Causes of Stroke
Brain ischemia:
- thrombosis
- embolism
- systemic hypoperfusion
Brain hemorrhage:
- intracerebral hemorrhage
- subarachnoid hemorrhage (Intracranial aneurysm, AV malformation)
Anterior Circulation of the brain stems from what artery? Posterior?
Anterior circulation of the brain stems from the internal carotid while the posterior circulation stems from vertebral-basilar artery
What is the most common type of stroke? What artery is usually affected?
Ischemic stroke is most common type, the MCA is usually the artery affected.
Common Cardiac causes of stroke?
- ASD/VSD/PFO
- afib
- MI (anterior wall infarct or left ventricular wall mural thrombi)
- endocarditis
- Valvular disorders: Rhematic valvular stenosis is MC
Causes of Spontaneous Intracerebral hemorrhage?
- poorly controlled HTN
- bleeding disorders
- amyloid angiopathy (amyloid deposition leading to weakening of the cerebral blood vessels)
Causes of SAH?
- trauma
- spontaneous related to AVM or aneurysm rupture*
- abnormal vascular composition (amyloid/dissection)
Intracranial Aneurysm
- most commonly located where?
- sx
- what size carries a high risk of rupture?
- most commonly found in circle of willis
- usually asymptomatic until rupture
- size over 1cm
Arteriovenous Malformation
-what is this?
abnormal arterial to venous connection; tangle of artery and veins
-venous side developes pressure as high as arterial which leads to rupture.
What are the stroke subtypes?
Hemorrhagic:
- intracerebral hemorrhage
- subarachnoid hemorrhage
Ischemic:
-anterior, posterior, lacunar circulation
Intracerebral Hemorrhage:
- what is this?
- sx onset
- sx
WHat: arterial bleeding directly into the brain parenchyma; pressure on the brain is life threatening
-sx worsen as the hematoma grows
Sx:
- HA
- vomiting
- LOC with large hematoma
- vary depending on location and size of bleed, similar to ischemic
- may be preceeded by heavy exertion or sex
Subarachnoid Hemorrhage:
- what is this?
- sx
-bleeding into the CSF and the space surrounding the brain, this increased the ICP producing sx. Blood within the CSF induces vasoconstriction which can be intense and severe leads to ischemia.
Sx:
- abrupt HA, thunderclap
- vomiting, NO focal neurological signs
- knees may buckle. loss of memory
- may be preceeded by heavy exertion or sex
Ischemic Stroke:
-2/3 of all ischemic strokes affect which brain circulation?
-MCA and ACA
MCA is most commonly involved d/t the direct flow from the internal carotid and its large size.
Posterior Stroke Outcomes
-terrible, basilar artery occlusion = 90% mortality
Ischemic Stroke: Lacunar infarcts
- which artery do these branch from?
- what can you expect to see on CT?
- What are some risk factors for development of these strokes?
Lacunar infarcts branch from the MCA
CT: punched out hypodense areas
Uncontrolled HTN and DM
What is the most common type of stroke?
Most common culprit vessel in ischemic stroke?
Anterior strokes occur from occlusion of what vessel?
Posterior strokes occur from occlusion of what vessel?
HTN may cause what specific types of strokes?
Ischemic
MCA
Internal Carotid
Vertebral Artery
Intracerebral hemorrhages or lacunar infarcts
Risk factors of Stroke
HTN
DM
Hyperlipidemia
Smoking
Cardiac dz
AIDS
Drug abuse
ETOH
FHx
Obesity
PVD
Sedentary
Oral contraceptives
Age 45M 55W
Sleep apnea
Define:
- aphasia types
- -global
- -anomic
- -brocas
- -wernickes
Global:
-cannot speak, understand speech, read or write
Anomic:
- can understand what youre saying and can read
- difficulty writing and speaking (word finding)
Brocas:
“expressive aphasia”
-cannot read, write, or speak (short utterances, aware of their garbled speech)
-comprehension intact
Wernickes:
“receptive aphasia”
-fluent but meaningless spont. speech - jargon of real words and non-words
-unaware of their language errors
-poor comprehension, reading, and writing
Define:
- dysarthria
- dysconjugate gaze
- apraxia
- dystaxia
- agnosia
Dysarthria: problem with muscles that produce speech
Dysconjugate gaze: both eyes track together
Apraxia: difficulty with motor planning to perform tasks or movements when asked (2 step instruction)
dystaxia: lack of muscle coordination
agnosia: inability to process sensory info, loss of ability to recognize objects, persons, sounds, shapes, or smells.
Sx of Anterior Circulation Stroke (ACA and MCA)
Sx of ACA occclusion
Sx of MCA occlusion
ACA and MCA
- face-hand-arm-leg contralateral hemiparesis
- aphasia
- dysarthria
ACA sx:
- leg weakness and sensory loss; contralateral side affected
- prox arm weakness and sensory loss; contralateral side affected
- urinary incontinence
MCA:
- contralateral hemiplegia in the face*-arm-leg
- homonymous hemianopsia
- if on the left side= aphasia (wernickes or brocas)
- if on the right side = confusion, spatial disorientation, emotional neglect
- apraxia
Posterior Circulation Stroke Sx
sx depend upon which brain structure is affected;
- Midbrain = CN III, IV
- Pons = V, VI, VII, VIII
- Medulla = IX, X, XI, XII
- vertigo
- diplopia, dysconjugate gaze, homonymous hemianopsia
- sensory deficits= ipsilateral face & contralateral limbs
- dysarthria
- ataxia
When sx are not all on the same side of the body this is a tip off that they are having what kind of stroke?
-posterior stroke
What are the 5 D’s of posterior stroke?
- Dizziness
- Diplopia
- Dysarthria
- Dysphagia
- Dystaxia
Lacunar Stroke Sx
-pure motor loss (weakness) OR pure sensory loss
NIH Stroke Scale scores and severities..
0 = no stroke 1-4 = minor 5-15 = moderate 16-20 = moderate to severe 21-42 = severe
Stroke Evaluation
- labs
- imaging
Labs:
- lipid profile
- blood sugar
- CBC
- CMP
- PT/PTT
- Cardiac biomarkers (R/O cardiac ischemia)
Imaging:
- ACUTE: non-contrast CT
- later; MRI +/- MRA
- ekg
- ultrasound carotids
- echo
Acute Stroke treatment
- window of opportunity for tx
- time frame that a pt must be evaluated and recieve tx once they are at the hospital
-Acute tx of ischemic stroke & hemorrhagic
- 3-4.5hrs
- 60minutes
Ischemic:
- Fibrinolytic: clot buster = tPA given within 3-4.5hrs
- ASA
- Heparin/Lovenox
- PCI
Hemorrhagic: correct cause of hemorrhage
Inclusion criteria for
thrombolytics? Exclusion?
Inclusion:
ischemic stroke, onset of sx less than 4.5hrs ago, greater than 18yo
Exclusion:
- stroke or head trauma in previous 3 mo
- previous intracranial hemorrhage
- intracranial neoplasm
- av malformation/aneurysm
- recent intracranial or intraspinal surgery
- arterial puncture at a non-compressible site
- SBP greater than 185mmHg or 110DBP
- glucose less than 50
- active internal bleeding or diathesis
- INR greater than 1.7
- Heparin use within 48hrs and elevated PTT
Relative exclusion of Thrombolytics for tx 3-4.5hrs from sx onset.
- greater than 80yrs
- oral anticoagulation use
- very severe stroke
- previous ischemic stroke and DM
Discharge medications post stroke
- aspirin
- statin (unless hemorrhagic)
- anticoagulaton
- Plavix
- Antihypertensive
- control blood sugar if DM
After stroke, if sx last longer than 2-3mo complete recovery from aphasia is likely or unlikely?
What are some residual effects of strokes?
unlikely.
Residual:
- emotional lability
- difficulty recognizing familiar objects
- difficulty planning
- loss of awareness
- dysphagia
What are some complications of stroke?
- bowel/bladder dysfunction
- pressure ulcers
- malnutrition/dehydration
- recurrent strokes
- VTE
- Dysphagia
- aspiration pna
- seizures
TIA
- what is this?
- types
- work up
- tx
What: stroke like event lasting less than 24hrs (usually 20minutes) that occurs secondary to cerebral ischemia
Types:
- amarosis fugax
- low flow
- ebolic
- thrombotic
Work up:
- CT or MRI
- Carotid ultrasound
- eval for source of emboli or thrombus
Tx:
- admit if seen within 72hrs of sx
- treat risk factors (same as stroke)