Tremors are severely disabling, causing involuntary shakes affecting the hands, head, legs, or other body parts. The movements are thought to result from rogue brain waves – or aberrant oscillations – in regions associated with motor functions. But their underlying cause is still largely unknown, making it difficult to treat symptoms with drugs.
In a new study by the UK Dementia Research Institute, scientists have discovered a way of suppressing the brain waves underpinning tremors without the need for invasive techniques. Using electrical pulses, scientists help suppress the tremors.
At first, scientists developed a way to calculate and track these rogue brainwaves’ phase in real-time. Their method shows the synchronized peaks and troughs of activity as they ripple through the brain.
Then by using a non-invasive form of electrical stimulation, scientists targeted the cerebellum.
They found that by synchronizing the brain stimulation with specific phases of these aberrant oscillations, they could reduce tremors in people with Essential Tremor Syndrome (ETS), the most common neurological disorder to cause such tremors.
During the study, scientists applied electrodes to the scalp of eleven people with ETS. They then adjusted the electric fields to maintain a fixed phase corresponding to the ongoing tremor movement, called ‘phase-locking.’
They found the reduction of symptoms lasted during stimulation and for a short period afterward. The reduction in the tremor amplitude (or severity) was associated with a disruption of the movement’s regularity, meaning the more the brain stimulation made the tremor irregular, the more it reduced its amplitude.
Dr. Nir Grossman from the Department of Brain Sciences at Imperial College London said: “Tremor symptoms can be upsetting and get in the way of doing basic, everyday things that most of us take for granted. In the worst cases, they can be severely debilitating.”
“Tremors are caused by abnormal synchronization in the motor areas of the brain, but the biological processes underlying them are still not well understood. By targeting the temporal pattern of the brain’s abnormal synchronization, we may treat it, non-invasively, despite the limited knowledge of the precise causes.”
“Our work presents an early-stage feasibility study of this approach. We hope to continue to develop it into a widely available treatment for tremors, as well as other symptoms that are underpinned by abnormal synchronization in the brain.”
- Sebastian R. Schreglmann et al. Non-invasive Amelioration of Essential Tremor via Phase-Locked Disruption of its Temporal Coherence. DOI: 10.1101/2020.06.23.165498