As a cause of death stroke is surpassed only by heart disease, worldwide; in the
USA, stroke ranks behind cancer and heart disease. It accounts for about 10% of all deaths in most developed countries.
About 30% of stroke victims, and even more of those aged over 65 years, die within 1 year. In the USA stroke victims
stay in hospital for an average of 7.3 days.
Framingham Study
An NIH-funded study that is administered by researchers at Boston University. In 1948, the
Framingham Heart Disease Epidemiology Study enrolled 5,209 residents of the Framingham, Massachusetts community
between the ages of 28 and 62, and followed up by examining them every 2 years since that time. Through this study,
the longest running prospective epidemiological study in history, which has been on-going continuously for over 50
years, most of the currently known risk factors for stroke have been identified. Newer modifiable risk factors are also
being recognized such as elevated blood levels of homocysteine and C-Reactive protein in stroke-prone persons. This
elucidation of risk factors has facilitated to the institution of therapies that can substantially reduce the risk
of stroke in high risk individuals.
Of 123 survivors of documented completed stroke from the Framingham Cohort, 119 received objective evaluations of
functional status along with an equal number of controls matched for age and sex. Of the stroke survivors, 16% were
institutionalized, 31% dependent in self-care, and 20% dependent in mobility. In addition, 71% had decreased vocational
function, and 62% decreased socialization outside the home. Each of these frequencies was significantly greater than
the corresponding rate in the control group.
The severity of the stroke and the brain territory it affects determine the type and severity of residual
disabilities, which may include speech difficulties, loss of sensory function, bilateral loss of motor control,
or hemiparesis.
References:
American Heart Association. 2002 Heart and Stroke Statistical Update.
Wolf PA. www.bumc.bu.edu/www/busm/nu/files/StrokeProgram.html
Kiely et al. Stroke 1993; 24:1366-1371.
Gresham et al. N Engl J Med 1975; 293 (19): 954-956.
Prognosis of Ischaemic Stroke
Reference:
Grau AJ, et al. Stroke 2001;32:2559-2566.
| Modified Rankin Scale (mRS) Scores |
 |
|
| 0 |
No symptoms at all |
|
| 1 |
No significant disability despite symptoms; able to carry out all usual duties and activities |
|
| 2 |
Slight disability; unable to carry out all previous activities, but able to look after own affairs without assistance |
|
| 3 |
Moderate disability; requiring some help, but able to walk without assistance |
|
| 4 |
Moderately severe disability; unable to walk without assistance and unable to attend to own bodily needs without assistance |
|
| 5 |
Severe disability; bedridden, incontinent and requiring constant nursing care and attention |
|
| 6 |
Dead |
|
Reference:
Grau et al. Stroke 2001; 32: 2559-2566.
Short-term Prognosis after Emergency Department of TIA
During the 90 days after index TIA, 428 of 1707 patients (25.1%) experienced a stroke or other
adverse event (recurrent TIA, cardiovascular event or death).
The results show that, in patients who present at an emergency department with a TIA, the short-term risk of stroke,
other adverse events and death is high. Half of the strokes occurred within 2 days of the TIA. Currently available
interventions for patients with TIA may not be cost-effective if used in all such patients. This study identified
five independent risk factors for stroke within 90 days after TIA: age over 60 years, diabetes mellitus, episode
longer than 10 min, and weakness and speech impairment with the episode. These risk factors may identify patients
whose symptoms are more likely due to cerebral ischaemia or may indicate pathophysiological conditions associated
with greater risk.
Reference:
Johnston et al. JAMA 2000; 284: 2901-2906.
TIA / Stroke Survivor’s Greatest Risk is Stroke, not myocardial infarction (MI)
This study collected data from four secondary prevention trials, the CATS trial with aspirin,
the TASS trial with ticlopidine, the CAPRIE trial with clopidogrel and ESPS 2 with ASA/ER-DP. Virtually all studies
have shown that stroke-related deaths are considerably more common than cardiac deaths during the first few years
after stroke onset, when patients are most likely to participate in clinical trials of antiplatelet agents.
In later years cardiac-related deaths increase.
Reference:
Albers, GW. Neurology 2000;14;54 (5):1022-1028.
Mortality Following Stroke
This was a population-based study conducted in Rochester, Minnesota in which people suffering a
stroke were followed for up to 18 years to determine the cause of death.
For those with an initial stroke, the risk of death from stroke is more than 2.5 times the risk of death from MI.
Reference:
Petty GW, et al. Neurology 1998; 50:208-216.
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