Stroke is the third most common cause of death in most of the countries, following coronary diseases and cancer. It affects 0.2% of a population all but fatal in a third of cases. At least half of survivors of stroke are permanently disabled, making stroke a major cause of long-term physical, cognitive, emotional, social and work disability.
Stroke is a clinical syndrome characterized by acute loss of brain function that takes place for 24 hours or leading to death. Occurs due to spontaneous bleeding in the brain parenchyma (intracerebral hemorrhage), or in the space surrounding the brain (subarachnoid haemorrhage) or hemorrhagic stroke, or as a result of inadequate supply of blood to brain tissue (ischemic stroke) resulting thrombosis, embolism or poor blood flow, associated with diseases of the blood vessels, heart or blood.
This definition should include patients with subarachnoid hemorrhage who present only with acute, severe headache with or without neck stiffness, no other signs of focal or global neurological dysfunction. Stroke presents with sudden loss of function of a part of body or speech, or loss of consciousness due to interruption of the blood supply.
How To Recognize a Stroke – Symptoms And Signs
Each stroke is manifested differently, the symptoms depend on which region of the brain is affected by its size. The symptoms and signs of disease usually occur suddenly and they are immediately detectable. At some patients it can occur during sleep and the patient detects it the morning after awakening. Sudden and rapid symptoms is the most recognized sign of stroke, so if symptoms develop slowly and gradually, get worse over several days, weeks or months, is likely not a stroke.
- The most common symptoms of a stroke are:muscle weakness (paralysis) – can paralyse various parts of the body but mostly one side of the face, hand and foot (hemiparesis).
- Weakness on the right side of the Thelon becomes in impaired function of the left side of the brain and vice versa.
- Loss of sensation – stroke may cause a reduction in the sense of certain parts of the body. Usually causes numbness of the face, arm and leg on one side of the body (hemianesthesia).
- Trouble speaking – stroke can cause difficulty speech as a result of weakness and loss of coordination of the muscles of the face, mouth or throat. As a result it appears badly articulated speech (dysarthria).
- Another type of speech disorder is dysphasia when they’re presented with an inability to understand others’ speech or inability to find words and non-fluent speaking, reading difficulties (dyslexia) or writing (discography).
- Dysphasia (speech disorder) occurs due to malfunction of the dominant hemisphere of the brain. The left hemisphere of the brain is dominant hemisphere in nearly all people who are right-handed. The right side of the brain is dominant in about half of the individuals who are left-handed, and at the other half of the left handed people is dominant the left side again.
- Visual symptoms – stroke and TIA (transient ischemic attack), causing loss of vision that encompasses the entire field of view (Monocular blindness) or half visual field (hemianopia) or causing double vision (diplopia). The loss of vision in one eye that occurs suddenly and improves within 24 hours (usually 5-10 min) usually presents transient lack of blood supply to the eye and is called amaurosis fugax.
- Homonymous hemianopia is loss of vision to one side, so that the patient can not see half of the visual field (right or left side depends of the stroke). Double vision occurs when the visual axis of both eyes is different, which occurs as a result of nerve damage that control the movements of the eye apples.dizziness – stroke and TIA may cause dizziness and loss of balance. Sometimes it’s accompanied by a feeling of nausea and vomiting.
- Headache – stroke and TIA usually do not cause headache. However, headache may occur during stretching, or irritation of the lining of the brain (meninges) or blood vessels in the brain. Stretching of the meninges may occur during swelling of the brain which can occur a short time (minutes to hours) by bleeding in the brain or a few days from a heart attack when the brain swelling (edema) is the largest. Bleeding on the surface of the brain (subarachnoid hemorrhage) typically causes a very strong headache because the blood directly irritates the pain sensitive meninges. In some cases, stroke may be caused by the termination of the inner layer of the arteries wall of the brain (dissection) and cause severe pain which is transferred to the head or if dissection is a blood vessel in the neck.
- Vomiting – vomiting may be caused by direct lesion of the centers to retrieve the base of the brain (medulla) or increased pressure in the skull (increased intracranial pressure) which puts pressure on them. When the nerves which receive information to maintain balance are getting damaged it also occurs dizziness and feelings of nausea and vomiting.
- Disturbance of consciousness – stroke and TIA can cause degradation or loss of consciousness. It may occur as a complication of strokes (eg. seizures), further due to the direct involvement of the centers to maintain awareness found in part of the brain (brain stem), when attacks happen in that region or increased intracranial pressure which directly or indirect pressures on centers in the brainstem.