Selective gating of lower limb cortical somatosensory evoked potentials (SEPs) during passive and active foot movements

Tinazzi, Michèle; Zanette, Giampietro; Porta, Fabio La; Polo, A.; Volpato, D.; Fiaschi, Antonio; Mauguı̀ere, François

doi:10.1016/s0168-5597(97)00023-3

Cited by 43 publications

(22 citation statements)

References 37 publications

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“…contrast, most earlier studies on gating maintained that only some cortical waves diminished in amplitude during movement. [6][7][8]15,16,25,27,34,37,41 Similarly, in our raw data ( Figs. 1 and 2), the earliest cortical component (N20 and N37 potentials for median and tibial SEPs, respectively) shows only a slight amplitude reduction in the gating condition.…”

Section: Discussionsupporting

confidence: 61%

“…This last explanation may account for the SEP reduction during passive movement. 19,24,25,34 Our findings show a greater reduction of cortical dipolar strengths in the active than passive gating condition, suggesting that both centrifugal and centripetal mechanisms contribute to the phenomenon of gating. Only the first peak of dipole 2 in both median and tibial nerve models had a larger mean reduction in strength during passive than active movement, even if the difference was not statistically significant (P > 0.05).…”

Section: Discussionmentioning

confidence: 53%

“…30 So far, a number of somatosensory evoked potential (SEP) studies have dealt with this subject and have shown a reduction in amplitude of either the subcortical 15,31 or cortical [6][7][8]15,16,24,25,27,34,37,41 responses induced by movement. The conclusion from most of these studies is that the gating phenomenon does not involve all the cortical SEP components, but only selected responses (more often the frontal ones).…”

mentioning

confidence: 99%

“…The conclusion from most of these studies is that the gating phenomenon does not involve all the cortical SEP components, but only selected responses (more often the frontal ones). [6][7][8]15,16,25,27,34,37,41 However, the SEP resolution between different cerebral generators is poor and may be misleading. Although magnetoencephalographic (MEG) studies on gating 18,19 have several advantages in localizing brain dipoles, their results can be limited by the poor sensitivity of this technique in detecting radially oriented sources.…”

mentioning

confidence: 99%

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Effect of movement on dipolar source activities of somatosensory evoked potentials

et al. 1999

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Section: Discussionsupporting

confidence: 61%

Section: Discussionmentioning

confidence: 53%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Effect of movement on dipolar source activities of somatosensory evoked potentials

et al. 1999

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“…Gating of lower-limb SSEPs occurs due to passive and active lower-limb movement (Tinazzi et al 1997, Morita et al 1998). It was not feasible to record SSEPs under general anaesthetic before proceeding to surgery.…”

Section: Discussionmentioning

confidence: 99%

Somatosensory evoked potentials as a means of assessing neurological abnormality in congenital talipes equinovarus

Nadeem¹,

Brown

Lawson

et al. 2000

Develop Med Child Neuro

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Somatosensory evoked potentials (SSEPs) are a very sensitive measure of the functional integrity of the neuroaxis, including peripheral and central structures. When used in diagnostic mode they can provide additional information regarding the probable areas of dysfunction. SSEPs were recorded from 44 children (64 feet with congenital talipes equinovarus, CTEV), between the ages of 2 to 15 years, who had structural CTEV deformity previously treated by surgery, with no clinical evidence of neurological deficit. SSEPs were elicited after sequential and bilateral stimulation (0.1 ms/5 Hz/10 to 20 mA) of the posterior tibial nerve and the common peroneal nerve and were recorded cortically (P40). In half the children, additional recordings were conducted at the knee (N5), the first lumbar spinous process (N14), and the seventh cervical spinous process (N20). Eighteen children had abnormal responses, four children had non‐reproducible responses, and 22 children had normal responses. Analysis of the data at different levels of the nervous system showed that eight children had abnormality at the spinal level. The surgical outcome was influenced by the neurological abnormality, with an excellent or good outcome in 34 of 36 feet with normal neurology and 19 of 28 feet where a deficit was present (p<0.05). These findings support the neurological theory as an etiological factor in CTEV deformity.

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Characterizing somatosensory evoked potential sources with dipole models: Advantages and limitations

2001

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Several methods have been developed to investigate the cerebral generators of scalp somatosensory evoked potentials (SEPs), because simple visual inspection of the electroencephalographic signal does not allow for immediate identification of the active brain regions. When the neurons fired by the afferent inputs are closely grouped, as usually occurs in SEP generation, they can be represented as a dipole, that is, as a linear source with two opposite poles. Several techniques for dipolar source modeling, which use different algorithms, have been employed to build source models of early, middle‐latency, and late cognitive SEPs. Modifications of SEP dipolar activities after experimental maneuvers or in pathological conditions have also been observed. Although the effectiveness of dipolar source analysis should not be overestimated due to the intrinsic limitations of the approach, dipole modeling provides a means to assess SEPs in terms of cerebral sources and voltage fields that they produce over the head. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 325–339, 2001

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Selective gating of lower limb cortical somatosensory evoked potentials (SEPs) during passive and active foot movements

Cited by 43 publications

References 37 publications

Effect of movement on dipolar source activities of somatosensory evoked potentials

Effect of movement on dipolar source activities of somatosensory evoked potentials

Somatosensory evoked potentials as a means of assessing neurological abnormality in congenital talipes equinovarus

Characterizing somatosensory evoked potential sources with dipole models: Advantages and limitations

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