Management Of Stroke Health Article

Prognosis

Patients who have suffered a stroke are at high risk of vascular death. Heart disease (40%) is the most common cause of death after the immediate post-stroke period, followed by further stroke (25%) and other vascular causes (5%). The most common vascular event in the first year is recurrent stroke.

Recovery: about 10% of patients die within 30 days of stroke – one-half from immobility-related causes and one-quarter from direct neurological sequelae. Of those who survive, about 50% remain disabled after 6 months and one-third are functionally dependent at 1 year. Most stroke patients experience some degree of recovery. Various mechanisms have been postulated, including restoration of blood supply, resolution of oedema, and neuroplasticity in which intact areas of the brain take over the functions of neighbouring damaged areas. Adaptive changes are also important, particularly in the later phases of recovery, when patients learn means of overcoming their impairments.

The extent of recovery is difficult to predict for individual patients, particularly immediately after stroke. Improvement is most rapid in the first few days and weeks, but may continue more slowly for 1–2 years. Data from the Oxford Community Stroke Project suggest that patients with lacunar infarcts or posterior circulation infarcts have a better prognosis as a group than those with total anterior circulation infarcts or primary intracerebral haemorrhage ( Figure 7). ⁹ However, some patients with relatively small-volume lacunar infarcts remain severely handicapped if the infarct is located in an area containing densely packed fibres (e.g. pyramidal tract).

In individual patients, measures of clinical severity at stroke onset (closely correlated with volume of brain lesion) are at least as useful as more sophisticated methods in predicting outcome.

Risk of recurrent stroke: it has recently become clear that the early risk of recurrent stroke after TIA or minor stroke is higher than previously thought ( Figure 8 a): ¹⁰

• 7-day risk is 8–12%

• 1-month risk is 18%.

A simple six point clinical score, the ‘ABCD’ score, has recently been developed that allows the early risk of stroke recurrence after TIA to be assessed in an individual patient ¹¹ : age [>or = 60 years = 1], blood pressure [systolic>140 mm Hg and/or diastolic > or = 90 mm Hg = 1], clinical features [unilateral weakness = 2, speech disturbance without weakness = 1, other = 0], and duration of symptoms in min [> or = 60 = 2, 10–59 = 1, <10 = 0]. The 7-day risk is 0.4% in patients with a score less than 5, 12% with a score of 5, and 31% with a score of 6.

In patients with carotid atheroma, the risk of stroke is strongly related to the severity of ipsilateral extracranial carotid stenosis, and to whether the stenosis is symptomatic (15%, 5% and 2% in successive years after the index event) or asymptomatic (2% per year). In those on medical treatment, the annual risk of stroke from symptomatic stenosis involving the intracranial carotid or the middle cerebral artery is about 7–10%. Extracranial vertebral artery stenosis is thought to be relatively benign, but basilar stenosis is associated with a higher risk of stroke.

In patients with primary intracerebral haemorrhage, available data suggest an annual risk of recurrent stroke of about 7% (25% haemorrhagic). The risk is increased in those with an underlying cause (e.g. arteriovenous malformation, cerebral amyloid angiopathy, poorly controlled hypertension).

• Heart disease is the most common cause of death after the first 30 days in patients who have suffered an ischaemic stroke

• All patients admitted to hospital with stroke should be managed on a stroke unit, because such units reduce death and dependency

• Thrombolysis is effective in acute ischaemic stroke if given within 3 hours of stroke onset

• Patients with TIA or minor stroke should undergo urgent assessment, because the risk of recurrent ischaemic stroke is highest in the first few days

• Atherothromboembolic strokes are most likely to recur early, and in patients with carotid atheroma the risk of recurrence is strongly correlated with the degree of stenosis

• Carotid endarterectomy for high-grade symptomatic stenosis prevents recurrent stroke, but the benefit declines with time since stroke