Stem Cell Treatments for Stroke: A Biopsychosocial Perspective

Abstract

Fifteen million people have a stroke each year. The majority survive due to improvements in medical care, although most experience ongoing physical, cognitive and psychological difficulties. Preliminary data suggest that stem cell (SC) therapy may improve stroke survivor outcomes but, in the absence of large-scale clinical trials, the overall effectiveness and medical and psychological risks remain unclear. Moreover, SC therapies administered throughout the acute, sub-acute and chronic phases of stroke are assumed to work differently due to differences in blood-brain-barrier permeability, however, the optimal treatments for each phase remain unknown due to current technological limitations. Interest in the experimental SC treatments offered by private clinics throughout Asia, South America and Russia – known as ‘stem cell tourism’ – is increasing among some patient groups, although, whether this is true for stroke survivors is unknown. Additionally, whether patients with particular biopsychosocial and attitudinal characteristics are more likely to consider experimental SC treatments is undetermined. Patient educational resources have been developed to warn patients with neurodegenerative conditions about the risks associated with ‘stem cell tourism’, however, their content, format and design may impact upon their effectiveness with stroke survivors, due to differences in the physical, cognitive and psychological sequelae. Four studies explored these issues. Two meta-analyses examined the safety and efficacy of SC therapies. Study 1 examined 11 SC therapies (Nstudies-=-28) administered in the hyper-acute, acute, and sub-acute phases of stroke (≤-90 days). Serious adverse events were observed following five therapies; improved neurological, functional and/or radiological outcomes were noted following six therapies. Study 2 analysed 17 SC therapies (Nstudies-=-23) administered in the chronic phase of stroke (>-90 days). Safety concerns were identified for three therapies; four reported improved neurological and/or functional outcomes. Across both meta-analyses, few studies tracked the SCs post-implantation, employed sham treatment control groups, performed psychological screening or evaluated participants’ psychological wellbeing pre-/post-treatment. Next, a cross-sectional survey of 183 Australian stroke survivors was conducted to assess patient attitudes toward experimental SC treatments (Study 3). Twenty-five percent were considering ‘stem cell tourism’. Individuals with positive SC attitudes, longer post-stroke intervals, poorer physical functioning, and greater perceived caregiver burden were most likely to be considering treatment. Lastly, a randomised controlled trial (Study 4) was conducted to evaluate whether an online International Society for Stem Cell Research booklet or Stem Cell Network video deterred stroke survivors’ (N-=-112) from considering experimental SC treatments. Forty-five percent of participants were considering SC treatments at study commencement; significantly fewer were still considering SC treatments after reading the booklet. However, after 30 days, neither intervention was found to have altered participants’ attitudes. Overall, the findings suggest that whilst a small number of SC therapies may improve stroke outcomes, further large-scale, placebo-controlled clinical trials are required to clarify the medical and psychological risks. The level of interest in ‘stem cell tourism’ identified among patients with specific biopsychosocial and attitudinal characteristics suggests a potential role for clinicians to initiate discussions with higher-risk groups. The need for stroke-specific SC education resources, in conjunction with more proactive dissemination, is also highlighted.