We studied 18 patients with low back pain with segmental spinal and cortical evoked potentials recorded over both spine and scalp following saphenous, superficial peroneal, and sural nerve stimulation.

The spinal evoked potential findings were compared to CT, myeloram, physical findings, and EMG and the sensitivity and specificity were measured between them.

The results were summarized as follow:

1) The number of patients with abnormal finding were 10(55%) in spinal SEP, 9(50%) in cortical SEP, 8(47%) in CT and myelogram, 7(38%) in EMG, respectively.

2) The sensitivity and specificity of spinal SEP findings to the CT and myelogram were 75%, 55%, respectively and these findings were higher than that of the cortical SEP.

3) With 2 exception, all patients with abnormal spinal SEP findings were matched with physical finding, CT and myelogram on the level of dermatomal abnormality.

4) The 6 patients with abnormal spinal SEP finding with normal EMG finding were matched with physical finding, CT and myelogram on the level of dermatomal abnormality.