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Assessing Oromotor Capacity in ALS: The Effect of a Fixed-Target Task on Lip Biomechanics

Alternating motion rate (AMR) is a standard measure often included in neurological examinations to assess orofacial neuromuscular integrity. AMR is typically derived from recordings of patients producing repetitions of a single syllable as fast and clear as possible on one breath. Because the task p...

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Autores principales: Eshghi, Marziye, Stipancic, Kaila L., Mefferd, Antje, Rong, Panying, Berry, James D., Yunusova, Yana, Green, Jordan R.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6906194/
https://www.ncbi.nlm.nih.gov/pubmed/31866935
http://dx.doi.org/10.3389/fneur.2019.01288
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author Eshghi, Marziye
Stipancic, Kaila L.
Mefferd, Antje
Rong, Panying
Berry, James D.
Yunusova, Yana
Green, Jordan R.
author_facet Eshghi, Marziye
Stipancic, Kaila L.
Mefferd, Antje
Rong, Panying
Berry, James D.
Yunusova, Yana
Green, Jordan R.
author_sort Eshghi, Marziye
collection PubMed
description Alternating motion rate (AMR) is a standard measure often included in neurological examinations to assess orofacial neuromuscular integrity. AMR is typically derived from recordings of patients producing repetitions of a single syllable as fast and clear as possible on one breath. Because the task places high demands on oromotor performance, particularly articulatory speed, AMRs are widely considered to be tests of maximum performance and, therefore, likely to reveal underlying neurologic deficits. Despite decades of widespread use, biomechanical studies have shown that speakers often circumvent the presumed speed challenge of the standard AMR task. Specifically, speakers are likely to manipulate their displacements (movement amplitude) instead of speed because this strategy requires less motor effort. The current study examined the effectiveness of a novel fixed-target paradigm for minimizing the truncation of articulatory excursions and maximizing motor effort. We compared the standard AMR task to that of a fixed-target AMR task and focused specifically on the tasks' potential to detect decrements in lip motor performance in persons with dysarthria due to amyotrophic lateral sclerosis (ALS). Our participants were 14 healthy controls and 17 individuals with ALS. For the standard AMR task, participants were instructed to produce the syllable /bα/ as quickly and accurately as possible on one breath. For the fixed-target AMR task, participants were given the same instructions, but were also required to strike a physical target placed under the jaw during the opening phase of each syllable. Lip kinematic data were obtained using 3D electromagnetic articulography. 16 kinematic features were extracted using an algorithmic approach. Findings revealed that compared to the standard task, the fixed-target AMR task placed increased motor demands on the oromotor system by eliciting larger excursions, faster speeds, and greater spatiotemporal variability. In addition, participants with ALS exhibited limited ability to adapt to the higher articulatory demands of the fixed-target task. Between the two AMR tasks, the maximum speed during the fixed-target task showed a moderate association with the ALSFRS-R bulbar subscore. Employment of both standard and fixed-target AMR tasks is, however, needed for comprehensive assessment of oromotor function and for elucidating profiles of task adaptation.
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spelling pubmed-69061942019-12-20 Assessing Oromotor Capacity in ALS: The Effect of a Fixed-Target Task on Lip Biomechanics Eshghi, Marziye Stipancic, Kaila L. Mefferd, Antje Rong, Panying Berry, James D. Yunusova, Yana Green, Jordan R. Front Neurol Neurology Alternating motion rate (AMR) is a standard measure often included in neurological examinations to assess orofacial neuromuscular integrity. AMR is typically derived from recordings of patients producing repetitions of a single syllable as fast and clear as possible on one breath. Because the task places high demands on oromotor performance, particularly articulatory speed, AMRs are widely considered to be tests of maximum performance and, therefore, likely to reveal underlying neurologic deficits. Despite decades of widespread use, biomechanical studies have shown that speakers often circumvent the presumed speed challenge of the standard AMR task. Specifically, speakers are likely to manipulate their displacements (movement amplitude) instead of speed because this strategy requires less motor effort. The current study examined the effectiveness of a novel fixed-target paradigm for minimizing the truncation of articulatory excursions and maximizing motor effort. We compared the standard AMR task to that of a fixed-target AMR task and focused specifically on the tasks' potential to detect decrements in lip motor performance in persons with dysarthria due to amyotrophic lateral sclerosis (ALS). Our participants were 14 healthy controls and 17 individuals with ALS. For the standard AMR task, participants were instructed to produce the syllable /bα/ as quickly and accurately as possible on one breath. For the fixed-target AMR task, participants were given the same instructions, but were also required to strike a physical target placed under the jaw during the opening phase of each syllable. Lip kinematic data were obtained using 3D electromagnetic articulography. 16 kinematic features were extracted using an algorithmic approach. Findings revealed that compared to the standard task, the fixed-target AMR task placed increased motor demands on the oromotor system by eliciting larger excursions, faster speeds, and greater spatiotemporal variability. In addition, participants with ALS exhibited limited ability to adapt to the higher articulatory demands of the fixed-target task. Between the two AMR tasks, the maximum speed during the fixed-target task showed a moderate association with the ALSFRS-R bulbar subscore. Employment of both standard and fixed-target AMR tasks is, however, needed for comprehensive assessment of oromotor function and for elucidating profiles of task adaptation. Frontiers Media S.A. 2019-12-05 /pmc/articles/PMC6906194/ /pubmed/31866935 http://dx.doi.org/10.3389/fneur.2019.01288 Text en Copyright © 2019 Eshghi, Stipancic, Mefferd, Rong, Berry, Yunusova and Green. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Neurology
Eshghi, Marziye
Stipancic, Kaila L.
Mefferd, Antje
Rong, Panying
Berry, James D.
Yunusova, Yana
Green, Jordan R.
Assessing Oromotor Capacity in ALS: The Effect of a Fixed-Target Task on Lip Biomechanics
title Assessing Oromotor Capacity in ALS: The Effect of a Fixed-Target Task on Lip Biomechanics
title_full Assessing Oromotor Capacity in ALS: The Effect of a Fixed-Target Task on Lip Biomechanics
title_fullStr Assessing Oromotor Capacity in ALS: The Effect of a Fixed-Target Task on Lip Biomechanics
title_full_unstemmed Assessing Oromotor Capacity in ALS: The Effect of a Fixed-Target Task on Lip Biomechanics
title_short Assessing Oromotor Capacity in ALS: The Effect of a Fixed-Target Task on Lip Biomechanics
title_sort assessing oromotor capacity in als: the effect of a fixed-target task on lip biomechanics
topic Neurology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6906194/
https://www.ncbi.nlm.nih.gov/pubmed/31866935
http://dx.doi.org/10.3389/fneur.2019.01288
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