Neurology Flashcards
What are the types of stroke?
Ischemic and hemorrhagic stroke
What are the classes of ischemic stroke?
Transient ischemic attack (TIA) Reversible ischemic neurologic deficit Evolving stroke (worsening) Completed stroke (maximal deficit has occured)
What is TIA?
Neurologic deficit usually due to an emboli that lasts from a few minutes to no more than 24 hours, symptoms are transient because reperfusion occurs and the blockage in the blood flow doesn’t last long enough to cause permanent infarction.
What are the evaluation tests that are done after TIA?
Brain and neurovascular imaging
ECG and cardiac monitoring
Echocardiogram
Labs: CBC, chemistry, lipids, diabetes, screening, and others
What are the most important risk factors of ischemic stroke?
Age and HTN
What are the risk factors of ischemic stroke to consider in young patients?
OCPs, hypercoagulable states, vasoconstrictive drug use, polycythemia vera and sickle cell disease
What is the score that is often used as a risk stratification tool to identify patients at highest risk of early stroke and require emergency assessment?
Age Blood pressure elevation shortly after TIA Clinical features of stroke Duration of TIA symptoms Diabetes
What are the causes of ischemic stroke?
Emboli: most commonly from the heart due to atrial fibrillation
Thrombotic: atherosclerotic in large and medium sized vessels
Lacunar: small vessel thrombotic disease, narrowing of arterial lumen is due to thickening of vessel wall
Nonvascular
What are the clinical features of ischemic thrombotic stroke?
Classically the patient awakens from sleep with neurologic deficits depending on distribution:
Anterior cerebral artery: deficiency of contralateral lower extremity and face
Middle cerebral artery: aphasia, contralateral hemiparesis
Vertebral/basilar: ipsilateral (ataxia, diplopia, dysphagia, dysarthria and vertigo) contralateral (homonymous hemianopsia with basilar PCA lesions)
Lacunar: internal capsule (pure motor hemiparesis), pons (dysarthria, clumsy hand), thalamus (pure sensory deficit)
What are the clinical features of ischemic embolic stroke?
The onset of symptoms is very rapid and deficits are maximal initially, MCA is most commonly affected and neurologic deficits seen include:
Contralateral hemiparesis and hemisensory loss
Aphasia
Apraxia, contralateral body neglect, confusion
What are the clinical features of ischemic lacunar stroke?
Pure motor lacunar stroke if lesion involves internal capsule
Pure sensory lacunar stroke if lesion involves the thalamus
Ataxic hemiparesis, incoordination ipsilaterally
Clumpsy hand dysarthria
What is the initial assessment of ischemic stroke?
-History and neurologic exam including NHSS score
-Brain imaging:
CT scan without contrast (but it may take 24 to 48 hours to visualize an infarct)
MRI (more sensitive)
Can be combined with neurovascular imaging
-ECG
-Labs: CBC, electrolytes, creatinine, coagulation, cardiac enzymes and others
How is ischemic stroke managed?
- Acute:
Supportive (airway protection, oxygen, IV fluids)
t-PA (given within 4.5 hours only and if no contraindications are present)
Aspirin not given within 24 hours if t-PA is given
Neurologic checks and careful monitoring of BP keeping it <185/110 mmHg
Endovascular thrombectomy in patients with large artery occlusion
Keep NPO, protect against hypo- or hyperglycemia, avoid fever, elevate head of the bed 30 degree to prevent aspiration
-BP control: don’t give unless:
BP is very high (systolic >220, diastolic >120 or MAP >130)
Patient has significant medical indication for antihypertensive therapy
Patient is recieving t-PA
-Prevention of stroke recurrence:
Lifestyle and pharmacotherapy for risk factors
Long-term antiplatelet therapy
High intensity statin
Anticoagulation for cardioembolic strokes
Surgery for strokes due to carotid artery disease for symptomatic patients
What are the two major categories of hemorrhagic stroke?
Intracranial hemorrhage
Subarachnoid hemorrhage
What are the causes of intracerebral hemorrhage?
- HTN (sudden increase in BP causes rupture of small vessels, and chronic HTN causes degeneration of small arteries leading to microaneurysms)
- Ischemic stroke that may convert to hemorrhagic stroke
- Amyloid angiopathy
- Anticoagulant/antithrombolytic use
- Brain tumors
- AV malformations
What is the main cause of stroke in young patients?
Cocaine use
Where is the common location of hemorrhagic stroke?
Basal ganglia
What are the clinical features of hemorrhagic stroke?
Abrupt onset of focal neurologic deficit that worsens steadily over 30 to 90 minutes
Altered level of consciousness, stupor, or coma
Headache, vomiting
Signs of increased ICP
How does pupillary findings in ICH corresponds to level of involvement?
Pinpoint pupils: pons
Poorely reactive pupils: thalamus
Dilated pupils: putamen
How is ICH diagnosed?
CT scan of the head
Coagulation panel and platelets (to check for bleeding diathesis)
How is ICH managed?
-Admit to ICU
-ABC’s
-BP reduction (must be gradual) indicated if systolic BP >180 or MAP >130
IV agents such as nicardipine, labetalol, and nitroprusside
-Management of elevated ICP: elevating the head of the bed to 30 degrees, appropriate sedation and pain control. Mannitol is often used to lower ICP
-Reversal agents for anticoagulant or antiplatelets if patient uses them: vitamin K for warfarin, protamine sulfate for heparin
Where are the common sites of SAH?
Junction of anterior communicating artery with anterior cerebral artery
Junction of posterior communicating artery with internal carotid artery
Bifurcation of MCA
What are the causes of subarachnoid hemorrhage?
Ruptured saccular aneurysms
Trauma
AV malformation
What are the clinical features of subarachnoid hemorrhage?
- Sudden, severe headache (worst headache of my life)
- Sudden, transient loss of consciousness
- Vomiting
- Meningeal irritation, nuchal rigidity and photophobia
- Death
- Retinal hemorrhages
