Transcranial Pulse Stimulation (TPS): new study demonstrates sham-controlled long-term effects for the first time
A study by Matt et al. (Medical University of Vienna, University Department of Neurology) published in January 2022 investigates the long-term effects of Transcranial Pulse Stimulation (TPS) with the NEUROLITH® system on human brain and behaviour.1 The randomised, sham-controlled and double-blinded study provides sham-controlled evidence for such effects for the first time.
In two experimental blocks, twelve healthy participants (18 – 35 years, all right-handed) received three sham and three verum sessions with Transcranial Pulse Stimulation (TPS), which focused on the cortical somatosensory representation of the right hand. The total study duration was seven weeks (one week break between the two blocks).
One week before and after the sham and verum applications, comprehensive structural and functional resting state MRI investigations and behavioural tests targeting tactile spatial discrimination and sensorimotor dexterity were performed.
Compared to sham, global efficiency (GE) significantly increased within the cortical sensorimotor network after verum TPS, indicating an upregulation of the stimulated functional brain network. Axial diffusivity in left sensorimotor areas decreased after verum TPS, demonstrating an improved axonal status in the stimulated area. As in the pilot clinical trial2 published in 2019, in which patients with Alzheimer's dementia were treated, repeated TPS stimulation was well tolerated by the participants.
Neuronal functional changes persist after treatment completion
TPS increased the functional and structural coupling within the stimulated left primary somatosensory cortex and adjacent sensorimotor areas up to one week after the last stimulation. These findings suggest that TPS induces neuroplastic changes that go beyond the spatial and temporal stimulation settings. According to the research group, this evidence of sham-controlled long-term effectivity, safety and feasibility encourages further clinical applications of TPS.
Additional comment and explanation:
The new study by Matt et al. is excellently done and provides an academically sound argument for the raison d'être of TPS and its indications. It provides important evidence that the effect of TPS on brain activity goes beyond a placebo effect. Further clinical evaluations must now follow to establish TPS as an evidence-based treatment method for various indications.
The study shows that a static TPS (the handpiece was fixed to the participants head) applied only 3 times leads to neuroplastically consolidated improvement of motor and sensory functions in healthy persons, without these functions having been practised over weeks and months (e.g. physiotherapy). This can be described as sensational. Moreover, this effect is far superior to the minute effect/maximum hour effect of tFUS and is indeed a long-term effect.
Structural effects: Cortex and associated structures responsible for data coordination of hand movement, deeper, distant, only accessible by axons (electrical conduits of the brain) are activated (axons make up most of the white matter of the brain). They become better protected against »creeping currents» for at least a week and thus become more conductive.
The metabolism of the neurons and axons seems to improve. The ratio of water to solid brain mass improves in favour of brain mass. The stimulus of the TPS leads to an increase in the number of cells recruited for movement-specific sensory motor function and the associated synapses (both!) for at least a week. This is what the term neuroplasticity describes.
Functional effects: The specific fine motor skills improve sustainably. This improves the sensitivity of the muscles (muscles are sensory organs).
Possible indications as a result of the study: All chronic neurodegenerative diseases that should be slowed down in their symptomatic course regardless of their cause. In addition to Alzheimer's disease, these include Parkinson's disease, multiple sclerosis, the large family of motor and sensory neuropathies, visual disturbances due to inflammatory retinal diseases and circulatory disorders, etc. Likewise, all acute brain damage, from infantile cerebral palsy to coma vigil and stroke, becomes a compelling indication (provided the extent of the brain damage allows it).
Sources:
- 1. Matt E, Kaindl L, Tenk S, Egger A, Kolarova T, Karahasanović N, Amini A, Arslan A, Sariçiçek K, Weber A, Beisteiner R. First evidence of long-term effects of transcranial pulse stimulation (TPS) on the human brain. J Transl Med. 2022 Jan 15;20(1):26. doi: 10.1186/s12967-021-03222-5. PMID: 35033118.
- 2. Beisteiner R, Matt E, Fan C, Baldysiak H, Schönfeld M, Philippi Novak T, Amini A, Aslan T, Reinecke R, Lehrner J, Weber A, Reime U, Goldenstedt C, Marlinghaus E, Hallett M, Lohse-Busch H. Transcranial Pulse Stimulation with Ultrasound in Alzheimer's Disease-A New Navigated Focal Brain Therapy. Adv Sci (Weinh). 2019 Dec 23;7(3):1902583. doi: 10.1002/advs.201902583. PMID: 32042569; PMCID: PMC7001626
