Author/Editor		Bošnjak, Roman
Title		Motorični odziv na električno draženje spinalnih korenov L4, L5 in S1 pri človeku
Type		monografija
Place		Ljubljana
Publisher		Medicinska fakulteta
Publication year		1999
Volume		str. 94
Language		slo
Abstract		The functional topography of lumbosacral spinal nerve roots in humans was investigated using spacely-defined stimulation of spinal nerve roots from epiduraly placed spiral cuff multielectrodes. The motor response to monopolar electric stimulation of nerve roots L3, L4, L5, and S1 was evaluated by the magnitude and direction of the 3D torque vector of the ankle in response to stimulation at each electrode location in the cuff. Sixteen spinal nerve roots of fourteen patients were stimulated intraoperativelly after removal of a herniated dics. Stimulus position-depence of the motor response was found for the magnitude of prthogonal ankle torques, for thresholds of biomechanical and electromyographic responses and for torque recruitment. Saturation (maximum) of orthogonal torques and their ratios at saturation level were not influenced by changing the position of the stimulus. In addition, the pattern of ankle torques was not influenced by changing the stimulus position. Different patterns of ankle torques, expressed by a change in direction of at least one of the ankle torques, could not be elicited by the present methodology. There was only one oattern of ankle torque per nerve root regardless of the position of the stimulating electrode in the cuff. Similar patterns of ankle torques were found for stimulating nerve roots L5 or S1. Stimulation of nerve root S1 produced a uniforma motor response: palntarflexion (-Mx), external rotation of the talocrural segment (+My) and foot inversion (-Mz). The low specificy of motor responses in the ankle to stimulation of nerve roots L5 and S1 is a consequence of poliradicular innervation of leg muscles and geometry of the leg. Dorsiflexion of the foot cannot be produced by stimulation nerve root L5 alone, but can be elicited by stimulation of nerve toots L3 and L4 (where cross-innervation to plantarflexors and dorsiflexors is less expressed). (Abstract truncated at 2000 characters).
Descriptors		LOW BACK PAIN ELECTRIC STIMULATION THERAPY INTERVERTEBRAL DISK DISPLACEMENT SPINAL NERVE ROOTS INTRAOPERATIVE PERIOD ANKLE BIOMECHANICS ELECTROMYOGRAPHY EPIDURAL SPACE ELECTRODES, IMPLANTED MUSCLE DENERVATION