Cerebrovascular diseases

Cerebrovascular diseases

• Vascular occlusive diseases (ischemic stroke)

• Intracerebral hemorrhage (hemorrhagic stroke)

Incidence of stroke

• 150-600 new cases per 100.000 population per year

• 2-3rd leading cause of death

• 1st leading cause disability

Ischemic stroke

• Atherosclerosis of great cerebral vessels 20-40%– Stenosis of vessels– Atherothromboembolism

• Cardiac embolism 15-30%

• Nonatherosclerotic vasculopaties and hematological abnormalities 10-20%

• Unknown 10-30%

Common sites of atherosclerotic disease.

Normal blood flow

• 55 ml/100g per min - average – 80-100 ml/100g per min for gray mater– 25-30 ml/100g per min for white matter

• <20 ml/100g - ischemic stroke

Acute ischemia

• Transient Ischemic attack – neurological deficit that resolves during 24 hours

• Reversible neurological deficit (minor stroke) – deficit that resolves completely during more then 24 hours

• Ischemic stroke – persistent neurological deficit

Clinical presentations of ischemic stroke

• Subacute begining (acute in cases of embosilsm)

• Consciousness is clear or short term lost of consiousness. Not often unconsciousness

• Focal neurological deficit – main in clinical picture

• Headaches, meningeal signs are not often

• History of TIAs, no history of hypertention

Treatment of acute ischemia

• 1. Acute resuscitation

• 2. Reperfusion of the ischemic brain

• 3. Decreasing cerebral metabolic demands

• 4. Inhibition of the degradative ischemic cascade

1. Acute resuscitation

• Respiration– Intubation with ventilation for patients in coma– Supplementary oxygen for other patient

• Arterial pressure– Maintaining mild hypertension (if there is no evidence

of hemorrhage) or at least normal blood pressure

• Maintaining of adequate intravessel volume• Controling heart output and arrhythmias• Controlling of glucose level

2. Reperfusion of the ischemic brain

• Thrombolytic therapy – recombinant activator for tissue plasminogen– In first 4-6 hours after onset– If intracerebral hemorrhage is excluded with

CT

• Hypervolemic Hemodilution Therapy

• Anticoagulation ???

3. Decreasing cerebral metabolic demands

• Hypothermia ???

• Barbiturates

Surgical treatment for acute ischemia

• Possible only in cases of stenosis of great brain vessels (common carotid, internal carotid, middle cerebral arteries) – endarterectomia in first 2-3 hours.

Primary stroke prevention – controlling of risk factors

• Hypertension (increases risk of stroke in4-5 times)

• Smoking (1,5)

• Diabetes. (2,5-4)

• Lipids.

• Cardiac Disease.– Atrial fibrillation, (5)

– valvular heart disease, (4)

– myocardial infarction (5)

Secondary Stroke Prevention (After Transient Ischemic Attack or

Ischemic Stroke)• Aspirin 30-300 mg per day

• Or Ticlopidine

• Treatment or heart diseases

• Surgical

Surgical prevention of ischemia

• EXTRACRANIAL-TO-INTRACRANIAL CAROTID ARTERY BYPASS

• CAROTID ENDARTERECTOMY

CAROTID ENDARTERECTOMY

• Indications– Patients with TIAs with high grade stenosis of

CCA or ICA confirmed with ultrasound-dopler and angiography

– Patients after stroke (strokes) that do not cause severe diability

• angiograms of cervical carotid artery showing varied appearance of critical stenosis of the internal carotid artery.

• A Smoothly tapered segmental narrowing. • B Sharply demarcated stenosis.

endarterectomy

Causes of nontraumatic intracranial hemorrhage

• Intracerebral hemorrhage– Arterial hypertention (hemorrhagic stroke)

– Bleeding from Arterio-venous malformation (AVM)

– Rupture of aneurysm of cerebral vessel

– Coagulopathies

– vasculitis

• Subarachnoid hemorrhage– Rupture of aneurysm of cerebral vessel

– Bleeding from Arterio-venous malformation (AVM)

Clinical signs of hemorrhagic stroke due to hypertension

• Sudden and fast onset (seconds – minutes)

• Unconsciousness (semicoma-coma)

• Severe neurological deficit

• Vegetative symptoms: high arterial pressure; bradycardia, red face and cyanotic limbs, sweating.

• Severe headache in contact patients

Diagnostic procedures

• Computed tomography (CT)

• Angiography

• EchoEG

Medial (thalamic) hematoma

Lobar hematoma

Brainstem (pontine) hemorrhage

Treatment

• Conservative only –– for patients in clear consciousness or severe

coma (GCS 3-5)– Medial hemorrhage (into basal ganglia)– Hemorrhage into brainstem

• Surgical + conservative - for other patients

Conservative treatment

• Respiration control– Intubation for comatose patients– Supplementary oxygen

• Arterial pressure control– Severe hypertention must be treated gently –

decrease pressure to mild hypertention during several hours.

• Coagulative status control and correction

Surgical treatment

• Removal of intracerebral hematoma

• Ventricular draining in case of occlusive hydrocephalus

Clinical presentation of SAH

• Sudden onset• Severe headache• Meningeal signs• Minimal focal neurological deficit

• More rarely depressed level of consciousness and major neurological deficit

Diagnostic procedures for SAH

• CT • Lumbar puncture with CSF examination

– Blood in the CSF– High pressure of CSF– SAH and possible intracerebral hemorrhage

• Angiography – the main to reveal the cause of SAH – aneurisms and arterio-venous malformations

Aneurisms of cerebral arteries

• Localization– Anterior cerebral a. and anterior communicans .

- 45%– Internal carotid a. – 32%– Middle cerebral a. – 20%– Vertebrobasilar circulation – 4%

Aneurisms of cerebral arteries

• Saccular• Others (traumatic, atherosclerotic, mycotic,

neoplastic, inflamatory)

• Saccular aneurisms – ovoid-shaped outpouching of vessel wall, cased by congenital insufficiency of elastic component of vessel wall

SAH due to ruptured aneurism

• First rupture of aneurism – SAH only• Repeated rupture in 20-50% of cases, most

of them during 3-20 days after first • 50-85% mortality after repeated rupture, • Intracerebral hemorrhage are often at

repeated rupture• Often complicated with vasospasm and

consequent ischemical changes

Surgical treatment of aneurism

• Any aneurism should be excluded from circulation as early as possible– Putting clips on the neck of aneurism– Endovascular embolisation of aneurism

• With coils

• With balloons

• Angiography

• 1 – in first day

• 2 – 3rd day – angiospasm of middle cerebral atery

• 3 – 4th day (after treatment)

Internal carotid

bifurcation aneurysm.

Arteriovenous malformations

• heterogeneous group of vascular developmental anomalies of the brain

• composed of a mass of abnormal arteries and veins of different sizes.

• Functionally, they represent direct artery-to-vein shunting with no intervening capillaries,

• angiographically are seen as early filling of veins.

Schematic drawing of AVM

Clinical presentations of AVMs

• Intracranial hemorrhage– Intraparenchymal– Subarachnoid

• Seizures

• headache,

• progressive neurological deficit,

• cardiac failure.

Diagnosis

• Angiography

• MRI

Angiography

MRI – AVM in occipital lobe

Treatment of AVMs

• Observation

• Surgical excision

• Endovascular embolization

• Radiosurgery– Hamma-knife– Linear proton accelerator

Hamma-knife