Shock waves are acoustic pulse waves and allow physical energy to take effect in localised areas of tissue. In Neurology, we refer to the use of shock waves as Transcranial Pulse Stimulation (TPS). TPS is performed with the NEUROLITH® system and is approved as a treatment option for patients with Alzheimer's disease.
The history and physics of shock waves in medicine
Since the late 1980s, we have used shock waves for the extracorporeal treatment of kidney stones. Today, shock waves are applied in a variety of medical applications, for example in musculoskeletal disorders and in regenerative medicine. This includes successful applications in diseases of the musculoskeletal system as well as in pseudarthrosis, for stimulating angiogenesis, for wound healing disorders and for treating angina pectoris and heart failure.
Shock waves are acoustic pulses generated mechanically and characterised by a discrete pulse and ultra-short duration. These properties mean that the shock wave does not cause any thermal effects and therefore no tissue heating. They are introduced non-invasively into the body tissue. In order to propagate and be transferred into the body, they require an elastic medium such as water or coupling gel. Shock waves allow physical energy to take effect in localised areas of tissue.
Read more about the physics of shock waves here: What are shock waves? Physics and technology
When the therapy is used in the field of lithotripsy, high-energy shock waves are applied to fragment stones. By contrast, when it is used in pain therapy or for neurological applications, low-energy waves are used to introduce energy into the tissue to generate a stimulating effect.
Shock waves are invisible to the naked eye, but can be rendered visible with special optical setups. These create images – streak images – that highlight the beauty of shock waves.
How do shock waves work?
Mechanotransduction is considered the basic mechanism of shock waves in tissue. It describes the conversion of physical pulses – like shock waves – into cellular processes that are responsible for the positive effects on cell metabolism and the cell cycle. This includes migration and differentiation of stem cells, release of nitric oxide (NO) as well as stimulation of growth factors (VEGF, BDNF). This results in the formation of new blood vessels, improvement in blood flow and regeneration of nerves.*
Transcranial Pulse Stimulation (TPS) for patients with Alzheimer’s disease
In Neurology, we refer to shock wave treatment with the NEUROLITH® as Transcranial Pulse Stimulation – TPS for short. The NEUROLITH® has been a CE-marked device since 2018 for treating patients with symptoms of Alzheimer's disease.
TPS involves controlled transmission of the pulses through the scalp and skull in a non-invasive manner into the regions of the patient's brain typically affected by Alzheimer's disease.
The results of recent studies suggest that TPS leads to neuroplastic and morphological changes and they indicate improvement in cognitive function in patients with Alzheimer's disease. Studies and investigations are currently being conducted on the long-term effects, mechanisms of action and biological effects of TPS.
*The effects stated in connection with shock wave treatments relate to different tissues and cannot be generalised to all indications without scientific evidence.
(1) d´Agostino, M. C. et al.: International Journal of Surgery, 24(Pt B):147-153, 2015.
(2) Mariotto, S. et al.: Nitric Oxide, 12(2):89-96, 2005.
(3) Yahata, K. et al.: Journal of Neurosurgery, 25(6):745-755, 2016.
(4) Hatanaka, K. et al.: American Journal of Physiology-Cell Physiology, 311(3):C378-85, 2016.