Brain Stimulation Reduces Spasticity after Spinal Cord Injury

A new study claims that excitatory intermittent theta burst stimulation (iTBS) is successful in reducing spasticity in patients with spinal cord injury (SCI).

Researchers at Paracelsus Medical University (Salzburg, Austria), the University of Verona (Italy), and other institutions conducted a study to investigate if iTBS, a safe, non-invasive and well-tolerated protocol of excitatory repetitive transcranial magnetic stimulation (rTMS), is effective in modulating spasticity. The study included ten subjects with incomplete cervical or thoracic SCI. Five patients received 10 days of real or iTBS, and the remaining five received sham treatment. After two months, the sham group was switched to real iTBS and the study continued.

The researchers measured motor-evoked potentials (MEP) in the soleus (calf muscle), during magnetic stimulation over the most responsive area of the scalp. M-wave and H reflexes, which are measures of muscle contractions due to stimulation of the tibial nerve, were assessed for each subject, and an H/M amplitude ratio was determined. Modified Ashworth Scale (MAS) and the Spinal Cord Injury Assessment Tool for Spasticity (SCAT) were also compared before and after the stimulation protocols.

The results showed that patients receiving real iTBS showed significant increased resting and active MEPs amplitude and a significant reduction of the H/M amplitude ratio. In addition, both MAS and SCAT scores were significantly reduced after treatment. The changes persisted up to one week after the end of the iTBS treatment, and were not observed under the sham-iTBS condition, suggesting that iTBS may be a promising therapeutic tool for spasticity in SCI patients. The study was published on June 6, 2017, in Restorative Neurology and Neuroscience.

“Patients receiving real iTBS, compared to those receiving sham treatment, showed significant improvement,” said lead author Raffaele Nardone, MD, PhD, of Paracelsus Medical University. “In comparison with standard rTMS protocols, iTBS represents a more feasible approach because of lower stimulation intensity and shorter duration of application in each single session.”

Spasticity is a muscle control disorder caused by an imbalance between signals from the central nervous system (CNS) to the muscles. It is often found in people with cerebral palsy, traumatic brain injury (TBI), SCI, stroke, and multiple sclerosis (MS). It is characterized by increased muscle tone, overactive reflexes, involuntary movements, which may include spasms and clonus, pain, decreased functional abilities, abnormal posture, contractures, and bone and joint deformities.

Related Links:
Paracelsus Medical University
University of Verona