Manual Dexterity Modifications After Application of tSMS Over the Primary Motor Cortex (M1)

Transcranial static magnetic field stimulation (tSMS) is a novel brain stimulation technique that has been shown to be safe and effective in modifying biological parameters when applied to the cerebral cortex. Its application decreases cortical excitability, regardless of the polarity of the magnetic field, reducing the amplitude of motor evoked potentials (MEP). tSMS is presented as a potentially useful tool in the management of the interhemispheric inhibition, a condition present in neurological pathologies such as stroke or multiple sclerosis. Despite having demonstrated neurophysiological effects in previous studies, the effects of tSMS application on force production and manual dexterity, have not yet been clearly established. The present study aims to evaluate changes in force production, manual dexterity, and fatigue after unilateral application of a tSMS session on the primary motor cortex (M1). It is hypothesized that the application of tSMS will momentarily decrease the parameters of strength and manual dexterity in the upper limb contralateral to the stimulated cortex, without changes in the strength and dexterity of the unstimulated hemibody. These parameters may show an increase in the unstimulated hemibody. If the hypothesis is confirmed, it could be considered a valid treatment for health conditions presenting interhemispheric inhibition.