STROKE

STROKE

Stroke has become Malaysia's number three killer after heart disease and cancer, with an average of 110 people dying of it every day, reported China Press. Prof Dr Tan Chong Tin, senior consultant at the Neurology Clinic of the Universiti Malaya Medical Centre, said that according to the centre’s statistics on stroke in 1994, 59% of the patients were male and the patients' average age was 62. He said the majority of the patients were Chinese, followed by 29% of Malays and 21% of Indians. Dr Tan said 70% of stroke patients who recovered stopped taking part in social activities, 30% needed assistance in coping with daily life and 15% died within a month.

A stroke, previously known medically as a cerebrovascular accident (CVA), is the rapidly developing loss of brain function(s) due to disturbance in the blood supply to the brain. It is also known as a type of injury to the brain. It is characterized by the sudden loss of function of particular part of the body due to sudden interruption in the flow of blood to a part of the brain. This can be due to ischemia (lack of blood flow) caused by blockage (thrombosis, arterial embolism), or ahemorrhage (leakage of blood). As a result, the affected area of the brain is unable to function, which might result in an inability to move one or more limbs on one side of the body, inability tounderstand or formulate speech, or an inability to see one side of the visual field.  A stroke is a medical emergency and can cause permanent neurological damage, complications, and death. It is the leading cause of adult disability in the United States andEurope and the second leading cause of death worldwide. Risk factors for stroke include old age, hypertension (high blood pressure), previous stroke or transient ischemic attack (TIA),diabetes, high cholesterol, cigarette smoking and atrial fibrillation. High blood pressure is the most important modifiable risk factor of stroke. 

A slice of brain from the autopsy of a person who suffered an acutemiddle cerebral artery (MCA) stroke.Strokes can be classified into two major categories: ischemic and hemorrhagic Ischemic strokes are those that are caused by interruption of the blood supply, while hemorrhagic strokes are the ones which result from rupture of a blood vessel or an abnormal vascular structure. About 87% of strokes are caused by ischemia, and the remainder by hemorrhage. Some hemorrhages develop inside areas of ischemia ("hemorrhagic transformation"). It is unknown how many hemorrhages actually start as ischemic stroke. 

In an ischemic stroke, blood supply to part of the brain is decreased, leading to dysfunction of the brain tissue in that area. There are four reasons why this might happen:Thrombosis (obstruction of a blood vessel by a blood clot forming locally). Embolism (obstruction due to an embolus from elsewhere in the body.Systemic hypoperfusion (general decrease in blood supply, e.g., in shock).Venous thrombosis.

Stroke without an obvious explanation is termed "cryptogenic" (of unknown origin); this constitutes 30-40% of all ischemic strokes.There are various classification systems for acute ischemic stroke. The Oxford Community Stroke Project classification (OCSP, also known as the Bamford or Oxford classification) relies primarily on the initial symptoms; based on the extent of the symptoms, the stroke episode is classified as total anterior circulation infarct (TACI), partial anterior circulation infarct (PACI), lacunar infarct (LACI) or posterior circulation infarct (POCI). These four entities predict the extent of the stroke, the area of the brain affected, the underlying cause, and the prognosis.The TOAST (Trial of Org 10172 in Acute Stroke Treatment) classification is based on clinical symptoms as well as results of further investigations; on this basis, a stroke is classified as being due to (1) thrombosis or embolism due to atherosclerosis of a large artery, (2) embolism of cardiac origin, (3) occlusion of a small blood vessel, (4) other determined cause, (5) undetermined cause (two possible causes, no cause identified, or incomplete investigation).

 Intracranial hemorrhage is the accumulation of blood anywhere within the skull vault. A distinction is made between intra-axial hemorrhage (blood inside the brain) and extra-axial hemorrhage (blood inside the skull but outside the brain). Intra-axial hemorrhage is due to intraparenchymal hemorrhage or intraventricular hemorrhage (blood in the ventricular system). The main types of extra-axial hemorrhage are epidural hematoma (bleeding between the dura mater and the skull),subdural hematoma (in the subdural space) and subarachnoid hemorrhage (between the arachnoid mater and pia mater). Most of the hemorrhagic stroke syndromes have specific symptoms (e.g.,headache, previous head injury).

  Overall, the most common risk factors for stroke are:high blood pressure,highcholesterol, smoking, diabetes and increasing age.Heart rhythm disturbances like atrial fibrillation, patent foramen ovale, and heart valve disease can also be the cause.When strokes occur in younger individuals (less than 50 years old), less common risk factors to be considered include illicit drugs, such as cocaine or amphetamines, ruptured aneurysms, and inherited (genetic) predispositions to abnormal blood clotting.An example of a genetic predisposition to stroke occurs in a rare condition called homocystinuria, in which there are excessive levels of the chemical homocystine in the body. Scientists are trying to determine whether the non-hereditary occurrence of high levels of homocystine at any age can predispose to stroke.

 When brain cells are deprived of oxygen, they cease to perform their usual tasks. The symptoms that follow a stroke depend on the area of the brain that has been affected and the amount of brain tissue damage.Small strokes may not cause any symptoms, but can still damage brain tissue. These strokes that do not cause symptoms are referred to as silent strokes. According to The U.S. National Institute of Neurological Disorders and Stroke (NINDS), these are the five major signs of stroke:Sudden numbness or weakness of the face, arm or leg, especially on one side of the body. The loss of voluntary movement and/or sensation may be complete or partial. There may an associated tingling sensation in the affected area. Sudden confusion or trouble speaking or understanding. Sometimes weakness in the muscles of the face can cause drooling. Sudden trouble seeing in one or both eyes.

Sudden trouble walking, dizziness, loss of balance or coordination.Sudden, severe headache with no known cause. There are various treatment of stroke. There is opportunity to use alteplase (TPA) as a clot-buster drug to dissolve the blood clot that is causing the stroke. There is a narrow window of opportunity to use this drug. The earlier that it is given, the better the result and the less potential for the complication of bleeding into the brain.Present American Heart Association guidelines recommend that if used, TPA must be given within 4 1/2  hours after the onset of symptoms. for patients who waken from sleep with symptoms of stroke, the clock starts when they were last seen in a normal state.TPA is injected into a vein in the arm but, the time frame for its use may be extended to six hours if it is dripped directly into the blood vessel that is blocked requiring angiography, which is performed by an interventional radiologist. Not all hospitals have access to this technology.TPA may reverse stroke symptoms in more than one-third of patients, but may also cause bleeding in 6% patients, potentially making the stroke worse.Secondly,usage of heparin and aspirin. Drugs to thin the blood (anticoagulation; for example, heparin) are also sometimes used in treating stroke patients in the hopes of improving the patient's recovery. It is unclear, however, whether the use of anticoagulation improves the outcome from the current stroke or simply helps to prevent subsequent strokes (see below). In certain patients, aspirin given after the onset of a stroke does have a small, but measurable effect on recovery. The treating doctor will determine the medications to be used based upon a patient's specific needs.

Rehabilitation is the process by which patients with disabling strokes undergo treatment to help them return to normal life as much as possible by regaining and relearning the skills of everyday living. It also aims to help the survivor understand and adapt to difficulties, prevent secondary complications and educate family members to play a supporting role.A rehabilitation team is usually multidisciplinary as it involves staff with different skills working together to help the patient. These include nursing staff, physiotherapy, occupational therapy, speech and language therapy, and usually a physician trained in rehabilitation medicine. Some teams may also include psychologists, social workers, and pharmacists since at least one third of the patients manifest post stroke depression. Validated instruments such as the Barthel scale may be used to assess the likelihood of a stroke patient being able to manage at home with or without support subsequent to discharge from hospital.Good nursing care is fundamental in maintaining skin care, feeding, hydration, positioning, and monitoring vital signs such as temperature, pulse, and blood pressure. Stroke rehabilitation begins almost immediately.For most stroke patients, physical therapy (PT), occupational therapy (OT) and speech-language pathology (SLP) are the cornerstones of the rehabilitation process. Often, assistive technology such as a wheelchair, walkers, canes, and orthosis may be beneficial. PT and OT have overlapping areas of working but their main attention fields are; PT focuses on joint range of motion and strength by performing exercises and re-learning functional tasks such as bed mobility, transferring, walking and other gross motor functions. Physiotherapists can also work with patients to improve awareness and use of the hemiplegic side. Rehabilitation involves working on the ability to produce strong movements or the ability to perform tasks using normal patterns. Emphasis is often concentrated on functional tasks and patient’s goals. One example physiotherapists employ to promote motor learning involves constraint-induced movement therapy. Through continuous practice the patient relearns to use and adapt the hemiplegic limb during functional activities to create lasting permanent changes. OT is involved in training to help relearn everyday activities known as the Activities of daily living(ADLs) such as eating, drinking, dressing, bathing, cooking, reading and writing, and toileting. Speech and language therapy is appropriate for patients with the speech production disorders: dysarthria and apraxia of speech, aphasia, cognitive-communication impairments and/or dysphagia (problems with swallowing).Patients may have particular problems, such as dysphagia , which can cause swallowed material to pass into the lungs and cause aspiration pneumonia. The condition may improve with time, but in the interim, a nasogastric tube may be inserted, enabling liquid food to be given directly into the stomach. If swallowing is still deemed unsafe, then a percutaneous endoscopic gastrostomy (PEG) tube is passed and this can remain indefinitely.Treatment of spasticity related to stroke often involves early mobilisations, commonly performed by a physiotherapist, combined with elongation of spastic muscles and sustained stretching through various positioning. Gaining initial improvements in range of motion is often achieved through rhythmic rotational patterns associated with the affected limb. After full range has been achieved by the therapist, the limb should be positioned in the lengthened positions to prevent against further contractures, skin breakdown, and disuse of the limb with the use of splints or other tools to stabilize the joint. Cold in the form of ice wraps or ice packs have been proven to briefly reduce spasticity by temporarily dampening neural firing rates. Electrical stimulation to the antagonist muscles or vibrations has also been used with some success. Stroke rehabilitation should be started as quickly as possible and can last anywhere from a few days to over a year. Most return of function is seen in the first few months, and then improvement falls off with the "window" considered officially by U.S. state rehabilitation units and others to be closed after six months, with little chance of further improvement. However, patients have been known to continue to improve for years, regaining and strengthening abilities like writing, walking, running, and talking. Daily rehabilitation exercises should continue to be part of the stroke patient's routine. Complete recovery is unusual but not impossible and most patients will improve to some extent: proper diet and exercise are known to help the brain to recover.Some current and future therapy methods include the use of virtual reality and video games for rehabilitation. These forms of rehabilitation offer potential for motivating patients to perform specific therapy tasks that many other forms do not. Many clinics and hospitals are adopting the use of these off-the-shelf devices for exercise, social interaction and rehabilitation because they are affordable, accessible and can be used within the clinic and home.