| Stroke Risk Factor |
|
|---|
| Hypertension (Systolic or diastolic) | increases risk x 2-4. Hypertension is a major risk factor for ischaemic and even more so for haemorrhagic stroke (x 9) . Hypertension (Each 100 mmHg diastolic or 20 mmHg systolic
doubles stroke rate). It is not acute rises but chronic sustained elevations in blood pressures which damage deep penetrating arteries which occlude or bleed and in larger vessels accelerate atherosclerosis as well as causing cardiac damage and atrial fibrillation. |
| Age | No age group is immune to stroke. There is even a baseline level of strokes in infants and children increasing gradually through all age groups with a steep rise in those over 75. Incidence doubles with every decade over 55. It is uncommon but any medium-sized unit will see several 18-30-year-olds per year with stroke. Stroke is often the cause of death in the frail elderly. |
| Male gender | Stroke is slightly more common in males ( x 1.2) really until age > 75 when the balance between sexes tends to reduce and equalise in old age. |
| Diabetes Mellitus | increased by 2-6 times |
| Race | All types of stroke is commoner in Blacks but especially ICH. Chinese, Asians and Blacks have an increased risk of ICH. Blacks and East Asians have an increased incidence of intracranial atherosclerotic disease |
| AF/PAF or atrial flutter and sick sinus syndrome | See CHADSVASC scoring for risk assessment |
| Valvular heart disease | rheumatic mitral stenosis with AF hugely increases cardioembolic risk |
| Previous stroke or TIA | |
| Carotid stenosis | is itself a direct marker of an
atherosclerosis process that can either result in the throwing of emboli or
occluding the carotid and causing ipsilateral infarction |
| Dyslipidaemia | Stroke is commoner with elevated Cholesterol
and LDL. The relationship is not as clear cut as with IHD. There may be
a relationship between low cholesterol and intracerebral haemorrhage. |
| Current Cigarette smoking | increases stroke risk by 50% which is far
less than the risk related to IHD. Stronger link with ischaemic stroke. Cessation reduces ischaemic stroke. |
| Oral contraceptive and HRT | Doubles the stroke risk for low
oestrogen content and increased by four times for higher oestrogen
content. Can increase risk of thromboembolic stroke and cerebral venous
thrombosis and subarachnoid haemorrhage though the absolute risk is
very low and pregnancy itself has stroke risks. Particularly concerning
is the combination of OCP with other risk factors such as smoking and
migraine with aura or thrombophilia |
| Family history | |
| Psychosocial stress | Mild increase in stroke risk by about x 1.3 |
| Physical inactivity | (increased risk by 2.5). Physical activity appears to be protective of both ischaemic ahd haemorrhagic stroke. |
| Excess alcohol | Increases risk by 50-100% once more than 30 drinks per month or binge drinking. Moderate alcohol appears protective. Relationship stronger for haemorrhage. |
| Obesity | Often complex and hard to disentangle risks for
instance it is suspected now that obesity itself is not a risk of
itself but the increased stroke risk is due to the additive risk from the
increased diabetes and hypertension associated with obesity. Still
management is to address the obesity and lose weight. |
| Pregnancy and puerperium | risk of stroke in the days before
birth and the 6 weeks after is rare it is one of the commoner settings
for stroke in young adults related possibly to a hypercoagulable state
and vessel wall changes. |
| Migraine | Record whether migraine with aura or not. Migraine
with aura appears to double stroke risk. Increased risk if under 45,
smoking and on OCP. Mostly posterior circulation. Migraine also
associated with dissections, Antiphospholipid syndrome, CADASIL and
MELAS and Essential thrombocythaemia. |
| Polycythaemia | HCT > 0.5 in males and 0.47 in females is associated with increased stroke risk |
| Antiphospholipid (aPL) antibodies | found in autoimmune conditions and can be associate with stroke mainly in young females. |
| Illicit drugs | Drugs with a sympathomimetic effect
(amphetamine, cocaine, crack) can cause ischaemic stroke through
several mechanisms such as acute hypertension enhanced platelet
aggregation, and rarely vasculitis (mainly related to amphetamine
intake) of the polyarteritis nodosa or giant cell-granulomatous types. |
