The presenting signs and symptoms of a stroke depend somewhat on the type of stroke and the age of the patient. AIS usually have a rapid onset, so there may be little in the history to warn of the impending event. Patients often suffer sudden seizures, or focal neurologic findings, especially hemiplegia. A history of recurrent headaches, transient ischemic attacks, or focal seizures may be obtained, but these do not provide a specific diagnosis, and often confuse the issue.1 An AIS involving a large vessel may present with loss of consciousness and multiple focal neurologic deficits.4 A stroke due to a metabolic disorder may have an episodic or progressive course. A prenatal AIS often does not present until age 4 months to 8 months as an evolving hemiparesis.4
An older child with a CSVT may present with slowly progressive signs, such as fever, vomiting, or headache. A young infant may have dilated scalp veins, eyelid swelling, and a large anterior fontanelle.1
An older child with a hemorrhagic stroke may have a history of severe headache or, especially in the case of subarachnoid hemorrhage, neck pain. A large bleed will usually result in a sudden alteration in consciousness and perhaps seizures, but a small bleed may result in subtle focal neurologic signs, including cranial nerve palsies.1
A history of cardiac disorders, especially complex congenital heart disease, prosthetic heart valve, or recent cardiac surgery should raise suspicion of an embolic phenomenon. The presence of an indwelling catheter is a risk factor for a thrombotic event.7 The presence of fever and headache should raise concern about meningitis. However, systemic infections, such as mycoplasma, Rocky Mountain spotted fever, and others, have been associated with cerebral infarction due to thrombophlebitis of cerebral vessels.1 A recent throat, peritonsillar, or parapharyngeal infection could lead to thrombophlebitis of the jugular vein (Lemierre's syndrome).10 A recent infection with varicella is of concern, because postvaricella angiopathy (also called transient cerebral arteriopathy) can include basal ganglia infarction and stenosis of large arteries.11 Inherited coagulation disorders such as deficiency of protein C, protein S, antithrombin III, and plasminogen, or the presence of factor V Leiden, lipoprotein (a), anticardiolipin antibody, or lupus anticoagulant can all lead to thromboembolism.1,2,5,9 A history of sickle cell disease is extremely important to elicit, because 25% of patients will develop cerebrovascular problems.1 The presence of systemic lupus erythematosus and other forms of vasculitis such as polyarteritis nodosa, mixed connective tissue disease, or Takayasu's arteritis have all been associated with arterial ischemic and sinovenous thrombosis.
Metabolic disorders, such as homozygous homocystinuria (hyperhomocysteinemia), which have a thrombotic effect, can cause arterial and venous thrombosis. Fabry's disease (deficiency of α-galactosidase A) can lead to lacunar infarcts, and hyperlipidemia has also been associated with childhood strokes. The MELAS syndrome (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes) is due to a mitochondrial disorder and is characterized by episodes of nausea, vomiting, headaches, seizures, and hemiparesis, which initially resolve, but ultimately lead to persistent deficits and cortical blindness.1,4 Neurocutaneous disorders such as neurofibromatosis, Sturge–Weber syndrome, and tuberous sclerosis are all associated with both ischemic and hemorrhagic strokes.
Any history of trauma is significant and suggests a hemorrhagic lesion. Intraoral trauma can cause dissection of the carotid artery, and injury to the vertebral arteries can occur after neck trauma. Recent head or neck trauma can also lead to AIS.7
Children who have had radiation for optic gliomas or pituitary or suprasellar tumors can develop postradiation vasculitis.3
Adolescents in particular are questioned regarding illicit drug use, particularly cocaine. Additional questions are directed toward detecting one of the underlying etiologies noted in Tables 57-1, 57-2, and 57-3.
Stabilization of the patient is the first priority, since seizures may occur in younger children at the time of, or shortly after, the stroke. Complete vital signs include temperature and blood pressure. If trauma is suspected, the head and neck are immobilized. A thorough examination includes auscultation over the head, eyes, and carotid arteries listening for bruits, as well as a careful auscultation of the heart for murmurs, clicks suggestive of valvular disease, arrhythmias, or indications of prior cardiac surgery. The eyes are examined for extraocular movements, pupillary responses, and the visual fields. The eyes will look toward the lesion if the cerebral hemisphere is involved, but away with brain stem involvement. The skin is examined for petechiae, café au lait spots, neurofibromas, or telangiectasias.
Neurologic assessment includes determination of degree of weakness, cranial nerve dysfunction, and the side and extent to which the extremities are involved. If the facial muscles and tongue are involved, there is dysarthria, but involvement of the basal ganglia, thalamus, or cerebral hemispheres can result in aphasia. It may be difficult to assess sensory impairment due to aphasia.
Some disorders that can be confused with a stroke include complicated migraines, partial seizures, Todd's paralysis, brain tumors, brain abscesses, and subdural hematoma. Most will be diagnosed during the workup of the suspected stroke (Fig. 57-1).
Differential diagnosis for stroke.
Baseline laboratory studies include a complete blood count with differential and platelet count and coagulation studies (PT, activated PTT, INR, fibrinogen, and D-dimer).2,12 If sickle cell disease is a possibility, a sickle cell preparation and hemoglobin electrophoresis are performed. Further coagulation studies are indicated if other coagulopathies, such as protein S or C or antithrombin III deficiencies, are suspected. Other studies should include electrolytes, BUN, creatinine, glucose, sedimentation rate, and CRP, as well as a urinalysis looking for red cells or protein, and a urine pregnancy test in females.1,4,8 Studies evaluating a hypercoagulable/prothrombotic state include antinuclear antibodies, protein S, protein C, factor V Leiden mutation, prothrombin 20210A, antithrombin III activity, lipoprotein (a), anti-beta 2 glycoprotein-1 antibodies, homocysteine concentration, anticardiolipin antibodies (IgG and IgM), and lupus anticoagulant.1,2,4,5,9,12 If a fever is present, blood culture, urine culture, and CSF studies are indicated. Blood and CSF viral titers of varicella zoster, herpes, EBV, enterovirus, and parvovirus may be helpful.4 If a metabolic disorder is suspected, blood lactate, pyruvate, carnitine, and serum amino acids are ordered, and urine is sent for organic acids.4 A urine toxicology screen should be sent if cocaine use is suspected. An electrocardiogram and an echocardiogram should be performed on all children in whom underlying heart disease is suspected.12
Imaging studies provide information that will help differentiate an ischemic from a hemorrhagic stroke. MRI with diffusion-weighted imaging is more sensitive than a CT scan in detecting small infarcts, infarcts of the brain stem and cerebellum, and infarcts that become hemorrhagic, and is more sensitive for acute ischemia.1,3,4,12 A CT scan will show a tumor, large bleed, or abscess, and may show loss of gray/white differentiation and the dense triangle sign (hyperdense thrombus in the posterior part of superior sagittal sinus).5,13 However, a CT scan may not detect a small acute hemorrhage.1,4,5 CT scan is also normal in up to 40% of CSVT, so MRI is the preferred study in these cases.3,5 MRA correlates well with angiography, and can be done at the time of the MRI to visualize the flow through the cerebral arteries.1,12 MRI can also be used with MRV to diagnose CSVT.3,5 The visualization of a thrombus and the absence of a flow-related signal provide the diagnosis.13 (Fig. 57-2).
MRI—T2 hyperintensity representing recent infarct in left parietal lobe.
Due to the availability of MRV and MRA, cerebral angiography to visualize intracranial and extracranial vessels is needed less often.13 For patients in whom a hemorrhagic stroke is suspected, in whom the CT scan is negative, and who have no signs of increased intracranial pressure, a lumbar puncture is indicated. Particularly in a small subarachnoid hemorrhage, the CT scan may not reveal blood. The CSF is evaluated for the presence of red blood cells, which, in the absence of a traumatic lumbar puncture, indicates hemorrhage, especially if the blood does not clear during CSF collection. In some cases, the CSF may appear xanthochromic, which is also consistent with hemorrhage.1