mimic stroke, including complicated migraine, structural brain lesion, central nervous system (CNS) infection, Todd paresis, and psychogenic causes (see Chapters 17 Coma and 82 Weakness ) Diagnostic Testing Investigations in a child for whom there is a concern for stroke should be directed at confirming the diagnosis of stroke and attempting to identify an underlying cause Cross-sectional neuroimaging is recommended for all children with suspected stroke MRI with diffusion-weighted imaging is considered the most sensitive imaging modality and can identify ischemic changes within hours of onset Limited, or Quick brain MRI with DWI series has demonstrated good sensitivity for the identification of acute ischemic stroke, however, it is not as sensitive in the identification of hemorrhage, which may limit its role for those patients for whom thrombolysis is a consideration Cranial CT without contrast is the study of choice for identifying acute hemorrhage; however, CT scan may be normal in the first 12 to 24 hours after an ischemic stroke Vascular imaging of the cervical vessels as well as proximal intracranial vessels should be included This can be done with magnetic resonance angiography in most patients MRV imaging should be strongly considered as a significant proportion of hemorrhages are secondary to cerebral venous sinus thrombosis Several factors should be considered in the choice of initial imaging modality; radiation exposure, sensitivity, and specificity in identifying acute ischemia and hemorrhage, ability to complete in a timely manner, the need for anesthesia, and consideration of thrombolytic therapy In a child without a known predisposing condition, ancillary tests may be helpful in revealing the cause of the stroke Studies worth considering in such patients, depending on the clinical picture, are listed in Table 97.6 In one series of 129 children with ischemic stroke, no cause was found in 35% Management Initial treatment after an acute stroke should focus on stabilization and prevention of secondary neuronal injury This includes maintenance of normotension, normothermia, euglycemia, and treatment of hypoxemia and seizures Hypertension must be treated cautiously, and the blood pressure lowered gradually in order to maintain adequate cerebral perfusion Both hypoglycemia and hyperglycemia can exacerbate ischemic stroke Careful monitoring of serum glucose levels and judicious use of insulin are important Fever, which can occur