الفهرس 
o Cerebral InfarctionOnly 14 pages are availabe for public view
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Abstract
Cerebrovascular disorders are an important cause of mortality and chronic morbidity in children, and are an emerging area for clinical research. These disorders are becoming a world-wide concern owing to the better methods of detection and subsequent diagnosis. International collaborations are currently underway to provide more information on risk factors and outcome, to develop a consensus on evaluation, and to establish a network to prevent its recurrence and optimize future prevention and treatment. Ischemic stroke is probably more common than hemorrhagic stroke in children, but this has not been confirmed in all studies.
Pediatric stroke - a cerebrovascular event in a child aged 30 days to 18 years - is estimated to occur in 2 to 3 of every 100,000 children in the United States per year (Fullerton et al., 2003). Long-term outcome for survivors of hemorrhagic and ischemic stroke is nearly the same in children.
The clinical presentation of stroke varies according to age and location, and may be subtle. In the first month of life; seizures, apnea, and persistent hypotonia are the predominant manifestations. Beyond the neonatal period, hemiplegia is the most common initial symptom. Other manifestations include headache, mental status changes, sudden collapse with loss of consciousness, speech disturbances, sensory complaints (numbness or tingling), and cranial nerve or cerebellar deficits.
Not surprisingly, most children with intraparenchymal brain hemorrhage present with pain or symptoms of increased intracranial pressure. Subarachnoid hemorrhage classically produces sudden severe headache, vomiting, meningismus, and alteration of consciousness. The clinical picture may be less distinct in younger children, who can present with unexplained irritability, vomiting, photophobia or seizures.
Several risk factors for stroke in children have been reported, but frequently no cause is identified. There are numerous reasons for strokes in children, yet cardiovascular disease and sickle cell disease are the most common etiologies. In 2002 Carlin and Chamnmugam reported that congenital heart disease has been the leading cause of childhood stroke (Carlin and Chanmugam, 2002).
Acquired heart diseases, collagen vascular diseases, CNS infections, hematologic and coagulation defects (hemophilias, thrombophilias), CNS vascular anomalies, inborn errors of metabolism (such as mitochondrial encephalopathies and homocystinuria), trauma (leading to vascular dissection), and other illnesses and their treatments (such as cancer and chemotherapy) are general classifications of the conditions that can increase a child’s risk of stroke. Several genetic disorders are associated with stroke or conditions that can lead to stroke, such as the association of trisomy 21 syndrome with moyamoya disease .Several Mendelian genetic disorders are associated with ischemic stroke including vasculopathies, metabolic or connective tissue diseases, and disorders of coagulation. Therefore genetic counceling is detrimental in the evaluation of this genre of pediatric stroke.
In the two largest studies of CVT in children, prothrombotic abnormalities were present in at least half of the cases and many had multiple risk factors. Common illnesses, including ear infections, meningitis, anaemia, diabetes and head injury, may be complicated by CSVT (deVeber et al., 2001). Structural vascular anomalies collectively constitute the largest cause of non-traumatic intraparenchymal and subarachnoid hemorrhage in children.
A detailed history of illness is necessary to support a diagnosis of stroke. What are the exact symptoms and when did they begin? Inquiries into family history of predisposing factors such as sickle cell disease, prothrombotic conditions, and collagen vascular disease should be made. In fact, a thorough physical examination, focusing on the cardiac and nervous systems, can reveal any signs of underlying heart disease (such as a murmur or cyanosis) or neurologic deficits, and is eligible to sustain a preliminary diagnosis.
Prompt evaluation, diagnosis and management in children are valuable to prognostic outcome. Stroke in children is a devastating event that should make physicians work relentlessly towards uncovering its etiology since many children have chronic diseases in parallel, and will require great efforts later on in their lives. The fact that the underlying cause of a significant proportion of pediatric stroke patients remains unknown despite exhaustive evaluation, adds insult to injury.
Moreover, a more in-depth evaluation involves neurologic and vascular imaging, laboratory and cardiac studies. Physicians are always encouraged to choose their investigations judiciously, with reason, based on the patient’s history and provisional examination.
The rapid acquisition time of CT makes it superior over other modalities as it salvages the unstable patient and in the patient whom acute ICH is likely. Not only that, but in addition, children with cochlear implants, cardiac pacemakers, or other contraindications to MRI are best evaluated with CT and typically begin without contrast. An MRI’s superiority over the CT scan in identifying areas of ischemic hypoperfusion, makes it a more attractive choice on the other hand; if time and resources are at its advantage. MRA is ideal for patients with predictable risk from standard angiography or for those with SCD for example (i.e. children whose disease is already suspected). MRA’s capacity to identify moyamoya vascularity has been identififed but still again, CA accurately delineates the vascular anatomy and is a better choice for pre-surgical patients, since it includes visualization of both the external and internal carotid arteries. As for perfusion studies, they can be performed with nuclear medicine, MR perfusion, or CT perfusion. Typically they’re done both pre-operatively for baseline assessment and post-operatively to evaluate the interventional benefit and outcome. Despite the predicament of these perfusion techniques, the reliability of these methods has not yet been established in the pediatric population. On a more serious note, it’s recommended that emergency vascular imaging should include magnetic resonanve venography (MRV) in both hemorrhagic and ischemic stroke, since 10% of hemorrhages in the pediatric population are secondary to CVT. Lastly, the fact that cranial ultrasound lacks research-proven results in the detection of cerebral ischemia; limits its overall usefulness.
Addressing the ABCs of life support in an intensive care unit setting is the initial treatment of a child with stroke. Securing the airway, monitoring cardiovascular parameters, and controlling seizures are paramount. Needless to say, a low threshold for the signs of cerebral edema in the first several hours must be an eye opener and urgently managed.
Information about the effectiveness or risks of thrombolytic agents such as recombinant tissue plasminogen activator (rTPA) in children are still scarce yet there are reports of both dramatic successes and serious hemorrhagic complications from these agents. If such agents are to be considered for use in children, they should as a minimum, be subject to the same exclusions that apply to adults. Individuals with hemorrhagic infarction or those whose stroke began more than 3 hours earlier are typically excluded (Santos et al., 2006).
The usefulness of anticoagulation in children with cerebral infarction is weighed depending on the likelihood of a second infarction that could be prevented by treatment, versus the risk of inducing a hemorrhage due to anticoagulation. Unfortunately, no published controlled treatment trials in children have seen the light this far, but limited expert experience with anticoagulants and antithrombotic agents has proven that these agents can be safely advocated in children.
According to the cumulative recommendations of recent guidelines; therapies directed at the inhibition of the platelet function or coagulation cascade play a role in the acute, subacute, and chronic phases of pediatric stroke treatment. Children with SCD related AIS should be given the opportunity to an exchange transfusion at the acute stage.
The treatment for hemorrhagic stroke (HS) in children depends firstly and most importantly on the child’s condition and its stabilization. Digging for the underlying etiology should start at once in parallel, since the proper characterization of the cause is essential to determine the best therapy. Guidelines for the treatment of spontaneous intra-cerebral hemorrhage in adults are quite similar to the pediatric group and should be considered in children.
Although outcome of children after stroke varies among studies due to differences in follow-up time, functional measures, stroke type, and population studied but it seems reasonable to say that twenty percent of stroke affected children don’t make it and over half of the survivors will develop lifelong cognitive or motor disability and up to one third will have a recurrent stroke. Hence lays the burden of the neurologist and the rest of his collaborative team of specialists and consultants to communicate these post-stroke disabilities and strongly recommend ongoing adjuvant interventions such as speech, occupational, and physical therapies along with close monitoring for the development of post-stroke seizures. Last but definitely not least comes the significance of a crucial, step by step familial psycho education that can reflect a less negative impact on their lives ahead all together, and alleviate upcoming destined challenges