Alex Pollock

Bio: Alex Pollock is an academic researcher from Glasgow Caledonian University. The author has contributed to research in topics: Stroke & Systematic review. The author has an hindex of 38, co-authored 111 publications receiving 7230 citations. Previous affiliations of Alex Pollock include University of Glasgow & Glasgow Royal Infirmary.

Motor recovery after stroke: a systematic review

Abstract: Loss of functional movement is a common consequence of stroke for which a wide range of interventions has been developed. In this Review, we aimed to provide an overview of the available evidence on interventions for motor recovery after stroke through the evaluation of systematic reviews, supplemented by recent randomised controlled trials. Most trials were small and had some design limitations. Improvements in recovery of arm function were seen for constraint-induced movement therapy, electromyographic biofeedback, mental practice with motor imagery, and robotics. Improvements in transfer ability or balance were seen with repetitive task training, biofeedback, and training with a moving platform. Physical fitness training, high-intensity therapy (usually physiotherapy), and repetitive task training improved walking speed. Although the existing evidence is limited by poor trial designs, some treatments do show promise for improving motor recovery, particularly those that have focused on high-intensity and repetitive task-specific practice.

Interventions for improving upper limb function after stroke

Abstract: Background Improving upper limb function is a core element of stroke rehabilitation needed to maximise patient outcomes and reduce disability. Evidence about effects of individual treatment techniques and modalities is synthesised within many reviews. For selection of effective rehabilitation treatment, the relative effectiveness of interventions must be known. However, a comprehensive overview of systematic reviews in this area is currently lacking. Objectives To carry out a Cochrane overview by synthesising systematic reviews of interventions provided to improve upper limb function after stroke. Methods Search methods: We comprehensively searched the Cochrane Database of Systematic Reviews; the Database of Reviews of Effects; and PROSPERO (an international prospective register of systematic reviews) (June 2013). We also contacted review authors in an effort to identify further relevant reviews. Selection criteria: We included Cochrane and non-Cochrane reviews of randomised controlled trials (RCTs) of patients with stroke comparing upper limb interventions with no treatment, usual care or alternative treatments. Our primary outcome of interest was upper limb function; secondary outcomes included motor impairment and performance of activities of daily living. When we identified overlapping reviews, we systematically identified the most up-to-date and comprehensive review and excluded reviews that overlapped with this. Data collection and analysis: Two overview authors independently applied the selection criteria, excluding reviews that were superseded by more up-to-date reviews including the same (or similar) studies. Two overview authors independently assessed the methodological quality of reviews (using a modified version of the AMSTAR tool) and extracted data. Quality of evidence within each comparison in each review was determined using objective criteria (based on numbers of participants, risk of bias, heterogeneity and review quality) to apply GRADE (Grades of Recommendation, Assessment, Development and Evaluation) levels of evidence. We resolved disagreements through discussion. We systematically tabulated the effects of interventions and used quality of evidence to determine implications for clinical practice and to make recommendations for future research. Main results Our searches identified 1840 records, from which we included 40 completed reviews (19 Cochrane; 21 non-Cochrane), covering 18 individual interventions and dose and setting of interventions. The 40 reviews contain 503 studies (18,078 participants). We extracted pooled data from 31 reviews related to 127 comparisons. We judged the quality of evidence to be high for 1/127 comparisons (transcranial direct current stimulation (tDCS) demonstrating no benefit for outcomes of activities of daily living (ADLs)); moderate for 49/127 comparisons (covering seven individual interventions) and low or very low for 77/127 comparisons. Moderate-quality evidence showed a beneficial effect of constraint-induced movement therapy (CIMT), mental practice, mirror therapy, interventions for sensory impairment, virtual reality and a relatively high dose of repetitive task practice, suggesting that these may be effective interventions; moderate-quality evidence also indicated that unilateral arm training may be more effective than bilateral arm training. Information was insufficient to reveal the relative effectiveness of different interventions. Moderate-quality evidence from subgroup analyses comparing greater and lesser doses of mental practice, repetitive task training and virtual reality demonstrates a beneficial effect for the group given the greater dose, although not for the group given the smaller dose; however tests for subgroup differences do not suggest a statistically significant difference between these groups. Future research related to dose is essential. Specific recommendations for future research are derived from current evidence. These recommendations include but are not limited to adequately powered, high-quality RCTs to confirm the benefit of CIMT, mental practice, mirror therapy, virtual reality and a relatively high dose of repetitive task practice; high-quality RCTs to explore the effects of repetitive transcranial magnetic stimulation (rTMS), tDCS, hands-on therapy, music therapy, pharmacological interventions and interventions for sensory impairment; and up-to-date reviews related to biofeedback, Bobath therapy, electrical stimulation, reach-to-grasp exercise, repetitive task training, strength training and stretching and positioning. Authors' conclusions Large numbers of overlapping reviews related to interventions to improve upper limb function following stroke have been identified, and this overview serves to signpost clinicians and policy makers toward relevant systematic reviews to support clinical decisions, providing one accessible, comprehensive document, which should support clinicians and policy makers in clinical decision making for stroke rehabilitation. Currently, no high-quality evidence can be found for any interventions that are currently used as part of routine practice, and evidence is insufficient to enable comparison of the relative effectiveness of interventions. Effective collaboration is urgently needed to support large, robust RCTs of interventions currently used routinely within clinical practice. Evidence related to dose of interventions is particularly needed, as this information has widespread clinical and research implications.

Physical rehabilitation approaches for the recovery of function and mobility following stroke

Abstract: Background Various approaches to physical rehabilitation may be used after stroke, and considerable controversy and debate surround the effectiveness of relative approaches. Some physiotherapists base their treatments on a single approach; others use a mixture of components from several different approaches. Objectives To determine whether physical rehabilitation approaches are effective in recovery of function and mobility in people with stroke, and to assess if any one physical rehabilitation approach is more effective than any other approach. For the previous versions of this review, the objective was to explore the effect of 'physiotherapy treatment approaches' based on historical classifications of orthopaedic, neurophysiological or motor learning principles, or on a mixture of these treatment principles. For this update of the review, the objective was to explore the effects of approaches that incorporate individual treatment components, categorised as functional task training, musculoskeletal intervention (active), musculoskeletal intervention (passive), neurophysiological intervention, cardiopulmonary intervention, assistive device or modality. In addition, we sought to explore the impact of time after stroke, geographical location of the study, dose of the intervention, provider of the intervention and treatment components included within an intervention. Search methods We searched the Cochrane Stroke Group Trials Register (last searched December 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 12, 2012), MEDLINE (1966 to December 2012), EMBASE (1980 to December 2012), AMED (1985 to December 2012) and CINAHL (1982 to December 2012). We searched reference lists and contacted experts and researchers who have an interest in stroke rehabilitation. Selection criteria Randomised controlled trials (RCTs) of physical rehabilitation approaches aimed at promoting the recovery of function or mobility in adult participants with a clinical diagnosis of stroke. Outcomes included measures of independence in activities of daily living (ADL), motor function, balance, gait velocity and length of stay. We included trials comparing physical rehabilitation approaches versus no treatment, usual care or attention control and those comparing different physical rehabilitation approaches. Data collection and analysis Two review authors independently categorised identified trials according to the selection criteria, documented their methodological quality and extracted the data. Main results We included a total of 96 studies (10,401 participants) in this review. More than half of the studies (50/96) were carried out in China. Generally the studies were heterogeneous, and many were poorly reported. Physical rehabilitation was found to have a beneficial effect, as compared with no treatment, on functional recovery after stroke (27 studies, 3423 participants; standardised mean difference (SMD) 0.78, 95% confidence interval (CI) 0.58 to 0.97, for Independence in ADL scales), and this effect was noted to persist beyond the length of the intervention period (nine studies, 540 participants; SMD 0.58, 95% CI 0.11 to 1.04). Subgroup analysis revealed a significant difference based on dose of intervention (P value < 0.0001, for independence in ADL), indicating that a dose of 30 to 60 minutes per day delivered five to seven days per week is effective. This evidence principally arises from studies carried out in China. Subgroup analyses also suggest significant benefit associated with a shorter time since stroke (P value 0.003, for independence in ADL). We found physical rehabilitation to be more effective than usual care or attention control in improving motor function (12 studies, 887 participants; SMD 0.37, 95% CI 0.20 to 0.55), balance (five studies, 246 participants; SMD 0.31, 95% CI 0.05 to 0.56) and gait velocity (14 studies, 1126 participants; SMD 0.46, 95% CI 0.32 to 0.60). Subgroup analysis demonstrated a significant difference based on dose of intervention (P value 0.02 for motor function), indicating that a dose of 30 to 60 minutes delivered five to seven days a week provides significant benefit. Subgroup analyses also suggest significant benefit associated with a shorter time since stroke (P value 0.05, for independence in ADL). No one physical rehabilitation approach was more (or less) effective than any other approach in improving independence in ADL (eight studies, 491 participants; test for subgroup differences: P value 0.71) or motor function (nine studies, 546 participants; test for subgroup differences: P value 0.41). These findings are supported by subgroup analyses carried out for comparisons of intervention versus no treatment or usual care, which identified no significant effects of different treatment components or categories of interventions. Authors' conclusions Physical rehabilitation, comprising a selection of components from different approaches, is effective for recovery of function and mobility after stroke. Evidence related to dose of physical therapy is limited by substantial heterogeneity and does not support robust conclusions. No one approach to physical rehabilitation is any more (or less) effective in promoting recovery of function and mobility after stroke. Therefore, evidence indicates that physical rehabilitation should not be limited to compartmentalised, named approaches, but rather should comprise clearly defined, well-described, evidenced-based physical treatments, regardless of historical or philosophical origin.

What are the components of effective stroke unit care

Abstract: Background: the effectiveness of organized inpatient (stroke unit) care has been demonstrated in systematic reviews of clinical trials. However, the key components of stroke unit care are poorly understood. Methods: we conducted a survey of recent trials (published 1985–2000) of a stroke unit/ward which had demonstrated a beneficial effect consistent with the stroke unit systematic review. Results: we identified 11 eligible stroke unit trials of which the majority described similar approaches to i) assessment procedures (medical, nursing and therapy assessments), ii) early management policies (e.g. early mobilization; avoidance of urinary catheterization; treatment of hypoxia, hyperglycaemia and suspected infection), iii) ongoing rehabilitation policies (e.g. co-ordinated multidisciplinary team care, early assessment for discharge). Conclusions: this survey provides a description of stroke unit care which can serve as a benchmark for general stroke patient care and future clinical research.

Cognitive rehabilitation for spatial neglect following stroke.

Abstract: Background Unilateral spatial neglect causes difficulty attending to one side of space. Various rehabilitation interventions have been used but evidence of their benefit is lacking. Objectives To assess whether cognitive rehabilitation improves functional independence, neglect (as measured using standardised assessments), destination on discharge, falls, balance, depression/anxiety and quality of life in stroke patients with neglect measured immediately post-intervention and at longer-term follow-up; and to determine which types of interventions are effective and whether cognitive rehabilitation is more effective than standard care or an attention control. Search methods We searched the Cochrane Stroke Group Trials Register (last searched June 2012), MEDLINE (1966 to June 2011), EMBASE (1980 to June 2011), CINAHL (1983 to June 2011), PsycINFO (1974 to June 2011), UK National Research Register (June 2011). We handsearched relevant journals (up to 1998), screened reference lists, and tracked citations using SCISEARCH. Selection criteria We included randomised controlled trials (RCTs) of cognitive rehabilitation specifically aimed at spatial neglect. We excluded studies of general stroke rehabilitation and studies with mixed participant groups, unless more than 75% of their sample were stroke patients or separate stroke data were available. Data collection and analysis Two review authors independently selected studies, extracted data, and assessed study quality. For subgroup analyses, review authors independently categorised the approach underlying the cognitive intervention as either 'top-down' (interventions that encourage awareness of the disability and potential compensatory strategies) or 'bottom-up' (interventions directed at the impairment but not requiring awareness or behavioural change, e.g. wearing prisms or patches). Main results We included 23 RCTs with 628 participants (adding 11 new RCTs involving 322 new participants for this update). Only 11 studies were assessed to have adequate allocation concealment, and only four studies to have a low risk of bias in all categories assessed. Most studies measured outcomes using standardised neglect assessments: 15 studies measured effect on activities of daily living (ADL) immediately after the end of the intervention period, but only six reported persisting effects on ADL. One study (30 participants) reported discharge destination and one study (eight participants) reported the number of falls. Eighteen of the 23 included RCTs compared cognitive rehabilitation with any control intervention (placebo, attention or no treatment). Meta-analyses demonstrated no statistically significant effect of cognitive rehabilitation, compared with control, for persisting effects on either ADL (five studies, 143 participants) or standardised neglect assessments (eight studies, 172 participants), or for immediate effects on ADL (10 studies, 343 participants). In contrast, we found a statistically significant effect in favour of cognitive rehabilitation compared with control, for immediate effects on standardised neglect assessments (16 studies, 437 participants, standardised mean difference (SMD) 0.35, 95% confidence interval (CI) 0.09 to 0.62). However, sensitivity analyses including only studies of high methodological quality removed evidence of a significant effect of cognitive rehabilitation. Additionally, five of the 23 included RCTs compared one cognitive rehabilitation intervention with another. These included three studies comparing a visual scanning intervention with another cognitive rehabilitation intervention, and two studies (three comparison groups) comparing a visual scanning intervention plus another cognitive rehabilitation intervention with a visual scanning intervention alone. Only two small studies reported a measure of functional disability and there was considerable heterogeneity within these subgroups (I² > 40%) when we pooled standardised neglect assessment data, limiting the ability to draw generalised conclusions. Subgroup analyses exploring the effect of having an attention control demonstrated some evidence of a statistically significant difference between those comparing rehabilitation with attention control and those with another control or no treatment group, for immediate effects on standardised neglect assessments (test for subgroup differences, P = 0.04). Authors' conclusions The effectiveness of cognitive rehabilitation interventions for reducing the disabling effects of neglect and increasing independence remains unproven. As a consequence, no rehabilitation approach can be supported or refuted based on current evidence from RCTs. However, there is some very limited evidence that cognitive rehabilitation may have an immediate beneficial effect on tests of neglect. This emerging evidence justifies further clinical trials of cognitive rehabilitation for neglect. However, future studies need to have appropriate high quality methodological design and reporting, to examine persisting effects of treatment and to include an attention control comparator.

Heart Disease and Stroke Statistics—2017 Update: A Report From the American Heart Association

Abstract: WRITING GROUP MEMBERS Emelia J. Benjamin, MD, SCM, FAHA Michael J. Blaha, MD, MPH Stephanie E. Chiuve, ScD Mary Cushman, MD, MSc, FAHA Sandeep R. Das, MD, MPH, FAHA Rajat Deo, MD, MTR Sarah D. de Ferranti, MD, MPH James Floyd, MD, MS Myriam Fornage, PhD, FAHA Cathleen Gillespie, MS Carmen R. Isasi, MD, PhD, FAHA Monik C. Jiménez, ScD, SM Lori Chaffin Jordan, MD, PhD Suzanne E. Judd, PhD Daniel Lackland, DrPH, FAHA Judith H. Lichtman, PhD, MPH, FAHA Lynda Lisabeth, PhD, MPH, FAHA Simin Liu, MD, ScD, FAHA Chris T. Longenecker, MD Rachel H. Mackey, PhD, MPH, FAHA Kunihiro Matsushita, MD, PhD, FAHA Dariush Mozaffarian, MD, DrPH, FAHA Michael E. Mussolino, PhD, FAHA Khurram Nasir, MD, MPH, FAHA Robert W. Neumar, MD, PhD, FAHA Latha Palaniappan, MD, MS, FAHA Dilip K. Pandey, MBBS, MS, PhD, FAHA Ravi R. Thiagarajan, MD, MPH Mathew J. Reeves, PhD Matthew Ritchey, PT, DPT, OCS, MPH Carlos J. Rodriguez, MD, MPH, FAHA Gregory A. Roth, MD, MPH Wayne D. Rosamond, PhD, FAHA Comilla Sasson, MD, PhD, FAHA Amytis Towfighi, MD Connie W. Tsao, MD, MPH Melanie B. Turner, MPH Salim S. Virani, MD, PhD, FAHA Jenifer H. Voeks, PhD Joshua Z. Willey, MD, MS John T. Wilkins, MD Jason HY. Wu, MSc, PhD, FAHA Heather M. Alger, PhD Sally S. Wong, PhD, RD, CDN, FAHA Paul Muntner, PhD, MHSc On behalf of the American Heart Association Statistics Committee and Stroke Statistics Subcommittee Heart Disease and Stroke Statistics—2017 Update

Heart Disease and Stroke Statistics—2016 Update: A Report From the American Heart Association

Abstract: Author(s): Writing Group Members; Mozaffarian, Dariush; Benjamin, Emelia J; Go, Alan S; Arnett, Donna K; Blaha, Michael J; Cushman, Mary; Das, Sandeep R; de Ferranti, Sarah; Despres, Jean-Pierre; Fullerton, Heather J; Howard, Virginia J; Huffman, Mark D; Isasi, Carmen R; Jimenez, Monik C; Judd, Suzanne E; Kissela, Brett M; Lichtman, Judith H; Lisabeth, Lynda D; Liu, Simin; Mackey, Rachel H; Magid, David J; McGuire, Darren K; Mohler, Emile R; Moy, Claudia S; Muntner, Paul; Mussolino, Michael E; Nasir, Khurram; Neumar, Robert W; Nichol, Graham; Palaniappan, Latha; Pandey, Dilip K; Reeves, Mathew J; Rodriguez, Carlos J; Rosamond, Wayne; Sorlie, Paul D; Stein, Joel; Towfighi, Amytis; Turan, Tanya N; Virani, Salim S; Woo, Daniel; Yeh, Robert W; Turner, Melanie B; American Heart Association Statistics Committee; Stroke Statistics Subcommittee

Heart disease and stroke statistics-2015 update: A report from the American Heart Association

Abstract: Author(s): Mozaffarian, Dariush; Benjamin, Emelia J; Go, Alan S; Arnett, Donna K; Blaha, Michael J; Cushman, Mary; de Ferranti, Sarah; Despres, Jean-Pierre; Fullerton, Heather J; Howard, Virginia J; Huffman, Mark D; Judd, Suzanne E; Kissela, Brett M; Lackland, Daniel T; Lichtman, Judith H; Lisabeth, Lynda D; Liu, Simin; Mackey, Rachel H; Matchar, David B; McGuire, Darren K; Mohler, Emile R; Moy, Claudia S; Muntner, Paul; Mussolino, Michael E; Nasir, Khurram; Neumar, Robert W; Nichol, Graham; Palaniappan, Latha; Pandey, Dilip K; Reeves, Mathew J; Rodriguez, Carlos J; Sorlie, Paul D; Stein, Joel; Towfighi, Amytis; Turan, Tanya N; Virani, Salim S; Willey, Joshua Z; Woo, Daniel; Yeh, Robert W; Turner, Melanie B; American Heart Association Statistics Committee and Stroke Statistics Subcommittee

Heart Disease and Stroke Statistics—2014 Update A Report From the American Heart Association

Abstract: Author(s): Go, Alan S; Mozaffarian, Dariush; Roger, Veronique L; Benjamin, Emelia J; Berry, Jarett D; Blaha, Michael J; Dai, Shifan; Ford, Earl S; Fox, Caroline S; Franco, Sheila; Fullerton, Heather J; Gillespie, Cathleen; Hailpern, Susan M; Heit, John A; Howard, Virginia J; Huffman, Mark D; Judd, Suzanne E; Kissela, Brett M; Kittner, Steven J; Lackland, Daniel T; Lichtman, Judith H; Lisabeth, Lynda D; Mackey, Rachel H; Magid, David J; Marcus, Gregory M; Marelli, Ariane; Matchar, David B; McGuire, Darren K; Mohler, Emile R; Moy, Claudia S; Mussolino, Michael E; Neumar, Robert W; Nichol, Graham; Pandey, Dilip K; Paynter, Nina P; Reeves, Matthew J; Sorlie, Paul D; Stein, Joel; Towfighi, Amytis; Turan, Tanya N; Virani, Salim S; Wong, Nathan D; Woo, Daniel; Turner, Melanie B; American Heart Association Statistics Committee and Stroke Statistics Subcommittee

Research Methods in Health. Investigating health and health services

Abstract: This new edition of Ann Bowling's well-known and highly respected text has been thoroughly revised and updated to reflect key methodological developments in health research. It is a comprehensive, easy to read, guide to the range of methods used to study and evaluate health and health services. It describes the concepts and methods used by the main disciplines involved in health research, including: demography, epidemiology, health economics, psychology and sociology.The research methods described cover the assessment of health needs, morbidity and mortality trends and rates, costing health services, sampling for survey research, cross-sectional and longitudinal survey design, experimental methods and techniques of group assignment, questionnaire design, interviewing techniques, coding and analysis of quantitative data, methods and analysis of qualitative observational studies, and types of unstructured interviewing. With new material on topics such as cluster randomization, utility analyses, patients' preferences, and perception of risk, the text is aimed at students and researchers of health and health services. It has also been designed for health professionals and policy makers who have responsibility for applying research findings in practice, and who need to know how to judge the value of that research.