Advances in Stroke 2017

Julie Bernhardt, PhD; Richard D. Zorowitz, MD; Kyra J. Becker, MD; Emanuela Keller, MD; Gustavo Saposnik, MD, PhDc; Daniel Strbian, MD, PhD, MSc; Martin Dichgans, MD; Daniel Woo, MD, MS; Mathew Reeves, BVSc, PhD; Amanda Thrift, BSc, PhD, PGDipBiostat; Chelsea S. Kidwell, MD; Jean Marc Olivot, MD, PhD; Mayank Goyal, MD, FRCPC; Laurent Pierot, MD, PhD; Derrick A. Bennett, PhD; George Howard, DrPH; Gary A. Ford, FMedSci; Larry B. Goldstein, MD; Anna M. Planas, PhD; Midori A. Yenari, MD; Steven M. Greenberg, MD, PhD; Leonardo Pantoni, PhD; Sepideh Amin-Hanjani, MD; Michael Tymianski, MD


Stroke. 2018;49(5):e174-e199. 

In This Article

Brain Recovery and Rehabilitation

For stroke rehabilitation and recovery, 2017 was a year of reviews and research advances. Reviews included all aspects of poststroke rehabilitation and recovery. Cognitive rehabilitation for memory deficits was effective for memory improvements in the short term, but not in the long term.[1] Circuit class therapy could improve mobility after stroke in a clinically meaningful way, even after 12 months poststroke.[2] Electromechanical-assisted training for walking was most beneficial for subacute stroke survivors who were not ambulatory.[3] Repetitive task training was effective regardless of the amount of task practice, type of intervention, or time since stroke.[4] Physical activity training could positively affect poststroke cognition with small-to-moderate treatment effects that were apparent even in the chronic stroke phase.[5] In all cases, more research was required to improve the quality of the findings, and a review of poststroke fatigue reported that the overall quality of the research was poor.[6]

Discovery research provided more insight into basic aspects of stroke rehabilitation and recovery. Stradecki-Cohan et al[7] studied Sprague–Dawley rats subjected to 5 to 6 days of no (0 m/min), mild (6 m/min), moderate (10 m/min), or heavy (15–18 m/min) treadmill exercise 3 to 4 days poststroke and demonstrated that moderate exercise enhanced cognitive function for 1 week after exercise completion, independent of changes in physical fitness. Chang et al[8] demonstrated that the number of Met alleles in brain-derived neurotrophic factor genotypes and corticospinal tract (CST) functional integrity may be independent predictors of upper extremity motor outcome 3 months poststroke. Tu et al[9] found that concentrations of FABP4 (fatty acid–binding protein 4), an intracellular lipid chaperone involved in coordination of lipid transportation and atherogenesis, were a novel independent prognostic marker for poor functional outcome and mortality 3 months poststroke.

Imaging of the CST also played a role in poststroke functional prognosis. Schulz et al[10] found that different degrees of CST disruption differed in their dependency on structural premotor–motor connections for residual motor output using diffusion-weighted imaging and probabilistic tractography. Liu et al[11] reported that local diffusion homogeneity, a complementary marker for white matter alterations of the brain, in the ipsilesional CST paired with clinical assessment in acute stroke may accurately predict resolution of upper limb impairment within 12 weeks after subcortical infarction. Stinear et al[12] demonstrated that stroke survivors with functional CSTs recovered proportionally to their initial upper limb motor impairments, but those without functional CSTs did not recover proportionally and were impacted by greater CST damage. Furthermore, lower limb motor impairment resolved by [almost equal to]70% within 3 months after stroke and did not follow the proportionality rule.[13] Finally, Stinear et al[14] applied the Predict Recovery Potential algorithm, consisting of an assessment of paretic shoulder abduction and wrist extension strength, transcranial magnetic stimulation to assess the functional integrity of the ipsilesional lateral CST 5 to 7 days poststroke, and diffusion-weighted magnetic resonance imaging (MRI) to a cohort of acute stroke patients and found that it predicted the primary clinical outcome for 80% of recruited subjects. They reported reduced length of stay by 6 days in subjects for whom therapy content was modified based on the algorithm, when compared with a historical control.[14]

Clinical research continued to play a role in clarifying patterns of functional prognosis. Itaya et al[15] reported that living situation, type of stroke, Functional Independence Measure motor and cognitive scores on admission, and paresis predicted discharge to home after acute stroke with a sensitivity of 88.0% and a specificity of 68.7%. Scrutinio et al[16] developed a predictive models to assist clinicians in decision-making and planning rehabilitation care, including measures of time from stroke occurrence to rehabilitation admission, admission motor and cognitive Functional Independence Measure scores, and neglect; and age, male sex, time since stroke onset, and admission motor and cognitive Functional Independence Measure scores. MacIsaac et al[17] developed a short-form Barthel Index that condensed function to bladder control, transfer, and mobility items. Wang et al[18] developed a Functional Assessment of Stroke consisting of 29 items from 4 short-form tests of the Fugl-Meyer Assessment upper extremity, Fugl-Meyer Assessment lower extremity, Postural Assessment Scale for Stroke patients, and Barthel Index. Kapoor et al[19] reported that the modified Rankin Scale (mRS; modified Barthel index) was inadequate to measure overall stroke outcomes as more than half of stroke survivors with excellent functional recovery measured this way continued to have cognitive impairment and participation restrictions, and one third of patients continue to have depression 2 to 3 years poststroke.

Drug trials continued to have mixed results. A phase IIb double-blind, randomized, placebo-controlled trial of intravenous infusions of the monoclonal antibody GSK249320 within 72 hours of stroke demonstrated no improvement on gait velocity compared with placebo.[20] However, stroke survivors with persistent fatigue reported reduced fatigue and improved quality of life after taking modafinil 200 mg by mouth daily.[21]

Technology played a role in stroke rehabilitation. A preliminary study of the Fitbit One positioned on the nonparetic ankle accurately measured walking steps during inpatient rehabilitation physical therapy sessions.[22] A powered exoskeleton driven by a brain–computer interface, using neural activity from the unaffected cortical hemisphere, produced significant average increases in the Action Research Arm Test score, as well as improvements in grasp strength, Motricity Index, and the Canadian Occupational Performance Measure.[23]

Finally, 2 groups are attempting to facilitate or advocate for quality stroke rehabilitation and recovery research. First, the National Institutes of Health (NIH) instituted NIH StrokeNet, a network of centers that forms a foundation for stroke recovery and rehabilitation research. Several issues that the Working Group are addressing to improve the ability to complete meaningful clinical trials successfully include variable patterns of postacute stroke care delivery; challenges in recruiting and retaining subjects after discharge from the acute care setting; challenges in dealing with social and pragmatic factors in stroke rehabilitation research; the importance of concomitant activity and therapy during research participation; the competition among stroke rehabilitation and recovery research, other stroke trials, and healthcare business practices; the need to implement biomarkers; and standardization of outcomes measures.[24] The other group is an international roundtable of stroke rehabilitation and recovery research experts who are developing a conceptually rigorous framework for stroke rehabilitation and recovery research. They have defined the concepts of rehabilitation and recovery and made recommendations in the areas of basic science, biomarkers of stroke recovery, measurement in clinical trials, and intervention development and reporting.[25] Subsequently, they have defined the concept of sensorimotor recovery and measures consistent with this definition.[26]