Stroke is a phenomenon characterized by sudden loss of blood supply to a certain area of the brain resulting in loss of nerve function in the same area.
The term stroke is generic and includes a diverse group of diseases consisting of thrombosis, embolism, and bleeding. The incidence of the phenomenon is overall for the pediatric population around 2-3 cases per 100,000 children. That number coincides with the rate of oncological diseases of the central nervous system, making strokes among the top ten deadly diseases in children.
Strokes are divided into ischemic and hemorrhagic.
Ischemic strokes are due to clogging of the brain and are caused by thrombosis or embolism.
In adults 9 out of 10 cases are due to ischemia while in children there is almost equal distribution of ischemic and bleeding episodes with ischemic episodes accounting for approximately 55-60% of all strokes in the pediatric population.
In the past, almost nothing was possible to treat and treat the stroke. The last 25 years have been important steps in the prevention, management and physical rehabilitation of stroke patients.
In 1995, the use of intravenous thrombolysis with tissue plasminogen activator (tPA) was first introduced in clinical practice in patients with ischemic stroke.Today, acute ischemic stroke is considered an emergency medical emergency that needs to be treated immediately.
Stroke in children is most common during the neonatal period (<1 month). One in 100 newborns is affected by some kind of intracranial hemorrhage and about one in 4,000 newborns is affected by arterial ischemic attack. The incidence of stroke in children beyond infancy varies and is reported to range from 2 to 13 cases per 100,000 children per year according to various statistics. However, the incidence of stroke in children appears to be increasing and higher in more recent studies.The increased rate may be due to the increased survival rate of very early neonates as well as children with oncological diseases and children with congenital heart diseases who are now more successfully treated.
Boys have a higher risk of stroke than girls with a 1.5 to 1 ratio.
Initial symptoms are different from infants and older children.
In cases of neonatal stroke, the clinical picture is often unclear with unclear and generalized symptoms such as hypotension, tremor, apnea and episodes. A major symptom that occurs mainly in newborns in the first few days of their life is seizures. About 40% of newborns with stroke do not have initially focused symptoms, such as hemiparesis, making it difficult to diagnose. Typical symptoms such as early right or left hand preference, hemiparesis or dystonia appear much later, after a few months.
In older children, sudden onset (> 1 month) of mechanical or unpleasant phenomena, hemiparesis, ataxia, dysphagia, vision disorder or focused epilepsy may occur.
In children, these symptoms are similar to those in adults from the brain region that has been damaged by bloodstream disruption. Specifically there are four areas:
Circulatory disturbance in the anterior cerebral artery affects the function of the anterior lobes by disrupting the critical ability to walk inactivity and appearing in the lower limb of weakness and hypersensitivity.
Circulatory disturbance in the middle cerebral artery causes unilateral hypersensitivity hypersensitivity unilateral hemianopia and blindness to the lesion side. The patient may experience emission or even aphasia if the lesion is found in the dominant hemisphere. The middle cerebral artery supplies almost exclusively the motor cortex for the upper extremity and the face is much more intense than the lower extremity.
Circulatory disorder in the posterior cerebral artery causes homogenous cortical blindness, visual impairment in alertness and memory.
Circulatory disturbance in the spinal cord artery causes multifaceted symptomatology with dysfunction of the cranial nerves, cerebellum, or strain.Symptoms include vertigo, nystagmus, diplopia, dysphagia, dysarthria, hypersensitivity to the face, visual field disorders and loss of pain and temperature ipsilateral to the face and partially to the body.
A recent study found that the median time from onset of symptoms to diagnosis was approximately 25 hours, although all children in this study had previously been hospitalized.
Ischemic Brain Injuries
At the macroscopic level, ischemic strokes are caused by extracranial embolism or intracranial thrombosis.
A clot is the adhesion of blood components to a vessel, which blocks blood flow through it. The most common site of arterial occlusion due to thrombosis is in the area of the internal carotid artery. The main causes are arterial stenosis and turbulent blood flow, atherosclerosis with plaque ulceration and platelet adhesion leading to the formation of thrombi that either occlude the artery locally or constitute embolism in another vessel. Less common causes of thrombosis are polycythemia, protein C deficiency, fibrous brain dysplasia, and prolonged vasoconstriction due to migraine. Any cause that causes segregation in the arterial wall can cause thrombosis and stroke, for example injury or inflammation of the vessels. Occasionally, a reduction caused by a narrowing of the artery or a deleterious area such as the transition zones between two cerebral arteries can cause ischemic stroke.
One embolism is the clot detachment from one point that blocks the vessel to another. It can start from the extracranial arteries or the heart. The source of a cardiogenic embolism may be thrombi in the heart valves (due to mitral stenosis, endocarditis, prosthetic valve use, etc.), dilated cardiomyopathy or vaginal myxomas. Vaccinations usually result in lacunar infarcts and make up 15-20% of all cerebral infarcts, usually affecting small vessels and leading to subcortical infarcts in the brain and strain.
Bleeding cerebral episodes
Mortality in hemorrhagic strokes is about 25% in children. Of the 40% who survive, they may be disabled including. Bleeding strokes are caused by blood spreading out of the vessel lumen causing joint infections usually due to an anatomical problem in it. In neonatal age, hemorrhages are more common than ischemic strokes. The term includes spontaneous intraparenchymal hemorrhage (SIH) where the bleeding is located within the brain tissue – the parenchyma, and non – traumatic subarachnoid hemorrhage (SAH) where the bleeding is localized.
Hemorrhagic strokes in children are usually prone to atherosclerotic malformations (AVM) and blood clotting disorders.
The classic risk factors found in adults such as smoking, hypertension, heart failure and diabetes are of little or no importance in childhood.
Children have a primary role in genetic, developmental, environmental and some medical factors. Thus many diseases of the hematopoietic system increase the risk of thrombosis and bleeding and can result in a stroke in the child. For example, hemoglobinopathies with first sickle cell anemia where children with this condition have a 300-fold increased risk of stroke. Congenital hyperacidity or otherwise thrombophilia and congenital lack of coagulation factors or otherwise hemophilia. Factors affecting blood circulation such as congenital heart disease and factors affecting the internal vessels such as infections, inflammation, collagen disease or even prolonged use of intravascular catheters also increase the risk for stroke.
There are two main hypotheses regarding neonatal perinatal stroke.
The primary etiology for ischemic stroke in neonates is considered to be a cerebral embolism from the placenta through the ovarian cavity and usually affects the left hemisphere. Most of the increased risk factors in neonates such as neonatal or maternal thrombophilia, preeclampsia, sporadic amniocentesis, gestational diabetes and endometrial growth restriction are factors that signal or cause placental pathology.
Another possible reason is carotid injury during childbirth.
Every child affected by a stroke must be investigated to find out the causal factors that led to it.
Cardiology and vascular testing are included in the investigation. The causes of a stroke in children can be identified in about 75% of cases.
The treatment of ischemic stroke in the last decade has improved significantly in part due to the application of thrombolysis that restores blood circulation but also to the appearance of specific sections exclusively for the treatment of strokes.
The purpose of treatment is to save the area of the brain that has not yet been irreversibly damaged. This area is called penumbra. Children with cerebral palsy should be monitored at special treatment units where blood pressure, temperature and blood sugar are monitored and where special physical rehabilitation treatment can be started immediately.
To date there is no specific protocol for treatment of thrombolysis in children due to lack of research results. Specific and personalized treatment with thrombolytic drugs is at the discretion of the treating physician and usually in children aged 15 years and over.
The recommended treatment in children is with anticoagulants and the prophylactic treatment is with acetylsalicic acid. Hemorrhagic stroke may require treatment with medications that help control bleeding such as desmopressin or even neurosurgeon evaluation for surgical control of bleeding.