Ischemic Stroke Flashcards
Ischemic Stroke Definition
Fixed focal neurological deficit attributable to arterial or venous territory, with evidence of acute infarction.
So what’s a TIA
a brief episode of neurological dysfunction caused by focal brain or retinal ischemia, with clinical symptoms typically lasting less than one hour, and without evidence of acute infarction
Large vessel s/s
ACA: legs
MCA: “Classic” one sided weakness/numbness
PCA: vision
Basilar: quickly leads to coma and death
tPA! (aka alteplase)
Used in the acute stroke setting up to 3 or 4.5 Hours
SHOULD HAVE NORMAL CT SCAN, Abnormal perfusion scan
Catheter Options
MERCI/ PENUMBRA (vacuum)
Stent retriever + vacuum (faster)
Clopidogrel
Antiplatelet agents that work by a different mechanism than ASA
Effectiveness and tolerability about the same as ASA
Stronger may be good for heart, bad for Brain and GI
Way more expensive (x100)
ASA Therapy and Stroke
Effective in secondary prevention of stroke and TIA
Heart and peripheral vascular disease benefits
Well understood / known safety profile
Cheaper than dirt
Underused
metabolic, lifestyle, and structural risk factors for stroke.
HTN** Lipid disorders Homocysteine elevation Smoking Obesity Physical inactivity Diabetes Alcohol
non-atherosclerotic causes of stroke in a young patient
General
Vasculpothy Hematologic Inflammatory Venous infarction Vasospasms
non-atherosclerotic causes of stroke in a young patient
Vasculpothy
fibromuscular dystrophy, Moya- Moya, arterial dissection
non-atherosclerotic causes of stroke in a young patient
Hematologic-
Hematologic- familial deficiency, malignancies, sickle cell, hyperviscoity, birth control, antiphospholipid antibodies
non-atherosclerotic causes of stroke in a young patient
Inflammatory-
Inflammatory- vasculitis, migraine
fibromuscular dystrophy
F, 30 yo
media layer hypertrophy
dilate arteries to avoid stenosis
acs. w/ intracranial saccular aneurysm
Moya-Moya
F, 30-40 (asian/ african)
Middle cerebral artery occlusion
Intimal hyperplasia
acs. w/ intracranial saccular aneurysm & disection
Spontaneous dissection
FMD, marfran, coarc, intracranial ansm. Stroke risk
Familial Deficiency
Protein C, Protein S, or Antithrombin, or the presence of Factor V Leiden, or Prothrombin Gene
. Treatment for symptomatic individuals is often with anticoagulation.
Malignancies
can cause a poorly understood hypercoagulable state too. No specific testing is done when this is suspected beyond the search for the malignancy. As above, the peripheral venous events are much more common than any arterial event.
Sickle Cell Anemia:
SSA responds to transfusion. The Sickle Cell Trait cells can on occasion ‘sickle’ with dehydration or altitude, but this doesn’t seem to impart any additional risk of stroke or CNS hemorrhage.
Hyperviscosity States:
Protein, elevated hematocrit (60%), thrombocytosis (1,000,000), etc. can generate slowness of flow beyond the pump & pipes ability to compensate.
Oral contractive
implicated as a cause of stroke or venous thrombosis. This is a concern in patients who smoke, have other risks, or have subtle increases in blood pressure from OCP use.
. Hormone Replacement Therapy can either increase, or decrease your risk depending on the study.
Anecdotally, Neurologists note the triad of Migraine/Smokers/OCP increase risk by 25 times. Bonus if you add Cocaine or Meth, eh?
Antiphospholipid antibodies
cause a triad of spontaneous miscarriage, thrombocytopenia, and recurrent large vessel thrombosis, arterial or venous. attack of the phospholipid membranes in the platelet, and endothelium.
Rx is directed at the individual problem, and can involve no treatment, any antithrombotics, or even anticoagulation with warfarin.
Vasculitis
can affect the cns in many ways. T
Vasculitis has traditionally been considered a manifestation of immunological disorders, but over time, infectious causes are emerging. Varicella-Zoster Virus is increasingly being found in CNS vasculitis.
Venous Infarction
The most common cause is major head trauma. Most non-traumatic venous infarction occurs from dehydration, CNS infections, and hypercoagulable states (transient or genetic). Post-partum Sagittal Sinus Thrombosis around days 3-5 is a popular board question
Vasospasm
still being better defined to distinguish them from more typical inflammatory causes, but certainly sympathometic drugs, severe hypertension, primary vessel irritation (intrathecal drug, catheter contrast, SAH blood) trigger vasospasm that can cause permanent injury.
Reducing the Risk of Stroke
Good health + antiplatelet (aspirin, Thienopyridines (Clopidogrel, Prasurgrel, Ticlopidine) and Anticoagulants )
Aspirin
established as the standard antiplatelet agent to prevent recurrent stroke.
81mg or 325mg
GI catastrophes occur, and the cost can be increased if an H2 blocker or a proton pump inhibitor is required on a regular basis.
Clopidogrel plus aspirin
is quite useful after a catheter based cardiac re-vascularization procedure, may be useful in the first few months after a CNS ischemic event, and longterm may hold an advantage over aspirin alone in arteriopaths
_____ are used together in some highest risk patients, but there are no data in stroke to guide such use
. Aspirin and Warfarin
Dipyridamole
an extended release 75mg formulation that is available with 25mg of aspirin. This combination in a single pill has generated conflicting data, but overall works as well as any single agent.
Warfarin
highly effective in primary prevention of stroke with atrial fibrillation.
international normalized ratio (INR) targets for anticoagulation has resulted in lower bleeding complication rates then expected
The goal of______________ is to preserve the non-infarcted areas of the brain, prevent progression of infarction, to avoid notorious complications of stroke, and to initiate a rational evaluation to guide future long-term therapy.
ischemic stroke management
Resuscitation
Tissue plasminogen activator (TPA)
Used within the first three hours after stroke.
Therapy carries a significant risk of hemorrhage
- If diastolic BP is >140 mm Hg on two readings 5 minutes apart, then start an infusion of __________
Algorithm for Emergency Antihypertensive Therapy in Acute Stroke
sodium nitroprusside
Algorithm for Emergency Antihypertensive Therapy in Acute Stroke
If systolic BP is >220 mm Hg and/or diastolic BP is 121-140 mm Hg on two readings 20 minutes apart, them give_________
labetalol
dose may be repeated or doubled every 10-20 minutes until a satisfactory BP reduction is achieved
Algorithm for Emergency Antihypertensive Therapy in Acute Stroke
In acute stroke patients with systolic BP of
usually not indicated
TIA
ONSET
Instantaneous
HEADACHE
Rare
STUPOR/COMA
Rare
EXAM
Deficit in Vascular Pattern
CT/MRI
Normal
MECHANISM
Embolism (thrombus or platelet)
Small vessel occlusion, Thrombosis-in-situ
EMERGENCY TREATMENT
Fluids
Anti-thrombotic agent
STROKE- ischemic
STROKE
ONSET
Instantaneous
HEADACHE
Unusual or mild
STUPOR/COMA
Rare
EXAM
Deficit in Vascular Pattern
CT/MRI
Abnormal after hours
MECHANISM
Embolism (thrombus or platelet)
Small Vessel occlusion
Thrombosis-in-situ
EMERGENCY TREATMENT
TPA
Fluids
SUBARACHNOID HEMORRHAGE
ONSET
Instantaneous
HEADACHE
Universal & Severe
STUPOR/COMA
Often at Onset
EXAM
Normal or Mild to Severe Deficit
CT/MRI
Abnormal for Days
MECHANISM
Aneurysm
AVM
EMERGENCY TREATMENT
ICU Support
Hyperdynamic Therapy Ventriculostomy
Nimodipine
INTRACEREBRAL
HEMORRHAGE
ONSET
Minutes
HEADACHE
Common
STUPOR/COMA
Common by 30-60 minutes
EXAM
Progressive Hemiparesis
CT/MRI
Abnormal
MECHANISM
Hypertension, Coagulation disorder, Vessel degeneration, Stroke (Trauma)
EMERGENCY TREATMENT
ICU Support,
ICP Management
Surgery
