Inputs to the swallowing medullary neurons from the peripheral afferent fibers and the swallowing cortical area

Jean, André; A, Car

doi:10.1016/0006-8993(79)90715-7

Cited by 137 publications

(70 citation statements)

References 12 publications

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“…Our observation that the highest stimulation frequencies of the pharynx also produced the greatest facilitation suggests that there may exist, at least for the pharynx, a frequencydependent pattern for afferent feedback. In support of this, animal studies have indicated that the facilitation of reflex swallowing by SLN and glossopharyngeal nerve stimulation is also frequency dependent, with an optimal frequency of 30-50 Hz (Sinclair, 1971;Miller, 1972;Jean & Car, 1979;Weerasuriya, Bieger & Hockman, 1980). Although there was a clear shortening of response latency, repetitive stimulation of the pharynx or oesophagus had no consistent effects on the amplitude of cortically evoked responses.…”

Section: Interaction Between Pathways From Each Hemispherementioning

confidence: 92%

“…As in the latter case, it might be that conditioning with pharyngeal or oesophageal stimuli excited brainstem motoneurones, whilst the motor cortex was inhibited. Direct excitation of brainstem vagal neurones seems likely in view of the strong projections from the pharynx and oesophagus to the CPG of the brainstem (Jean & Car, 1979). The mechanism of a possible cortical inhibition is less obvious.…”

Section: Interaction Between Pathways From Each Hemispherementioning

confidence: 99%

“…that repetitive stimulation of either hemisphere can evoke a swallow, that stimulation of both cerebral hemispheres, simultaneously, can enhance the number of swallows evoked compared with unilateral stimulation (Sumi, 1969), and that concurrent afferent excitation can facilitate swallowing in an intensity-and frequency-dependent manner (Sumi, 1969;Miller, 1972;Beiger & Hockman, 1976;Jean & Car, 1979). We have shown that the cortical pathways to human swallowing musculature can be studied by applying transcranial magneto-electric stimuli to the motor cortex whilst recording the electromyographic (EMG) responses evoked from the oro-pharynx and upper oesophagus (Aziz et al 1994;Hamdy et al 1996).…”

mentioning

confidence: 99%

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Sensorimotor modulation of human cortical swallowing pathways

Hamdy

Aziz

Rothwell

et al. 1998

The Journal of Physiology

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Transcranial magnetic stimulation over motor areas of cerebral cortex in man can activate short latency bilateral cortical projections to the pharynx and oesophagus. In the present paper we investigate the interaction between pathways from each hemisphere and explore how activity in these pathways is modulated by afferent feedback from the face, pharynx and oesophagus. Comparison of unilateral and bilateral stimulation (using interstimulus intervals (ISIs) of 1, 5 or 10 ms between shocks) showed spatial summation of responses from each hemisphere at an ISI of 1 ms, indicating that cortical efferents project onto a shared population of target neurones. Such summation was not evident at ISIs of 5 or 10 ms. There was little evidence for transcallosal inhibition of responses from each hemisphere, as described for limb muscles. Single stimuli applied to the vagus nerve in the neck or the supraorbital nerve, which alone produce intermediate (onset 20‐30 ms) and long (50‐70 ms) latency reflex responses in the pharynx and oesophagus, were used to condition the cortical responses. Compared with rest, responses evoked by cortical stimulation were facilitated when they were timed to coincide with the late part of the reflex. The onset latency was reduced during both parts of the reflex response. No facilitation was observed with subthreshold reflex stimuli. Single electrical stimuli applied to the pharynx or oesophagus had no effect on the response to cortical stimulation. However, trains of stimuli at frequencies varying from 0.2 to 10 Hz decreased the latency of the cortically evoked responses without consistently influencing their amplitudes. The effect was site specific: pharyngeal stimulation shortened both pharyngeal and oesophageal response latencies, whereas oesophageal stimulation shortened only the oesophageal response latencies. Cortical swallowing motor pathways from each hemisphere interact and their excitability is modulated in a site‐specific manner by sensory input. The latter may produce a mixture of excitation and inhibition at both brainstem and cortical levels.

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Section: Interaction Between Pathways From Each Hemispherementioning

confidence: 92%

Section: Interaction Between Pathways From Each Hemispherementioning

confidence: 99%

mentioning

confidence: 99%

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Sensorimotor modulation of human cortical swallowing pathways

Hamdy

Aziz

Rothwell

et al. 1998

The Journal of Physiology

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“…Thus, the problem of dysphagia in patients with WS is important from 2 perspectives. On one hand, some patients do not clinically demonstrate dysphagia and aspiration from the onset of stroke, although the major swallowing centers of the nucleus tractus solitaries (NTS) and nucleus ambiguous (NA) and the reticular formation around them are located in the dorsolateral medulla oblongata [8] [9] (Figure 3 and Figure 4). …”

Section: Discussionmentioning

confidence: 99%

Case Report on Hiccup and Lateral Medullary Syndrome

Ibrahim¹,

Fadhil²,

Ali³

et al. 2015

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The case study is aimed at providing a more thorough analysis of a case of lateral medullary syndrome presented only with persistent hiccup after eating lunch the study hopes to generate an interest for further studies into the topic and focuses on abnormal unusual presentations of lateral medullary syndrome. Ethical committee has approved this case after taking consent from the patient and explaining to him the importance of the case in clinical practice.

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“…Afferents for the swallowing reflex run mainly in the superior laryngeal nerve (SLN). The SLN stimulation activates the NST, which contains neurons involved in the generation of the swallowing motor pattern (Jean and Car, 1979;Kessler and Jean, 1985;Ezure et al, 1993).…”

Section: Introductionmentioning

confidence: 99%