Stroke, also known as cerebrovascular accident, cerebrovascular attack or apoplexy, is the transient or permanent alteration of brain functions as a consequence of ischemia or hemorrhage that has occurred in any territory of any of its three major elements: the cerebrum, the cerebellum and the medulla oblongata. The term stroke comes from Latin and means “blow”, which denotes its sudden or abrupt onset.
The most frequent form of stroke is ischemic, caused by a lack of blood supply in 80% of cases. Cerebral or subarachnoid hemorrhages are less frequent but no less relevant.
Patients who suffer a stroke have symptoms related to the area of the brain affected. The most prominent symptoms are loss of speech, loss of limb mobility, or loss of vision. It may be accompanied by severe headache, loss of consciousness or convulsions.
The symptoms may be transitory if the lesions revert in a few minutes or hours, or they may be permanent when there is irreparable damage or cerebral infarction. Stroke can be fatal if it affects vital areas of the brain or if it is global. Stroke is the third leading cause of death in the Western world, the leading cause of permanent disability among adults and one of the main causes of neurological deficit in the elderly (vascular dementia).
A stroke is a medical emergency. Even transient strokes should be adequately studied to ascertain the cause and possible prevention of further accidents. Unfortunately, when permanent strokes occur, the ability to regress symptoms is limited. The time elapsed from the onset of symptoms to specialized action is of vital importance to minimize the consequences or sequelae of neurological deficit. For this reason, in some communities the so-called “stroke code” has been successfully implemented for the identification and health action from the point of origin of the patient until his or her admission to highly specialized centers. The aim is to restore blood flow to the occluded arteries or stop bleeding from the bleeding arteries. The aim is to lose the minimum number of neurons in order to have the minimum sequelae or neurological deficit.
Causes of stroke
More than 80% of strokes are of the ischemic type. This lack of irrigation may be due to embolisms from the heart (due to arrhythmias, valvular diseases or post myocardial infarction) or from the arteriosclerotic arteries that carry blood to the brain, carotid and vertebral arteries. The cause may also be due to thrombosis of intracranial vessels. Hemorrhages are usually generated by spontaneous rupture of small intracranial aneurysms or fragile vessels that rupture due to arterial hypertension.
Other less common causes are traumatic brain accidents and iatrogenic causes due to diagnostic or therapeutic actions related to the cerebral arteries.
Strokes are treated in so-called multidisciplinary “stroke units”. The diagnosis of certainty is made by radiological imaging techniques. Depending on the causes, stroke is treated in one way or another. Ischemic strokes with less than 6 hours of evolution are attempted to be recanalized with neuro-interventional techniques with the application of special catheters to open the arteries and combined with pharmacological treatments such as fibrinolytics from the same place where the patient is picked up and continued with anticoagulants and/or antiplatelet agents.
Carotid strokes are intervened by the vascular surgeon to remove the plaque causing the embolism or alternatively, stents are applied. Hemorrhages are either blocked with therapeutic embolization by catheterization or must be intervened by neurosurgeons. A fundamental chapter in the recovery of damaged functions is early and sustained rehabilitation over a period of months. Rehabilitation physicians, physiotherapists and speech therapists play an important role in minimizing the sequelae.
How to prevent stroke
Prevention, as in other cardiovascular diseases, consists of avoiding or controlling the so-called risk factors: hypertension, smoking, hypercholesterolemia and diabetes.
Cerebral aneurysms are congenital in origin. Their early detection occurs especially in those patients with a family history of cerebral hemorrhages. Of course, if the patient has suffered a transient ischemic attack or stroke, it is advisable to investigate the cause in order to eliminate it.
On the other hand, it should not be forgotten that consulting a specialist in the event of suffering from one of these factors or having had a transient ischemic attack or stroke is the most guaranteed form of prevention. Carotid stenosis is detected by Doppler ultrasound. This test should be performed in all patients with a history of cardiovascular disease at any level, coronary or lower limb. Patients with cardiovascular risk factors can also benefit from this painless and rapid test.