Stroke (main)
Background
- Vascular injury that reduces CBF to specific region of brain causing neuro impairment
- Accurate determination of last known time when pt was at baseline is essential
Anatomy
- Anterior Circulation (internal carotid system)
- Ophthalmic artery - optic nerve and retina
- ACA - frontal pole, anteromedial cortex, ant corpus callosum
- MCA - frontoparietal lobe, anterotemporal lobe
- Posterior circulation (vertebral system)
- Vertebral artery - brainstem
- Posteroinferior cerebellar - Cerebellum
- Basilar - Thalamus
- Post cerebral - Auditory/vestibular structures, medial temporal lobe, occipital cortex
Causes
- Ischemic (87%)
- Thrombotic (80% of ischemic CVA)
- Atherosclerosis
- Vasculitis
- Arterial dissection
- Polycythemia
- Hypercoagulable state
- Infection
- Embolic (20% of ischemic CVA)
- Valvular vegetations
- Mural thrombi
- Arterial-arterial emboli from proximal source
- Fat emboli
- Septic emboli
- Hypoperfusion
- Cardiac failure resulting in systemic hypotension
- Thrombotic (80% of ischemic CVA)
- Hemorrhagic (13%)
- Intracerebral
- HTN
- Amyloidosis
- Anticoagulation
- Vascular malformations
- Cocaine use
- SAH
- Berry aneurysm rupture
- Vascular malformation rupture
- Intracerebral
Clinical Features
- Thrombotic
- Stuttering or waxing and waning
- TIA involving same vascular distribution
- Embolic
- Sudden onset of symptoms
- TIAs involving different vascular distributions
- A-fib
- Valvular replacement
- Recent MI
- Hemorrhagic
- Sudden onset of symptoms
- Preceded by severe headache
- Recent neck trauma/manipulation
DDX
- Seizures/postictal paralysis (Todd paralysis)
- Transient paralysis following a seizure which typically disappears quickly
- Note: seizures can be secondary to a CVA
- Syncope
- No persistent or associated neurologic symptoms
- Brain neoplasm or abscess
- Focal neurologic findings, signs of infection, detectable by imaging
- Epidural/subdural hematoma
- History of trauma, ETOH, anticoagulant use, bleeding disorder; detectable by imaging
- Hypoglycemia
- Can be detected by bedside glucose measurement, history of DM
- Hyponatremia
- History of diuretic use, neoplasm, excessive free water intake
- Hypertensive encephalopathy
- Gradual onset; global cerebral dysfunction, HA, delirium, HTN, cerebral edema
- Meningitis/encephalitis
- Fever, immunocompromise may be present, meningismus, detectable on LP
- Hyperosmotic coma
- Extremely high glucose levels, history of DM
- Wernicke encephalopathy
- History of ETOH or malnutrition; triad of ataxia, ophthalmoplegia, and confusion
- Labyrinthitis
- Predominantly vestibular symptoms; pt should have no other focal findings
- Drug toxicity
- Lithium, phenytoin, carbamazepine
- Bell's palsy
- Neuro deficit confined to isolated peripheral 7th nerve palsy; often a/w younger age
- Complicated migraine
- History of similar episodes, preceding aura, HA
- Meniere disease
- History of recurrent episodes dominated by vertigo symptoms, tinnitus, deafness
- Demyelinating disease (MS)
- Gradual onset, may have hx of multiple episodes of findings in multiple distributions
- Conversion disorder
- No cranial nerve findings, nonanatomic distribution of findings
Work-Up
- Glucose
- CBC
- Chemistry
- Coags
- Troponin
- Lipid profile
- Head CT
- ECG
- Also consider:
- Pregnancy test
- Utox
- TTE with bubble study
Treatment
Ischemic
- Glycemic control
- Use insulin to maintain blood sugar < 185
- Temperature control
- Treat fever > 37.5 (99.5)
- If pt is tPA candidate go to --> CVA (tPA Criteria)
- Consider tPA
- If give tPA DO NOT give antiplatelets/anticoagulants for at least 24 hours
- BP Control
- If potential candidate for tPA but BP > 185/110:
- Labetalol 10-20mg IV over 1-2min, may repeat x 1, OR
- Nicardipine IV 5mg/hr, titrate up by 2.5mg/hr q5-15min, max 15mg/hr; when desired BP reached lower to 3mg/hr OR
- other agents (hydralazine, enalaprit, etc) may be considered when appropriate
- If potential candidate for tPA but BP > 185/110:
- Consider tPA
- If pt is NOT a tPA candidate:
- Aspirin
- BP control
- Only tx BP if > 220/120
- Anticoagulation
- Heparin only if cardiac embolic source/ a-fib
Hemorrhagic
See Intracranial Hemorrhage (ICH)
Cerebellar Stroke
- Can be confused w/ acute vestibular syndrome (e.g. labyrinthitis)
- HINTS Exam can reliably distinguish the two (more effective than early DWI MRI)
- Head Impulse Testing
- Tests vestibulo-ocular reflex
- Have pt fix their eyes on your nose
- Move their head in the horizontal plane to the left and right
- If reflex is intact their eyes will stay fixed on your nose
- If reflex is abnormal their head will move 1st and then their eyes will "catch up"
- It is reassuring if the reflex is abnormal (due to dysfunction of the nerve)
- Nystagmus
- Benign nystagmus only beats in one direction no matter which direction their eyes look
- Bad nystagums beats in every direction their eyes look
- If pt looks left, get left nystagmus, if looks right, get right-beating nystagmus
- Test of Skew
- Vertical dysconjugate gaze is bad
- Alternating cover test
- Have pt look at your nose w/ their eyes and then cover one eye
- When rapidly uncover the eye look to see if the eye quickly moves to re-align
- Have pt look at your nose w/ their eyes and then cover one eye
- If any of the above are abnormal obtain full CVA w/u (including MRI)
- Head Impulse Testing
See Also
- Transient Ischemic Attack (TIA)
- CVA (tPA Criteria)
- CVA (Post-tPA Hemorrhage)
- Intracranial Hemorrhage (ICH)
- Subarachnoid Hemorrhage (SAH)
Source
- UpToDate
- AHA/ASA Acute Stroke Guidelines
- EMCrit