Epidural spinal cord stimulation: calculation of field potentials with special reference to dorsal column nerve fibers

The effect of electrical stimulation with several electrode combinations on nerve fibers with different orientations in the spinal cord was investigated by computing the steady-state field potentials and activating functions. An infinite homogeneous model was used, and the spinal cord and its surrounding tissues where then modeled as an inhomogeneous anisotropic volume conductor. The effect of mediodorsal epidural stimulation was calculated. It was concluded that the cathodal stimulation, mediodorsally in the epidural space, longitudinal fibers are depolarized, but dorsoventral ones are hyperpolarized. With anodal stimulation the opposite will occur. It was found that parameters substantially affecting the potential distribution in the dorsal columns are the conductivity of the white matter and the width and the conductivity of the cerebrospinal fluid layer.<<ETX>>

[1]  D. Mcneal.  Analysis of a Model for Excitation of Myelinated Nerve , 1976, IEEE Transactions on Biomedical Engineering.

[2]  Anthony Sances,et al.  Spinal Cord Implant Studies , 1976, IEEE Transactions on Biomedical Engineering.

[3]  Akademisk Avhandling,et al.  THE SAGITTAL DIAMETER OF THE SPINAL CORD AND SUBARACHNOID SPACE IN DIFFERENT AGE GROUPS. A ROENTGENOGRAPHIC POST-MORTEM STUDY. , 1964, Acta radiologica: diagnosis.

[4]  L Penning,et al.  CT myelographic findings in degenerative disorders of the cervical spine: clinical significance. , 1986, AJR. American journal of roentgenology.

[5]  P. Wall,et al.  Pain mechanisms: a new theory. , 1965, Science.

[6]  F Rattay,et al.  Ways to approximate current-distance relations for electrically stimulated fibers. , 1987, Journal of theoretical biology.

[7]  Shealy Cn,et al.  Electrical inhibition of pain by stimulation of the dorsal columns: preliminary clinical report. , 1967 .

[8]  P. D. Wall,et al.  The gate control theory of pain mechanisms. A re-examination and re-statement. , 1978 .

[9]  R. A. Davidoff.  Handbook of the spinal cord , 1983 .

[10]  H C ELLIOTT,et al.  Cross‐sectional diameters and areas of the human spinal cord , 1945, The Anatomical record.

[11]  Barry Coburn,et al.  A Theoretical Study of Epidural Electrical Stimulation of the Spinal Cord Part I: Finite Element Analysis of Stimulus Fields , 1985, IEEE Transactions on Biomedical Engineering.

[12]  F. Rattay.  Analysis of Models for External Stimulation of Axons , 1986, IEEE Transactions on Biomedical Engineering.

[13]  Mary N. Morrow,et al.  A Comparison of Finite Element and Integral Equation Formulations for the Calculation of Electrocardiographic Potentials , 1985, IEEE Transactions on Biomedical Engineering.

[14]  J. Holsheimer,et al.  A modeling study of nerve fascicle stimulation , 1989, IEEE Transactions on Biomedical Engineering.

[15]  S. Ahlback,et al.  Osteoarthrosis of the knee. A radiographic investigation. , 1968 .