A study conducted in Taiwan has examined the ability of a patient’s circulating peripheral blood stem cells to benefit stroke patients.
In this study, one of two groups of stroke patients received injections of their own peripheral blood stem cells (PBSCs) directly into the brain but the other group received standard care. Those patients who received the PBSCs experienced some improvement in stroke scales and functional capabilities. Patients who received their own PBSCs also were given injections of granulocyte-colony stimulating factor (G-CSF), which seems to protect the nervous system after trauma to it.
“In this phase 2 study, we provide the first evidence that intracerebral injection of autologous (self-donated) PBSCs can improve motor function in those who have suffered a ,” said stroke and have motor deficits as a result,” said Woei-Cheng Shyu of the China Medical University, who is the corresponding author of this study. “Our study demonstrates that this therapeutic strategy was feasible and safe in stroke patients who suffered a prior stroke, but within five years from the onset of symptoms.”
Strokes, also known as trans-ischemic attacks (TIAs) result from blockage in blood vessels that feed the brain. The lack of blood flow to the brain starves it of oxygen, and the cells of the brain begin to die off. Because neuronal death as a result of stroke limits functional recovery, stem cell therapy is advancing as a potentially effective regenerative treatment for stroke.
Also, in many types of stem cell trials, PBSCs are the stem cell of choice. The ease of isolating these cells without invasive procedures makes them the stem cell choice for many clinical trials. In order to utilize PBSCs, patients must amplify their supply of PBSCs, and injections of G-CSF seems to do just that.
In this study, all patients had suffered a prior stroke as long as five years prior to being treated.
At the end of the 12-month follow-up, the group of 15 patients with neurological deficits who received the PBSC injections into the brain experienced neurological and functional improvements, according to several different clinical measurements.
On the other hand, the 15-patient control group who had neurological deficits but did not receive the PBSC injections did not experience the same beneficial results.
In the experimental group, nine of the 15 patients showed proper activation of the motor nerves after stimulating that part of the brain with a magnet. This procedure, called transcranial magnetic stimulation or TMS, places a magnet above skull, directly above the part of the brain you want to stimulate. The rapidly changing magnetic field generated by the magnet produces weak electrical currents in the brain, which stimulates nearby neurons. In this experiment, researchers targeted the precentral gyrus, which is the portion of the brain where the primary motor cortex. Because strokes sometimes kill off neurons in the primary motor cortex, stimulation of the primary motor cortex will not lead to stimulation of motor nerves, but in this experiment, 9 of 15 patients who received the PBSC injections who positive motor evoke potential or MEPs after TMS. Why this ratio was not 15 out of 15 remains unclear at this time.
One of the main conclusions of this work, is that “Despite this success, it should be noted that this was a preliminary study and, due to the small number of patients, are tentative. In the future we plan to conduct a multi-center, large-scale, double-blind, placebo-controlled randomized studies [sic] to better evaluate the effect of PBSC implantation in patients suffering from the effects of past stroke.”