O-1-13. Diagnosis of lumbar radiculopathy using magnetospinography

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Introduction We previously reported noninvasive visualization of neural activities in the lumbar spine using magnetospinography (MSG). We report here MSG findings of a patient with lumbar radiculopathy. Methods Using a newly developed superconducting quantum interference device (SQUID) magnetometer, we measured the neuromagnetic fields of a patient with L4/-5 disc herniation at the surface of the lumbar spine area after stimulation of the peroneal nerves at the fibular head. Current sources were estimated using spatial filter techniques and were superimposed on X-ray images of the lumbar spine. Results and discussion The action currents calculated from MSG showed a distribution pattern of axonal activity with an intra-axonal current and depolarization/repolarization current. On the contralateral healthy side, the nerve action current passed through the L5 intervertebral foramen and propagated in the caudal-to-cranial direction. On the affected side, the nerve action current attenuated at the L4/-5 intervertebral disc level. Thus, noninvasive surface MSG visualizes propagating spinal nerve excitation in response to peroneal nerve stimulation with high spatial and temporal resolution, allowing us to quantitatively evaluate the decreased action current in lumbar radiculopathy. MSG obtains a different perspective from MRI for the diagnosis of neuropathic pain and is expected to be a clinically useful modality.