1Pavlov Institute of Physiology of the Russian Academy of Sciences, St.-Petersburg, Russia, 2N.P. Behtereva Institute of Human Brain of the Russian Academy of Sciences, St.-Petersburg, Russia; 3All India Institute of Medical Sciences, New Delhi, India
The influence on the man of subthreshold impulses transcranial magnetic stimulation (iTMS) carries cumulative effect and is externally shown after 5-7 consecutive procedures. It is confirmed by parameters of a motor output and by the therapeutic effects of an application of subthreshold (mT) iTMS on the patients with central dysfunctions of movements. We establish the acting of iTMS into the motor areas in the medical purposes on change of parameters of registered isometric effort used as test procedure for an objective estimation of subliminal iTMS influence. Sensory-motor cortex areas is stimulated by separate series of stimulus with frequencies 0,66 and 30 Hz at moving the coil along the central fissure by steps during 20-30 min. After stimulation the increase of meanings of spectral density is observed in the diapasons of voluntary (0-2 Hz) control and/or involuntary (more than 3 Hz) regulation of movements. In chronic experiments on rats with metered contusion of a spinal cord are investigated effects of influence of low intensity (17,9 µT, 50 Hz) magnetic field on processes of recovery of movement functions and sensory-motor reflex reactions, work of excretory systems and on prevention of self-damage limbs. The movements were estimated on international 21-rank scale (BBB score); and sensory motor reactions were estimated on reflex answer (tail flick) on thermal and electrical stimulation of a tail (its sensory nerves). In control group within the first week after a contusion of a spinal cord at a level Th13 the estimation (on BBB score) decrease from 21 up to 1. Then within of 8 weeks the estimation grew up to 3. There was a hypersensitivity to thermal and electrical stimulation of afferent painful fibers of a tail. Under influence of magnetic field on spinal cord injury the BBB score estimations are decreased from 21 to1 on the first week and grew up to 9 at 8 subsequent weeks. The hypersensitivity to painful stimulus of a tail did not arise. The functions of urinary bladder were restored on 85%. The received data demonstrate therapeutic effects of influence of magnetic field on restoration of movement functions at contusions of a spinal cord. The research has shown, that therapeutic effects of a magnetic field onto restoration of motor functions are shown both under an impulse subthreshold magnetic stimulation, and under influence by a weak low-frequency sine magnetic field.