Thursday, August 22

The silent brain attack


Strokes do not develop out of the blue. It’s important to know the risks that might predispose the affliction


A, B and C show MRI scans, while D is a CT scan of the brain, which helps doctors to diagnose stroke.

THERE are many diseases and illnesses which can be described as ‘silent killers’ due to their subtle symptoms that often go unnoticed.

Among those so regarded are diabetes, colon cancer, and cardiovascular diseases, the latter of which claim millions of lives every year.

According to the World Health Organisation (WHO), around 17.7 million people die each year from cardiovascular diseases of which 80 per cent were due to heart attacks and strokes.

The WHO also noted that 15 million people around the world suffer from stroke each year and, of these, five million die while another five million end up permanently disabled.

Gleneagles Kota Kinabalu consultant neurologist Dr Chris Chong said a stroke is a term used to describe brain injury caused by an abnormality of the blood supply to a part of the brain.

“The brain, like every other organ in the body, depends on a constant supply of energy to function normally. The brain’s fuel (oxygen and sugar) is carried in the blood.

“When a part of the brain is not provided with an adequate supply of blood or when the blood does not carry enough oxygen or sugar, that portion of the brain becomes unable to perform its normal functions.

“When a brain area stops working, the function located in that area ceases, at least until energy is restored,” he told thesundaypost.


Dr Chris Chong

Risk factors

Hoping to educate people on the risk factors of stroke as well as their prevention, Dr Chong stressed that strokes do not just develop “out of the blue”.

“Everyone should be aware of their own risks and behaviours that might predispose them to stroke.

“Prevention should begin early in life and continue throughout it. There is much that everyone can and should do to prevent stroke. Some risk factors are modifiable but some are not. Some risk factors are beyond control.”

He pointed out that most people were aware that age, being male, and a history of stroke among close family members were risk factors.

“As you get older, you have a greater chance of having one too. If you are male, your chances of stroke before the age of 60 are higher than if you are female.

“If a parent or sibling has coronary heart disease or stroke, you have a higher chance of stroke than a person whose family members do not have a history of vascular disease.

“These are some of the risk factors that cannot be modified – one cannot choose one’s parents or stop the ageing process,” he explained.

On the different symptoms of stroke, which usually occur suddenly, Dr Chong said the signs could vary from individual to individual and this also depended on the region of the brain involved as well as the size of the stroke.

“Common symptoms of stroke include limb and/or facial weakness and/or numbness; vision difficulties; dizziness, vertigo as well as loss of balance and coordination; speech and language difficulties; abnormalities in thinking, memory and behaviour; and decreased level of consciousness,” he said.

However, he also emphasised that brain symptoms were not specific for stroke.

“Loss of brain functions can be caused by many different conditions, not just stroke.

Also, neurologic symptoms can come from parts of the nervous system other than the brain. Doctors need to consider all the symptoms when trying to discover where in the brain the dysfunction lies.

“Suspicion and confirmation of the diagnosis of stroke comes from history taking, physical examination and performance of certain tests such as neuroimaging studies (Computed Tomography, Magnetic Resonance Imaging) of the brain and blood vessels and laboratory tests to better pinpoint the abnormalities in the brain and the blood,” he said.

Motor abnormalities

While strokes affect different portions of the brain and can lead to dysfunctions of many different types and severity levels, Dr Chong noted this could also be temporary.

“When symptoms persist and impair activities of daily living, they are often referred to as disabilities or handicaps. There are different types of disabilities or handicaps, depending on the severity and regions of the brain involved in stroke.”

Among them are motor abnormalities where many patients’ limbs become weak, stiff or uncoordinated after a stroke; sensory abnormalities, which can include loss of feeling, abnormal sensations (often described as tingling, pins and needles), and pain; cognitive

and behavioural abnormalities where the thinking ability (cognition) is often affected by stroke and this can relate to the making of new memories, speaking, reading, writing, calculating and recalling where things and places are located; as well as language abnormalities in which abnormal use and understanding of language can persist and abnormalities in planning, judgment and performing complex activities.

Regardless, Dr Chong said a great majority of stroke patients do get better in a sense where some improve so much that they return to normal or near normal functions.

“The ability to return to normal functions varies widely between individuals. Some have persistent or permanent disabilities.”

Promoting recovery

For stroke survivors, they often undergo rehabilitation to promote recovery and help them relearn the skills lost due to part of the brain being damaged.

“A stroke patient should be managed by a multidisciplinary team comprising doctors (neurologist, neurosurgeon, physician), nurses, physiotherapist, occupational therapist, speech therapist, pharmacist, dietitian, social worker, psychologist, and so on,” Dr Chong said.

He pointed out that another important aspect of rehabilitation is to educate family members or the carers on the nature of the various disabilities and how they should be handled in a home environment.

“The carers can help with the therapy and should know the patient’s abilities and limitations. Although one person has a stroke, the effect of that stroke is quite widespread. The spouse or the significant other now must become a caregiver in addition to previous roles and responsibilities.

“The stroke patient’s role in his or her workplace may end or be altered. The physical, social, psychological and economic burden is enormous. Therefore, the significance of stroke cannot be overemphasised,” he cautioned.

Stroke prevention

On stroke prevention, Dr Chong said while risk factors such as age and family history could cause a person to be more susceptible to having a stroke, there were many other risk factors, which could be

prevented or minimised by behavioural change and medical treatment.

“The major modifiable risk factors that account for strokes are high blood pressure (hypertension), cigarette smoking, diabetes mellitus, high cholesterol, and other abnormalities of lipid, certain heart diseases such as irregular heart rhythms, obesity, physical inactivity, and excessive alcohol intake.

“For instance, if a person’s hypertension can be controlled with diet, regular exercise and medication, the risk of stroke can be minimised.”

He noted that for patients with ischemic stroke, a type of blood thinner (antiplatelet or anticoagulant) would be needed to reduce the risk of future stroke other than controlling the individual risk factors.