systemic thrombolytic therapy with recombinant tissue plasminogen activator ( rt - pa ) , intra - arterial thrombolytic therapy , and mechanical revascularization are therapeutic options in acute ischemic stroke ( ais ) in adults [ 1 , 2 , 3 ] . published experience in ais in childhood a previously healthy 14-year - old boy was admitted with acute onset of severe left hemiparesis with a national institute of health stroke scale ( nihss ) score of 12 . there was no prior history of trauma , infection or family history of migraine or other cerebrovascular disease , but the boy was complaining of frontal headache over the last 2 weeks . intravenous rt - pa infusion ( 0.9 mg / kg ) was started 3 h after onset of symptoms but was discontinued after 2/3 of dosage because of serious neurological deterioration . we immediately performed an mri which revealed acute ischemic lesions in both territories of the anterior cerebral arteries ( aca ) and the left middle cerebral artery ( mca ) . mr angiography ( mra ) showed the right aca without flow signal , the left internal carotid artery ( ica ) with an intracranial stenosis , and several mca branches with lack of flow ( fig . several differential diagnoses were considered : dissection , isolated cerebral vasculitis , arterial spasms , infection , multiple cardiac embolism , and intoxication . screening for heroin , amphetamine , ecstasy , ethanol , and cocaine in blood and urine was negative . a previously healthy 10-year - old boy was admitted with acute severe left hemiparesis ( nihss 16 ) and headache after jumping on a trampoline . there was no history of infection or family history of migraine or other cerebrovascular disease . mri revealed an acute ischemic lesion in the right mca territory , occlusion of the right ica , and a thrombus in the right mca ( fig . 2 ) . intravenous rt - pa infusion ( 0.9 mg / kg ) was started within 3 h after onset of symptoms . as no improvement was observed at the end of the rt - pa infusion , mechanical revascularization was performed . a goose neck snare was passed through the thrombus which was partially fragmented and finally dissolved . flow was established in the right mca and the branches 5 h after the onset of stroke ( fig . the potential trauma ( bouncing trampoline ) and thrombus formation in the ica made an intima dissection most likely , but could not be confirmed by angiography . no stent was used and platelet inhibition was started the next day . transesophageal echocardiography and routine blood samples , including extensive coagulation tests , were all normal . the boy improved ( nihss 13 the next day ) and was transferred to the department of pediatric neurorehabilitation on day 3 . at 3 month , he was back to school , but was still suffering a slight hemiparesis ( modified rankin scale ( mrs ) 2 ) . a previously healthy 14-year - old boy was admitted with acute onset of severe left hemiparesis with a national institute of health stroke scale ( nihss ) score of 12 . there was no prior history of trauma , infection or family history of migraine or other cerebrovascular disease , but the boy was complaining of frontal headache over the last 2 weeks . intravenous rt - pa infusion ( 0.9 mg / kg ) was started 3 h after onset of symptoms but was discontinued after 2/3 of dosage because of serious neurological deterioration . we immediately performed an mri which revealed acute ischemic lesions in both territories of the anterior cerebral arteries ( aca ) and the left middle cerebral artery ( mca ) . mr angiography ( mra ) showed the right aca without flow signal , the left internal carotid artery ( ica ) with an intracranial stenosis , and several mca branches with lack of flow ( fig . several differential diagnoses were considered : dissection , isolated cerebral vasculitis , arterial spasms , infection , multiple cardiac embolism , and intoxication . screening for heroin , amphetamine , ecstasy , ethanol , and cocaine in blood and urine was negative . a previously healthy 10-year - old boy was admitted with acute severe left hemiparesis ( nihss 16 ) and headache after jumping on a trampoline . there was no history of infection or family history of migraine or other cerebrovascular disease . mri revealed an acute ischemic lesion in the right mca territory , occlusion of the right ica , and a thrombus in the right mca ( fig . 2 ) . intravenous rt - pa infusion ( 0.9 mg / kg ) was started within 3 h after onset of symptoms . as no improvement was observed at the end of the rt - pa infusion , mechanical revascularization was performed . a goose neck snare was passed through the thrombus which was partially fragmented and finally dissolved . flow was established in the right mca and the branches 5 h after the onset of stroke ( fig . the potential trauma ( bouncing trampoline ) and thrombus formation in the ica made an intima dissection most likely , but could not be confirmed by angiography . transesophageal echocardiography and routine blood samples , including extensive coagulation tests , were all normal . the boy improved ( nihss 13 the next day ) and was transferred to the department of pediatric neurorehabilitation on day 3 . at 3 month , he was back to school , but was still suffering a slight hemiparesis ( modified rankin scale ( mrs ) 2 ) . the current american heart association pediatric stroke guidelines advocate thrombolytic therapy for childhood ais only in the setting of clinical trials . in contrast , the european stroke organization guidelines suggest that intravenous rt - pa may be administered in selected patients under the age of 18 beyond the current european recommendations . experience with systemic thrombolytic therapy and intra - arterial revascularization in ais in children is limited . the nationwide inpatient sample in the us recorded data of 2,904 children with stroke . ( 687 children ) , 2% of children received thrombolytic therapy , 9% received intravenous and 6% intra - arterial therapy . both studies showed increased in - hospital mortality and worse outcome in children treated with thrombolytic therapy compared to conservative treatment , probably reflecting a treatment selection bias towards more severe stroke . furthermore , the thrombolytic therapy often deviated from the current adult stroke guidelines by delayed initiation . in contrast , a review of 17 cases published in the literature , which were treated with systemic thrombolytic therapy or intra - arterial revascularization ,   probably reflects a publication bias towards positive results with good outcome and low mortality . our two children were treated according to the stroke treatment guidelines for adults , and no rt - pa related intracranial hemorrhage or other side effects were seen . lower concentration of tissue plasminogen activator and higher concentration of plasminogen activator inhibitor type 1 in children   might influence the dose - response relation of rt - pa . systemic thrombolytic therapy is approved in ais in adults , in whom atherothrombosis is the most frequent cause of ischemic stroke . in contrast , in children , cardiac disease , prothrombotic or hematologic disorders , dissection , moyamoya disease and vasculitis are common etiologies . however , our children were both previously healthy . in the first case , endovascular therapy was not available in our center at that time . the history of headache over the last 2 weeks was suspicious for vasculitis , but now signs of inflammation were found and the later organ transplantations caused no systemic vasculitis . there were no other medical conditions that might have indicated that the changes on mra were associated with the moyamoya syndrome . another consideration was arterial spasm due to intoxication , but the screening for toxins was negative . autopsy was not permitted by the parents , and the stroke etiology remained unclear . in the second case , the history of a potential trauma and thrombus formation in the distal ica made an intima dissection most likely , but could not be confirmed on angiography or mri after successful mechanical revascularization . the clinical outcome after 3 month was good ( mrs 2 ) and full recovery was seen after 5 month . in conclusion , treatment of ais in childhood without being part of a randomized controlled trial needs a careful individual approach . differences in the fibrinolytic system and the different etiology of ais in childhood may limit a simple extrapolation of the adult guidelines for systemic thrombolytic therapy . acute multimodal imaging with mra , ct angiography , or angiography to clarify the etiology of ais might help to select the most appropriate treatment modality .
thrombolytic therapy is not recommended for acute ischemic stroke ( ais ) in patients under the age of 18 and published experience is limited . in this case report , we describe two children treated with systemic thrombolytic therapy . 
 one child received additional mechanical revascularization and achieved a good clinical outcome . 
 the differences in the fibrinolytic system and the different etiology of ais in childhood may limit a simple extrapolation of the adult guidelines for systemic thrombolytic therapy . 
 acute multimodal imaging to clarify the etiology of ais might help to select the most appropriate treatment modality .