Stroke

The Basics

Let’s begin with a potentially vital first aid tip from the Retired & Senior Volunteer Programme (RSVP). Is It A Stroke? – Sometimes the symptoms of a stroke are difficult to identify. The person suffering the stroke may be saved from unnecessary brain damage if those nearby recognise what’s happening. Ask the person to perform 3 simple tasks:

• Smile
• Raise both arms
• Speak a simple sentence

We remember this as S-A-S (smile – arms – speak). If a person has any difficulty with any of these tests call 999 immediately. Prompt treatment can prevent brain damage. Do not wait to see if things improve. Minutes count.

If you or someone you are with experiences:

• Sudden numbness or weakness of the face, arm or leg (especially on one side of the body)
• Sudden confusion, trouble speaking or understanding speech
• Sudden trouble seeing in one or both eyes
• Sudden trouble walking, dizziness, loss of balance or coordination
• Sudden severe headache with no known cause

Act fast. Do not hesitate. Call 999.

Reports cited by the BBC says that Stroke is the greatest single cause of severe disability in the country. From Medline Plus, The Mayo Clinic and other sites we learn that:

A Stroke occurs when an area of the brain is deprived of its blood supply – usually because of a blockage or burst blood vessel – for long enough to cause vital brain tissue to die. It’s essentially the same as what happens in the arteries leading to the heart when someone has a heart attack, which is why a stroke is sometimes described as a ‘brain attack’.

The brain is the most complex organ in the body. It regulates absolutely everything the rest of your body does. To do so it must have a constant supply of blood to deliver oxygen and nutrients to the brain cells. If the blood supply fails, as in a stroke, the brain cells become damaged or die within a very short space of time. Unlike other cells in the body, once brain cells have died they cannot re-grow.

If brain cells lose their supply of oxygen from the blood, they will be irreversibly damaged within minutes. This is so sudden that there is little that medical science can do to prevent it. But surrounding these dead cells is an area of tissue where the blood supply is poor but not completely lost, so the nerve cells are receiving barely enough oxygen to stay alive. One of the main aims of treating a stroke is to act fast enough to save this threatened brain tissue by restoring blood flow to the area, and minimising the damage.

Medline Plus takes us to information estimating that roughly 10 percent of stroke survivors recover almost completely, approximately 25 percent recover with minor impairments, 40 percent experience moderate-to-severe impairments, 10 percent require care in a nursing home or other long-term care facility, and 15 percent die shortly after the stroke.

There are two main types of stroke:

Ischaemic Stroke 

In this, the most common type of stroke, the artery is blocked by a blood clot, which interrupts the brain’s blood supply (ischaemia means to restrain blood in Greek). This may be due to a cerebral thrombosis (sometimes called a thrombotic stroke) where a blood clot forms in one of the main arteries leading to the brain, or to a cerebral embolism (sometimes called an embolic stroke) in which a blood clot forms elsewhere in the body and is swept into the arteries serving the brain. Fatty tissue or air bubbles may also form emboli which cause stroke, especially after major trauma.

A blood clot within an artery is known as an arterial thrombosis. Arterial thrombosis usually affects individuals who already have atherosclerosis, or narrowing of the arteries.

Another type of thrombotic ischaemic stroke, known as lacunar stroke, may occur. In lacunar stroke one of the tiny blood vessels deep inside the brain tissue becomes blocked, leading to the death of the small area of tissue that it supplies. Lacunar strokes are usually less severe.

Haemorrhagic Stroke

In this type of stroke a blood vessel in or around the brain ruptures causing bleeding, or a haemorrhage. The build up of blood presses on the brain damaging its delicate tissue, while other brain cells in the area are starved of blood and damaged.

In an intra-cerebral haemorrhage the bleeding occurs inside the brain itself. In a subarachnoid haemorrhage the burst blood vessel bleeds into the space surrounding the brain. Subarachnoid haemorrhage is more common in the 25-50 age group than in older people. Warning signs include severe headache, facial pain, double vision or other visual problems, brief loss of consciousness followed by feeling confused and sleepy. Intra-cerebral haemorrhage accounts for about 10% of all strokes but for a much higher percentage of deaths due to stroke. Among people older than 60, intra-cerebral haemorrhage is far more common than subarachnoid haemorrhage. Causes of intra-cerebral haemorrhage include high blood pressure and, in older people, fragile blood vessels.

An intra-cerebral haemorrhage begins abruptly. In about half of the people, it begins with a severe headache. Neurological symptoms develop and steadily worsen. They include weakness, paralysis, numbness, loss of speech or vision, and confusion. Symptoms worsen as the haemorrhage expands. Nausea, vomiting, seizures, and loss of consciousness are common and may occur within seconds to minutes.

Stroke due to intra-cerebral haemorrhage is more dangerous than ischemic stroke. The stroke is usually large and catastrophic, especially in people who have chronic high blood pressure. More than half of the people who have large haemorrhages die within a few days. Those who survive usually recover consciousness and some brain function as the body absorbs the leaked blood. Even after surgery, many people continue to have some neurological symptoms. Symptoms may include weakness, paralysis, loss of sensation on one side of the body, or difficulty understanding and using language (aphasia). However, people with small haemorrhages recover to a remarkable degree.

Transient Ischaemic Attack (TIA)

A Transient Ischaemic Attack, often known as a mini-stroke, is a brief episode where some brain function is temporarily lost because of a very short-lived disruption of the blood supply. Symptoms (such as weakness of a limb) last for just minutes (typically 2-15 minutes) before the blood supply returns and everything returns to normal, because the brain cells have not suffered permanent damage.

Traditionally it has been said that if symptoms last less than 24 hours then it is a TIA, but when symptoms persist for more than 24 hours then a stroke has occurred. But with more powerful and sophisticated brain scanning techniques it has become possible to show that permanent damage ( the real hallmark of a stroke) can usually be detected when symptoms last more than an hour or so.

TIAs are an important warning sign that all is not well with the blood supply to the brain. As many as 1 in 10 people with TIAs will have a stroke within 7 days, and 1 in 5 will have a stroke within a month. Heed the warning from a “mini-stroke”. Work with your doctor.

Immediate Causes of Strokes

Each of the different types of stroke has different causes. They include:

Diseased arteries – Blockage of the arteries is usually the result of atherosclerosis, furring and narrowing of the artery walls with a sludgy mixture of cholesterol and other debris, known as atheroma.

Aneurysm – This is a weakened spot on an artery wall that causes it to stretch a bit like a balloon. The vessel wall may become so thin and stretched it bursts causing bleeding into the brain – a haemmorhagic stroke.

Atrial fibrillation – This is a kind of irregular heartbeat (arrhythmia). It can cause a blood clot to form in the heart which can shear off and travel to the brain.

Effects of a Stroke

The physical damage stroke causes to the brain can have a wide range of effects that will depend on the type of stroke and its severity, the part of the brain affected, the extent of brain damage and how quickly other brain cells take over the function of those that are damaged or dead. Effects may include:

Weakness or paralysis – these can lead to difficulties in walking, movement or coordination. These often affect one side of the body – known as hemiparesis or hemiplegia.

Lack of feeling – or loss of awareness of objects on one side of the body, known as left- or right-sided neglect, depending on the side affected.

Swallowing difficulties – these can cause trouble with eating or drinking which, if not managed, can result in chest infections including pneumonia as food or liquid passes into the windpipe and lungs instead of the gullet. Dehydration or constipation may also result .

Speech or language difficulties – including difficulties in understanding (dysphasia), speaking (aphasia), reading, writing and calculation. Speech and language problems are usually a result of damage to the brain’s left hemisphere. Aphasia is a partial or complete loss of the ability to express or understand spoken or written language because of damage to the language areas of the brain. There are a number of different kinds and severities of aphasia. Speech Therapists can help people who develop aphasia after brain damage due to such disorders as a stroke or head injury. Treatment is usually started as soon as the person is able to participate.

Problems of perception – these can include trouble recognising or being able to use everyday objects such as a kettle or teapot, difficulties telling the time, and problems interpreting what the eyes see, even where vision is not affected.

Cognitive difficulties – these include problems caused by damage to areas of the brain controlling mental processes such as thinking clearly and logically, learning, paying attention, memory, decision-making and forward planning. Among these problems are:

Apraxia – loss of the ability to perform tasks that require remembering patterns or sequences of movements. Occupational Therapy can help some people with apraxia learn to compensate for their losses.

Agnosia – loss of the ability to associate objects with their usual role or function (relatively rare). Some people with agnosia improve or recover spontaneously; others must learn to cope with their disability.

Amnesia – total or partial loss of the ability to recall experiences or events that happened in the preceding few seconds (immediate memory), in the preceding few seconds to few days (intermediate memory), or further back in time (remote or long-term memory). The causes of amnesia are only partly understood. Damage to the brain can produce memory loss of events that occurred just before (retrograde amnesia) or just after (posttraumatic amnesia) the damage occurred. Depending on the severity of the damage, most amnesias last for only minutes or hours and disappear without treatment. However, with severe brain damage, amnesia can be permanent.

Behaviour changes – these may include being slower to react than before the stroke, excessive caution, disorganisation, finding it difficult to adjust to change and becoming confused or irritated.

Difficulties with bowel or bladder control (urinary or faecal incontinence) – these may be caused by a variety of different problems following stroke. These can often be considerably improved or overcome with medical help and physiotherapy.

Fatigue – although a recognised phenomenon, the reason for fatigue is not fully understood. There may be sleep disturbance caused by damage to areas of the brain controlling the body’s sleep-wake cycle and it could also be linked to depression.

Mood changes – these include mood swings, irritability, laughing or crying even when you do not feel particularly happy or sad. Depression is extremely common following a stroke, with symptoms such as loss of appetite, insomnia, crying, low self-esteem and anxiety that can all be signs of depression.

Post-stroke pain – a small number of people develop a burning, shooting, throbbing pain that does not respond to painkillers following a stroke.

Epilepsy – 7-20 per cent of people who have strokes develop epilepsy. This can usually be treated with anti-epileptic drugs.

BBC Health reminds that: Although this list of problems may seem long and daunting, it’s important to bear in mind that most people who have strokes do not experience all of them. Moreover, with time, patience, and the help of a number of different specialists many of them can be treated, overcome or reduced.

Short-term effects disappear with time as any swelling in the brain goes down and the damaged cells surrounding the dead brain cells are repaired. Long-term effects are caused by the death of brain tissue, and although they will not go away, they can often be modified with rehabilitation.