Stroke Flashcards
What is a stroke?
A stroke is a medical condition in which poor blood flow to the brain causes cell death.
What distinguishes a TIA from a stroke?
A 24 hour limit
Stroke = neurological deficit of cerebrovascular cause that persists beyond 24 hours or is interrupted by death within 24 hours
What are the two types of stroke?
- Ischaemic
2. Haemorrhagic
What type of stroke is most common?
Ischaemic: 87% of all strokes
What are the four causes of an ischaemic stroke?
- Thrombosis
- Embolism
- Systemic hypoperfusion
- Cerebral venous sinus thrombosis
What are the two main types of haemorrhagic stroke?
- Intracerebral hemorrhage - bleeding within the brain itself
- Subarachnoid hemorrhage- between the arachnoid mater and pia mater
What are the three layers of the meninges?
Dura mater (on the outside) Arachnoid mater Pia mater (inside)
What are the signs and symptoms of a stroke?
Stroke symptoms typically start suddenly, over seconds to minutes, and in most cases do not progress further.
A mnemonic to remember the warning signs of stroke is FAST (facial droop, arm weakness, speech difficulty, and time to call emergency services)
What is a tract lesion caused by stroke?
When the brain area affected by the stroke affects a prominent central nervous system pathway:
- Spinothalamic tract
- Corticospinal tract
- Dorsal column-medial lemniscus pathway
What are symptoms of a stroke-induced tract lesion?
Hemiplagia and muscle weakness of the face
Numbness
Reduction in sensory or vibratory sensation
Initial flaccidity, replaced by spasticity and excessive reflexes
What is the prognosis after a stroke?
Disability affects 75% of stroke survivors enough to decrease their ability to work
Emotional and mental dysfunctions correspond to areas in the brain that have been damaged (disruption of self-identity)
30 to 50% of stroke survivors suffer post-stroke depression, which is characterised by lethargy, irritability, sleep disturbances, lowered self-esteem and withdrawal
How would you manage an ischaemic stroke?
Definitive therapy within the first few hours is aimed at removing the blockage by breaking the clot down (thrombolysis with alteplase 900mg/kg), or by removing it mechanically (thrombectomy)
How would you manage a haemorrhagic stroke?
Mainly: discontinuation of warfarin-like substances, start of blood pressure control
People with intracerebral haemorrhage require supportive care, including blood pressure control if required. People are monitored for changes in the level of consciousness, and their blood sugar and oxygenation are kept at optimum levels. Anticoagulants and antithrombotics can make bleeding worse and are generally discontinued
What is primary prevention of a stroke?
The most important modifiable risk factors for stroke are high blood pressure and atrial fibrillation
Other modifiable risk factors include:
- high blood cholesterol levels
- diabetes mellitus
- end-stage kidney disease
- cigarette smoking (active and passive)
- heavy alcohol use
How would you diagnose a stroke?
Stroke is diagnosed through several techniques: a neurological examination (such as the NIHSS), CT scans (most often without contrast enhancements) or MRI scans, Doppler ultrasound, and arteriography.
The diagnosis of stroke itself is clinical, with assistance from the imaging techniques.
