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Somatosensory potentials evoked by magnetic stimulation of lumbar roots, cauda equina, and leg nerves
Author(s) -
Tsuji Sadatoshi,
Murai Yoshiyuki,
Yarita Masaru
Publication year - 1988
Publication title -
annals of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.764
H-Index - 296
eISSN - 1531-8249
pISSN - 0364-5134
DOI - 10.1002/ana.410240414
Subject(s) - cauda equina , somatosensory system , stimulation , somatosensory evoked potential , anatomy , lumbar , medicine , neuroscience , spinal cord , psychology , anesthesia
Cortical somatosensory evoked potentials (Septembers) were studied by noninvasive magnetic stimulation at T‐10, T‐12, and L‐5 vertebral levels and in mid‐gluteus muscle and ankle in 27 normal subjects and 7 patients with neurological diseases. Cortical components P2 and N2 were recorded in all normal subjects. The mean peak latencies of P2 were 20.3 ± 0.9 (standard deviation), 21.1 ± 1.2, 23.5 ± 1.4, 27.9 ± 2.0, and 38.1 ± 1.8 msec at the T‐10, T‐12, L‐5, mid‐gluteal and ankle sites of stimulation, respectively. No substantial difference in morphology of P2 and N2 was seen between magnetic and electrical stimulation at T‐12. Amplitudes of P2 and N2 were maximal after magnetic stimulation at motor threshold. P2 and N2 may originate from the sensory cortex. P2 and N2 evoked by T‐10 and T‐12 stimulation were normal in peak latency and morphology in patients with polyneuropathy or polyradiculoneuropathy. Peak latencies of P2 and N2 evoked by T‐10 and T‐12 stimulation were significantly delayed in patients with myelopathy. The patients with radiculopathy showed a delayed peak latency and conduction time of P2 evoked by L‐5 stimulation. Magnetic stimulation of spinal root is able to detect lesions of spinal cord noninvasively.