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44. Diffusion Weighted Imaging Lesion Reversal is rare after IV thrombolysis in Acute Ischemic Stroke
1540
Abstracts / Journal of Clinical Neuroscience 16 (2009) 1514–1546
2
Department of Medicine, Hawke’s Bay Hospital, Hastings, New Zealand Department of Neurology, Christchurch Hospital, Christchurch, New Zealand 3
Background: The early risk of stroke in patients presenting with a transient ischemic attack (TIA) is high. Recent studies have shown that early intervention can reduce this risk significantly, but relies on the ability to rapidly assess patients with TIA and implement secondary prevention measures. We wanted to compare current practice in New Zealand with recommended guidelines. Methods: In August 2008 a written questionnaire was sent to all District Health Boards (DHBs) in New Zealand concerning provision of TIA services, access to relevant investigations, clinical management and quality improvement activity related to TIA patients. Results: All 21 DHBs returned the questionnaire. Eight DHBs (38%) did not have a lead stroke clinician. Acute services were responsible for the assessment and management of patients with TIA in 18 DHBs (86%), with patients managed in emergency departments or acute assessment units in 15 DHBs (72%) or routinely admitted to medical wards or stroke units in 3 DHBs(14%). Three of 21 DHBs (14%) see most TIA patients in outpatient clinics and have a usual waiting time for patients to be seen of one or more weeks. Delays of more than one week were common for carotid ultrasound scans (10 DHBs, 48%) and carotid endarterectomy when indicated (16 DHBs, 76%). Thirteen DHBs (62%) have guidelines for the management of patients with TIA but only 9 DHBs (43%) incorporate the ABCD2 score. Only 4 (19%) DHBs had audited TIA services. Conclusions: There is a substantial under-provision of TIA services in New Zealand resulting in significant discrepancies between current practice and recommendations in national and international guidelines. Large regional variations in the standard of care also exist. In order to reduce the burden of stroke, the development of dedicated appropriately resourced TIA services should be seen as a priority for DHBs in New Zealand. doi:10.1016/j.jocn.2009.07.068
44. Diffusion Weighted Imaging Lesion Reversal is rare after IV thrombolysis in Acute Ischemic Stroke Chemmanam Thomas 1, Christensen Soren 1, Bladin Christopher F 2, Desmond Patricia M 1, Ebinger Martin 1,3, De Silva Deidre A 1,4, Parsons Mark W 5, Levi Christopher R 5, Barber Alan P 6, Donnan Geoffrey A 7, Davis Stephen M 1, for the EPITHET investigators 1
Department of Neurology and Radiology, The Royal Melbourne Hospital, University of Melbourne, Parkville, Australia 2 Department of Neurology, Box Hill Hospital, Monash University, Melbourne, Australia 3 Center for Stroke Research Berlin (CSB), Charité – University Medicine Berlin, Germany 4 Singapore General Hospital campus, National Neuroscience Institute, Singapore 5 Departments of Neurology and Hunter Medical Research Institute, John Hunter Hospital, University of Newcastle, Australia 6 Department of Neurology, Auckland Hospital, University of Auckland, New Zealand 7 National Stroke Research Institute, Austin Hospital, University of Melbourne, Australia Introduction: In ischemic stroke, the acute Diffusion Weighted Imaging (DWI) abnormality generally represents irreversibly infarcted brain tissue. However, animal and human studies have shown that the acute DWI lesion may be reversible. We aimed to
determine the relationship of DWI lesion reversal with intravenous tPA in the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET). Material and Methods: In EPITHET patients with acute ischemic stroke presenting within 3-6 hours were randomized to tPA or placebo. Pre-treatment DWI was compared visually with 3 - 5 day DWI and day-90 FLAIR or T2 images, to identify the frequency of DWI reversal. We aimed to assess the relationship of DWI reversal with tPA, reperfusion and timing of treatment. After co-registration of the acute and follow up images in those patients with any DWI lesional reduction, we divided the acute DWI lesion into reversible and irreversible regions and compared their ADC values. Results: Of 101 in EPITHET, 91 patients had subacute DWI and 72 patients had a day 90 scan. Any reduction in volume from pretreatment DWI was seen in 32/72 (44%) on day-90 scans, but in only 4/ 91(4.3%) on day 3-5 DWI scans. After excluding cases with appreciable brain shrinkage and hemorrhagic change, true DWI reversal was observed in only 11/92 patients (11.9%), 7 of whom had received tPA. The median volume in these 11 patients reduced from 24.17 ml (IQR 7.28-45.74) in the acute DWI to 18.13 ml (IQR 8.68-43.20) in the day 3 - 5 DWI and 6.93 ml (IQR 2.69-27.07) in the day 90 scan. Major reperfusion occurred more commonly in patients with DWI reversal compared to those with no reversal (82% vs 32%; p = 0.002). DWI reversal was not associated with tPA or earlier time of treatment. Median volumes of DWI reversal from the acute DWI to day-90 scan (7.92 ml) and to subacute DWI (10.7 ml) were very small compared to the median mismatch volume of 137.9 ml, with the estimated median difference being 117 and 160 ml. (p = 0.011 and 0.007 respectively). On comparing the acute and day-90 scan, the mean relative ADC values in the irreversible and reversible parts of the DWI lesion were different [0.75 (SD 0.13) vs 0.95 (SD 0.18) (p = 0.014)]. Conclusions: DWI reversal is uncommon in ischemic stroke patients treated with intravenous tPA within 3 – 6 hours. Reperfusion, whether spontaneous or tPA induced, appears to be the major determinant of DWI reversal. The relative ADC value of areas with DWI reversal is higher in comparison to the non-reversed areas. The volume of DWI lesions that go on to reverse represents a small proportion of tissue at risk compared to the mismatch volume and should not alter patient selection for thrombolysis. doi:10.1016/j.jocn.2009.07.069
45. Prognosis of Intracranial Dissection relates to site and presenting features Li Simon 1, Yan Bernard 1, Mitchell Peter 2, Dowling Richard 2, Hand Peter 1, Collins Marnie 3, Davis Stephen 1 1
Department of Neurology Royal Melbourne Hospita, Victoria, Australia Department of Radiology Royal Melbourne Hospital, Victoria,Australia 3 The University of Melbourne, Victoria, Australia 2
Background: Intracranial arterial dissection is relatively rare and generally considered to have worse outcome than extracranial arterial dissection. It is however a clinically significant entity which causes severely disabling ischaemic stroke or subarachnoid haemorrhage. Only a few large case series have been reported, but there is increased recognition with advance in non-invasive angiographic diagnostic procedures. Patients with posterior circulation dissection appear to present more commonly with subarachnoid hemorrhage and are said to have a worse outcome. The choices of treatment including medical therapy, and endovascular and surgical intervention, remain controversial.
Abstracts / Journal of Clinical Neuroscience 16 (2009) 1514–1546
2
Department of Medicine, Hawke’s Bay Hospital, Hastings, New Zealand Department of Neurology, Christchurch Hospital, Christchurch, New Zealand 3
Background: The early risk of stroke in patients presenting with a transient ischemic attack (TIA) is high. Recent studies have shown that early intervention can reduce this risk significantly, but relies on the ability to rapidly assess patients with TIA and implement secondary prevention measures. We wanted to compare current practice in New Zealand with recommended guidelines. Methods: In August 2008 a written questionnaire was sent to all District Health Boards (DHBs) in New Zealand concerning provision of TIA services, access to relevant investigations, clinical management and quality improvement activity related to TIA patients. Results: All 21 DHBs returned the questionnaire. Eight DHBs (38%) did not have a lead stroke clinician. Acute services were responsible for the assessment and management of patients with TIA in 18 DHBs (86%), with patients managed in emergency departments or acute assessment units in 15 DHBs (72%) or routinely admitted to medical wards or stroke units in 3 DHBs(14%). Three of 21 DHBs (14%) see most TIA patients in outpatient clinics and have a usual waiting time for patients to be seen of one or more weeks. Delays of more than one week were common for carotid ultrasound scans (10 DHBs, 48%) and carotid endarterectomy when indicated (16 DHBs, 76%). Thirteen DHBs (62%) have guidelines for the management of patients with TIA but only 9 DHBs (43%) incorporate the ABCD2 score. Only 4 (19%) DHBs had audited TIA services. Conclusions: There is a substantial under-provision of TIA services in New Zealand resulting in significant discrepancies between current practice and recommendations in national and international guidelines. Large regional variations in the standard of care also exist. In order to reduce the burden of stroke, the development of dedicated appropriately resourced TIA services should be seen as a priority for DHBs in New Zealand. doi:10.1016/j.jocn.2009.07.068
44. Diffusion Weighted Imaging Lesion Reversal is rare after IV thrombolysis in Acute Ischemic Stroke Chemmanam Thomas 1, Christensen Soren 1, Bladin Christopher F 2, Desmond Patricia M 1, Ebinger Martin 1,3, De Silva Deidre A 1,4, Parsons Mark W 5, Levi Christopher R 5, Barber Alan P 6, Donnan Geoffrey A 7, Davis Stephen M 1, for the EPITHET investigators 1
Department of Neurology and Radiology, The Royal Melbourne Hospital, University of Melbourne, Parkville, Australia 2 Department of Neurology, Box Hill Hospital, Monash University, Melbourne, Australia 3 Center for Stroke Research Berlin (CSB), Charité – University Medicine Berlin, Germany 4 Singapore General Hospital campus, National Neuroscience Institute, Singapore 5 Departments of Neurology and Hunter Medical Research Institute, John Hunter Hospital, University of Newcastle, Australia 6 Department of Neurology, Auckland Hospital, University of Auckland, New Zealand 7 National Stroke Research Institute, Austin Hospital, University of Melbourne, Australia Introduction: In ischemic stroke, the acute Diffusion Weighted Imaging (DWI) abnormality generally represents irreversibly infarcted brain tissue. However, animal and human studies have shown that the acute DWI lesion may be reversible. We aimed to
determine the relationship of DWI lesion reversal with intravenous tPA in the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET). Material and Methods: In EPITHET patients with acute ischemic stroke presenting within 3-6 hours were randomized to tPA or placebo. Pre-treatment DWI was compared visually with 3 - 5 day DWI and day-90 FLAIR or T2 images, to identify the frequency of DWI reversal. We aimed to assess the relationship of DWI reversal with tPA, reperfusion and timing of treatment. After co-registration of the acute and follow up images in those patients with any DWI lesional reduction, we divided the acute DWI lesion into reversible and irreversible regions and compared their ADC values. Results: Of 101 in EPITHET, 91 patients had subacute DWI and 72 patients had a day 90 scan. Any reduction in volume from pretreatment DWI was seen in 32/72 (44%) on day-90 scans, but in only 4/ 91(4.3%) on day 3-5 DWI scans. After excluding cases with appreciable brain shrinkage and hemorrhagic change, true DWI reversal was observed in only 11/92 patients (11.9%), 7 of whom had received tPA. The median volume in these 11 patients reduced from 24.17 ml (IQR 7.28-45.74) in the acute DWI to 18.13 ml (IQR 8.68-43.20) in the day 3 - 5 DWI and 6.93 ml (IQR 2.69-27.07) in the day 90 scan. Major reperfusion occurred more commonly in patients with DWI reversal compared to those with no reversal (82% vs 32%; p = 0.002). DWI reversal was not associated with tPA or earlier time of treatment. Median volumes of DWI reversal from the acute DWI to day-90 scan (7.92 ml) and to subacute DWI (10.7 ml) were very small compared to the median mismatch volume of 137.9 ml, with the estimated median difference being 117 and 160 ml. (p = 0.011 and 0.007 respectively). On comparing the acute and day-90 scan, the mean relative ADC values in the irreversible and reversible parts of the DWI lesion were different [0.75 (SD 0.13) vs 0.95 (SD 0.18) (p = 0.014)]. Conclusions: DWI reversal is uncommon in ischemic stroke patients treated with intravenous tPA within 3 – 6 hours. Reperfusion, whether spontaneous or tPA induced, appears to be the major determinant of DWI reversal. The relative ADC value of areas with DWI reversal is higher in comparison to the non-reversed areas. The volume of DWI lesions that go on to reverse represents a small proportion of tissue at risk compared to the mismatch volume and should not alter patient selection for thrombolysis. doi:10.1016/j.jocn.2009.07.069
45. Prognosis of Intracranial Dissection relates to site and presenting features Li Simon 1, Yan Bernard 1, Mitchell Peter 2, Dowling Richard 2, Hand Peter 1, Collins Marnie 3, Davis Stephen 1 1
Department of Neurology Royal Melbourne Hospita, Victoria, Australia Department of Radiology Royal Melbourne Hospital, Victoria,Australia 3 The University of Melbourne, Victoria, Australia 2
Background: Intracranial arterial dissection is relatively rare and generally considered to have worse outcome than extracranial arterial dissection. It is however a clinically significant entity which causes severely disabling ischaemic stroke or subarachnoid haemorrhage. Only a few large case series have been reported, but there is increased recognition with advance in non-invasive angiographic diagnostic procedures. Patients with posterior circulation dissection appear to present more commonly with subarachnoid hemorrhage and are said to have a worse outcome. The choices of treatment including medical therapy, and endovascular and surgical intervention, remain controversial.