Global Health Asia-Pacific April 2021 April 2021 | Page 12

You Ask , They Answer

Q

: What is a silent stroke , how common is it , and what causes it ?

A

: A stroke is a sudden loss of blood supply to an area of the brain due to either arterial blockage , called an ischaemic stroke , or bleeding from a burst vessel , known as a haemorrhagic stroke . Patients experience a sudden onset of weakness or neurological deficit corresponding to the area of the brain where blockage or bleeding has occurred . It can easily be recognised by such symptoms as facial weakness , arm drift , and slurred speech .
Some patients may not be aware of their neurological deficit despite suffering from a stroke . This is known as a silent stroke . Most of the time , a patient will develop an occlusion or closure of the small or tiny arteries in the brain , resulting in damage in the innermost part of it or in less functional areas . As they will not experience sudden speech or vision disorders , the condition can only be recognised clinically through a diagnostic scan .

Q

: Since silent stroke usually causes few or no symptoms , when and how are patients usually diagnosed with it ?

A

: Silent stroke does not have easy-to-recognise symptoms . Common symptoms that are often disregarded and dismissed as age-related degeneration of the brain can actually be due to silent stroke . Examples of these symptoms include recurrent falls due to lower-limb weakness or imbalance , temporary lack of coordinated muscle movement , urinary incontinence , mood or personality changes , and poor memory or cognitive skills .
The gold standard for the diagnosis of silent stroke is through brain imaging . This can be done either with an MRI or CT scans . In patients with risk factors for stroke , such as uncontrolled diabetes , hypertension , and a family history of stroke occurring at a younger age , stroke screening can be done on a case-to-case basis .

Q

: What sort of damage can be caused by silent stroke ? Do they put patients at greater risk of symptomatic stroke and dementia in the future ?

A

: Gradual and slow occlusion of minute arteries in the brain causes ongoing damage . As a cumulative effect , it results in multiple neurological diseases over a period of time . Examples include vascular Parkinson ’ s disease , vascular dementia , or mixed dementia , which is Alzheimer ’ s with vascular dementia . Usually , a silent stroke involves smaller arteries . It rarely appears as a symptomatic stroke but can cause lower-body Parkinson ’ s disease or dementia-like symptoms .

Q

: What can be done to prevent silent stroke ?

A

: A silent stroke is not different from a symptomatic stroke as far as its reasons or causes are concerned , with cardiovascular risk factors topping the list for both . Modifiable risk factors include diabetes , hypertension , high cholesterol , smoking , and irregular heartbeat . Non-modifiable risk factors are age , gender , family history , or genetic influences .
Modifiable risk factors can be easily controlled or mitigated by taking precautionary steps , medical advice , and medication .
Maintaining good blood sugar control , keeping to low blood pressure targets , and lowering cholesterol and triglycerides levels would also be useful in avoiding a silent stroke .
Physical exercise , weight reduction , and lifestyle modification similarly play important roles in mitigating these modifiable cardiovascular risk factors .
Dr Mohammed Tauqeer Ahmad
Dr Mohammed Tauqeer Ahmad is a neurologist at Gleneagles Hospital , Singapore . He has a special interest in strokes , epilepsy movement disorders , and neuroimmunology .
10 APRIL 2021 GlobalHealthAsiaPacific . com