A treatment known as median nerve stimulation (MNS) can significantly reduce tic frequency, tic intensity and the urge-to-tic in people with Tourette syndrome (TS), according to a new study at the University of Nottingham in the U.K.
In MNS, researchers administer repetitive trains of stimulation to a person’s median nerve (entered at the wrist) to entrain rhythmic electrical brain activity, or brain-oscillations, associated with the suppression of movements.
“The results of this study were quite remarkable, especially in those people with the most severe tics and showed that this type of stimulation has real potential as a treatment aid for Tourette’s,” said lead author Barbara Morera Maiquez.
“Our aim is to develop a wearable ‘watch-like’ MNS stimulator that looks like an Apple watch or Fitbit and can be used by the individual outside of the clinic as and when they need to control their tics.”
TS is a neurodevelopmental disorder that causes involuntary sounds and movements called tics. Tics are involuntary, repetitive, stereotyped movements and vocalizations that occur in bouts, typically many times in a single day, and are often preceded by a strong urge-to-tic, referred to as a premonitory urge (PU).
“We understand that the tics are caused by alterations in chemical signals within brain networks linked to the formation of habits and the initiation of habitual movements,” said co-author Professor Stephen Jackson.
“These changes lead to hyper-excitability in the brain regions involved in generating movements. Our research successfully used pulses of electrical current, delivered at the wrist, to increase the strength of brain-oscillations that must ordinarily be reduced in strength to generate a movement, resulting in significantly reduced tics and in many cases removal of the urge-to-tic. This work has huge potential for the development of a safe and effective treatment for tics with no side effects.”
For the study, 19 participants with TS were observed for random 1-minute periods, during which they were given constant rhythmic pulses of the MNS to their right wrist, and 1-minute periods during which they received no stimulation. In all cases the stimulation reduced the tics, and also the urge-to-tic, and had the most significant effect on those individuals with the most severe tics.
One of the participants was 21-year-old Charlie, from Lincolnshire. Charlie has had TS for three years and found out about the study through Tourettes Action, which has been supporting him and his family.
“I’ve tried a lot of different medications, therapies, relaxation techniques, support groups and diet changes to try to relieve my Tourette’s, and although I was skeptical I was keen to be involved in this study,” he said.
“The whole experiment was very surreal. When the electrical pulses on the wrist started to increase, the tic urges decreased, which was a completely shocking experience for me — I was silent and still.”
“For a further three sessions I noticed the same result, also the stimulation did decrease my tics at home. At the first session of the stimulation, I felt as if finally, a new treatment may have been found to free myself from my Tourette’s and wanted to cry with happiness.”
Suzanne Dobson, chief executive of the charity Tourettes Action, which helped fund the research, said “This wearable and self-managing treatment could potentially change the lives of thousands of people living with TS. We will continue to support the team at the University of Nottingham as this amazing treatment continues to evolve.”
The findings are published in the journal Current Biology.
Source: University of Nottingham