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The Heart Foundation of Barbados evolves to embrace stroke.
By Dr. David Corbin
Currently, there is no non-governmental organisation in
Barbados that champions the cause of stroke patients. In his report at the 19th
annual general meeting held on March 23, 2005, President Dru Symmonds SCM, J.P. introduced
the plan to expand the organisational structure of the Heart Foundation of
Barbados (HFOB) to embrace stroke. This move is to be welcomed by all interested
in the welfare of patients with either condition and will bring the HFOB in line
with similar NGO’s in Canada, Ireland and the USA that have combined Heart & Stroke interests.
Stroke is caused by abnormalities of blood vessels and like,
heart attacks, is often due to sudden occlusion or blockage of an artery. While
heart attacks involve the coronary arteries, most forms of stroke occur when a
brain (or cerebral) artery becomes blocked. Thus, stroke and heart attacks are
simply different manifestations of blood vessel disease in different parts of
the body and the risk factors for these two conditions are basically the same
and include hypertension, tobacco smoking, diabetes, high blood cholesterol, and
obesity.
Heart & Stroke Associations have been formed in many parts
of the world to the benefit of patients at risk of or who have suffered either
stroke or heart attack. The amalgamation of the two interests under one
organisation is likely to be mutually beneficial to both. Predictably our
membership will increase and consequently the power of advocacy for patient care
issues relating to heart disease and stroke will be better served.
Definition and subtypes of stroke
The term stroke is used to refer to sudden alteration of
brain function. Three subtypes may be identified.
• Ischaemic stroke is due to cessation of blood flow to a
part of the brain leading to irreversible injury, known as infarction. Symptoms
depend on the blood vessel involved and the area of the brain affected.
Cessation of blood flow within a brain artery may be due to a clot within a
vessel (thrombosis) or to blockage of a vessel by a floating blood clot (an
embolus) that has arisen in the heart or within a vessel leading from the heart.
Ischaemic stroke accounts for over 80%
of strokes in Barbados.
• The second commonest subtype is intracerebral haemorrhage,
which implies bleeding into a portion of the brain. The symptoms may be the same
as for ischaemic stroke, except that loss of consciousness may occur earlier in
the course of the illness.
• The third and least common form of stroke is subarachnoid
haemorrhage, meaning bleeding around the brain. This causes sudden excruciating
headache, often without any other symptom.
Symptoms
Symptoms include weakness or numbness on one side of the
body, slurred speech, impairment of language, inability to swallow, visual loss,
perceptual difficulty, and loss of coordination, combined with generalized
depression of brain function leading to drowsiness, confusion, or coma.
Diagnosis
The diagnosis can usually be made by careful physical
examination but a CT
brain scan is necessary to distinguish between intracerebral
haemorrhage and infarction. It was not until 1987, with the introduction of CT
brain scanning at the Queen Elizabeth Hospital (QEH), that stroke could be
accurately diagnosed in Barbados.
Stroke research in Barbados
Preliminary hospital surveys, done in the nineties, showed
that about 250 cases of stroke were admitted to the QEH each year. In 2001, a
formal register was established at the Chronic Disease Research Centre (CDRC) to
determine the true annual incidence of stroke (the number of cases that occur on
the entire island during one year), the distribution of stroke subtypes and the
outcome of stroke in Barbados. The initial planning team of Professor Henry
Fraser, Dr Anselm Hennis, Dr Vishal Poddar, Professor Rainford Wilks (from UWI,
Mona) and myself received valuable collaboration from colleagues working on a
similar register in South London, UK where the incidence of stroke among black
immigrants is twice as high as among the white population. The Wellcome Trust of
the UK funded the study but we also received vital support from the Ministry of
Health who seconded a public health sister (Mrs Sonia Connell) to the project
for the first year, and has approved her continuing attachment full time. The
Barbados Register of Strokes (BROS) is the first community-based incidence study
of stroke in the English-speaking Caribbean. The register team also includes a
research doctor, a data manager (Mrs Glenda Gay) and an administrator (Ms
Maureen Workman).
Further details of the methods are available from the
publication in the journal Stroke entitled Incidence and case fatality rates of
first-ever stroke in a black Caribbean population: The Barbados Register of
Strokes (BROS) (Stroke 2004; 35:1254-1258). Reprints are available from the CDRC.
During the first year, 352 patients were registered. The
highest incidence rate of stroke was in females over 85 years, where roughly 1
in 50 persons suffer a first-ever stroke each year.
Overall, the crude annual incidence of stroke in Barbados
for the entire population is approximately 1.31 cases per 1000 population, which
translates to 1.40 and 1.63 per 1000 for males and females respectively, among
the majority (95%) black population. These rates are not as high as rates
reported for UK or US black communities but are higher than those reported from
Africa. Similarly, prevalence of hypertension, diabetes and obesity increases
among peoples of the African Diaspora, with the lowest prevalence rates in rural
Africa, intermediate rates in the Caribbean and the highest rates in urban black
Americans. During the first 2 years of BROS, among black Barbadians with stroke,
about 60% men and 70% women had a previous physician diagnosis of hypertension,
27% men and 40% women had diabetes and 23% men and 33% women were obese. Our
collaborative research with South London has given us a unique opportunity to
analyse the reasons for the excess incidence of
stroke among black immigrants compared to their Caribbean
counterparts. This stage of the research is now beginning; the results are not
yet clear.
In Barbados the age range of persons suffering their
first-ever stroke was 16 -104 years with the vast majority being over age 65.
Stroke subtype
We were able to determine the stroke subtype in about 95% of
cases: 83% were ischaemic, while we observed intracerebral haemorrhage in 10%
and subarachnoid haemorrhage in 3%. Overall, about 2 of 3 patients with stroke
were admitted to hospital for investigation and management of clinical
complications. Patients who were admitted tended to have had more severe strokes
although the mean age of those admitted was very similar to those managed in the
community by their doctors.
Stroke outcome
Our results have shown that the chances of surviving an
acute stroke are closely linked to the stroke subtype. Overall, when all
ischaemic strokes are considered together, the risk of death is about 19%
whereas in ischaemic strokes due to blockage of a large (as compared to a very
small artery) prognosis is poor, and 2 of every 3 patients die within 30 days.
Likewise if the stroke is due to intracerebral haemorrhage the risk of death
within 30 days is 40%. Other studies have shown that outcomes can be improved
with less disability by providing intensive multidisciplinary hospital care to
as many stroke patients as possible. In the next phase of BROS, we aim to
examine and reform the process of hospital care in an effort to improve these
poor outcomes.
To date, over 1100 persons suffering their first ever stroke
have been registered with BROS. All surviving patients are contacted 3 months, 1
year and 2 years after the onset of the stroke, either by telephone or by
community visit, and a mutually convenient time is arranged for a person to
person structured questionnaire to be administered with a caregiver / helper
present when necessary. Details of living and social conditions, medical
treatment, level of independence, degree of disability, employment status, use
of community resources and stroke recurrence since the first-ever stroke are
recorded. Our follow up rates have been impressive. Over 99% of the first year
cohort has been accounted for: 62% were alive at 3 months, 54% at 1 year and 41%
at 2 years. These figures underline the fact that stroke is an important cause
of chronic disability in our community. In Barbados, most survivors live at home
with at least one other person, very few are in institutional care. Stroke is a
potential source of stress for the caregivers and their families. We believe
that supportive mechanisms for these groups need to be strengthened.
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