Cerebral Infarction
- Abrupt
focal cerebral deficit of greater than 24 hours duration
- Etiology:
- Hemorrhagic
(intracerebral, subarachnoid)
- Vascular
- Cerebrovascular
disease
- Large
vessel disease (carotid stenosis, artery-to-artery embolism,
thrombosis)
- Small vessel
disease
- Cardiogenic
source (rheumatic heart disease, prosthetic valve, infectious
endocarditis, myocardial infarction, atrial fibrillation, other
arrhythmia)
- Other
- Hyperviscosity,
vasospasm, hypercoagulability, systemic hypotension, arteropathy
- Diagnosis:
Clinical history and examination
- CT/MRI
evidence of infarction
- Appropriate
further work-up might include carotid ultrasound, ECHO, cerebral
angiogram
- Treatment: Depends
on etiology
- Embolic
anticoagulation, removal of embolic source
- Thrombotic
supportive care
- Pathological
changes
- Time
Course
- 1 hour
axonal swelling
- 12-24
hours necrosis, eosinophilia, pyknosis
- 24-48
hours neutrophils (peak 48 hours)
- 2-5
days blood brain barrier breaks down, axon retraction balls visible
- 1 week
gitter cells (lipid laden macrophages), neovascularity
- 10-20
days astrocytes (gemistocytes) around edge
- 3
months cystic area with sparse fibrillary astrocytes
- Most
vulnerable areas are hippocampus (CA1 and CA3), parieto-occipital layers with
largest neurons (3, 4, 6, leads to pseudolaminar necrosis),
caudate/putamen, Purkinje cells
- Sparing
of U-fibers, external capsule, claustrum
- Strokes
in infancy/peripartum: watershed areas
- Germinal
matrix in premature leads to periventricular leukomalacia
- Cortex/subcortical
white matter in term infants
- Strokes
in children (3%)
- Usually
caused by congenital heart disease with shunt; also infection,
dissection, syphilis, drugs, hypercoagulable state, Fabrys disease,
Marfans syndrome, neurofibromatosis type 1, tuberous sclerosis, moya
moya
- Strokes
calcify only in children
- Thrombolytic
Treatment
- Absolute
contraindictions:
- CT or
MRI evidence of hemorrhage
- Complete
resolution of symptoms
- Relative
contraindications:
- CT
changes > one-third of MCA territory
- Hypertension
(systolic > 185, diastolic > 110) that remains
unresponsive to antihyperstensive management (see below)
- History
of GU or GI bleeding within three (3) weeks
- History
of CPR, extensive trauma, or surgery within two (2) weeks
- History
of stroke within two (2) weeks
- PT >
15, platelets < 100,000, INR > 1.7
- LP or
non-compressible arterial puncture within one week
- History
of seizure at time of onset
- Clinical
Cautions:
- Clinical
presentation suggestive of SAH, even if CT negative
- Age >
80
- Active
pericarditis or pericardial infusion
- Glucose
< 50 or > 400
- NIH
Stroke Scale > 22
- Rapidly
improving symptoms
- Technique:
- Intravenous
rTPA (within 3 hours after onset)
- TPA
reconstituted in a solution of 1 mg rTPA/1 ml 0.9 NS
- Total
dose = 0.9 mg 1/kg (total dose not to exceed 90 mg)
- Ten
percent (10%) of dose given as IV push
- The
remaining balance infused over 60 minutes
- Intravenous
and intra-arterial therapy
- Consider
for the following patients:
- patients
with suspected large vessel occlusive disease (carotid terminus,
basilar artery, M1, proximal M2)
- patients
with a diffusion-perfusion mismatch on MR
- patients
being transferred from other institutions
- IV
given as above, except 0.6 mg/kg with total dose not to exceed 60 mg
and remaining balance over 30 minutes
- IA
therapy given only if persistent clot seen on angiography
- Intra-arterial
therapy (3-6 hours after onset):
- Obtain
ACT at Baseline, 1 hour, 2 hours
- Administer
2000 units heparin IV bolus thrombus is identified angiographically
- Start
maintenance infusion of heparin at 450 units/hour
- Position
2.3 French microcatheter just distal to occlusion
- Infuse
2 mg TPA (2 mg/2 cc normal saline) over 4 minutes distal to
thrombus
- Retract
catheter into thrombus
- Infuse
2 mg TPA (2 mg/2 cc normal saline) over 4 minutes into thrombus
- Start
maintenance infusion of 10 mg/hr TPA using infusion pump
- Perform
control angiogram every 15 minutes (or as needed) after start
of maintenance TPA infusion (option to mechanically disrupt every
15 minutes as well)
- Perform
neurological examination every 15 minutes to assess level of
consciousness and upper extremity motor function (items 1a, 1b, and 5
from NIHSS)
- Infuse
maintenance dose for a maximum of 2 hours to a maximum time after onset
of 8 hours
- Consider
more aggressive mechanical disruption (i.e., snare) if clot has not
resolved after 1 hour
- Terminate
infusion prior to 2 hours if complete clot lysis is achieved
- Total
IA TPA dose = 24 mg
- Anticoagulation
- Heparin
within the first 24 hours following thrombolytic therapy is not
recommended by the American Heart Association. It should be
considered only in patients judged to be at high risk for recurrent
thrombus and/or embolization. In such instances, heparin could be
considered if the size of infarction is <50% of the volume of MCA
territory, blood pressure is well-controlled (systolic < 180,
diastolic < 105), and CT scan post-completion of thrombolysis
shows no evidence of hemorrhage
- CT is
recommended prior to instituting anticoagulation to assess for
post-thrombolysis disposition. Patient should be admitted to a
monitored bed (preferably ICU) for at least 24 hours
post-thrombolysis. Additional monitored-bed stay may be required
for respiratory support or blood pressure management
- NIH
Stroke Scale
- 1a
Level of consciousness
- 0 =
Alert
- 1 =
Drowsy
- 2 =
Stuporous
- 3 =
Coma
- 1b
Level of consciousness questions
- 0 =
Answers both correctly
- 1 =
Answers one correctly
- 2 =
Both incorrect
- 1c
Level of consciousness commands
- 0 =
Obeys both correctly
- 1 =
Obeys one correctly
- 2 =
Obeys neither
- 2 Best
Gaze
- 0 = Normal
- 1 =
Partial gaze palsy
- 2 =
Forced deviation
- 3 Best
visual
- 0 = No
visual loss
- 1 =
Partial hemianopia
- 2 =
Complete hemianopia
- 3 =
Bilateral hemianopia
- 4
Facial palsy
- 0 = Normal
- 1 =
Minor
- 2 =
Partial
- 3 =
Complete
- 5 Best
motor arm
- 0 = No
drift
- 1 =
Drift
- 2 =
Cannot resist gravity
- 3 = No
effort against gravity
- 4 = No
movement
- 6
Other arm For brainstem stroke
- 0 = No
drift
- 1 =
Drift
- 2 =
Cannot resist gravity
- 3 = No
effort against gravity
- 4 = No
movement
- 7 Best
motor leg
- 0 = No
drift
- 1 =
Drift
- 2 =
Cannot resist gravity
- 3 = No
effort against gravity
- 4 = No
movement
- 8
Other leg For brainstem stroke
- 0 = No
drift
- 1 =
Drift
- 2 =
Cannot resist gravity
- 3 = No
effort against gravity
- 4 = No
movement
- 9 Limb
ataxia
- 0 =
Absent
- 1 = Present
in upper or lower
- 2 = Present
in both
- 10
Sensory
- 0 = Normal
- 1 =
Partial loss
- 2 =
Dense loss
- 11 Neglect
- 0 = No
neglect
- 1 =
Partial neglect
- 2 =
Complete neglect
- 12
Dysarthria
- 0 = Normal articulation
- 1 = Mild
to moderate dysarthria
- 2 =
Near unintelligible or worse
- 13
Best language
- 0 = No
aphasia
- 1 = Mild
to moderate aphasia
- 2 =
Severe aphasia
- 3 =
Mute