Tibial nerve SEPs in diagnosing lumbar spinal stenosis: The utility of segmental evaluation using P15 and N21
Objective: To establish the utility of the additional evaluation of the P15 potential generated at the greater sciatic foramen in the tibial nerve somatosensory evoked potentials (SEPs) in diagnosing lumbar spinal stenosis (LSS). Methods: We retrospectively reviewed tibial nerve SEP findings in pati...
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| Format: | Article |
| Language: | English |
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Elsevier
2023-01-01
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| Series: | Clinical Neurophysiology Practice |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2467981X23000033 |
| _version_ | 1827581132000985088 |
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| author | Kiyoshi Matsukura Keiichi Hokkoku Taiji Mukai Chizuko Oishi Takamichi Kanbayashi Toshiyuki Takahashi Masahiro Sonoo |
| author_facet | Kiyoshi Matsukura Keiichi Hokkoku Taiji Mukai Chizuko Oishi Takamichi Kanbayashi Toshiyuki Takahashi Masahiro Sonoo |
| author_sort | Kiyoshi Matsukura |
| collection | DOAJ |
| description | Objective: To establish the utility of the additional evaluation of the P15 potential generated at the greater sciatic foramen in the tibial nerve somatosensory evoked potentials (SEPs) in diagnosing lumbar spinal stenosis (LSS). Methods: We retrospectively reviewed tibial nerve SEP findings in patients having MRI-confirmed LSS at the cauda equina or conus/epiconus region. P15 and N21 potentials were recorded and the following findings were defined as localizing abnormalities: 1) normal P15 latency either with prolonged P15-N21 interval or with absent N21; 2) decreased ratio of the N21 amplitude to P15 amplitude. As non-localizing abnormalities, N21 and P38 latencies were also evaluated. Tibial nerve F-wave findings were also investigated. Results: According to the entry criteria, 18 patients were included, 15 with cauda equina lesions and 3 with conus/epiconus lesions. Localizing abnormalities in SEPs were found in 67% of patients, achieving significantly higher sensitivity than delayed P38 latency (28%), and higher sensitivity than N21 abnormalities (39%), though this was not significant. Localizing abnormalities were observed even in 6 out of 11 patients lacking both sensory symptoms and signs. Tibial nerve F-wave was abnormal in 36% of 14 patients with F-wave examinations, whereas the localizing abnormalities in SEPs were found in 64% of the same patient population. P15 amplitude was depressed in 4 patients (22%), which may indicate the involvement of the dorsal root ganglion in LSS, although its latency was normal even for these patients. Conclusions: Tibial nerve SEPs with the recording of P15 and N21 potentials achieved sufficiently high sensitivity in diagnosing LSS. They have the advantage over F-wave in that they can localize the lesion at the cauda equina or conus/epiconus level. Significance: Tibial nerve SEPs are promising in evaluating LSS, especially in documenting sensory tract involvement in cases lacking sensory symptoms/signs. |
| first_indexed | 2024-03-08T22:31:01Z |
| format | Article |
| id | doaj.art-136bd50bc4624167b78f7d6363c10b77 |
| institution | Directory Open Access Journal |
| issn | 2467-981X |
| language | English |
| last_indexed | 2024-03-08T22:31:01Z |
| publishDate | 2023-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Clinical Neurophysiology Practice |
| spelling | doaj.art-136bd50bc4624167b78f7d6363c10b772023-12-18T04:24:31ZengElsevierClinical Neurophysiology Practice2467-981X2023-01-0184957Tibial nerve SEPs in diagnosing lumbar spinal stenosis: The utility of segmental evaluation using P15 and N21Kiyoshi Matsukura0Keiichi Hokkoku1Taiji Mukai2Chizuko Oishi3Takamichi Kanbayashi4Toshiyuki Takahashi5Masahiro Sonoo6Department of Neurology, Teikyo University School of Medicine, Kaga 2-11-1, Itabashi-ku, Tokyo, JapanDepartment of Neurology, Teikyo University School of Medicine, Kaga 2-11-1, Itabashi-ku, Tokyo, JapanDepartment of Neurology, Teikyo University School of Medicine, Kaga 2-11-1, Itabashi-ku, Tokyo, JapanDepartment of Neurology, Teikyo University School of Medicine, Kaga 2-11-1, Itabashi-ku, Tokyo, Japan; Department of Neurology, Kyorin University School of Medicine, Shinkawa 6-20-2, Mitaka, Tokyo, JapanDepartment of Neurology, Teikyo University School of Medicine, Kaga 2-11-1, Itabashi-ku, Tokyo, JapanSpinal Disorders Center, Fujieda Heisei Memorial Hospital, Minakami 123-1, Fujieda, Shizuoka, JapanDepartment of Neurology, Teikyo University School of Medicine, Kaga 2-11-1, Itabashi-ku, Tokyo, Japan; Corresponding author at: Department of Neurology, Teikyo University School of Medicine, Kaga 2-11-1, Itabashi-ku, Tokyo 1738605, Japan.Objective: To establish the utility of the additional evaluation of the P15 potential generated at the greater sciatic foramen in the tibial nerve somatosensory evoked potentials (SEPs) in diagnosing lumbar spinal stenosis (LSS). Methods: We retrospectively reviewed tibial nerve SEP findings in patients having MRI-confirmed LSS at the cauda equina or conus/epiconus region. P15 and N21 potentials were recorded and the following findings were defined as localizing abnormalities: 1) normal P15 latency either with prolonged P15-N21 interval or with absent N21; 2) decreased ratio of the N21 amplitude to P15 amplitude. As non-localizing abnormalities, N21 and P38 latencies were also evaluated. Tibial nerve F-wave findings were also investigated. Results: According to the entry criteria, 18 patients were included, 15 with cauda equina lesions and 3 with conus/epiconus lesions. Localizing abnormalities in SEPs were found in 67% of patients, achieving significantly higher sensitivity than delayed P38 latency (28%), and higher sensitivity than N21 abnormalities (39%), though this was not significant. Localizing abnormalities were observed even in 6 out of 11 patients lacking both sensory symptoms and signs. Tibial nerve F-wave was abnormal in 36% of 14 patients with F-wave examinations, whereas the localizing abnormalities in SEPs were found in 64% of the same patient population. P15 amplitude was depressed in 4 patients (22%), which may indicate the involvement of the dorsal root ganglion in LSS, although its latency was normal even for these patients. Conclusions: Tibial nerve SEPs with the recording of P15 and N21 potentials achieved sufficiently high sensitivity in diagnosing LSS. They have the advantage over F-wave in that they can localize the lesion at the cauda equina or conus/epiconus level. Significance: Tibial nerve SEPs are promising in evaluating LSS, especially in documenting sensory tract involvement in cases lacking sensory symptoms/signs.http://www.sciencedirect.com/science/article/pii/S2467981X23000033Somatosensory evoked potentialsTibial nerveLumbar spinal stenosisF-wave |
| spellingShingle | Kiyoshi Matsukura Keiichi Hokkoku Taiji Mukai Chizuko Oishi Takamichi Kanbayashi Toshiyuki Takahashi Masahiro Sonoo Tibial nerve SEPs in diagnosing lumbar spinal stenosis: The utility of segmental evaluation using P15 and N21 Clinical Neurophysiology Practice Somatosensory evoked potentials Tibial nerve Lumbar spinal stenosis F-wave |
| title | Tibial nerve SEPs in diagnosing lumbar spinal stenosis: The utility of segmental evaluation using P15 and N21 |
| title_full | Tibial nerve SEPs in diagnosing lumbar spinal stenosis: The utility of segmental evaluation using P15 and N21 |
| title_fullStr | Tibial nerve SEPs in diagnosing lumbar spinal stenosis: The utility of segmental evaluation using P15 and N21 |
| title_full_unstemmed | Tibial nerve SEPs in diagnosing lumbar spinal stenosis: The utility of segmental evaluation using P15 and N21 |
| title_short | Tibial nerve SEPs in diagnosing lumbar spinal stenosis: The utility of segmental evaluation using P15 and N21 |
| title_sort | tibial nerve seps in diagnosing lumbar spinal stenosis the utility of segmental evaluation using p15 and n21 |
| topic | Somatosensory evoked potentials Tibial nerve Lumbar spinal stenosis F-wave |
| url | http://www.sciencedirect.com/science/article/pii/S2467981X23000033 |
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