Stroke management Flashcards
a stroke is defined as
a stroke is defined as a neurological deficit lasting greater than 24 hours and is cerebrovascular in nature.
Strokes can be classified into two main types, ischaemic and haemorrhagic, both being described as a cerebrovascular accident or CVA.
An ischaemic stroke is defined as:
“an episode of neurological dysfunction caused by focal cerebral, spinal or retinal infarction whose symptoms persist for longer than 24 hours”
- Ischaemic strokes are caused by interruption of the blood supply to part of the brain whilst haemorrhagic strokes are caused by rupture of a cerebral artery. Both types of stroke produce very similar clinical signs and symptoms.
A transient ischaemic attack or TIA (described as a mini-stroke) is defined as
“a transient episode of neurological dysfunction caused by focal cerebral, spinal or retinal infarction without acute infarction”.
The symptoms of a TIA are transient and can last from a few minutes to hours but for less than 24 hours. Patients who have a TIA are at high risk for developing an early acute ischaemic stroke
The most common causes of stroke are:
- Arterial embolism from another site (e.g. heart, carotid artery)
- Arterial thrombosis
- Haemorrhage (intracranial or subarachnoid)
Less common causes of stroke include
- Venous infarction
- Fat or air embolisms (e.g. from scuba diving)
- Multiple sclerosis
- Carotid or vertebral artery dissection
- Brain tumours
There are many risk factors for stroke, most of which are modifiable, including:
Hypertension Smoking / tobacco use Excessive alcohol intake Raised cholesterol Poor diet Lack of exercise Atrial fibrillation Obesity Diabetes Sleep apnoea
Presenting symptoms and diagnosis
Symptoms of stroke include: Numbness Weakness or paralysis of the face, arm and leg (usually only one side of the body) Slurring or loss of speech Confusion Blurring of vision Severe headache (uncommon)
Both ischaemic and haemorrhagic strokes will present with very similar symptoms. The location of the tissue damage within the brain determines these symptoms.
contralateral hemiplegia (complete paralysis) or contralateral hemiparesis (slight paralysis or weakness).
The most common forms of stroke are those where one of the middle cerebral artery branches is involved or (extracerebrally) one of the internal carotid arteries is stenosed or occluded. Within seconds or minutes of the infarct occurring, weakness on the opposite side to the infarct will begin.
Neurological features may be classified as ‘negative’ or ‘positive’ to aid differential diagnosis. Negative symptoms, which a stroke usually produces include:
Positive neurological symptoms such as:
Negative symptoms, which a stroke usually produces include:
- loss of sensation
- weakness, and
speech impairment
Positive neurological symptoms such as:
- shaking limbs
- tingling sensation
- flashing lights
- may sway diagnosis to that of what is described as a ‘stroke mimic’ instead.
The Face Arm Speech Test (FAST)
This is a reliable tool since it has good predictive value in identifying stroke, however it is not infallible. Using the FAST test in the pre-hospital setting can pinpoint the most symptomatic features for diagnosing a stroke. These are facial weakness, arm and leg weakness and disturbance of speech.
ROSIER (Recognition of Stroke in the Emergency Room)
Within A&E departments the ROSIER (Recognition of Stroke in the Emergency Room) scale is used. This is a much more thorough tool and takes minutes to use. The patient can be assessed promptly and then appropriate admissions pathway and rapid investigations followed.
Management and treatment
Any patient presenting with with signs and symptoms of acute stroke should be treated as a medical emergency. Treatment within the first 3 hours of symptoms onset is critical to restoring function and improving patient outcomes.
NICE CG68 states that patients diagnosed with stroke (either in the community setting or A&E) should be admitted to a Specialist Stroke Unit as soon as possible. NICE defines a Specialist Stroke Unit as a ‘discrete area’ in the hospital staffed by a specialist stroke multidisciplinary team. It has access to equipment for monitoring and rehabilitating patients. Regular multidisciplinary team meetings occur for goal setting.
Imaging
Before appropriate treatment can be given the nature of the stroke must be established e.g. ischaemic or haemorrhagic in nature. Both CT (most commonly used) and MRI scans are indicated with MRI scans being the better tool to detect ischaemia in the early stages of the stroke. Imaging scans will allow the medical team to rule out intracranial bleeding as a cause. Scanning should ideally be undertaken within one hour of presentation of symptoms
Drug treatment
- Thrombolysis
- Antiplatelets and anticoagulants
- Blood pressure control and antihypertensives
- Statins
statins
A statin should be initiated 48 hours after symptom onset irrespective of serum cholesterol measurements. A statin of high intensity (refer to your BNF statin table) should be offered to the patients diagnosed with either a TIA or a stroke.
thrombolysis
If an ischaemic cause is confirmed (or a haemorrhagic one ruled out) then thrombolysis with a thrombolytic (fibrinolytic) agent such as alteplase is indicated provided it can be given, ideally, within the first 3 hours of symptom onset. There is little data to support the safety and efficacy of alteplase in patients presenting for treatment after 4.5 hours of symptom onset. The shorter the ‘door to needle’ time the better.
Careful consideration to the use of a thrombolytic is given since there are contraindications to their use.
