Center for Stroke Recovery

Toronto, Canada

Center for Stroke Recovery

Toronto, Canada
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Meusel L.A.C.,Rotman Research Institute | Meusel L.A.C.,Center for Stroke Recovery | Hall G.B.C.,St Josephs Healthcare | Hall G.B.C.,McMaster University | And 4 more authors.
Psychiatry Research - Neuroimaging | Year: 2013

Little is known about the brain changes that mediate improvement following cognitive remediation. We used neuropsychological tests and functional magnetic resonance imaging to study working memory and recollection memory in patients with mood disorders, before (PRE) and after (POST) 10 weeks of cognitive remediation. Thirty-eight patients completed a recollection memory task at PRE (28 had complete PRE and POST scans) and 35 patients completed an n-back working memory task at PRE (23 had complete PRE and POST scans). We also compared patients at PRE with two groups of healthy controls subjects ( n=18 for the recollection memory task and n=15 for the working memory task). At PRE, compared to controls, patients had (i) poorer backward digit span scores, (ii) lower accuracy scores and weaker frontopolar activation during the 2-back condition, and (iii) poorer recollection scores and altered medial temporal activation on the recollection memory task. Following remediation, patients (i) improved on the backward digit span, (ii) activation increased in lateral and medial prefrontal, superior temporal, and lateral parietal regions in the 2-back condition, and (iii) recollection-related activation increased in the bilateral hippocampus. Improvements in 2-back accuracy correlated with activation increases in lateral and medial prefrontal and lateral parietal regions, and improved recollection scores correlated with activation increases in the left hippocampus. PRE-POST improvements on the backward digit span correlated with PRE-POST improvements in 2-back task accuracy; however, there was no direct association between improvement on the backward digit span following training and change in functional activation. These findings suggest that cognitive remediation may lead to behavioural improvements on tests of working memory. The relation between behavioural change and changes in functional activation following remediation requires further study. © 2013 Elsevier Ireland Ltd.

Marzolini S.,University of Toronto | Marzolini S.,Toronto Rehabilitation Institute | McIlroy W.,University of Toronto | McIlroy W.,Toronto Rehabilitation Institute | And 7 more authors.
Journal of Cardiopulmonary Rehabilitation and Prevention | Year: 2012

PURPOSE: Cardiac rehabilitation (CR) has been recommended to provide exercise guidance poststroke. However, it has not been established whether minimal exercise training levels, sufficient for obtaining health benefits, can be attained in CR. Therefore, we assessed the ability of stroke patients to achieve recommended exercise levels during a single standard CR session following completion of CR. METHODS: Sixteen patients (10 males and 6 females) with mild/moderate motor impairments who had completed CR participated in the study. Resting metabolic rate and oxygen uptake during 30 minutes each of aerobic and resistance training (AT, RT, respectively) were assessed by ambulatory oxygen monitor. Obtained values were compared with recommended minimal levels, that is, 20 or more minutes of exercise at 40% or more of peak oxygen uptake ((Equation is included in full-text article.)O2peak), 30 or more minutes of exercise at 3 or more metabolic equivalents (METs) (multiples of resting metabolic rate), and an energy expenditure of approximately 200 kcal per session. RESULTS: Mean time sustaining 40% or more of (Equation is included in full-text article.)O2peak was 47.6 ± 9 minutes, exceeding the minimal target of 20 minutes (P < .001). Time sustaining 3 or more METs was 30.8 ± 12.2 minutes, matching the target of 30 minutes (P = .8). Total energy expenditure (252 ± 49.9 kcal) was significantly greater than the target value of 200 kcal (P = .001). CONCLUSIONS: Chronic stroke patients with mild/moderate motor impairments are able to meet or exceed minimal recommended exercise target levels for intensity, duration, and energy expenditure during a typical exercise session consisting of 30 minutes of AT combined with 30 minutes of RT after completing CR. These data contribute to the evidence promoting the efficacy and feasibility of CR for people following stroke. Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Marzolini S.,University of Toronto | Marzolini S.,Toronto Rehabilitation Institute | Oh P.,Toronto Rehabilitation Institute | Oh P.,Center for Stroke Recovery | And 7 more authors.
Stroke | Year: 2012

Background and Purpose-Despite the importance of exercise training in mitigating cardiovascular risk, the development of exercise programs for people poststroke has been limited by lack of feasibility data concerning cardiopulmonary exercise testing (CPET) to inform the exercise prescription. Therefore, we examined the feasibility of CPETs for developing an exercise prescription in people ≥3 months poststroke. Methods-CPET results from 98 consecutively enrolled patients poststroke with motor impairments and 98 age-and sex-matched patients with coronary artery disease were examined at baseline and after 6 months of exercise training. Results-The proportion of patients with stroke and coronary artery disease attaining an intensity sufficient for prescribing exercise at baseline was 68.4% versus 82.7%, respectively (P=0.02) and 84.7% versus 83.8% (P=0.9) at 6 months. Women were less likely than men poststroke to achieve a sufficient intensity at baseline (40% versus 80.9%, P<0.001) but not at 6 months (78.3% versus 87.1, P=0.3). A clinically relevant abnormality occurred in 11.2% of stroke and 12.2% of patients with coronary artery disease on baseline CPETs (P=0.8) and 10.6% of stroke and 5.9% of patients with coronary artery disease on the 6-month CPET (P=0.4). No serious cardiovascular events occurred during 349 CPETs. Conclusions-Most patients after stroke achieved a level of exertion during the CPET sufficient to inform an exercise prescription. At least 1 of 10 patients poststroke developed a clinically relevant abnormality on baseline and postprogram CPETs with no serious cardiovascular events. These data support the feasibility and safety of CPETs for prescribing exercise poststroke. Strategies to improve use of baseline CPETs for women poststroke require further investigation. © 2012 2012 American Heart Association, Inc.

Atir-Sharon T.,Haifa University | Atir-Sharon T.,Yezreel Valley College | Gilboa A.,Rotman Research Institute | Gilboa A.,Center for Stroke Recovery | And 4 more authors.
Neural Plasticity | Year: 2015

Neocortical structures typically only support slow acquisition of declarative memory; however, learning through fast mapping may facilitate rapid learning-induced cortical plasticity and hippocampal-independent integration of novel associations into existing semantic networks. During fast mapping the meaning of new words and concepts is inferred, and durable novel associations are incidentally formed, a process thought to support early childhood's exuberant learning. The anterior temporal lobe, a cortical semantic memory hub, may critically support such learning. We investigated encoding of semantic associations through fast mapping using fMRI and multivoxel pattern analysis. Subsequent memory performance following fast mapping was more efficiently predicted using anterior temporal lobe than hippocampal voxels, while standard explicit encoding was best predicted by hippocampal activity. Searchlight algorithms revealed additional activity patterns that predicted successful fast mapping semantic learning located in lateral occipitotemporal and parietotemporal neocortex and ventrolateral prefrontal cortex. By contrast, successful explicit encoding could be classified by activity in medial and dorsolateral prefrontal and parahippocampal cortices. We propose that fast mapping promotes incidental rapid integration of new associations into existing neocortical semantic networks by activating related, nonoverlapping conceptual knowledge. In healthy adults, this is better captured by unique anterior and lateral temporallobe activity patterns, while hippocampal involvement is less predictive of this kind of learning. © 2015 Tali Atir-Sharon et al.

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