer from recurrent fatal attacks
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TTT of **SAH**
- Conservative
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TTT of **SAH**
- Surgical
- As early as the general condition of the patient allows angiography, Surgical treatment of the aneurysm should be carried (Excision or Clipping of the aneurysm or feeding vessel) out.
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TTT of **SAH**
- Others
Embolization (coiling) or Stereotactic radiotherapy.
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Def of **CVT**
Thrombosis in the Dural sinuses and / or cerebral veins.
137
Incidence of **CVT**
- < 2% of all strokes.
- Predominantly affects young adults and children.
- Accounts for up to 50% of strokes during pregnancy and Puerperium.
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Causes of **CVT**
1. Primary idiopathic thrombosis.
2. Secondary thrombosis
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Causes of **CVT**
- Secondary thrombosis
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Causes of **CVT**
- Secondary thrombosis (Local Conditions)
141
Causes of **CVT**
- Secondary thrombosis (Systemic Disorders)
142
CP of **CVT**
143
CP of **CVT**
- Intracranial Hypertension
- 25% of patients with intracranial hypertension are due to dural sinus thrombosis.
- Prognosis is good but may cause optic atrophy.
144
CP of **CVT**
- Disturbed Conscious level
Due to widespread thrombosis in cerebral veins & dural sinuses.
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CP of **CVT**
- Presentations According to affected Sinus
146
CP of **CVT**
- Presentations According to affected Sinus
(Cavernous Sinus)
147
CP of **CVT**
- Presentations According to affected Sinus
(Superior Sagittal Sinus)
148
CP of **CVT**
- Presentations According to affected Sinus
(Lateral Sinus)
149
CP of **CVT**
- Presentations According to affected Sinus
(DVT - Straight Sinus & Its Branches)
150
Investigations for **CVT**
151
Investigations for **CVT**
- MRV
- Visualize thrombus in the sinuses but less often visualize cerebral veins
152
Investigations for **CVT**
- CT Brain
153
Investigations for **CVT**
- Cerebral Angiography
Provides the Definitive Diagnosis
154
Investigations for **CVT**
- CSF
Non-specific & can be normal
155
TTT of **CVT**
156
Def of **TIA**
- Acute focal loss of brain function with symptoms lasting less than 24 hours due to inadequate cerebral blood supply
157
Duration of **TIA**
- Most TIAs last only 10 seconds to 15 minutes but occasionally as long as 24 hours (followed by complete recovery).
- Episodes that last longer than 1 hour are usually caused by small infarctions.
158
**TIA** & Stroke
- TIA is an important predictor of stroke risk.
159
Pathogenesis of **TIA**
160
Symptoms of Carotid **TIA**
161
Symptoms of Vertebrobasilar **TIA**
162
INVx for **TIA**
163
TTT of **TIA**
