Magnetic stimulation of the human motor cortex evokes skin sympathetic nerve activity

• Published in: Journal of applied physiology (1985) Vol. 88; no. 1; pp. 126 - 134
• Main Authors: Silber, David H, Sinoway, Lawrence I, Leuenberger, Urs A, Amassian, Vahe E
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Am Physiological Soc 01.01.2000; American Physiological Society
• Subjects: Acoustic Stimulation; Adult; Afferent Pathways - physiology; Biological and medical sciences; Blood Pressure - physiology; Dominance, Cerebral - physiology; Electromagnetic Fields; Electromyography; Evoked Potentials, Somatosensory - physiology; Exercise - physiology; Feedback; Fingers - innervation; Fingers - physiology; Forearm - innervation; Forearm - physiology; Fundamental and applied biological sciences. Psychology; Humans; Magnetism; Male; Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration; Motor Cortex - cytology; Motor Cortex - physiology; Motor Neurons - physiology; Muscle, Skeletal - innervation; Muscle, Skeletal - physiology; Muscular system; Nervous system; Neurology; Peroneal Nerve - physiology; Physical Stimulation; Skin; Skin - innervation; Sympathetic Nervous System - physiology; Vertebrates: nervous system and sense organs; Human; Sympathetic nerve; Motor pathway; Central nervous system; Electrophysiology; Activation; α-Motor neuron; Sympathetic nervous system; Autonomic nervous system; Motor cortex; Magnetic stimulus; Skin; Motor evoked potential; Brain (vertebrata); Response stimulus relation; Non-programmatic
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/jappl.2000.88.1.126

1  Section of Cardiology, The Milton S. Hershey Medical Center, The Pennsylvania State University, Hershey 17033; 2  Lebanon Veterans Affairs Medical Center, Lebanon, Pennsylvania 17042; and 3  Departments of Physiology and Neurology, State University of New York, Health Science Center of Brooklyn, Brooklyn, New York 11203 Single-pulse magnetic coil stimulation (Cadwell MES 10) over the cranium induces without pain an electric pulse in the underlying cerebral cortex. Stimulation over the motor cortex can elicit a muscle twitch. In 10 subjects, we tested whether motor cortical stimulation could also elicit skin sympathetic nerve activity (SSNA; n  = 8) and muscle sympathetic nerve activity (MSNA; n  =   5) in the peroneal nerve. Focal motor cortical stimulation predictably elicited bursts of SSNA but not MSNA; with successive stimuli, the SSNA responses did not readily extinguish (94% of discharges to the motor cortex evoked SSNA responses) and had predictable latencies [739 ± 33 (SE) to 895 ± 13 ms]. The SSNA responses were similar after stimulation of dominant and nondominant sides. Focal stimulation posterior to the motor cortex elicited extinguishable SSNA responses. In three of six subjects, anterior cortical stimulation evoked SSNA responses similar to those seen with motor cortex stimulation but without detectable movement; in the other subjects, anterior stimulation evoked less SSNA discharge than that seen with motor cortex stimulation. Contrasting with motor cortical stimulation, evoked SSNA responses were more readily extinguished with 1 ) peripheral stimulation that directly elicited forearm muscle activation accompanied by electromyograms similar to those with motor cortical stimulation; 2 ) auditory stimulation by the click of the energized coil when off the head; and 3 ) in preliminary experiments, finger afferent stimulation sufficient to cause tingling. Our findings are consistent with the hypothesis that motor cortex stimulation can cause activation of both -motoneurons and SSNA. central command; motor cortex; muscle sympathetic nerve activity; autonomic nervous system