Searching for the Mechanism of Action of Extremely Low Frequency Electromagnetic Field-The Pilot fNIRS Research.

There is an ongoing debate on the benefits of magnetic stimulation in neurological disorders. OBJECTIVES: We aimed to evaluate the influence of magnetic stimulation on blood oxygenation of the motor cortex using functional near-infrared spectroscopy (fNIRS). METHODS: A total of 16 healthy volunteer participants were subjected to four protocols. In the first two protocols, the participants remained at rest without (and then with) magnetic stimulation. In the next two protocols, motor cortex stimulation was achieved using a finger-tapping task, with and without magnetic stimulation. Changes in blood oxygenation levels within the motor cortex were recorded and analysed. RESULTS: No characteristic changes in the blood oxygenation level-dependent responses were observed in resting participants after magnetic stimulation. No statistically significant difference was observed in the amplitude of the fNIRS signal before and after magnetic stimulation. We observed characteristic blood oxygenation level-dependent responses after the finger-tapping task in the second protocol, but not after magnetic stimulation. CONCLUSIONS: Although we did not observe any measurable effect of the magnetic field on the haemodynamic response of the motor cortex, understanding the mechanism(s) of magnetic stimulation may be important. Additional, detailed studies are needed to prove or negate the potential of this medical procedure.

High Signal Resolution Pulse Oximetry as a Prognostic Indicator of Radiotherapy Toxicity: A Pilot Study.

INTRODUCTION: Radiotherapy plays a prominent role in the multidisciplinary treatment of cancers. Despite new irradiation techniques, radiation-induced cardiotoxicity remains a leading cause of morbidity and mortality. Therefore, prognostic indicators of radiotherapy toxicity are essential. This study aimed to investigate the influence of applied radiotherapy on the pulse wave recording and thereby on cardiovascular health, as well as to assess whether high signal resolution (HSR) pulse oximetry could be used as a prognostic indicator of radiotherapy toxicity. METHODS: A total of 19 patients treated with radiotherapy to the lung or left breast were analyzed. Pulse oximetry was performed on all eligible patients (before and after the administration of a radiation dose) using the PULS-HSR program, which increases the resolution of the pulse wave recording. RESULTS: Among the analyzed variables, we found the total dose administered to the target, as well as the treatment duration, significantly positively correlated with the change in ventricle/aorta volume ratio. The ventricle/aorta volume ratio parameter is the ratio between the area under the HSR pulse wave generated by the contraction of the left ventricle until the aortic valve closes and the area of the HSR pulse wave responsible for expansion and contraction of the aorta. CONCLUSION: The pilot study indicates HSR pulse oximetry, especially the ventricle/aorta volume ratio parameter, as a potential prognostic indicator of toxicity from radiation for breast and lung cancers.