BIOMED - Pathophysiology

🧠 𝘚𝘵𝘳𝘰𝘬𝘦 (𝘊𝘝𝘈)

Welcome to the Pathophysiology of the ✨ Cerebral vascular accident ✨ (some people also hate pressing space, so it appears as cerebro vascular. Look, does it make a difference? I honestly dgaf 🤙)

Overview of CVA

Essentially, a CVA is an event wherein there is a reduction or cease of blood flow to the brain of which causes neurological deficit, and irreversible tissue death (necrosis).

There are a number of flavours to strokes, and come under the packaging of being ischaemic (caused by a thrombus [blood clot]/embolus [foreign matter]/stenosis [narrowing]), transient ischaemic attack [TIA] (a "warning stroke" or "mini stroke" that are still a medical emergency, but are also a warning of a stroke to come), or hemorrhagic (from a bleed into the brain from a burst/ruptured blood vessel, often an aneurysm, or by ways of high blood pressure).

Obviously, we need to maintain oxygenation to our brain in order to ✨survive✨, so in cases of severe cellular necrosis from prologued or significant cerebral damage, unfortunately serious disability or death may result from the accident.

A TIA has been defined as an "Episode of sudden focal neurological deficit lasting less than 24 hours and of vascular origin."

Whereas a stroke has been defined as "Rapidly developing symptoms and/or signs of focal (or global) loss of brain function lasting longer than 24 hours or leading to death with no apparent cause other than vascular origin." There is a 10-20% chance of a stroke occurring after a TIA.

Pathophysiology

Vascular origin where there is an interruption of blood flow and therefore reduction or complete absence of oxygen and nutrients delivery to the brain, causing an ischaemic event that affects bodily function.

A TIA is a transient interruption of blood flow to an area of the brain supplied by that particular artery. It is a brief period of ischaemic, where blood flow is restored quickly, and therefore brain tissue is not permanently damaged. One may experience memory loss, and can be caused by a build up of atherosclerotic plaque in an artery or one of its branches supplying oxygen and nutrients to a portion of the brain.

Signs & Symptoms

As mentioned previously, TIAs are often refered to as warning strokes. These warning strokes are temporary periods of symptomatic experiences identical to a full CVA that can indicate that a stroke is to come in the coming hours, days, weeks or months, and thus require monitoring. These may last minutes, and symptoms (incl. unilateral weakness, vision/sspeech issues) often resolve fully within 24 hours.

These are a medical emergency.

Other symptoms may include:
"☞ numbness/weakness in face
☞ change in mental status
☞ Trouble speaking or understanding speech
☞ Visual disturbances
☞ Homonymous Hemianopsia (Loss of half the visual field)
☞ Hemiparesis
☞ Hemiplegia
☞ Ataxia
☞ Dysphagia
☞ Paresthesia
☞ Expressive aphasia
☞ Receptive aphasia
☞ Global aphasia
☞ Motor loss
☞ Communication loss
☞ Perceptual Disturbances & Sensory loss
☞ Impaired cognitive and psychological effects"

See more on this at:
https://nurseslabs.com/cerebrovascular-accident-stroke/

Nursing Cares

Nursing interventions post TIA/CVA are very primarily focussed on managing deficits as a result of the accident, and commencing rehabilitations asap.

We should however in the acute phase be looking at and monitoring level of consciousness, eye opening & pupillary response, presence of involuntary movements, and other observations that relate to the above symptoms that may surface post CVA.

These should include:
- Neurological observations (especially in areas experiencing weakness) [Particularly relevant post TIA]
- General Observations
- Falls risk assessment
- Ability to complete ADLs
- Ability to swallow/speak (incl. risk of aspiration)
- Pain
- Skin integrity
- Elimination / Incontinence
etc.

There may be a care pathway for CVA/TIA specifically with your hospital or doctor to follow.

Risk Factors

1 | Hypertension
2 | Heart disease
3 | ↑ Blood Cholesterol
4 | Smoking / Substance abuse
5 | Diabetes Mellitus
6 | Indigenous Australians have twice the chance of experiencing CVA
7 | Over 75yrs of age have highest incidence
8 | Clotting issues

Diagnostics

CT scan
PET scan
MRI
Cerebral angiography
Lumbar puncture
EEG
Transcranial Doppler Ultrasonography

Treatment & Prevention
of subsequent ischaemic attacks

Post TIA, Anticoagulants will likely be commenced (such as Xarelto, mizart, rrouvastatin, metroprolol). They will do an MRI to determine what has happened and monitor weakness with neurovascular obs alongside neurological obs.. A minor stroke may follow in the coming hours, days, weeks or months.

☞ Quit smoking
☞ Adop low fat, low sodium diet
☞ Regular exercise
☞ Avoiding excessive alcohol consumption
☞ Long term Antiplatelets
☞ After a CT excludes haemorrhage, commencing warfarin in all TIA patients with Atrial Fibrillation, recent MI & cardiac-emboli stroke from valvular heart disease
☞ Statins ☞ Cholesterol lowering agent with dietary advice 

References:
CDC - Stroke Home: https://www.cdc.gov/stroke/about.htm?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fstroke%2Ftypes_of_stroke.htm
Nurse Labs: https://nurseslabs.com/cerebrovascular-accident-stroke/