Stroke Cause Management Prevention and Treatment

what is stroke 

Stroke

A stroke is defined as a sudden onset of non-traumatic
focal neurological defect of a vascular aetiology, that either
causes death or lasts more than 24 hours

or

a stroke or a (cva)occurs when blood supply to part of the brain is disrupted,causing brain cell to die
types there are two types of the stroke
the most common are called ischemic and 2nd is hemorrhagic stroke
Incidence
Third commonest cause of death in Western World (1–2
per 1000 per year).

effect of  Age 

Uncommon under 40 years.

Aetiology

20% of strokes are haemorrhagic and 80% are ischaemic,
of which two-thirds arise from extracranial lesions and
one-third arise from intracranial lesions. Strokes may
also be due to subarachnoid haemorrhage. Risk factors
for stroke can be divided into
Intra- or extra-cranial atherosclerosis: In particular
hypertension, smoking, hyperlipidaemia, family history
of stroke or ischaemic heart disease and diabetes
mellitus.
Heart disease: Valvular heart disease such as mitral
stenosis, infective endocarditis, and any condition
which predisposes to mural thrombus such as atrial
fibrillation or myocardial infarction.
Less common causes: Hyperviscosity or prothrombotic
states, e.g.polycythaemia, oral contraceptive pill;
vasculitis; clotting disorders

Pathophysiology

Haemorrhagic strokes are discussed elsewhere. Ischaemic
strokes are due to the interruption of arterial blood
supply, and the clinical picture depends on the size of
artery and hence extent of territory affected, the area
affected, and whether there is temporary or permanent
ischaemia and hence infarction

Clinical features

Anterior circulation (carotid territory) strokes are the
most common, in particular those involving a branch of
the middle cerebral artery. This causes infarction of the
motor pathways (at the level of the motor cortex or the
internal capsule) and usually results in a contralateral
hemiparesis. This is an upper motor neurone (UMN)
deficit, i.e. increased tone, reduced power and brisk tendon
reflexes, although acutely there may be a flaccid,
areflexic paralysis. The arm tends to be affected more
than the leg (the motor cortex for the leg is supplied by
the anterior cerebral artery).
Other features of an MCA territory infarct include
an ipsilateral UMN lesion of the face (weakness of
the lower facial muscles), hemianopic visual field
loss and if the dominant hemisphere is affected
dysphasia may occur due to infarction of areas governing
speech (Wernicke’s and Broca’s areas).
Posterior circulation (the vertebral, basilar arteries and
their branches) strokes affect the brainstem, cerebellum
and occipital lobes. One characteristic but uncommon
pattern is lateral medullary syndrome which can
be caused by thromboembolism of the posterior inferior
cerebellar artery (PICA) or the vertebral artery. It causes
sudden vertigo and vomiting. On examination there is
ipsilateral ataxia (loss of co-ordination), contralateral
loss of pain and temperature sensation and there may
be nystagmus, diplopia and an ipsilateral Horner’s syndrome

Macroscopy

In the first 24 hours, there is little macroscopic change.
The tissue may look paler and lose differentiation between
white and grey matter.
The normal pattern of tissue change within the
brain following a stroke is liquifactive necrosis. Structural
breakdown takes place, the infarcted tissue becomes
soft and is at risk of reperfusion haemorrhage

Management

Patients who present within 3 hours of onset of symptoms
who have no evidence of haemorrhage or large
infarct on CT head scan should be considered for
thrombolysis.
Acutely, treat any exacerbating factors such as hypotension,
hypoglycaemia, hyperglycaemia, or severe
hypertension (with caution, to prevent sudden loss
of perfusion pressure, particularly in the acute stages,
when the brain is unable to autoregulate BP well).
Prevent and treat any complications such as deep vein
thrombosis due to immobility, aspiration pneumonia
due to disordered swallow, pressure sores and limb
contractures.
Inpatient or outpatient rehabilitation is used to regain
maximal functional improvement, and so reduce
the impact on the patient’s life, including physiotherapy,
speech therapy, and occupational therapy. Patients
who are admitted to a dedicated stroke unit have
been shown to have improved functional outcomeand
reduced mortality.

Prevention of recurrence

Any risk factors present
should be treated. All patients with ischaemic (not
haemorrhagic) stroke should ideally be on an antiplatelet
agent such as aspirin. Cholesterol-lowering
agents (statins) and anti-hypertensive agents have also
been shown to reduce recurrence. Anti-coagulants are
indicated in certain conditions such as atrial fibrillation
and valvular heart disease, but only after approximately
2weeks andwhen blood pressure is controlled,
to reduce the risk of haemorrhage into infarcted
tissue

Prognosis

Overall, 40% of patients die as the result of their stroke
(mainly in the first month), 40% are left significantly
disabled and 30% have reasonable recovery

treatment 

A stroke is medical emergency .immediate treatment can save lives and reduce disability,
so it is very important for people who are having stroke symptoms to get hospital as a quickly
as  possible
treatment depend upon type of stroke .in hospital a ct scan or MRI must be done to see
whether the stoke is from a clot or from bleeding .clot-busting drugs such is
(thrombolytic therapy)
and blood thinner such as heparin are prescribed for treatment