A preliminary study has shown that it may be possible to help people who have suffered partial damage to their spinal cord by applying magnetic stimulation to their brain.
Writing in this month’s ‘Spinal Cord’, a team of UK doctors describe how patients with incomplete spinal cord injuries received repetitive transcranial magnetic stimulation (rTMS), leading to improvements in their ability to move muscles and limbs, and ability to feel sensations.
rTMS uses an electromagnet placed on the scalp to generate brief magnetic pulses, about the strength of an MRI scan, which stimulate the part of the brain called the cerebral cortex. Incomplete spinal cord injuries are a type of spinal injury where the spinal cord has not been entirely severed, but the patient has still lost the ability to move or feel properly below the injury point.
Dr. Nick Davey from Imperial College London and Charing Cross Hospital, and one of the study’s authors, says: “Through rTMS we may be able to help people who have suffered partial injuries to the spinal cord recover some of their movement and feeling. We think it works by strengthening the information leaving the brain through the undamaged neurons in the spinal cord. It may work like physiotherapy but instead of repeating a physical task, the machine activates the surviving nerves to strengthen their connections.”
The researchers from Imperial College London, the National Spinal Injuries Centre, Stoke Mandeville Hospital, UK, and Charing Cross Hospital, UK, tested rTMS on four patients with incomplete spinal injuries. The patients had all sustained their injuries at least 18 months previously and had already received conventional rehabilitation including physiotherapy. They were all considered stable in that they were no longer undergoing natural improvement. The patients received both real and sham rTMS treatment over a three-week period. The rTMS treatment involved five consecutive days of magnetic stimulation for one hour per day.
They noticed no difference between the baseline and the sham treatment, but found that the rTMS treatment resulted in a 37.5 (+/- 8) percent drop in intracortical inhibition, compared with normal physiotherapy. Weaker intracortical inhibition makes it easier for messages from the brain to pass down the spinal cord to the rest of the body. This reduction in intracortical inhibition was accompanied by improvement in both motor and sensory function, which lasted for at least three weeks after the treatment. Reduced intracortical inhibition also occurs naturally and can facilitate functional recovery, and this is reflected in improvements to the patients’ ability to move and feel.
rTMS was a treatment designed to treat psychiatric disorders, and has been used in treating some of the symptoms of schizophrenia.
Dr. Davey adds: “Despite this, we still need to be extremely careful in interpreting these results as we only sampled a small number of patients. Further studies on larger groups of patients will need to be carried out before we will know if this treatment is fully effective. Similarly we have no idea how long the treatment benefits will last over a longer period.”
This work was supported by the International Spinal Research Trust, and Dr. Davey and his team have recently received a further grant, again from the International Spinal Research Trust, to carry out further, larger trials.