Summary
Median nerve somatosensory evoked potentials (SEPs) were studied in a patient before and after the development of a cervico-medullary lesion. The first examination demonstrated normal subcortical generated potentials N13 and N14. The second examination, following a subarachnoid haemorrhage at the cervico-medullary junction, displayed a delayed and reduced amplitude P14/N14 peak on both sides. P14/N14 showed the same latency in all montages, using noncephalic, cephalic and anterior neck references. The N13 component was not significantly changed in latency compared with the first examination. The latencies of the N13 peak were variable in the different montages. They increased from the lower (C7) to the upper (C2) neck, whereas the latency of the N13 onset was identical in all montages. This alteration might be caused by a delayed near-field activity at C2 overlapping the N13 component. These results fit the hypothesis of two major generators responsible for subcortical SEPs; a near-field N13 component at the level of the lower neck and a far-field P14 component arising from the level of the cervico-medullary junction. An additional minor near-field activity generated by the cuneate nucleus is suspected.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Buchner H, Ferbert A, Scherg M, Hacke W (1986) Evoked potential monitoring in brain death; generators of BAEP and spinal SEP. In: Kunze K, Zangemeister WH, Arlt A (eds) Clinical problems of brainstem disorders. Thieme, Stuttgart New York
Cracco RQ, Cracco JB (1976) Somatosensory evoked potential in man: far field potentials. Electroencephalogr Clin Neurophysiol 41:460–466
Delestre F, Lonchampt P, Dubas F (1986) Neural generator of P14 far-field somatosensory evoked potential studied in a patient with a pontine lesion. Electroencephalogr Clin Neurophysiol 65:227–230
Desmedt JE, Cheron G (1980) Central somatosensory conduction in man: neural generators and interpeak latencies of the far-field components recorded from neck and right or left scalp and earlobes. Electroencephalogr Clin Neurophysiol 50:382–403
Desmedt JE, Cheron G (1981) Prevertebral (oesophageal) recording of subcortical somatosensory evoked potentials in man: the spinal P13 component and the dual nature of the spinal generators. Electroencephalogr Clin Neurophysiol 52:257–275
Desmedt JE, Nguyen TH (1984) Bit-mapped colour imaging of the potential fields of propagated and segmental subcortical components of somatosensory evoked potentials in man. Electroencephalogr Clin Neurophysiol 58:481–497
Donchin E, Callaway E, Cooper R, Desmedt JE, Goff WR, Hillyard SA, Sutton S (1977) Publication criteria for studies of evoked potentials (EP) in man; report of a committee. In: Desmedt JE (ed) Progress in clinical neurophysiology, vol 1. Karger, Basel, pp 1–11
Emerson RG, Seyal M, Pedley TA (1984) Somatosensory evoked potentials following median nerve stimulation. I. The cervical components. Brain 107:167–182
Kayi R, Tanaka R, Kawaguchi S, McCormick F, Kameyama M (1986) Origin of short-latency somatosensory evoked potentials to median nerve stimulation in the cat — comparison of the recording montages and effect of laminectomy. Brain 109:443–468
Kimura J, Mitsudome A, Beck DO, Yamada T, Dickins QS (1983) Field distribution of antidromically activated digital nerve potentials: model for far-field recording. Neurology 33:1164–1169
Lorente de No R (1947) A study of nerve physiology. Studies from the Rockefeller Institute, New York
Lueders H, Lesser R, Hahn J, Little J, Klem G (1983) Subcortical somatosensory evoked potentials to median nerve stimulation. Brain 106:341–372
Mauguière F, Ibañez V (1985) The dissociation of early SEP components in lesions of the cervico-medullary junction: a cue for routine interpretation of abnormal cervical responses to median nerve stimulation. Electroencephalogr Clin Neurophysiol 62:406–420
Mauguière F, Courjon J, Schott B (1983) Dissociation of early SEP components in unilateral traumatic section of the lower medulla. Ann Neurol 13:309–313
Stöhr M, Riffel B (1982) Short-latency somatosensory evoked potentials to median nerve stimulation: components N13–P13, N14–P14, P15, P16 and P18 with different recording methods. J Neurol 228:39–47
Stöhr M, Riffel B (1985) Generatoren der somatosensorisch evozierten Potentiale nach Armnervenstimulation. Z EEG-EMG 16:130–133
Stöhr M, Buettner UW, Riffel B, Koletzki E (1982) Spinal somatosensory evoked potentials in cervical lesions. Electroencephalogr Clin Neurophysiol 54:257–265
Yamada T, Kimura J, Nitz DM (1980) Short latency somatosensory evoked potentials following median nerve stimulation in man. Electroencephalogr Clin Neurophysiol 48:367–376
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Buchner, H., Ferbert, A., Brückmann, H. et al. The subcortical generated somatosensory evoked potentials in non-cephalic, cephalic, and anterior neck referenced recordings in a patient with a cervico-medullary lesion: a clue to the identification of the P14/N14 and N13 generators. J Neurol 234, 412–415 (1987). https://doi.org/10.1007/BF00314087
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF00314087