A non-surgical brain stimulation technique improved Parkinson’s movement symptoms in a small pilot study.
The approach targets deep brain circuits from outside the skull, without the need to implant electrodes.
Researchers said the early findings must be tested in larger studies before the technique can be considered for clinical use.
The study, involving researchers from Hebrew SeniorLife, Shanghai University of Sport and other institutions, tested transcranial temporal interference stimulation, known as TIs, in 30 people with early to mid-stage Parkinson’s disease.
Parkinson’s is a progressive neurological condition that affects movement and can cause tremor, stiffness, slow movement and problems starting movement.
Deep brain stimulation, or DBS, is already used for some people with advanced symptoms. It involves surgery to implant electrodes into specific areas of the brain.
TIs aims to stimulate similar deep brain regions without surgery, using overlapping electrical currents delivered through the scalp.
Alvaro Pascual-Leone, one of the researchers, medical director at The Deanna & Sidney Wolk Center for Memory Health, Hebrew SeniorLife, and professor of neurology at Harvard Medical School, said: “TIs represents a fundamentally different approach to non-invasive neuromodulation, one that can reach deep brain targets without surgery.
“We also need to find out which is the best target in the brain for a given effect and a given patient.
“Other deep brain nuclei may induce greater benefit and be able to affect different core symptoms of Parkinson’s Disease.”
In the randomised, double-blind crossover study, participants received one 20-minute session of individualised TIs targeting the subthalamic region, a deep brain area involved in movement control. They also received a sham, or placebo, treatment in a separate session.
Researchers reported movement improvements immediately after stimulation, with effects lasting for at least an hour.
Using a standard Parkinson’s motor symptom scale, 70 per cent of participants had clinically meaningful improvement after TIs, compared with 15 per cent after sham treatment.
The strongest effects were seen in bradykinesia, which means slowness of movement, and tremor. Improvements in rigidity and balance-related symptoms were less consistent.
No serious adverse events were reported. Mild sensations such as tingling or warmth occurred at similar rates during active and sham treatment.
Junhong Zhou, co-corresponding author at the Hinda and Arthur Marcus Institute for Aging Research, Hebrew SeniorLife, said: “These early results are promising, so we are already moving forward, together with our collaborators from Shanghai University of Sport, the UK and Germany, to conduct larger studies applying multiple sessions of stimulation in subsequent days to induce lasting effects and determine how long the benefits can last, how treatments should be spaced, and which patients are most likely to respond.”
Brad Manor, senior scientist at the Hinda and Arthur Marcus Institute for Aging Research, Hebrew SeniorLife, said: “One of the most promising aspects of this work is the ability to individualise stimulation based on each patient’s own brain anatomy.
“That level of precision could become increasingly important as we learn how to tailor neuromodulation therapies to different Parkinson’s symptoms and different patients.
“A non-invasive technique like TIs could someday provide a valuable new option either before surgery is considered or alongside existing therapies.”
Researchers cautioned that the trial only tested short-term effects after a single session.
Further studies will need to examine repeated treatments, longer follow-up and whether TIs can deliver sustained improvements in everyday function over time.
