Brainstem reflex excitability changes in patients with amyotrophic lateral sclerosis

Çengiz, Bülent; Ercan, Merve; İskender, Mustafa; Kuruoğlu, Hidayet Reha

doi:10.1002/mus.25580

Cited by 6 publications

(7 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Using the discharge rate method, we found that the electrical lip stimulation only generates a long-lasting single or compound inhibitory response that is followed by a late, long-lasting excitation in the masseter motor units. These findings have important implications on the redrawing of the neuronal pathways of the trigeminal nerve that are frequently used to judge neuromuscular disorders of the trigeminal region (Cengiz et al 2017;İnan et al 2017). Moreover, it is clinically important to elucidate the nature of the changes in bite force during electrical lip stimulation, because it represents the response of the entire masticatory system to painful intraoral impacts that can occur accidently in everyday life during eating.…”

Section: Discussionmentioning

confidence: 99%

Reevaluation of reflex responses of the human masseter muscle to electrical lip stimulation

Uginčius

Yılmaz

Sebik

et al. 2017

Journal of Neurophysiology

View full text Add to dashboard Cite

We examined the reflex response of the human masseter muscle to electrical stimulation of the lip using both single motor unit and surface electromyogram based methods. Using the classical analysis methods, reflex response to mild electrical stimuli generated two distinct short-lasting inhibitions. This pattern may reflect the development of combinations of short- and long-latency inhibitory postsynaptic potentials as a result of the mildly painful electrical lip stimulation. However, this pattern appearing in the classical analysis methods may have developed as a consequence of earlier responses and may not be genuine. This study examined the genuineness of these responses using both the classical analysis methods and the discharge rate method to uncover the realistic postsynaptic potentials in human trigeminal motor nucleus. Using the discharge rate method, we found that the electrical lip stimulation only generated a long-lasting single or compound inhibitory response that is followed by late, long-lasting excitation. These findings have important implications on the redrawing of the neuronal pathways of the trigeminal nerve that are frequently used to judge neuromuscular disorders of the trigeminal region. We examined the human masseter reflex response to electrical stimulation of lower lip to uncover realistic postsynaptic potentials in the trigeminal motor nucleus. We found that the stimulation generates a long-lasting single or compound inhibitory response that is followed by a late, long-lasting excitation. These findings have important implications on the redrawing of the neuronal pathways of the trigeminal nerve that are frequently used to judge neuromuscular disorders of the trigeminal region.

show abstract

Section: Discussionmentioning

confidence: 99%

Reevaluation of reflex responses of the human masseter muscle to electrical lip stimulation

Uginčius

Yılmaz

Sebik

et al. 2017

Journal of Neurophysiology

View full text Add to dashboard Cite

show abstract

“…In CP, such changes in neuronal excitability can result from direct damage to the brain stem. In other neurological conditions where there is direct damage to the brain stem, as occurs in amyotrophic lateral and multiple sclerosis, there is a decrease in inhibitory masseter reflexes, augmentation of excitatory blink reflexes (Cengiz et al 2017), and a delayed latency of various other brain stem reflexes, including the TCR (Magnano et al 2014). Given that the brain stem in CP can show decreases in mean volume (Kułak and Sobaniec 2007) and fractional anisotropy (Mu et al 2014), alterations in TCR excitability shown in this study may arise from direct damage to brain stem structures.…”

Section: Hyperexcitable Scm Tcrs In Cpmentioning

confidence: 99%

“…Reflexes evoked from trigeminal afferent stimulation (cranial nerve V) have been used to assess brain stem damage in several neurological disorders (Cengiz et al 2017;Di Lazzaro et al 1996;Magnano et al 2014;Serrao et al 2011). In humans, the shortlatency (~13 ms) component of the trigeminocervical reflex (TCR) is thought to have a similar pathway to that in the cat (Manni et al 1975;Nishimura et al 1992) whereby afferents from the trigeminal nerve synapse in the rostral portion of the spinal trigeminal nucleus in the pons (Di Lazzaro et al 1995).…”

Section: Introductionmentioning

confidence: 99%

Hyperexcitability of brain stem pathways in cerebral palsy

Smith

Gorassini

2018

Journal of Neurophysiology

View full text Add to dashboard Cite

Individuals with cerebral palsy (CP) experience impairments in the control of head and neck movements, suggesting dysfunction in brain stem circuitry. To examine if brain stem circuitry is altered in CP, we compared reflexes evoked in the sternocleidomastoid (SCM) muscle by trigeminal nerve stimulation in adults with CP and in age/sex-matched controls. Increasing the intensity of trigeminal nerve stimulation produced progressive increases in the long-latency suppression of ongoing SCM electromyography in controls. In contrast, participants with CP showed progressively increased facilitation around the same reflex window, suggesting heightened excitability of brain stem pathways. We also examined if there was altered activation of cortico-brain stem pathways in response to prenatal injury of the brain. Motor-evoked potentials (MEPs) in the SCM that were conditioned by a prior trigeminal afferent stimulation were more facilitated in CP compared with controls, especially in ipsilateral MEPs that are likely mediated by corticoreticulospinal pathways. In some participants with CP, but not in controls, a combined trigeminal nerve and cortical stimulation near threshold intensities produced large, long-lasting responses in both the SCM and biceps brachii muscles. We propose that the enhanced excitatory responses evoked from trigeminal and cortical inputs in CP are produced by heightened excitability of brain stem circuits, resulting in the augmented activation of reticulospinal pathways. Enhanced activation of reticulospinal pathways in response to early injury of the corticospinal tract may provide a compensated activation of the spinal cord or, alternatively, contribute to impairments in the precise control of head and neck functions. NEW & NOTEWORTHY This is the first study to show that in adults with spastic cerebral palsy, activation of brain stem circuits by cortical and/or trigeminal afferents produces excitatory responses in anterior neck muscles compared with inhibitory responses in age/sex-matched controls. This may reflect a more excitable reticulospinal tract in response to early brain injury to provide a compensated activation of postural muscles. On the other hand, a hyperexcitable brain stem may contribute to impairments in the precise control of head and neck functions.

show abstract

“…In this assessment, stimulation response to mandibular nerves is recorded with EMG of the jaw muscles. Nerve stimulation is known to elicit two periods of muscle silence: first or early component reflecting the shorter oligosynaptic spinal pathway and the second reflecting the longer or long-loop transcortical reflex [4]. Latencies and durations of the silent periods are able to reveal the excitability of the brainstem and the sensorimotor system.…”

mentioning

confidence: 99%

Rhythmic Jaw Movements in Amyotrophic Lateral Sclerosis: Is It Clonus or Tremor?

Kumar,

Blackband,

Wagle Shukla

2024

Tremor and Other Hyperkinetic Movements

View full text Add to dashboard Cite

Background: Jaw clonus refers to involuntary, rhythmic jaw contractions induced by a hyperactive trigeminal nerve stretch reflex; however, the movements, when triggered without a stretch, can be confused with a tremor.Phenomenology Shown: This video demonstrates a patient with amyotrophic lateral sclerosis presenting with rapid rhythmic jaw movements seen at rest, alongside a power spectrum analysis revealing a narrow high-frequency peak of 10 Hz.Educational Value: Rhythmic jaw movements are seen in many disorders such as Parkinson's disease, essential tremor, tardive syndromes, and cranial myorhythmias; however, a high-frequency movement, regardless of clonus or tremor, can indicate amyotrophic lateral sclerosis when accompanied by typical upper and lower motor neuron signs. HighlightsThe presented video abstract shows a patient with amyotrophic lateral sclerosis with rhythmic jaw movements seen at rest. A power spectrum analysis of the rhythmic movements revealed a 10 Hz peak, a frequency higher than those seen in patients with Parkinson's disease, essential tremor, myorhythmia, and tardive syndromes.

show abstract

Brainstem reflex excitability changes in patients with amyotrophic lateral sclerosis

Abstract: Brainstem inhibitory and excitatory interneuronal activity is altered in ALS, possibly brought about by physiological and morphological changes at the cortical or bulbar levels. Muscle Nerve 56: 925-929, 2017.

Cited by 6 publications

References 17 publications

Reevaluation of reflex responses of the human masseter muscle to electrical lip stimulation

Reevaluation of reflex responses of the human masseter muscle to electrical lip stimulation

Hyperexcitability of brain stem pathways in cerebral palsy

Rhythmic Jaw Movements in Amyotrophic Lateral Sclerosis: Is It Clonus or Tremor?

Contact Info

Product

Resources

About