A stroke is classified as a loss of function due to injury or death of brain cells after insufficient oxygen supply. Strokes are a common endpoint for existing cerebrovascular disease and can cause an abrupt onset of persisting neurological symptoms resulting in brain cell atrophy. Strokes can result in death or have permanent brain damaging, however people can recover from strokes depending on severity.
Common signs and symptoms of stroke
When looking out for strokes, it is important to remember the following attributes:
-Numbness or weakness in the face, arm, or leg (especially in one side of the body)
-Sudden confusion or trouble speaking or understanding
-Sudden visual impairment in one or both eyes
-Sudden trouble walking, dizziness, or loss of balance and coordination
-Sudden severe headache with unknown cause
Types of Strokes
Transient Ischaemic Attack (TIA): TIA is a condition related to a stroke which is caused by a temporary block of blood supply to the brain which produces stroke like symptoms that only last for a short period of time (eg. A few minutes). Unlike a stroke, TIA’s do not result in permanent damage to the brain nor cause prolonging symptoms due to the lack of brain cell atrophy. However, TIA precedes 10% of strokes and is a major risk factor for strokes occurring in the future. Specifically, is approximated 33% of people who have had an episode of TIA will have a stroke in the next 5 years.
Ischaemic stroke
-Ischaemic strokes or “thromboembolic” make up approximately 75-80% of all strokes. This type of stroke is caused by a thrombosis, stenosis, or embolism which means that blood supply to part of the brain is interrupted or reduced prevent brain cells/ tissue from getting oxygen and nutrients which results in death/ atrophy. There are two ways an ischaemic stroke can occur:
Embolic Stroke: If a blot clot resides within the arteries (typically within the heart), this clot can transport within the bloodstream towards the brain. The blockage occurs when the clot travels to a blood vessel that is too small to pass through, thus also stopping further blood flow to pass through.
Thrombotic Stroke: Over time, cholesterol-laden plaques stick to the walls of arteries and gradually increase in size over time. Eventually, these plaques become narrow or block the artery which stops blood from getting through. Typically, these types of clots/ plaques affect the major arteries in the neck.
Haemorrhagic Stroke
-Haemorrhagic strokes make up 15-20% of strokes and are caused by a weakened vessel which ruptures and bleeds into the brain. This blood accumulates and compresses the surrounding tissues of the brain causing cellular death/ atrophy. There are two subtypes/ causes of haemorrhagic strokes, these are subarachnoid haemorrhages and inter-cerebral haemorrhages.
Subarachnoid haemorrhages: or “haemorrhages on the surface of the brain” make up 5-10% of haemorrhagic strokes and are caused when the vessel surface ruptures within one of the three layers or membrane (meninges) and bleeds into the layer closest to the brain and the second layer.
Inter-cerebral haemorrhages: or “haemorrhages within the brain” Make up ~10% of haemorrhagic strokes and occurs when an artery inside the brain bursts and bleeds into the brain. The most common cause of this is hypertension (high blood pressure).
Causes of haemorrhagic strokes:
Aneurysm: a weak of thin spot in the wall of an artery that balloons out which grows weaker in size until it bursts. These can be caused by either high blood pressure or trauma (force/ injury) to the head.
Vascular Malformations: defects of blood vessels which present at birth and get weaker with age. Types of vascular malformations include arteriovenous malformation (abnormal tangled connected between arteries and veins) and cavernous malformation (tangle of tiny blood vessels creating weak walled “cavern” of blood)
Prevalence:
In 2018, 387000 Australians aged 15 and over (1.4% of the population) had experienced a stroke within their lifetime. Strokes are more prevalent in men compared to women as found in 2018 alone, where an estimated 20200 stroke events occurring among males and 18400 occurring among females. Stroke risk increases with age, with the rate of strokes increasing dramatically over the age of 55-64+ for both males and females. The most at risk age bracket is 85 years and over which has more than double the amount of stroke events compared to the 75–84-year age bracket and 6 times the rate of 65–74-year age group.
Primary Risk factors:
Atherosclerosis: One of the main causes of ischaemic strokes. Individuals with coronary artery disease are at increased risk of developing stroke.
Atrial Fibrillation (AF): AF and resultant irregular heartbeat can lead to pooling of blood in the heart and contribute to clot formation, resulting in ischaemic strokes.
Smoking and hypertension: accounted for 21% of stroke incidence in med and 42% in women
Secondary Risk Factors:
Low exercise (Inability to complete 150minutes of moderate intensity aerobic/ resistance training per week or 75minutes vigorous intensity)
High Sedentary Behaviour
Poor diet
Obesity
High visceral fat/ fat around stomach region
Cholesterol
Family history of cardiovascular diseases
Alcohol consumption
How can exercise aid in strokes?
Exercise can reduce the risk of having a stroke or TIA with just 30minutes of moderate activity five times per week by over 25%. Other physiological benefits of exercise include:
lowering your blood pressure
• lowering cholesterol levels
• reducing risk type 2 diabetes
• helping lose weight if needed, and maintain a healthy weight
• increase muscle strength and flexibility
• reduce levels of anxiety and depression
• increase energy levels
• improve self esteem
• improve sleep
• maintaining/regulating or improving cardiovascular health
It is recommended for all adults to aim for 150minutes of moderate aerobic activity a week total, or 75 minutes of vigorous aerobic activity. It is also recommended to complete strength/ resistance training on two or more days per week focusing on all major muscle groups. Resistance training can include bodyweight exercises, free weights, or machines/ cables. Fitness and strength can be gradually increased throughout your exercise journey, however, ensure to have rest days and to stay within guidelines recommended by your exercise physiologist or exercise professional. Even if you are participating in regular exercise and stay active, it can also be highly beneficial to avoid high bouts of sedentary behaviour which is important for reducing risk of diabetes and heart diseases. Completing the recommended exercise guidelines can manage/ significantly reduce the physiological risk factors contributing to cardiovascular diseases such as strokes and heart attacks.
Avoiding complications and injuries:
Before completing exercise, it always best to seek the professional advice of your general practitioner regarding cardiovascular conditions you have and which may impact your exercise. It is highly recommended to seek professional advice from an exercise physiologist. Exercise can be tailored towards any individual and their conditions given it is medically safe to do so. Whether it is exercise to decrease the risk of cardiovascular diseases such as strokes or even completing exercise after a stroke, an exercise professional such as exercise physiologist can implement evidence-based exercises and practices in order to achieve the best and safest results. Not only can exercises aid in post stroke rehabilitation, but it can also significantly reduce the recurrence of a stroke and improve an individual’s quality of life and reduce the risk of overall mortality. There are multiple types of exercises and locations which exercises can be completed, however finding the perfect intervention of exercise for you is essential into starting and continuing your exercise journey. Please seek medical advice before completing exercise if there any concerns or current conditions which may place you at risk.
