World Stroke Day is on October 29:

Prevent, minimise stroke risks with timely treatment

By Carol Aloysius

Stroke continues to be one of the leading disabling diseases and cause of death in Sri Lanka and worldwide.

Recent studies in Colombo and Gampaha districts have shown that around one percent of the population develop stroke every year. The numbers could be higher as there are no national statistics. A worrying fact is that stroke once perceived to be a disease that affects mostly elderly persons over 70 years of age, is now seen among younger people in their late fifties and early sixties. Modifiable and non modifiable risk factors have contributed to this, says a leading authority on the subject, who says preventing the modifiable risk factors can eliminate the danger of developing stroke, while timely interventions and treatment can minimise the severity of disabilities that result from a stroke.

Consultant Neurologist and Secretary National Stroke Association Dr Harsha Gunasekara spells out some of the Do’s and Don’ts to prevent and to minimise disabilities from the disease, in this interview on the eve of World Stroke Day.

Excerpts…

Question: Stroke is one of the leading causes of illness and death worldwide and in Sri Lanka. Compared to the incidence about a decade ago, is there a significant increase? If so why?

Answer: Stroke is the third leading cause of death and the leading cause of disability worldwide. In Sri Lanka, stroke has taken the second or the third place for hospital deaths. However, national statistics on stroke incidence are not available to date in Sri Lanka. Two community based studies done in Colombo and Gampaha districts however, show that around one percent of the population develop stroke annually.

Q. Is it because we are a developing country, or is it the same in developed countries in the west? What is the cause of the difference?

A. There is a definite increasing trend in the stroke incidence and mortality in the developing countries such as Sri Lanka. In developed countries, the incidence of stroke is declining, largely due to efforts to lower blood pressure and reduce smoking.

However, the overall rate of stroke remains high due to the aging of the population.

Q. What are the main reasons for stroke? Stress? Ageing? Modern life styles? Poverty?

A. The three major causes for this in developing countries such as ours include change in lifestyle associated with urbanisation, increase in the ageing population and poor socio-economic status which hinders successful strategies for prevention and treatment of stroke.

Q. Are they similar to the factors that have led to a rise in other non communicable diseases (NCDs)?

A. There is considerable overlap among the risk factors for stroke and other NCDs (heart disease and cancer), and they are more or less same for heart disease and stroke.

Risk factors

The five major risk factors for stroke are smoking, high blood pressure, diabetes, atrial fibrillation (irregular heart rhythm which predisposes to stroke) and Carotid artery disease (narrowing of the major arteries which feed the brain).

All these five major risk factors are modifiable, which means that if you correct them (for example quitting smoking, treating high blood pressure, diabetes and irregular heart beat) you can prevent a stroke.

The other modifiable risk factors include obesity, physical inactivity, high blood cholesterol levels, some heart diseases, use of contraceptive pill and post-menopausal hormone replacement, diseases which predisposes to abnormal blood clotting, excessive alcohol consumption, and narcotic drug use.

The non-modifiable risk factors include advanced age, male gender, and family member with stroke. Those with Asian and afro-Caribbean ethnicity and low birth weight are also at risk.

Q. Is stroke the cause of heart attacks or vice versa?

A. Stroke is not a cause of heart attacks but due to the similarity of causative risk factors, a person with a stroke has a higher risk of developing a heart attack. On the contrary, heart attacks can give rise to stroke, especially in the early stages due to the development of blood clots within the damaged heart.

Q. When a person gets a stroke how soon should he or she be taken to hospital to prevent complications?

A. Most of us are aware that a person with symptoms of a heart attack should be taken to the nearest hospital immediately. The practice should be exactly the same after a stroke.

Heart attacks occur due to blockage of a blood vessel feeding the heart muscle. Similarly, over 85 percent of stroke occur due to blockage of a blood vessel feeding the brain (the rest due to ruptured blood vessel causing a brain bleed).

Therefore stroke is a “brain attack”. A person with symptoms of a suspected stroke should be taken to the nearest hospital immediately.

There are two main reasons for this. Firstly, to perform a CT scan to rule out or confirm a brain bleed and secondly to initiate treatment without delay.

Symptoms

Q. What are the early symptoms? How do you recognise them if a family member develops them at home?

A. As the name implies, symptoms of stroke “strike” you suddenly.

There is a wide range of symptoms depending on the area of the brain affected and the common ones are numbness or weakness of one side of the body or one limb alone, disturbance of speech, impaired vision in one eye or double vision, impaired balance and co-ordination and impaired swallowing and bladder control.

Sometimes headache, vomiting and impaired level of consciousness can occur especially in the case of a brain bleed.

Since remembering all these symptoms is difficult, Stroke Organisations have put forward a simple test called FAST – Face, Arm, Speech, Time which is explained in the diagram. If any of the three checks are positive, the patient should be taken to the nearest hospital immediately.

Around a quarter of patients with stroke may experience a Transient Ischaemic Attack (TIA or mini stroke). Here the symptoms of stroke last only for a few minutes and then rapidly resolve. This condition should be given serious consideration and treatment initiated as it may be the only warning one may get before developing a major stroke.

Treatment

Q. What is the first line of treatment?

A. Doctors will first assess the patient to confirm a stroke and determine the risk factors, then do investigations including a CT scan. Initial treatment involves monitoring and controlling the blood pressure (which should not be too high or too low in the early stages after a stroke), blood glucose level, oxygen level, and if needed measures to reduce brain swelling.

Once a brain bleed is ruled out, blood thinning (anti-platelet) treatment is initiated. Patients will also be given cholesterol lowering drugs.

If the patient is brought to the hospital and a brain bleed is ruled out within three hours, clot buster treatment is given in a few hospitals where it’s available.

All patients with stroke should also be assessed and treated for possible complications such as infections (of the lungs and the urinary passage), DVT (clots in the leg veins), pressure ulcers and depression. Stroke patients should be managed with the aim of preventing these complications which would otherwise adversely affect recovery from stroke.

Q. Thereafter what is the next step towards rehabilitating victims?

A. Rehabilitation of a stroke victim requires multidisciplinary support and is best - undertaken in the setting of a stroke unit. A Stroke Unit is a hospital unit (may be separate or part of a ward) that cares for stroke patients exclusively or almost exclusively, with specially trained staff and a multidisciplinary approach to treatment and care. The multidisciplinary team consists of doctors, nurses, physiotherapists, occupational therapists, speech and language therapists, psychologists/counsellors and a social worker.

It has been proven that treatment in a stroke unit improves chances of survival and reduces both disability and length of hospital stay.

Q. After a stroke, are there any dietary guidelines?

A. Dietary guidelines are not specific for stroke victims but should be followed by all to prevent a first or a recurrent stroke and other NCDs.

The diet should be rich in fruits and vegetables and low-fat dairy products and reduced saturated and total fat, sugar and salt. Cessation of smoking and limitation of alcohol intake are essential.

Q. What about exercise? Can a stroke victim cycle, swim, walk, climb stairs, carry weights/play tennis?

A. Guidelines for exercise recommend increased moderate aerobic physical activity for 150 minutes a week (i.e. 30 minutes a day for five days).

There is no limitation of the type of aerobic physical activity as long as the patient can cope with it safely (especially with the aim of avoiding falls).

Q. Is there a limit to such exercises? Do they have to be under medical supervision?

A. Supervision and guidance by a physiotherapist or carer may be needed in the initial period. In the presence of heart or lung disease, close medical supervision may be required.

Q. Once a stroke victim, are you always a stroke victim?

A. Not necessarily. On average after a stroke, one-third of patients fully recover or will be left with only minor disability.

Another third will be significantly disabled for life. One-third of patients will die, either directly as result of the stroke or due to one of its complications.

Duration of recovery is variable and depends on the severity of stroke, age of the patient, presence of complications and the setting of post-stroke care. Majority of patients who do recover usually regain physical functions and activities of daily living over a period of approximately two - four weeks.

Stroke victims carry a higher risk of developing a second stroke, irrespective of their level of recovery.

Approximately one quarter of strokes occur in patients who have already suffered a stroke.

Therefore, patients should strictly adhere to the advice given on lifestyle modifications and the treatment prescribed to prevent another stroke.

Q. In some countries there are stroke units where patients get everything they need from treatment to rehabilitation and counselling. Does the National Hospital have this facility and also any private hospital? Tell us more about the functions of this unit.

A. The first Stroke Unit in Sri Lanka was set up at the Institute of Neurology of the National Hospital in 1998 by Consultant Neurologist Dr Jagath Wijesekera who was also the Founder President of the National Stroke Association.

Thereafter, stroke units have been established in several provincial hospitals largely due to the advocacy of the National Stroke Association and its past presidents together with the initiative taken by the Ministry of Health.

Some private hospitals too have Stroke Units.

Q. Your message to the public?

A. Avoid all modifiable risk factors such as smoking, drinking excessive alcohol, and narcotic use.

If you have a non communicable disease like diabetes or hypertension, take the prescribed medication regularly.

If you are a stroke patient, adhere to the advice given on lifestyle modifications and treatment prescribed, to avoid another stroke.

World faces looming stroke epidemic, health experts warn

The world is facing a “looming stroke epidemic” experts have warned after a global study revealed a huge leap in the numbers of younger people suffering from a condition previously associated with old age.

A third of all strokes now occur in 20 to 64-year-olds, according to the Global and Regional Burden of Stroke study.

Incidence in this age group has increased by a “startling” 25 percent in just 20 years said the authors of the report, published in The Lancet.

In the under 20s, more than 83,000 strokes are recorded every year - one in every 200 cases.

A second report, published in The Lancet Global Health, shows that, while overall death rates were down, the number of people dying from stroke was ten times higher in low and middle income countries compared to rich countries. The authors predict that the amount of disability, illness and premature death caused by stroke will more than double worldwide by 2030.

In the UK, there are around 152,000 strokes every year, and the new findings reveal that the poorest areas of the country had a three times higher death rate than the richest.

Jon Barrick, chief executive of the Stroke Association, said that the report revealed “shocking disparity” between rich and poor.

“These new findings lay bare the formidable challenge facing local health services, not only in the UK, but also in countries around the world, to tackle a looming stroke epidemic…” he said. “To help close this health inequality gap, we need more investment in stroke prevention and research.”

He warned that rising rates of obesity and diabetes could “wipe out” gains made in reducing stroke mortality in the UK and said that “at least half of strokes” could be prevented by keeping blood pressure under control and exercising more.

More than half of the global deaths and the majority of the disability caused by stroke were a result of haemorrhagic strokes, the most deadly form, which is mainly caused by high blood pressure and unhealthy lifestyles.

Commenting on the studies for The Lancet, Maurice Giroud, Agnes Jacquin, and Yannick Béjot from the University of Burgundy’s department of neurology said: “Despite some improvements in stroke prevention and management in high-income countries, the growth and ageing of the global population is leading to a rise in the number of young and old patients with stroke.

“Urgent preventive measures and acute stroke care should be promoted in low-income and middle-income countries, and the provision of chronic stroke care should be developed worldwide.”

The Independent

Protecting the brain starts at the synapse

New research by scientists at San Francisco shows that one of the brain's fundamental self-protection mechanisms depends on coordinated, finely calibrated teamwork among neurons and non-neural cells known as glial cells, which until fairly recently were thought to be mere support cells for neurons.

The study, which has implications for understanding neurodegenerative diseases, stroke, and other nervous system disorders, adds to a growing body of evidence that glial cells are integral to brain function.

Because this mechanism is localised at synapses, the sites where communication between neurons takes place, said Marta Margeta, assistant professor of pathology and senior author of the new study, it ensures that protective measures will only be taken when and where they're most needed.

“The President needs more bodyguards than a Congressman, and with this system you can have your cake and eat it too: protection when you need it, without having to have it everywhere.”

The brain is the body's hardest-working organ, consuming as much as 25 percent of our overall energy. This metabolic demand makes brain cells particularly vulnerable to damage from oxidative stress, in which reactive oxygen species (ROS), sometimes called free radicals, exert toxic effects on cellular components.

ROS damage to neurons has been implicated in Alzheimer's disease, Parkinson's disease, and other neurodegenerative conditions.

The brain can also be severely damaged when disease or injury - especially stroke - causes neurons to repetitively fire, flooding brain tissue with toxic levels of the excitatory neurotransmitter glutamate, a condition known as excitotoxicity.

To counteract the potential damage arising from ROS, excitotoxicity, and other dangers, animals including humans have evolved sophisticated physiological defenses such as the Nrf2 pathway, a molecular network that triggers the expression of a suite of protective genes when cellular function is under threat.

It is Neuroscience 101 that neurons pass on electrochemical messages at communication sites called synapses, but it is less well appreciated that the vast majority of synapses are “tripartite,” consisting not just of a neuron sending a message and one receiving it, but also, nestled alongside each synapse, a star-shaped glial cell called an astrocyte.

Experiments in mouse models of Parkinson's disease and amyotrophic lateral sclerosis (ALS, or Lou Gehrig's disease) have demonstrated that Nrf2-based neural protection is primarily conferred by astrocytes, but how neurons might alert astrocytes to stressful conditions is poorly understood.

When the research team tried to activate the Nrf2 pathway in predominantly neural or astrocytic cultures by bathing them with a substance that creates conditions mimicking excitotoxicity, they had little success, but in mixed cultures the pathway was set in motion.

These experiments demonstrated that both neurons and astrocytes are necessary for Nrf2 activity.

However, because the treatments affected the cultures globally and did not precisely target synapses, the researchers next applied substances that increase the firing of glutamate neurons by acting solely at synaptic sites.

Again, Nrf2-related activity was observed only when astrocytes were present in cultures, but significantly, Nrf2 signalling increased in tandem with neuronal firing, suggesting that neurons calibrate Nrf2 activity in astrocytes to keep pace with neural activity.

This precise calibration remained intact even when there was no physical contact between neurons and astrocytes in culture, indicating that neurons secrete some soluble factor that activates Nrf2 in astrocytes.

When excitatory neurons fire and release glutamate neurotransmitter into the synapse, the released glutamate can reach nearby astrocytes, so glutamate seemed a good candidate for the neuronal messenger that induces Nrf2 activity.

- MNT