and demyelination, as well as increased astrocyte survival rates. MSC treatment also appears to improve the control of cerebral blood flow and blood–brain barrier permeability, as well as what is currently thought to be the most important mechanism of MSC treatment after stroke, the activation of endogenous neuroprotection and neurorestoration pathways by the release of cytokines and trophic factors. Although activation of endogenous neuroprotection and neurorestoration probably has a major part in the improvement of brain function after stroke, it is likely that the functional improvements as a result of MSC treatment are due to combined action via multiple cellular and molecular mechanisms to affect neurorestoration and neuroprotection, rather than just a single mechanism. These effects are also modulated by key variables, including the number of and type of MSCs used, timing of treatment relative to when the patient's stroke occurred, route of delivery of the MSCs, as well as patient variables (e.g. age, underlying conditions). What this means for stroke patients and the limitations or concerns with MSCs as a potential treatment If MSC treatment becomes available for stroke patients, it is possible that current mortality and morbidity rates could substantially improve due to the direct enhancement of neuroprotection and neurorestoration mechanisms rather than only indirect facilitation or prevention of further damage, e.g. decompressive surgery. However, for MSC treatment to be used effectively and safely in a clinical setting, more research needs to be conducted, specifically in the areas of determining the relative influences of key variables (especially patient variables) on patient outcomes as well quantifying potential risks, e.g. tumour formation. Although ethical concerns are mostly limited to the use of embryonic stem cells, it may also be important to address any possible ethical concerns (however unlikely) over the use of somatic stem cells. Training of muscles affected by the upper motor neuron syndrome Muscles affected by the upper motor neuron syndrome have many potential features of altered performance including: weakness, decreased motor control, clonus (a series of involuntary rapid muscle contractions), exaggerated deep tendon reflexes, spasticity and decreased endurance. The term "spasticity" is often erroneously used interchangeably with upper motor neuron syndrome, and it is not unusual to see patients labeled as spastic who demonstrate an array of UMN findings. It has been estimated that approximately 65% of individuals develop spasticity following stroke, and studies have revealed that approximately 40% of stroke patients may still have spasticity at