Comparison of motor recovery after neonatal and adult hemidecortication.

Hemidecortication produces a wide range of cognitive and motor symptoms in both children and lab animals that are generally far greater than smaller bilateral focal lesions of cerebral cortex. Although there have been many studies of motor functions after hemidecortication, the analyses largely have been of general motor functions rather than of more skilled motor functions such as forelimb reaching. The objective of the present experiment was to analyze the sensorimotor forelimb function of rats after infant or adult hemidecortication by utilizing multiple motor analyses. Rats were given hemidecortications either on postnatal day 10 (P10) or day 90 (P90). Both groups were then tested on a number of behavioural tasks (two tests of skilled reaching, forelimb placing during spontaneous vertical exploration, and a sunflower seed opening task) beginning at P 120. In a portion of the P10 female animals, topographic movement representations were derived in the hemisphere contralateral to lesion using Intracortical Microstimulation (ICMS). The brains of the male animals were prepared for Golgi-Cox staining and subsequent analysis of dendritic arborisation and spine density. There were three main findings. 1) Both groups of hemidecorticate animals were impaired when tested on the motor tasks, but the impairments were qualitatively different in the neonatal and adult operates. For example, the P 10 hemidecorticate animals displayed simultaneous bilateral forelimb movement, or "mirror movements." 2) Hemidecortication at P90 but not P10, led to increased dendritic arborisation of Layer III pyramidal cells in the intact parietal cortex but whereas P90 animals showed a decrease in cortical thickness in the intact hemisphere, the P10 animals do not, even though there are no callosal connections. 3) P10 hemidecortication altered the details of the ICMS-delineated motor maps in a small group of female hemidecorticates that were studied. In conclusion, there was postinjury compensation for motor impairments in both P10 and P90 rats but the mechanisms were different. Furthermore, comparisons of postinjury behavioral and anatomical compensation in rats with focal cortical injuries at those ages in our previous studies showed marked differences. These results suggest that there is a fundamental difference in the way that the brain compensates from hemidecortication and focal injury in development.

Stroke: working toward a prioritized world agenda.

BACKGROUND AND PURPOSE: The aim of the Synergium was to devise and prioritize new ways of accelerating progress in reducing the risks, effects, and consequences of stroke. METHODS: Preliminary work was performed by 7 working groups of stroke leaders followed by a synergium (a forum for working synergistically together) with approximately 100 additional participants. The resulting draft document had further input from contributors outside the synergium. RESULTS: Recommendations of the Synergium are: Basic Science, Drug Development and Technology: There is a need to develop: (1) New systems of working together to break down the prevalent "silo" mentality; (2) New models of vertically integrated basic, clinical, and epidemiological disciplines; and (3) Efficient methods of identifying other relevant areas of science. Stroke Prevention: (1) Establish a global chronic disease prevention initiative with stroke as a major focus. (2) Recognize not only abrupt clinical stroke, but subtle subclinical stroke, the commonest type of cerebrovascular disease, leading to impairments of executive function. (3) Develop, implement and evaluate a population approach for stroke prevention. (4) Develop public health communication strategies using traditional and novel (eg, social media/marketing) techniques. Acute Stroke Management: Continue the establishment of stroke centers, stroke units, regional systems of emergency stroke care and telestroke networks. Brain Recovery and Rehabilitation: (1) Translate best neuroscience, including animal and human studies, into poststroke recovery research and clinical care. (2) Standardize poststroke rehabilitation based on best evidence. (3) Develop consensus on, then implementation of, standardized clinical and surrogate assessments. (4) Carry out rigorous clinical research to advance stroke recovery. Into the 21st Century: Web, Technology and Communications: (1) Work toward global unrestricted access to stroke-related information. (2) Build centralized electronic archives and registries. Foster Cooperation Among Stakeholders (large stroke organizations, nongovernmental organizations, governments, patient organizations and industry) to enhance stroke care. Educate and energize professionals, patients, the public and policy makers by using a "Brain Health" concept that enables promotion of preventive measures. CONCLUSIONS: To accelerate progress in stroke, we must reach beyond the current status scientifically, conceptually, and pragmatically. Advances can be made not only by doing, but ceasing to do. Significant savings in time, money, and effort could result from discontinuing practices driven by unsubstantiated opinion, unproven approaches, and financial gain. Systematic integration of knowledge into programs coupled with careful evaluation can speed the pace of progress.

Stroke: working toward a prioritized world agenda.

BACKGROUND AND PURPOSE: The aim of the Synergium was to devise and prioritize new ways of accelerating progress in reducing the risks, effects, and consequences of stroke. METHODS: Preliminary work was performed by 7 working groups of stroke leaders followed by a synergium (a forum for working synergistically together) with approximately 100 additional participants. The resulting draft document had further input from contributors outside the synergium. RESULTS: Recommendations of the Synergium are: Basic Science, Drug Development and Technology: There is a need to develop: (1) New systems of working together to break down the prevalent 'silo' mentality; (2) New models of vertically integrated basic, clinical, and epidemiological disciplines; and (3) Efficient methods of identifying other relevant areas of science. Stroke Prevention: (1) Establish a global chronic disease prevention initiative with stroke as a major focus. (2) Recognize not only abrupt clinical stroke, but subtle subclinical stroke, the commonest type of cerebrovascular disease, leading to impairments of executive function. (3) Develop, implement and evaluate a population approach for stroke prevention. (4) Develop public health communication strategies using traditional and novel (e.g., social media/marketing) techniques. Acute Stroke Management: Continue the establishment of stroke centers, stroke units, regional systems of emergency stroke care and telestroke networks. Brain Recovery and Rehabilitation: (1) Translate best neuroscience, including animal and human studies, into poststroke recovery research and clinical care. (2) Standardize poststroke rehabilitation based on best evidence. (3) Develop consensus on, then implementation of, standardized clinical and surrogate assessments. (4) Carry out rigorous clinical research to advance stroke recovery. Into the 21st Century: Web, Technology and Communications: (1) Work toward global unrestricted access to stroke-related information. (2) Build centralized electronic archives and registries. Foster Cooperation Among Stakeholders (large stroke organizations, nongovernmental organizations, governments, patient organizations and industry) to enhance stroke care. Educate and energize professionals, patients, the public and policy makers by using a 'Brain Health' concept that enables promotion of preventive measures. CONCLUSIONS: To accelerate progress in stroke, we must reach beyond the current status scientifically, conceptually, and pragmatically. Advances can be made not only by doing, but ceasing to do. Significant savings in time, money, and effort could result from discontinuing practices driven by unsubstantiated opinion, unproven approaches, and financial gain. Systematic integration of knowledge into programs coupled with careful evaluation can speed the pace of progress.

Stroke: working toward a prioritized world agenda.

BACKGROUND AND PURPOSE: The aim of the Synergium was to devise and prioritize new ways of accelerating progress in reducing the risks, effects, and consequences of stroke. METHODS: Preliminary work was performed by seven working groups of stroke leaders followed by a synergium (a forum for working synergistically together) with approximately 100 additional participants. The resulting draft document had further input from contributors outside the synergium. RESULTS: Recommendations of the Synergium are: Basic Science, Drug Development and Technology: There is a need to develop: (1) New systems of working together to break down the prevalent 'silo' mentality; (2) New models of vertically integrated basic, clinical, and epidemiological disciplines; and (3) Efficient methods of identifying other relevant areas of science. Stroke Prevention: (1) Establish a global chronic disease prevention initiative with stroke as a major focus. (2) Recognize not only abrupt clinical stroke, but subtle subclinical stroke, the commonest type of cerebrovascular disease, leading to impairments of executive function. (3) Develop, implement and evaluate a population approach for stroke prevention. (4) Develop public health communication strategies using traditional and novel (eg, social media/marketing) techniques. Acute Stroke Management: Continue the establishment of stroke centers, stroke units, regional systems of emergency stroke care and telestroke networks. Brain Recovery and Rehabilitation: (1) Translate best neuroscience, including animal and human studies, into poststroke recovery research and clinical care. (2) Standardize poststroke rehabilitation based on best evidence. (3) Develop consensus on, then implementation of, standardized clinical and surrogate assessments. (4) Carry out rigorous clinical research to advance stroke recovery. Into the 21st Century: Web, Technology and Communications: (1) Work toward global unrestricted access to stroke-related information. (2) Build centralized electronic archives and registries. Foster Cooperation Among Stakeholders (large stroke organizations, nongovernmental organizations, governments, patient organizations and industry) to enhance stroke care. Educate and energize professionals, patients, the public and policy makers by using a 'Brain Health' concept that enables promotion of preventive measures. CONCLUSIONS: To accelerate progress in stroke, we must reach beyond the current status scientifically, conceptually, and pragmatically. Advances can be made not only by doing, but ceasing to do. Significant savings in time, money, and effort could result from discontinuing practices driven by unsubstantiated opinion, unproven approaches, and financial gain. Systematic integration of knowledge into programs coupled with careful evaluation can speed the pace of progress.