- Email: [email protected]
Vascular Targeting Enhancement of Radiosurgery for AVMs
1516
Abstracts / Journal of Clinical Neuroscience 16 (2009) 1514–1546
p < 0.05), had symptoms for a longer duration prior to diagnosis (47 compared to 18 months, p = 0.05), and had predominately upper limb (83.9% compared to 63.6%, p = 0.2), asymmetrical (80.7% compared to 45.5%, p < 0.05) and distal weakness (54.8% compared to 9.1%, p < 0.05). All patients with detectable conduction block or anti-GM1 antibodies either improved or stabilised with treatment, but 20 patients (65%) who improved or stabilised did not have conduction block or anti-GM1 antibodies. Neither anti-GM1 antibodies nor conduction block were detected in patients who deteriorated. Conclusions: When considering IVIg treatment in clinically pure LMN syndromes, patients who present with upper limb, asymmetrical and distal weakness are more likely to respond positively to therapy. Anti-GM1 antibodies and conduction block are highly specific, but poorly sensitive, indicators of IVIg treatment responsiveness.
doi:10.1016/j.jocn.2009.07.008
Vascular Targeting Enhancement of Radiosurgery for AVMs Stoodley Marcus 1,2, Reddy Raj 2, Fairhall Jacob 2, Smee Robert 3, Tu Jian 1,2 1
Australian School of Advanced Medicine, Macquarie University, Sydney, Australia 2 Prince of Wales Medical Research Institute, University of New South Wales, Sydney, Australia 3 Department of Radiation Oncology, The Prince of Wales Cancer Centre, Sydney, Australia Introduction: Brain arteriovenous malformations (AVMs) are a major cause of death and disability in children and young adults. Each of the available treatments (surgery, radiosurgery and embolisation) has significant limitations. Radiosurgery is attractive as a relatively non-invasive treatment, but has the significant shortcomings of being limited to lesions smaller than 3 cm and of a latency to cure of up to 3 years. Stimulation of thrombosis using vascular targeting techniques is a theoretically possible means of overcoming these limitations, but has not previously been studied. In this experiment, lipopolysaccharide (LPS) and soluble tissue factor (sTF) conjugate was used as a nonligand vascular targeting technique in an animal model of AVM. Methods: Stereotactic radiosurgery (SRS) or sham radiation was administered to a model of AVM in 32 male Sprague-Dawley rats. Twenty-four hours after radiation, animals received an intravenous injection of LPS/sTF conjugate; control animals received normal saline. Animals were sacrificed at 1, 7, 30, or 90 days after treatment. Angiography was performed immediately prior to sacrifice and model AVM tissue was harvested for histological analysis to assess vessel thrombosis rates. Results: There was no systemic toxicity or thrombosis remote from the target region in any of the animals. SRS combined with saline resulted in thrombosis of 12% of small vessels (diameter < 200 lm). Thrombosis occurred in 58% of small vessels in animals that received SRS and LPS/sTF. An intermediate thrombosis rate of 43% was observed in animals given the LPS/sTF agent but no radiation. Conclusion: This study has demonstrated that vascular targeting can increase intravascular thrombosis after radiosurgery and that the vessel occlusion is durable. Radiosurgery is successful as a spacial localiser of endothelial change that can be exploited using vascular targeting to promote thrombosis. Further work is needed to determine the optimal vascular targeting technique.
Improvement in Care Processes using a TIA Pathway Brown H 1,2, Read S 1, Henderson R 1, O’Sullivan J 1, Broadley S 2 1
Stroke Unit, Department of Neurology, Royal Brisbane and Womens’ Hospital, Brisbane, Australia 2 Griffith University, School of Medicine, Gold Coast Campus, Australia Background: There is increasing evidence of a high early risk of stroke following TIA. Patients presenting after a TIA offer a unique opportunity for the urgent initiation of proven secondary preventive measures to prevent a subsequent stroke. Unfortunately, many TIA patients remain under-investigated and under-treated. The aim of this study was to assess whether a structured treatment pathway, which categorised TIA patients into high and low stroke risk according to the ABCD2 prognostic scoring system so as to guide their treatment accordingly, would improve patient management and thus bridge this evidence-to–practice gap. Methods: A retrospective pre-pathway audit of consecutive patients presenting with TIA to the Emergency Department of the Royal Brisbane and Women’s Hospital from 1 July 2006 - 31 Dec 2006 was conducted to determine the standard of TIA management practices prior to pathway implementation. A TIA management pathway was developed, based on current national stroke/TIA care guidelines, which stratified patients into high or low stroke risk according to their ABCD2 score (high risk 4-7 points, low risk 0-3 points), and guided decisions regarding investigations, medical management, and the need for hospital admission accordingly. All high risk patients were to be admitted. Low risk patients without co-morbidities were deemed suitable for discharge. The pathway advised appropriate timeframes for investigations and follow-up. Following an introductory pathway education and familiarisation period, a postpathway audit was conducted for patients presenting from 12 June 2007 - 12 Dec 2007. Results: The pre-pathway cohort comprised 112 patients (mean age 63.4 years; range 21-95), and the post-pathway cohort 138 patients (mean age 62.4 years; range 22-94). The percentages of patients prescribed secondary preventive medications at discharge rose following pathway implementation: anti-thrombotic agents 67.9% pre-pathway, 88.4% post-pathway (p < 0.001); anti-hypertensive agents 48.2% pre-pathway, 51.4% post pathway (p = 0.70); statins 38.4 % pre-pathway, 58.7% post pathway (p = 0.0015). No significant changes were seen in the rates of CT/MRI brain or carotid duplex use, but the mean number of days to carotid duplex decreased from 27.4 days pre-pathway to 10.9 days post-pathway (p = 0.001). Nonsignificant improvements in the use and timeliness of echocardiography were seen. For patients discharged from the emergency department (58% of the pre-pathway cohort and 45% of the post-pathway cohort), the mean number of days to hospital clinic follow-up fell from 25.2 days pre-pathway to 15.8 days post-pathway (p = 0.19). Conclusion: Significant improvements in the process of care were demonstrated following implementation of the TIA management pathway. The study has highlighted local issues within our hospital regarding access to investigations within an appropriate time-frame, and other areas where there is still room for improvement. doi:10.1016/j.jocn.2009.07.010
Abnormalities of Intracortical Pathways in Amyotrophic Lateral Sclerosis - Developing New Therapeutic Targets Vucic Steve 1, Matthew C Kiernan 2
doi:10.1016/j.jocn.2009.07.009
1
Department of Neurology, Westmead Hospital and Western Clinical School, University of Sydney
Abstracts / Journal of Clinical Neuroscience 16 (2009) 1514–1546
p < 0.05), had symptoms for a longer duration prior to diagnosis (47 compared to 18 months, p = 0.05), and had predominately upper limb (83.9% compared to 63.6%, p = 0.2), asymmetrical (80.7% compared to 45.5%, p < 0.05) and distal weakness (54.8% compared to 9.1%, p < 0.05). All patients with detectable conduction block or anti-GM1 antibodies either improved or stabilised with treatment, but 20 patients (65%) who improved or stabilised did not have conduction block or anti-GM1 antibodies. Neither anti-GM1 antibodies nor conduction block were detected in patients who deteriorated. Conclusions: When considering IVIg treatment in clinically pure LMN syndromes, patients who present with upper limb, asymmetrical and distal weakness are more likely to respond positively to therapy. Anti-GM1 antibodies and conduction block are highly specific, but poorly sensitive, indicators of IVIg treatment responsiveness.
doi:10.1016/j.jocn.2009.07.008
Vascular Targeting Enhancement of Radiosurgery for AVMs Stoodley Marcus 1,2, Reddy Raj 2, Fairhall Jacob 2, Smee Robert 3, Tu Jian 1,2 1
Australian School of Advanced Medicine, Macquarie University, Sydney, Australia 2 Prince of Wales Medical Research Institute, University of New South Wales, Sydney, Australia 3 Department of Radiation Oncology, The Prince of Wales Cancer Centre, Sydney, Australia Introduction: Brain arteriovenous malformations (AVMs) are a major cause of death and disability in children and young adults. Each of the available treatments (surgery, radiosurgery and embolisation) has significant limitations. Radiosurgery is attractive as a relatively non-invasive treatment, but has the significant shortcomings of being limited to lesions smaller than 3 cm and of a latency to cure of up to 3 years. Stimulation of thrombosis using vascular targeting techniques is a theoretically possible means of overcoming these limitations, but has not previously been studied. In this experiment, lipopolysaccharide (LPS) and soluble tissue factor (sTF) conjugate was used as a nonligand vascular targeting technique in an animal model of AVM. Methods: Stereotactic radiosurgery (SRS) or sham radiation was administered to a model of AVM in 32 male Sprague-Dawley rats. Twenty-four hours after radiation, animals received an intravenous injection of LPS/sTF conjugate; control animals received normal saline. Animals were sacrificed at 1, 7, 30, or 90 days after treatment. Angiography was performed immediately prior to sacrifice and model AVM tissue was harvested for histological analysis to assess vessel thrombosis rates. Results: There was no systemic toxicity or thrombosis remote from the target region in any of the animals. SRS combined with saline resulted in thrombosis of 12% of small vessels (diameter < 200 lm). Thrombosis occurred in 58% of small vessels in animals that received SRS and LPS/sTF. An intermediate thrombosis rate of 43% was observed in animals given the LPS/sTF agent but no radiation. Conclusion: This study has demonstrated that vascular targeting can increase intravascular thrombosis after radiosurgery and that the vessel occlusion is durable. Radiosurgery is successful as a spacial localiser of endothelial change that can be exploited using vascular targeting to promote thrombosis. Further work is needed to determine the optimal vascular targeting technique.
Improvement in Care Processes using a TIA Pathway Brown H 1,2, Read S 1, Henderson R 1, O’Sullivan J 1, Broadley S 2 1
Stroke Unit, Department of Neurology, Royal Brisbane and Womens’ Hospital, Brisbane, Australia 2 Griffith University, School of Medicine, Gold Coast Campus, Australia Background: There is increasing evidence of a high early risk of stroke following TIA. Patients presenting after a TIA offer a unique opportunity for the urgent initiation of proven secondary preventive measures to prevent a subsequent stroke. Unfortunately, many TIA patients remain under-investigated and under-treated. The aim of this study was to assess whether a structured treatment pathway, which categorised TIA patients into high and low stroke risk according to the ABCD2 prognostic scoring system so as to guide their treatment accordingly, would improve patient management and thus bridge this evidence-to–practice gap. Methods: A retrospective pre-pathway audit of consecutive patients presenting with TIA to the Emergency Department of the Royal Brisbane and Women’s Hospital from 1 July 2006 - 31 Dec 2006 was conducted to determine the standard of TIA management practices prior to pathway implementation. A TIA management pathway was developed, based on current national stroke/TIA care guidelines, which stratified patients into high or low stroke risk according to their ABCD2 score (high risk 4-7 points, low risk 0-3 points), and guided decisions regarding investigations, medical management, and the need for hospital admission accordingly. All high risk patients were to be admitted. Low risk patients without co-morbidities were deemed suitable for discharge. The pathway advised appropriate timeframes for investigations and follow-up. Following an introductory pathway education and familiarisation period, a postpathway audit was conducted for patients presenting from 12 June 2007 - 12 Dec 2007. Results: The pre-pathway cohort comprised 112 patients (mean age 63.4 years; range 21-95), and the post-pathway cohort 138 patients (mean age 62.4 years; range 22-94). The percentages of patients prescribed secondary preventive medications at discharge rose following pathway implementation: anti-thrombotic agents 67.9% pre-pathway, 88.4% post-pathway (p < 0.001); anti-hypertensive agents 48.2% pre-pathway, 51.4% post pathway (p = 0.70); statins 38.4 % pre-pathway, 58.7% post pathway (p = 0.0015). No significant changes were seen in the rates of CT/MRI brain or carotid duplex use, but the mean number of days to carotid duplex decreased from 27.4 days pre-pathway to 10.9 days post-pathway (p = 0.001). Nonsignificant improvements in the use and timeliness of echocardiography were seen. For patients discharged from the emergency department (58% of the pre-pathway cohort and 45% of the post-pathway cohort), the mean number of days to hospital clinic follow-up fell from 25.2 days pre-pathway to 15.8 days post-pathway (p = 0.19). Conclusion: Significant improvements in the process of care were demonstrated following implementation of the TIA management pathway. The study has highlighted local issues within our hospital regarding access to investigations within an appropriate time-frame, and other areas where there is still room for improvement. doi:10.1016/j.jocn.2009.07.010
Abnormalities of Intracortical Pathways in Amyotrophic Lateral Sclerosis - Developing New Therapeutic Targets Vucic Steve 1, Matthew C Kiernan 2
doi:10.1016/j.jocn.2009.07.009
1
Department of Neurology, Westmead Hospital and Western Clinical School, University of Sydney