Stroke: Pathology and Medical Management

What is a stroke?

a focal neurologic deficit resulting in cerebral vascular disease (CVA)

Stats

5th leading cause of death
prevalence goes up with age (both men and woman)
it is highest in black males (due to inequalities in healthcare)
preventable and treatable

Types of Stroke

ischemic (blockage of blood flow) and hemorrhagic (brain bleeds either intracerebral or subarachnoid)

Ischemic Stroke

Thrombus: a build up of clots in the blood stream
Embolus: a piece of thrombus breaking off and getting trapped in the blood stream

Hemorrhagic Stroke

This is where a blood vessel bursts leading to a brain bleed. Intracerebral: Subarachnoid

Mortality Rates

Ischemic: 8-12%
Hemorrhagic: 37-38%

Hemorrhagic Risk Factors

Hypertension
Low cholesterol and LDL
lower triglycerides
increasing age

Ischemic Risk Factors

hypertension
high cholesterol
obesity
drug abuse
alcohol abuse
diabetes
smoking
lack of exercise
irregular heart rhythm

Stroke F.A.S.T

F: facial drop
A: arm weakness
S: slurred speech
T: time is critical

Acute Stroke Examination

Data: CT Scan, vital signs, blood glucose level
brief patient history: PMH, meds, recent surgeries and trauma
National Insitute of Health Stroke Scale
Last known normal
ABC workup: artery, blood, cardiac

Head CT

is blood present?
Signs of stroke (either 24 hours or 3-6 hours)
early infarct signs

What would you see on a CT Scan

Hemorrhagic: blood
Ischemic: there will be no distinct between grey matter or white matter

What is the purpose of thrombolytics (tPA) in ischemic stroke management?

To decrease clotting
- tissue plasminogen activator
- used within 4.5 hours of symptom onset
- shown to improve functional outcomes

What is intra-arterial thrombectomy used for in ischemic stroke management?

- manual removal of arterial blockage
- 666 rule
less than 6 hours onset
NIHSS: greater than 6
ASPECTS greater than 6 (aka last normal)

Other factors of ischemic stroke management

- maintain/increase cerebral perfusion
-stabilize metabolic demands
-evaluate stroke etiology

Hemorrhagic Stroke Presentation (48-72 hours)

headache, nausea, vomiting, seizures, focal neurologic deficits, herniation syndromes (aka confusion)

Acute ICH management (hemorrhagic)

- blood pressure control
reverse
- coagulopathy (more clotting)
-intracranial pressure management
-surgical management

What is the surgical management of Ischemic CVA

posterior fossa decompression (removal of bone in order to relive inflammation)

What is stroke prognosis?

hemorrhagic stroke has higher morbidity and mortality
30-50% mortality
20% independent at 6 months post

What factors impact the neurological findings of ischemic stroke?

Size, location of lesion, and amount of collateral blood flow

What type of deficits are associated with the carotid vascular system in ischemic stroke?

Unilateral deficits

What type of deficits are associated with the vascular supply to the basilar system in ischemic stroke?

Bilateral deficits

Acute Stroke Symptoms

weakness, numbness, aphasia (memory around speech around brain), dysarthria (slurred speech around mouth), confusion, altered vision, gait/balance impaired, ataxia (disordered movement). vertigo, dysphagia (cannot chew), headache

Middle Cerebral Artery

If it is on one side (for example left) then there is weakness on the other side (right)

-hemiparesis
-sensory loss
- aphasia (L), neglect (r)
- visual field cut
- gaze preference (if L issue, L gp)

Anterior Cerebral Artery

- contralateral weakness
- contralateral sensory loss
- abulia (can't decide) (left)
- gaze preference
- incontinence

Central Posterior Cerebral Artery Syndrome

- visual field cut
- thalamic involvement
- weakness
- sensory changes (anesthesia, thalamic pain syndrome)
- hemiballismus

Peripheral Posterior Cerebral Artery Syndrome

- amnesia (hippocampus involvement)
- alexia (inability to read) without agraphia (inability to write)
- visual deficits (cortical blindness, visual field cuts)

Basilar Artery Syndrome

- supplies pons, midbrain, cerebellum,etc.
- altered mental status
- brainstem findings (weakness, cranial nerve deficits)

Damage to Pons with BAS

- tetraplegia
- coma
- locked-in syndrome (you know what is going on, but cannot move)

Stroke of the Cerebellum

nystagmus (eyeballs moving)
dizziness
nausea/vomiting
ipsilateral ataxia (disordered movement on the same side)

Hemorrhagic Stroke locations & depths

- intracerebral: basal ganglia/thalamus
- subarachnoid: cerebral white matter
- subdural: brainstem
- epidural: cerebellum

Intracerebral Hemorrhage

- bleeding from an arterial source into the brain parenchyma (most fatal)

Subarachnoid Hemorrhage (SAH)

- Bleeding into the subarachnoid space between the arachnoid and the pia mater

Most common non-traumatic causes of SAH

Aneurysms and vascular malformations

What happens with SAH

berry aneurysm where an rise in BP creates a strain which results in this bump that bursts (physical strain can be an orgasm and valsalve)

What are the most common sites of SAH

1) anterior communicating artery
2) posterior communicating artery
3) middle cerebral artery

Dangers of SAH?

- spewing blood, under high pressure, into brain tissue
- susceptibility to re-rupture
- obstruction of the SA space which can lead to hydrocephalus due to CSF blockage

Hemorrhagic CVA syndromes: Putaminal Hemorrhage

greater alteration of consciousness

Hemorrhagic CVA syndromes: Thalamic Hemorrhage

Results in contralateral hemiplegia with disproportionately greater sensory loss

Hemorrhagic CVA syndromes: Cerebellar Hemorrhage

ataxia (poor muscle control and coordination), and vestibulopathy (motion sickness)

Hemorrhagic CVA syndromes: Pontine Hemorrhage

Offers the poorest prognosis
Tetraplegia (motor and sensory loss in spinal cord) and coma

Lacunar CVA syndromes

• Pure motor • Pure sensory • Ataxic hemiparesis • Clumsy hand dysarthria • Mixed sensory and motor

Other common signs/symptoms

fatigue
cognitive dysfunction
depression
anxiety
PTSD

Recovery inital improvements

- Reduction of cerebral edema
- Absorption of damaged tissue
- Improved local vascular flow
- Damaged areas of the brain are circumvented (brain's plasticity)

Recovery

3-6 months (but also can take months to years)
- the beginning weeks show the most improvement
- chronically it can either get a little bit better plateau, or decline

Stroke Outcomes

- rehab is effective
- age does not factor in outcome
- good chance for functional recovery