Page 301 - Medicine and Surgery

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Chapter 7: Cerebrovascular disease 297

Macrophages enter the infarct and remove the dead beenshowntohaveimprovedfunctionaloutcomeand
tissue, whilst around the edges astrocytes proliferate reduced mortality.
and healing takes place by scarring (gliosis). Large Prevention of recurrence: Any risk factors present
infarcts cannot be completely replaced and heal as should be treated. All patients with ischaemic (not
spaces surrounded by gliosis. haemorrhagic) stroke should ideally be on an anti-
platelet agent such as aspirin. Cholesterol-lowering
agents (statins) and anti-hypertensive agents have also
Investigations
been shown to reduce recurrence. Anti-coagulants are
CT brain scanning is used to differentiate between

indicated in certain conditions such as atrial fibrilla-
haemorrhage,infarctionandaspaceoccupyinglesion.
tion and valvular heart disease, but only after approxi-
The scan may be normal in the first 24–48 hours, al-
mately 2 weeks and when blood pressure is controlled,
though large infarcts normally show due to oedema
to reduce the risk of haemorrhage into infarcted
and loss of differentiation between white and grey
tissue.
matter. MRI scans are more sensitive.
Internal carotid endarterectomy is not justified un-
Investigation of underlying cause

less there have been unequivocal transient ischaemic
Full blood count: Haemoglobin and platelets for poly-
attacks or stroke within 6 months with good recov-
cythaemia, anaemia or thrombocytopenia/ throm-
ery and significant ipsilateral carotid artery stenosis
bocytosis, ESR for vasculitis/arteritis.
(>70%). There is a 1–5% risk of stroke or death due to
Urinalysis and blood glucose for diabetes mellitus.
the surgery. The artery is clamped with cerebral blood
Cardiac investigation: Blood pressure measurement,
flowmaintainedbycollateralsupplyorbyashunt.The
chest X-ray, ECG for recent infarct/arrhythmia.
stenosing plaque is shelled out and the artery repaired
Transthoracic is indicated and transoesophageal
by suture or a patch. The procedure is increasingly be-
echocardiography may also be required.
ing done under local anaesthesia or by endovascular
Carotid doppler studies to examine for carotid vas-
stenting.
cular disease particularly in younger patients or if
signs dictate. Further investigation such as carotid
Prognosis
and vertebral angiography may be indicated.
Overall, 40% of patients die as the result of their stroke
(mainly in the first month), 40% are left significantly
Management disabled and 30% have reasonable recovery.
Patients who present within 3 hours of onset of symp-

toms who have no evidence of haemorrhage or large Transient ischaemic attack (TIA)
infarct on CT head scan should be considered for
thrombolysis. Definition
Acutely, treat any exacerbating factors such as hy- Non-traumatic focal neurological deficit due to cerebral

potension, hypoglycaemia, hyperglycaemia, or severe ischaemia lasting less than 24 hours with a complete
hypertension (with caution, to prevent sudden loss clinical recovery. TIAs may recur or precede a stroke.
of perfusion pressure, particularly in the acute stages,
when the brain is unable to autoregulate BP well). Aetiology/pathophysiology
Prevent and treat any complications such as deep vein 90% of transient ischaemic attacks are caused by ex-
thrombosis due to immobility, aspiration pneumonia tracranial thromboembolic disease within the great ves-
due to disordered swallow, pressure sores and limb sels, the carotid or vertebral arteries, or mural thrombi
contractures. following a myocardial infarction.
Inpatient or outpatient rehabilitation is used to re-

gain maximal functional improvement, and so reduce Clinical features
the impact on the patient’s life, including physiother- TheonsetofaTIAisidenticaltothatofastroke,buttends
apy, speech therapy, and occupational therapy. Pa- to last minutes or hours. The site of the lesion is often
tients who are admitted to a dedicated stroke unit have suggested by the clinical pattern. Common symptoms