What is the difference with a “silent” stroke?
Strokes are feared because of their neurological results, however the incidence of strokes without appreciable neurological deficits is high. Avoidance is better than cure!
About 20% of strokes are hemorrhagic due to uncontrolled bleeding in the brain, 80% ischemic due to clots.
AVOIDING SILENT STROKE
Stroke is the sudden reduction or loss of blood flow to a particular region of the brain and when associated with a transient and reversible neurological deficit, (Transient ischemic attack, TIA) or with permanent neurological dysfunction, symptomatic stroke and is termed “silent” when not.
It is worth noting that patients with obstructive sleep apnea (OSA) represent over 80% of strokes seen. Heavy snoring alone has also shown to be a significant risk factor, (see below) yet neither are generally considered either in prevention or postoperative care.
In Canada six percent of all deaths are due to stroke with 14,000 Canadians dying from stroke annually. There are an estimated 50,000 strokes in Canada each year, that’s one stroke every 10 minutes.
With around 315,000 Canadians living with the effects of stroke, the cost to the Canadian economy is around $3.6 billion per year. Every year, patients with stroke spend more than 639,000 days in acute care in Canadian hospitals and 4.5 million days in residential care facilities
Figures from the UK estimate that approximately 57,000 people experienced a stroke for the first time in 2016. Adjusting to the 2013 European standard population to account for differing age structures resulted in the incidence rate increasing slightly from 1.03 strokes per 1,000 population to 1.13 strokes per 1,000 population. (Public Health England)
Silent strokes (silent brain infarction or SBI ) only affect a small area of the brain, but the damage may be accumulative.
Factors increasing silent stroke risk.
Causes of silent strokes
Blood clots increasing silent stroke risk
High blood pressure increasing silent stroke risk
Narrowed arteries increasing silent stroke risk
High cholesterol increasing silent stroke risk
Diabetes increasing silent stroke risk
Snoring increasing silent stroke risk
Obstructive sleep apnea (OSA) increasing silent stroke risk
How is is it possible to have a stroke and not know it?
Silent strokes usually display no symptoms at all. Like ischemic strokes, silent strokes happen when blood supply to a part of the brain is suddenly cut off, depriving the brain of oxygen and damaging brain cells.
A silent stroke is, hard to recognize. Because a silent stroke disrupts blood supply to a part of your brain that doesn’t control any visible functions like speaking or moving it is less apparent, so the sufferer might never know a stroke occurred.
Following several silent strokes, recall and memory may be affected, or difficulty in concentrating. SBI my also increase risk of symptomatic stroke in the future. SBI damage is permanent and effects may be accumulative.
Multiple SBI increases risk for vascular dementia, the symptoms of multi-infarct dementia include:, memory problems, emotional issues, (laughing or crying at inappropriate times), changes to walking gait, getting lost in familiar places, difficulty in decision making, loss of bowel and/or bladder control.
Researchers have known for some time that silent strokes are fairly common, and a serious problem of developed countries. Studies have shown a significant and rapidly increasing prevalence after 65 years of age.
Can you prevent silent strokes ?
Stroke and obstructive sleep apnea.
MRI Studies have shown that ‘silent brain infarct’ may occur in up to 25% of patients with moderate to severe OSA.
These patients didn’t know that they’d had a stroke.
Stroke and antioxidants – prevention or treatment?
Antioxidants are believed to reduce cell damage within the body by countering the potentially dangerous effects of free radicals produced when the body processes oxygen.
Antioxidants are potentially a promising treatment for strokes because they can be given after a stroke occurs to help reduce cell damage.
Dr Stephen Bray 2019