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Approach to Acute Hemiparesis in Children
Unconfirmed DRAFT COPY
Yoko Ozawa, New York Medical College; Oya Tugal MD, Martin L. Kutscher MD,
Depts. of Pediatrics and Neurology, New York Medical College, Valhalla, NY.
Stroke is a relatively rare disorder in children with an incidence of
3-8/100,000. While atherosclerotic disease, hypertension, and diabetes are the most common
causes of stroke in adults, the causes in children are quite different.
Three pathophysiologic variants underlie cerebrovascular accidents: thrombosis
of a cerebral artery or vein, embolic disease, and intracranial hemorrhage. Classically,
each variant has a characteristic clinical picture. A thrombotic stroke typically
progresses in a crescendo manner, in which a mild deficit may progress to a maximum
deficit over time as the thrombus propagates. Headaches, seizures, or loss of
consciousness typically are absent. An embolic event typically presents with a sudden
deficit of maximal loss of function at the onset. Intracranial hemorrhages are typically
associated with a severe headache and altered mental state.
As shown below, the etiological differential diagnosis of a stroke in a child
basically falls into problems with emboli, problems with the blood elements, or problems
with the vessels. Non-vascular causes of acute hemiparesis must also be considered.
Selected Differential Diagnosis of Acute Hemiparesis
See discussion below. Children often have more than 1 risk factor.
A. Vascular Causes
1. Cardiac/Carotid (leading to throwing an embolic clot -- sterile or infected)
- Congenital heart disease (VSD, AS, MS, patent foramen ovale, etc.)
- Acquired heart disease (rheumatic fever, prosthetic heart valve, arrhythmia,
- Carotid vascular disease: carotid artery or basilar artery dissection at any age;
atherosclerotic disease in adults
2. Hematologic (factors in the blood stream leading to increased or decreased
Typically Ischemic Stroke
- deficiency of factors that are supposed to limit clotting: Prot S or C or
antithrombin III def., factor V Leiden. May account for increased stroke with pregnancy
and birth control pills.
- presence of abnormal antibodies interfering with regulation of clot:
Antiphospholipid Abs (which include the subclasses of Anticardiolipin Ab and lupus
anticoagulant). Only IgG has a strong link.
- increase or abnormal blood elements: increased platelets, or increased amount or
abnormal RBC (such as sickle cell or polycythemia)
- dehydration or infection with thrombosis of major cerebral veins or dural
Typically Hemorrhagic Stroke
- hemorrhagic tendancies such as hemophilia A and B and other clotting factor
- vitamin K defiiciency
- sometimes sickle cell
- hemorrhage into a (typically embolic) infarction, area of venous
infarction, tumor, or area of radiation
- hypernatremic dehydration (hyperosmolar endothelial damage with rupture of vessel
as surrounding brain shrinks.
3. Arterial problem (something wrong with the vessel itself)
a. Inflammation of vessel (leading to closing off)
- mycotic aneurism
- non-infectious vasculitis: SLE, primary CNS vasculitis, polyarteritis nodosa,
- infectious vasculitis: meningitis: TB, bacterial, HIV, Lyme, mycoplasma,
- inflammatory bowel disease (probably other causes for stroke as well.)
b. Abnormal vessels
- moya-moya (puff of telangiectatic vessels distal to carotid occlusion.
- fibromuscular dysplasia
c. Vessel spasm
- spasm due to SAH
Always broaden the diagnosis to include nonvascular causes of sudden
B. Non Vascular causes of sudden hemiparesis
- encephalitis (from virus)
- encephalitis (postinfectious from virus)
- transient paralysis after seizure
- [hemorrhage into a tumor]
Following are comments about selected etiologies:
Infection Acute bacterial meningitis may produce an infectious
arteritis, while a purulent meningitis that originates from an otitis media, mastoiditis,
or sinusitis may occlude veins or dural sinuses.
Dehydration Fever and dehydration in infants may cause venous or sinus
thrombosis. Clinically, patients present with multiple seizures, changing neurological
signs, coma and increased ICP. Children with hypernatremic dehydration may have seizures,
and depressed consciousness.
Trauma/Carotid or vertebral dissection
Pathology Trauma is a common cause of arterial thrombosis in children.
Commonly, a penetrating injury (via pen or stick) to the childs mouth may cause a dissecting
aneurysm, followed later by thrombosis of the internal carotid artery. Carotid or
basilar artery dissections due to insignificant head and neck trauma may also occur,
especially if there is an underlying defect in the artery. Fibromusclular dysplasia is a
common underlying pre-existin problem.Usually, the damage is bleeding within the wall of
the vessel, although sometimes emboli can be released. Dissections of the
verterbro-basilar arteries tend to occur between the media and adventitia, leading to
subarachnoid hemorrhae. Thus, ischemia, thrombosis, subarachnoid bleed, or
artery-to-distant-artery emboli can all occur.Symptoms can be immediate or delayed for
days. The classic adult symptoms of acute neurological defect with ipsilateral
oculosympathetic paresis and headache are rare in children, who require a high index of
External Carotid Sx
- Headache which may proceed symptoms by hours or days; may be severe or mild; may
radiate to ear or scalp
- Anterior neck pain
- Ischemic symptoms including TIAs may lag by >a week
- Monocular visual impaiment
- Cervical bruit, Horner's syndrome, or lower cranial neuropathies.
- Seizures in some patients.
Internal Carotid Sx
- Headache may preceed stroke by minutes to weeks.
- Less common, younger patients, more catastrophic
- Supraclinoid portion of the ICA, or MCA or ACA
- Anterior circulation in young adults; posterior circulation (Vertebral artery) in
Vertebral Artery Dissection
- Basilar artery dissection is less common than verterbral artery.
- May also occur with carotid dissection
- Abrupt vertigo, ataxia, dysarthria, and headache
- Alternating hemiparesis, ataxia, and head tilt in children.
- Lateral medullary syndrome in adults.
- Occipital headache may preceed or follow symptoms by days
- Distal basilar artery involvement may come from thrombotic extension or emboli.
- May have C1-C2 vertebral anomalies or fibromuscular dysplasia.
- Confusion and prostration if associated basilar artery of SAH.
- May also have subarachnoid bleed.
Radiographic Diagnosis of Vascular Dissections
- First test done is often whatever is available.
- Doppler Carotid Flow Studies seek indirect evidence and 68% sensitivity.
- Conventional Angiography usually reserved for unclear cases and pre-op.
- MRI with MRA considered by many to be best diagnostic test. 84% sensitive; 99%
specific, although may miss intimal flap.
- CTAngio may be easier for children.
- [Intracranial dissection and vertebral dissection best detected with angio or
MRA. Some feel that CTAngio is helpful for vertebral studies.
Treament of Dissection
- No concensus amongst the following choices:
- Heparin/warfarin to prevent embolic complications is the most widely
used treatment, but has risks (esp if intracranial) and is unproven to help.
- Endovascular treatment (angioplasty, stents, occlusion) is too limited in
children to make recommendations.Consider if persistant or worsening symptoms. Otherwise
medical therapy and radiographic follow-up. Catheterization may cause complete occlusion
while placing stent. Angioplasty is to too risky acutely.Occlusion (if demonstrated safe
by balloon) may be needed to stop spread of thromboembolus. Surgery is considered for
life-threatening hematomas or thrombi or expanding aneurism in accessible areas. Consider
bypass or clipping.
Hematologic: Thrombotic Sickle cell disease is the most common
hemoglobinopathy associated with CVD. Approximately 25% of sickle cell patients will
develop cerebrovascular complications. The primary mechanism of a sickle cell crisis is an
occlusion of small blood vessels by sickled erythrocytes. This forms an area of local
anoxia that leads to further sickling and progression of the occlusion A normal CBC makes
less likely other hyperviscosity conditions such as polycythemia vera, thrombocytosis and
leukemic blastic crisis. Sometimes, the viscosity of the blood needs to be directly
Deficiencies of inhibitors of coagulation, such as protein C, protein S,
antithrombin III, factor V Leiden, heparin cofactor II, and dysfunctional plasminogen or
fibrinogen, are prominent causes of venous thrombosis.
Anti Thrombin III (AT III) is a plasma inhibitor protein that blocks the
activity of some serine protease coagulation factors. AT III activity is increased by
heparin and is therefore necessary for heparins anticoagulant activity. Congenital
AT III deficiency is an autosomal dominant trait that affects both sexes. Diagnosis is by
detection of reduced AT III activity in plasma. There are two types: type I patients (most
common) lack both AT III functional activity and protein, and type II patients have a
dysfunctional protein but a normal amount of protein.
Protein C is a plasma inhibitor protein that, once activated, inhibits clot
formation and enhances fibrinolysis. Congenital protein C deficiency is an autosomal
dominant trait. Diagnosis is by detection of reduced protein C activity in plasma. Protein
S is a vitamin-K-dependent plasma protein that functions as a cofactor for the
anticoagulant affect of activated protein C. Congenital protein S deficiency is also an
autosomal dominant trait. In Activated Protein C resistance (APC), there is a
mutation in factor V molecule that makes it resistant to the inactivating effects of
protein C. Diagnosis is by detection of factorV Leiden.
The antiphospholipid antibody syndrome (lupus anticoagulant) may be primary
(idiopathic) or associated with systemic lupus erythematosus, infections, drug reactions,
or other autoimmune diseases. Patients with circulating lupus anticoagulant are at
increased risk of thrombus formation (despite the name). Associated features include
livedo reticularis, recurrent fetal loss, thrombocytopenia, and thrombosis. Of note, the
activated partial thromboplastin time (aPTT) may be prolonged. Diagnosis is by specific
assays to detect the antiphospholipid antibody. Treatment includes warfarin with or
Other causes of thrombosis include: systemic malignancy, pregnancy, birth
control pills, and inflammatory bowel disease.
Hematolgic: Hemorrhagic Thrombocytopenia usually
does not result in intracranial bleeding unless platelets are less than 20,000 or there is
trauma. ITP and chemotherapy are the most common causes. Hemophilia A, hemophelia B,
vitamin K deficiency, Factor VII and Factor VIII defiiciencies also lead to bleeds.
Hemorrhage into an area of infarction can also occur in ischemic and venous/dural sinus
occlusions.Hemorrhage may also occur into a tumor, and may even be the presenting sign.
Both hemorrhage in ischemic infarctions can occur after radiation therapy. Rarely,
hypertension can be a cause in children.
Dural sinus/venous occlusion may be secondary
to mastoiditis, otitis media, meningitis, dehydration, or underlying coagulapathy.
Cardiovascular Cyanotic congenital heart disease may cause both
thrombotic and embolic strokes, although the latter is more common. Thrombotic strokes
typically occur when the child is less than 2 years old; and present with sudden
hemiparesis, increased intracranial pressure, seizure and decreased consciousness. The
increased risk of thrombosis is related to polycythemia and hyperviscosity. Embolic
strokes in children with cyanotic CHD may involve paradoxical emboli through a patent
foramen ovali, or cardiac thrombus formation secondary to arrythmias or dilated
cardiomyopathies. Rheumatic heart disease or prosthetic valves are often associated with
bacterial endocarditis and therefore increase the risk of septic emboli. SBE should always
be considered in the setting of acute stroke in a child.
Vasculitis/Collagen vascular disease Systemic arteritis, such as
polyarteritis nodosa, causes a vascular disease in many organs in which the brain is just
one target. Henoch-Schonlein purpura and Takayasus disease also may be complicated
by cerebral infarcts, as can varicella zoster.
Systemic lupus erythematosus may cause a small vessel vasculitis that results in
multiple microinfarctions. Patients may present with cerebral symptoms and signs,
including hemiparesis due to arterial or venous thrombosis. On occasion, isolated primary
CNS vasculitis can occur. An angiogram may be required for diagnosis.
Metabolic Patients with homocystinuria are deficient in crystathionine
synthase. The pathophysiology appears to involve endothelial injury (from toxic amounts of
sulphur containing amino acids) and an increase in platelet consumption, with
resultant arterial and venous occlusions. Elevated levels of homocysteine in the serum or
urine would be diagnostic.Clinically, they may show skeletal and cutaneous findings along
with dislocated ocular lenses and developmental delay. MELAS (Myoclonic epilepsy
with lactic acidosis and strokes) is a mitochondrial metabolic disorder.
Neurocutaneous dermatologic signs suggestive of Neurofibromatosis,
Sturge-Weber, or Tuberous sclerosis.
Vascular abnormalities Arteriovenous
malformations typically have intraparenchymal bleeds presenting with headache and symptoms
of raised intracranial pressure. Aneurisms are less common in children, and usually
involve the subarchnoid space (and sometimes intraparenchymal as well).
In general, start with the studies with the highest yield and the lowest risk:
- ESR, CBC, PT, PTT, blood culture.
- MRI/MRA/MRV of the head
- MRA or preferably ctAngio of the neck vessels
- Lumbar Puncture routine, viral, tb, L/P
- Neurology, Hematology (see Appendix A), Rheumatology, Cardiology consults
- Consider true angiogram.
Treatment (Recommendations based on limited data and are in flux.
Adapted from Bodensteinter)
1. Identify and specifally treat any identifiable (disorders).
2. Treatment is often difficult due to delay in diagnosis in children.
3, Very limited data for treatment in children.
- Often used, apparently safely without Reye's syndrome seen in these doses, yet.
- 3-5mg/kg/day ASA is most common dose used to prevent recurrent arterial stroke.
No clear data on its use in children.
- Consider if 1) a high risk of recurrence of stroke and 2) low risk of
- Limited data suggest effective with less than 5% chance of bleed. Value is
unclear but consider when:
- arterial dissection
- dural sinus thrombosis
- coagulation disorders
- recurrent thrombosis or emboli
- stroke in evolution
- ? with a new stroke
- Heparin Dose: 20 U/kg/hr for children over 1 year of age
- Heparin Dose: 28 U/kg/hr for children <1 year of age
- Typically avoid any loading dose to reduce risk of hemorragic conversion of
- Target APTT is 60-85 seconds
- Low molecular weight heparin (Lovenex): 1mg/kg/dose (or 1.5mg/kg/dose in
neonates) q12hr SQ, and requires only weekly or less monitoring. Not clear that it helps
arterial strokes vs. risks and ASA might be better.
- Limited experience in children.
- Additonal concerns over children's activity level, but probably OK if avoid
- Consider indications like adults
- Cogenital/acquired heart disease
- hypercoagulable states
- arterial dissection
- dural sinus thrombosis
- INR of 2.0-3.0; unless mechanical heart valves 2.5 to 3.5
7. Thrombolytic Agents
- tPA (tissue Plasminogen Activator) not currently recommened for patients with
acute stroke becaue of rate of serious bleeding after systemic tP''a given for systemic
cots in children and the lack of safety data in childhood stroke.
- Clinical trials for stroke < 3 hours old are being considered.
- Limited data suggests tPA dissolves the clot, but 25-50% had minor or major
- Several cases of use of intrasinus urokinase or streptokinase were given without
- Overall: Insufficient data to comment on effectiveness of any of the thrombolytic
agents in children with ischemic stroke. If given more than 3-4 hours post event,
unacceptable rates of bleeding.
8. Sickle Cell Transfusion
- Half of Sickle Cell patients with one stroke will have another.
- Repeat transfusions to suppress sickle hemoglobin to <30% will lower repeat
risk, and must be continued.
- Transfusions can also help prevent first sickle stroke in patients at increased
- TCD can help identify sicklers at highest risk for first stroke.
- Iron toxicity might be reduced if even 50% HgS is maintained. Needs further
Reference: Bodensteiner JB, Roach ES, and deVeber G; Seminars in Pediatric
Neurology: Cerebrovascular Diseases in Childhood. WB Saunders. Vol.7 No.4. December
APPENDIX A: Standard work-up for prothrombotic disorder.
Section of Hematology/Oncology
Department of Pedicatrics
New York Medical College
||Type of tube-amount of blood
||Test done at
||PT, PTT, Thrombin time, Fibrinogen
||In dysfibrinogenemias thrombin time is
prolonged; fibrinogen is normal.
||Factor VIII, XI and XII
||Individuals with high levels of factor VIII,
XI or FXII deficiency are at increased risk for thrombosis.
||Antithrombin deficiency is usually associated
with venous thrombosis. Lupus anticoagulant and anticardiolipin antibodies are
antiphospholipid antibodies that can cause thrombotic problems; but in vitro, the PTT is
prolonged in these conditions.
||Increased homocysteine levels are associated
with various forms of arterial thrombosis.
||Protein C functional assay
|Blue- 3 ml x2
||Physiologically, protein C prevents excessive
clotting by inhibiting factors V and VIII; protein S is an essential cofactor that
activates the protein C. Thus deficiency of protein C or S results in thrombotic
MTHFR- Methylene Tetra hydro Folate Reductase (Monday, Thursday
|Lavender-3ml x 2
||Factor V Leiden is an abnormal protein that is
resistant to the inactivation by activated protein C. Prothrombin 20210A mutation causes
increased thrombin generation thus leads to increased thrombosis. Mutated MTHFR gene
results in deficiency of MTHFR leading to increased homocysteine levels.
APPENDIX I: Standard work-up for thrombophilia (prothrombotic disorders)
Note: All of the above inherited prothrombotic conditions are rare, and usually do not
cause thrombosis unless triggered by additional factors such as trauma, infection,
Note: Consider sucrose hemolysis test if there is a suspicion of PNH (call 493-1475
Special Hematology to arrange the test).
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