Stroke is one of the commonest causes of brain damage. However, the effects of stroke are not, as was once assumed, necessarily irreversible. Brains – even older ones – are incredibly ‘plastic’ and, with the right encouragement, they can rewire themselves to compensate for the damaged part. Research has shown that the brain can generate new connections after a stroke and recover some of its lost abilities.
A stroke occurs when a major blood vessel in the brain becomes blocked or ruptures. This reduces the supply of blood and oxygen to the brain tissue, killing brain cells. Even a brief interruption to the blood flow can decrease brain function. If the interruption lasts for more than a few seconds, cells are destroyed, causing permanent damage to that area of the brain.
Varied effects of stroke
The effects of a stroke depend on the amount of tissue damaged and the region of the brain in which it occurs. With some strokes, a few moments of dizziness or pain is all that the victim is aware of. But a major stroke can knock out a large part of the brain, producing radical changes in a person’s behaviour or abilities. A stroke in the area that controls movement, for example, n1ay paralyse a limb or even one side of the body. A stroke in Broca’s area in the left hemisphere will disrupt speech, while one further back in Wernicke’s area will cause problems with u nder standing language. Front-brain damage often results in personality changes, such as depression or, conversely, permanent optimism. Damage to the temporal lobes may remove a very specific type of knowledge, such as names of people and places, while a stroke deep in the limbic system may eradicate personal memories.
Recovery and regrowth
Recovery after stroke can be slow, difficult and sometimes only partial. However, it appears that healthy brain tissue can often take over the tasks of damaged adjacent regions. Research using magnetic resonance imaging (MRI) to find out which parts of the brain take over from damaged areas is helping to predict how much recovery is possible and whether rehabilitation is worthwhile. In the right circumstances, and with the right attitude and support, dramatic improvements can be made in the quality of life. Wherever the damage occurs, the brain has an in-built capacity for self-repair, and one of the primary ways of triggering this is through therapy. This can be either physical or n1ental, but the aim of all therapies is to encourage the development of new connections. On a large scale, these new connections lead to whole brain areas taking on tasks previously carried out by damaged areas. In some people with language problems, for example, the brain reorganises itself so that the right hemisphere takes over the task of processing words. This is more likely to happen in women than men because a greater proportion of women already have language abilities in both brain hemispheres, instead of just one.
The extent to which the brain can rewire itself depends largely on age: the younger the brain, the more readily it recovers. However, stimulation, practice and novelty can ‘ excite’ even older brains. Whatever your age, the more active you keep your brain, the more chance it has of compensating if it is damaged.
Self-repair
The area affected by stroke is vividly shown up on this MRI scan, with affected tissue coloured red. In some cases, the brain is able to re-establish connections and regain abilities that were lost.
Recovering From a Stroke
Although stroke is usually associated with old age, it can affect much younger people. David Hinds suffered a stroke at the age of 49. He vividly described how he came to realise one morning what had happened to him.
‘When, as if in a dream – or rather a nightmare – I probed myself disbelievingly with a finger that worked, I discovered that one corner of my mouth was an inch higher than the other. I cursed and swore, or rather I tried to, but all that would come out was gibberish! It dawned on me that I was living a nightmare, not dreaming it.’ David went on to make a full recovery. Originally employed as a successful stress-management consultant, he used many of the techniques from his profession to help him in his recovery.
RHYTHM THERAPY
New therapy approaches are helping stroke victims to recover lost abilities. Rhythm therapy involves colour recognition, sound and word enunciation, and physical movements, with an emphasis on rhythmic foundations.
Developed by a jazz drummer, and recognised by the Swedish medical establishment, rhythm therapy has been shown to enhance short-term memory, improve movement control and help impaired speech. Pati ents learn sequences of music and movements, beginning with easy sequences and gradually increasing the complexity and speed. The therapist helps them to follow the sequences, using coloured symbols that represent different parts of the body. Patients say what the colour symbol is while performing the corresponding movement in time to the rhythm. A major advantage of rhythm therapy is that it’s fun, allowing the brain to be challenged in an enjoyable way. And it seems to work: the all-around activity stimulates the growth of healthy new connections, creating alternative paths around damaged areas.
PREVENTING STROKE
Factors known to increase the risk of stroke include high blood pressure, high cholesterol, old age, diabetes, obesity, a previous ‘mini-stroke’, heart disease, smoking and heavy alcohol use. While some factors (such as age) cannot be changed, there are ways to reduce the risk of other factors :
- Have your blood pressure checked regularly, and take steps to keep it in the normal range.
- If you are diabetic, ensure that your blood sugar is well controlled.
- Don’t smoke.
- Lower your cholesterol by reducing your intake of fatty, high-cholesterol foods.
- Exercise regularly (but check with your doctor first) .
- Drink only in moderation.
