Cerebrovascular Diseases: Ischemic & Hemorrhagic Flashcards
What is the general presentation of a large vessel or small vessel ischemic stroke and TIA?
Ischemic stroke is an ischemic injury to the brain causing a persistent deficit at 24 hours. TIAs are ischemic neurological deficits that completely resolve within 24 hours (new guidelines suggest 1 hour).
Large vessel ischemic stroke often causes deficits in multiple systems, these systems correspond with arterial region supplied by the blocked artery.
⇒ Middle cerebral artery is commonly occluded causing hemiparesis, hemisensory loss and hemianopsia on the contralateral side of the occluded artery.
Small vessel strokes often have an isolated deficit on one side of the body, such as an isolated motor or sensory loss.
⇒ These strokes are often form occlusion of small, penetrating arteries that penetrate the brain and give rise to lacunar infarcts
What is the presentation of a ruptured intracranial (sub arachnoid) aneurysm?
A common cause of subarachnoid hemorrhage
Presents with: oCataclysmic onset, like a fire cracker oSudden onset neurological deficits oHeadache – “worst headache of my life” oNausea and vomiting oDepressed level of consciousness
What is the presentation of an intra-cerebral
hemorrhage?
- Often due to hypertension and age
- Commonly occur in Putamen, thalamus, pons and cerebellum
•Presents with: Begin with mild headache Some deficit Sometimes nausea PROGRESSES over a few hours Decreased level of consciousness that deteriorates into coma Hemiparesis progressing to hemiplegia
What is the presentation of a subdural hemorrhage?
- Usually trauma related (doesn’t have to be!)
- Bleed between dura and arachnoid layer
- Typically a VENOUS bleed
- Appear crescent shaped on imaging
•Presents with: Headache Nausea and vomiting Diminished eye, verbal and motor responses Confusion Loss of consciousness Localized weakness Speech and/or vision changes Seizure
What is the presentation of an epidural hemorrhage?
- Usually from trauma, usually have associated skull fracture
- Bleed between dura mater and skull
- Typically artery, Often middle meningeal
- Appear lens shaped on imaging
•Presents with:
Brief depression of or loss of consciousness
Followed by lucid interval where patient seems normal
Deterioration to loss of consciousness and/or coma
Nausea and vomiting
Headache
Seizure
Understand that there are non-atherosclerotic causes of stroke in younger patients. OK these can also happen to old farts, too
- Vasculopathy: non- inflammatory, non-atherosclerotic hyperplasia of arteries which weakens them. Conditions such as Fibromuscular Dysplasia, Moya-Moya, Arterial Dissection
- Hematological Disorders: Hypercoaguable states. Deficiences in Protein C and S, Antithrombin or presence of Factor V. Malignancies. Sickle Cell anemia. Oral contraceptives.
- Inflammatory Mechanisms such as vasculitis
- Migraine: can cause stroke, possibly through vasospasm or increased platelet aggregation
- Venous Infaction: Dehydration can produce hypercoaguable state.
- Vasospasm: Sympathomimetic drugs, Severe hypertension, Vessel irritation
Understand the importance of mechanism of stroke in both resuscitation and prevention.
Most strokes are related to atherosclerotic or thrombotic/embolic occlusion of vessels. Preventing thrombus formation is another way to reduce risk if your patient is known to have these risk factors or suffered a thrombotis ischemic stroke. Aspirin, ticlopidine and clopidogrel are anti-platelet agents that can decrease risk of thrombus. Anti-coagulation is preferred to prevent (or post) small vessel infarction and those with lower embolization risks.
In the ED, ischemic strokes are resuscitated with thrombolytic agents (TPA), maintaining fluids, maximizing cardiac output and maintaining blood pressure (even if its high). Treat hypoglycemia if present. However, Patients with vasospastic, vasculopathic or inflammatory strokes will not benefit from TPA.
What are the basic principles of emergency treatment of ischemic stroke or hemorrhage?
- Tissue plasminogen activator (TPA)
- Keep fluids up, maximize cardiac output
- Resist the temptation to lower blood pressure
Understand how to modify structural, metabolic, and lifestyle risk factors for stroke.
Treat:
•hypertension - so many choices
•hyperlipidemia – statins
•high homocysteine levels – folate, B6 and B12
- Smoking – stop
- Obesity – dietary/lifestyle modification
- Diabetes
- Physical inactivity – lifestyle modifications
- Alcohol abuse – stop
Structural Risk Factors:
•Lumen stenosis – can be repaired surgically or via IV catheter
•Cardiac issues – A-fib, CHF, valve disorders increase risk of embolus - treat with warfarin
•Atrial septal defects – can be repaired or treated medically to prevent embolus
•Atrial Myxomas – cardiac tumors can increase risk of embolus – remove
Deep vs Lobar Cerebral Hemorrhage
Deep: Located where small perforating arteries are (commonly in basal ganglia, thalamus, pons and cerebellar regions. Common risk factors include HTN and age. Generally a poor outcome). Non-Whites at higher risk.
Lobar: Frontal>Parietal>Occipital> Temporal .
Amyloid Angiopathy. Most common risk factors include Age, Dementia and Coagulopathy. They are well tolerated. White/Asian higher risk.
Common Mechanisms of Stroke
- Embolization from the heart to arteries of the brain
- Embolism from an artery (carotid, vertebral, arch) to the arteries of the brain
- Large Vessel thrombosis of the arteries leading to or around the brain
- Small vessel thrombosis
- Small vessel blocked by embolus lodged in its parent vessel
- Dissection of artery causing occlusion or creating embolus to the brain
- Vasospasm from drug, infection, hypertension, irritation of the artery
Common syndromes in lacunar infarct
- Clumsy hand dysarthria
- Pure motor hemiparesis
- Hemi sensory loss
- Mixed sensory-motor
