Vibrotactile feedback improves balance and mobility in patients with severe bilateral vestibular loss.

Related Articles

Vibrotactile feedback improves balance and mobility in patients with severe bilateral vestibular loss.

J Neurol. 2018 Dec 05;:

Authors: Kingma H, Felipe L, Gerards MC, Gerits P, Guinand N, Perez-Fornos A, Demkin V, van de Berg R

Abstract
The impact of vibrotactile feedback of the gravity vector, provided by a "balance" belt worn around the waist, was evaluated in 39 patients with a severe bilateral vestibular loss, confirmed by extensive laboratory testing and suffering from a low quality of life, mainly due to imbalance. The mobility and balance score (MBS) of all patients prior to the use of the belt was equal or less than 5 out of a scale of 10. Thirty-one out of the 39 patients experienced the effect of the belt on their balance and mobility as positive in a preselection trial of 2 h in the hospital. The 31 positive responders then used the belt for 1 month in daily life. The average MBS increased significantly from 4.2 to 7.9 (paired T test, T = 9.82, p < 0.00001). Twenty-three out of 31 patients reported a benefit ranging from an improvement of 60-200% in their MBS. Eight patients did not experience any benefit. In summary, 23 out of 39 patients with a severe imbalance due to a bilateral vestibular loss experienced a clear benefit of vibrotactile feed = back in daily life. We conclude that vibrotactile feedback via the waist can serve as an effective prothesis for patients with severe bilateral vestibular loss to improve the quality of life.

PMID: 30519776 [PubMed - as supplied by publisher]

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Therapeutic potential of the mitochondria-targeted antioxidant MitoQ in mitochondrial-ROS induced sensorineural hearing loss caused by Idh2 deficiency.

Related Articles

Therapeutic potential of the mitochondria-targeted antioxidant MitoQ in mitochondrial-ROS induced sensorineural hearing loss caused by Idh2 deficiency.

Redox Biol. 2018 Nov 20;20:544-555

Authors: Kim YR, Baek JI, Kim SH, Kim MA, Lee B, Ryu N, Kim KH, Choi DG, Kim HM, Murphy MP, Macpherson G, Choo YS, Bok J, Lee KY, Park JW, Kim UK

Abstract
Mitochondrial NADP+-dependent isocitrate dehydrogenase 2 (IDH2) is a major NADPH-producing enzyme which is essential for maintaining the mitochondrial redox balance in cells. We sought to determine whether IDH2 deficiency induces mitochondrial dysfunction and modulates auditory function, and investigated the protective potential of an antioxidant agent against reactive oxygen species (ROS)-induced cochlear damage in Idh2 knockout (Idh2-/-) mice. Idh2 deficiency leads to damages to hair cells and spiral ganglion neurons (SGNs) in the cochlea and ultimately to apoptotic cell death and progressive sensorineural hearing loss in Idh2-/- mice. Loss of IDH2 activity led to decreased levels of NADPH and glutathione causing abnormal ROS accumulation and oxidative damage, which might trigger apoptosis signal in hair cells and SGNs in Idh2-/- mice. We performed ex vivo experiments to determine whether administration of mitochondria-targeted antioxidants might protect or induce recovery of cells from ROS-induced apoptosis in Idh2-deficient mouse cochlea. MitoQ almost completely neutralized the H2O2-induced ototoxicity, as the survival rate of Idh2-/- hair cells were restored to normal levels. In addition, the lack of IDH2 led to the accumulation of mitochondrial ROS and the depolarization of ΔΨm, resulting in hair cell loss. In the present study, we identified that IDH2 is indispensable for the functional maintenance and survival of hair cells and SGNs. Moreover, the hair cell degeneration caused by IDH2 deficiency can be prevented by MitoQ, which suggests that Idh2-/- mice could be a valuable animal model for evaluating the therapeutic effects of various antioxidant candidates to overcome ROS-induced hearing loss.

PMID: 30508699 [PubMed - as supplied by publisher]

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Cannabinoid drugs: will they relieve or exacerbate tinnitus?

Related Articles

Cannabinoid drugs: will they relieve or exacerbate tinnitus?

Curr Opin Neurol. 2018 Nov 29;:

Authors: Zheng Y, Smith PF

Abstract
PURPOSE OF REVIEW: Recent enthusiasm for cannabinoid drugs for the treatment of chronic pain and some forms of epilepsy, raises the question of whether they could be useful for other disorders associated with abnormal neuronal activity in the brain, such as subjective tinnitus. Indeed, there is evidence to indicate that some tinnitus sufferers self-medicate using Cannabis. The aim of this review is to critically evaluate the available evidence relating to the effects of cannabinoids on tinnitus.
RECENT FINDINGS: Despite the fact that cannabinoids have been shown to decrease neuronal hyperactivity in many parts of the brain, the current evidence suggests that in auditory brain regions such as the dorsal cochlear nucleus, they have the potential to facilitate neuronal hyperactivity and exacerbate tinnitus. All of the available experimental evidence from animal studies suggests that cannabinoid CB1 receptor agonists will either have no effect on tinnitus or will worsen it.
SUMMARY: In our opinion, the use of the available cannabinoid drugs to alleviate tinnitus, based on their alleged efficacy for neuropathic pain conditions and some forms of epilepsy, is premature and not supported by the available evidence.

PMID: 30507635 [PubMed - as supplied by publisher]

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Effect of Rotating Auditory Scene on Postural Control in Normal Subjects, Patients With Bilateral Vestibulopathy, Unilateral, or Bilateral Cochlear Implants.

Related Articles

Effect of Rotating Auditory Scene on Postural Control in Normal Subjects, Patients With Bilateral Vestibulopathy, Unilateral, or Bilateral Cochlear Implants.

Front Neurol. 2018;9:972

Authors: Guigou C, Toupet M, Delemps B, Heuschen S, Aho S, Bozorg Grayeli A

Abstract
Objective: The aim of this study was to investigate the impact of a rotating sound stimulation on the postural performances in normal subjects, patients with bilateral vestibulopathy (BVP), unilateral (UCI), and bilateral (BCI) cochlear implantees. Materials and Methods: Sixty-nine adults were included (32 women and 37 men) in a multicenter prospective study. The group included 37 healthy subjects, 10 BVP, 15 UCI, and 7 BCI patients. The average of age was 47 ± 2.0 (range: 23-82). In addition to a complete audiovestibular work up, a dynamic posturography (Multitest Framiral, Grasse) was conducted in silence and with a rotating cocktail party sound delivered by headphone. The center of pressure excursion surface (COPS), sensory preferences, as well as fractal, diffusion, and wavelet analysis of stabilometry were collected. Results: The rotating sound seemed to influenced balance in all subgroups except in controls. COPS increased with sound in the BVP and BCI groups in closed eyes and sway-referenced condition indicating a destabilizing effect while it decreased in UCI in the same condition suggesting stabilization (p < 0.05, linear mixed model corrected for age, n = 69). BVP had higher proprioceptive preferences, BCI had higher vestibular and visual preferences, and UCI had only higher vestibular preferences than controls. Sensory preferences were not altered by rotating sound. Conclusions: The rotating sound destabilized BVP and BCI patients with binaural hearing while it stabilized UCI patients with monaural hearing and no sound rotation effect. This difference suggests that binaural auditory cues are exploited in BCI patients for their balance.

PMID: 30505289 [PubMed]

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Spatial and temporal inhibition of FGFR2b ligands reveals continuous requirements and novel targets in mouse inner ear morphogenesis.

Related Articles

Spatial and temporal inhibition of FGFR2b ligands reveals continuous requirements and novel targets in mouse inner ear morphogenesis.

Development. 2018 Nov 30;:

Authors: Urness LD, Wang X, Doan H, Shumway N, Noyes CA, Gutierrez-Magana E, Lu R, Mansour SL

Abstract
Morphogenesis of the inner ear epithelium requires coordinated deployment of several signaling pathways, and disruptions cause abnormalities of hearing and/or balance. The FGFR2b ligands, FGF3 and FGF10, are expressed throughout otic development and are required individually for normal morphogenesis, but their prior and redundant roles in otic placode induction complicates investigation of subsequent combinatorial functions in morphogenesis. To interrogate these roles and identify new effectors of FGF3 and FGF10 signaling at the earliest stages of otic morphogenesis, we used conditional gene ablation after otic placode induction, and temporal inhibition of signaling with a secreted, dominant-negative FGFR2b ectodomain. We show that both ligands are required continuously after otocyst formation for maintenance of otic neuroblasts and for patterning and proliferation of the epithelium, leading to normal morphogenesis of both the cochlear and vestibular domains. Furthermore, the first genomewide identification of proximal targets of FGFR2b signaling in the early otocyst reveals novel candidate genes for inner ear development and function.

PMID: 30504125 [PubMed - as supplied by publisher]

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Control Mechanisms of Static and Dynamic Balance in Adults With and Without Vestibular Dysfunction in Oculus Virtual Environments.

Related Articles

Control Mechanisms of Static and Dynamic Balance in Adults With and Without Vestibular Dysfunction in Oculus Virtual Environments.

PM R. 2018 Nov;10(11):1223-1236.e2

Authors: Lubetzky AV, Hujsak BD, Kelly JL, Fu G, Perlin K

Abstract
BACKGROUND: Deficits in sensory integration and fear of falling in complex environments contribute to decreased participation of adults with vestibular disorders. With recent advances in virtual reality technology, head-mounted displays are affordable and allow manipulation of the environment to test postural responses to visual changes.
OBJECTIVES: To develop an assessment of static and dynamic balance with the Oculus Rift and (1) to assess test-retest reliability of each scene in adults with and without vestibular hypofunction; (2) to describe changes in directional path and sample entropy in response to changes in visuals and surface and compare between groups; and (3) to evaluate the relation between balance performance and self-reported disability and balance confidence.
DESIGN: Test-retest, blocked-randomized experimental design.
SETTING: Research laboratory.
PARTICIPANTS: Twenty-five adults with vestibular hypofunction and 16 age- and sex-matched adults.
METHODS: Participants stood on the floor or stability trainers while wearing the Oculus Rift. For 3 moving "stars" scenes, they stood naturally. For a "park" scene, they were asked to avoid a virtual ball. The protocol was repeated 1-4 weeks later.
OUTCOME: Anteroposterior and mediolateral center-of-pressure directional path and sample entropy were derived from a force plate.
RESULTS: We observed good to excellent reliability in the 2 groups, with most intraclass correlations above 0.8 and only 2 at approximately 0.4. The vestibular group had higher directional path for the stars scenes and lower directional path for the park scene compared with controls, with large variability in the 2 groups. Sample entropy decreased with more challenging environments. In the vestibular group, less balance confidence strongly correlated with more sway for the stars scenes and less sway for the park scene.
CONCLUSION: Virtual reality paradigms can shed light on the control mechanism of static and dynamic postural control. Clinical utility and implementation of our portable Oculus Rift assessment should be further studied.
LEVEL OF EVIDENCE: II.

PMID: 30503230 [PubMed - in process]

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Vibrotactile feedback improves balance and mobility in patients with severe bilateral vestibular loss.

Related Articles

Vibrotactile feedback improves balance and mobility in patients with severe bilateral vestibular loss.

J Neurol. 2018 Dec 05;:

Authors: Kingma H, Felipe L, Gerards MC, Gerits P, Guinand N, Perez-Fornos A, Demkin V, van de Berg R

Abstract
The impact of vibrotactile feedback of the gravity vector, provided by a "balance" belt worn around the waist, was evaluated in 39 patients with a severe bilateral vestibular loss, confirmed by extensive laboratory testing and suffering from a low quality of life, mainly due to imbalance. The mobility and balance score (MBS) of all patients prior to the use of the belt was equal or less than 5 out of a scale of 10. Thirty-one out of the 39 patients experienced the effect of the belt on their balance and mobility as positive in a preselection trial of 2 h in the hospital. The 31 positive responders then used the belt for 1 month in daily life. The average MBS increased significantly from 4.2 to 7.9 (paired T test, T = 9.82, p < 0.00001). Twenty-three out of 31 patients reported a benefit ranging from an improvement of 60-200% in their MBS. Eight patients did not experience any benefit. In summary, 23 out of 39 patients with a severe imbalance due to a bilateral vestibular loss experienced a clear benefit of vibrotactile feed = back in daily life. We conclude that vibrotactile feedback via the waist can serve as an effective prothesis for patients with severe bilateral vestibular loss to improve the quality of life.

PMID: 30519776 [PubMed - as supplied by publisher]

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Therapeutic potential of the mitochondria-targeted antioxidant MitoQ in mitochondrial-ROS induced sensorineural hearing loss caused by Idh2 deficiency.

Related Articles

Therapeutic potential of the mitochondria-targeted antioxidant MitoQ in mitochondrial-ROS induced sensorineural hearing loss caused by Idh2 deficiency.

Redox Biol. 2018 Nov 20;20:544-555

Authors: Kim YR, Baek JI, Kim SH, Kim MA, Lee B, Ryu N, Kim KH, Choi DG, Kim HM, Murphy MP, Macpherson G, Choo YS, Bok J, Lee KY, Park JW, Kim UK

Abstract
Mitochondrial NADP+-dependent isocitrate dehydrogenase 2 (IDH2) is a major NADPH-producing enzyme which is essential for maintaining the mitochondrial redox balance in cells. We sought to determine whether IDH2 deficiency induces mitochondrial dysfunction and modulates auditory function, and investigated the protective potential of an antioxidant agent against reactive oxygen species (ROS)-induced cochlear damage in Idh2 knockout (Idh2-/-) mice. Idh2 deficiency leads to damages to hair cells and spiral ganglion neurons (SGNs) in the cochlea and ultimately to apoptotic cell death and progressive sensorineural hearing loss in Idh2-/- mice. Loss of IDH2 activity led to decreased levels of NADPH and glutathione causing abnormal ROS accumulation and oxidative damage, which might trigger apoptosis signal in hair cells and SGNs in Idh2-/- mice. We performed ex vivo experiments to determine whether administration of mitochondria-targeted antioxidants might protect or induce recovery of cells from ROS-induced apoptosis in Idh2-deficient mouse cochlea. MitoQ almost completely neutralized the H2O2-induced ototoxicity, as the survival rate of Idh2-/- hair cells were restored to normal levels. In addition, the lack of IDH2 led to the accumulation of mitochondrial ROS and the depolarization of ΔΨm, resulting in hair cell loss. In the present study, we identified that IDH2 is indispensable for the functional maintenance and survival of hair cells and SGNs. Moreover, the hair cell degeneration caused by IDH2 deficiency can be prevented by MitoQ, which suggests that Idh2-/- mice could be a valuable animal model for evaluating the therapeutic effects of various antioxidant candidates to overcome ROS-induced hearing loss.

PMID: 30508699 [PubMed - as supplied by publisher]

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via IFTTT

Cannabinoid drugs: will they relieve or exacerbate tinnitus?

Related Articles

Cannabinoid drugs: will they relieve or exacerbate tinnitus?

Curr Opin Neurol. 2018 Nov 29;:

Authors: Zheng Y, Smith PF

Abstract
PURPOSE OF REVIEW: Recent enthusiasm for cannabinoid drugs for the treatment of chronic pain and some forms of epilepsy, raises the question of whether they could be useful for other disorders associated with abnormal neuronal activity in the brain, such as subjective tinnitus. Indeed, there is evidence to indicate that some tinnitus sufferers self-medicate using Cannabis. The aim of this review is to critically evaluate the available evidence relating to the effects of cannabinoids on tinnitus.
RECENT FINDINGS: Despite the fact that cannabinoids have been shown to decrease neuronal hyperactivity in many parts of the brain, the current evidence suggests that in auditory brain regions such as the dorsal cochlear nucleus, they have the potential to facilitate neuronal hyperactivity and exacerbate tinnitus. All of the available experimental evidence from animal studies suggests that cannabinoid CB1 receptor agonists will either have no effect on tinnitus or will worsen it.
SUMMARY: In our opinion, the use of the available cannabinoid drugs to alleviate tinnitus, based on their alleged efficacy for neuropathic pain conditions and some forms of epilepsy, is premature and not supported by the available evidence.

PMID: 30507635 [PubMed - as supplied by publisher]

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via IFTTT

Effect of Rotating Auditory Scene on Postural Control in Normal Subjects, Patients With Bilateral Vestibulopathy, Unilateral, or Bilateral Cochlear Implants.

Related Articles

Effect of Rotating Auditory Scene on Postural Control in Normal Subjects, Patients With Bilateral Vestibulopathy, Unilateral, or Bilateral Cochlear Implants.

Front Neurol. 2018;9:972

Authors: Guigou C, Toupet M, Delemps B, Heuschen S, Aho S, Bozorg Grayeli A

Abstract
Objective: The aim of this study was to investigate the impact of a rotating sound stimulation on the postural performances in normal subjects, patients with bilateral vestibulopathy (BVP), unilateral (UCI), and bilateral (BCI) cochlear implantees. Materials and Methods: Sixty-nine adults were included (32 women and 37 men) in a multicenter prospective study. The group included 37 healthy subjects, 10 BVP, 15 UCI, and 7 BCI patients. The average of age was 47 ± 2.0 (range: 23-82). In addition to a complete audiovestibular work up, a dynamic posturography (Multitest Framiral, Grasse) was conducted in silence and with a rotating cocktail party sound delivered by headphone. The center of pressure excursion surface (COPS), sensory preferences, as well as fractal, diffusion, and wavelet analysis of stabilometry were collected. Results: The rotating sound seemed to influenced balance in all subgroups except in controls. COPS increased with sound in the BVP and BCI groups in closed eyes and sway-referenced condition indicating a destabilizing effect while it decreased in UCI in the same condition suggesting stabilization (p < 0.05, linear mixed model corrected for age, n = 69). BVP had higher proprioceptive preferences, BCI had higher vestibular and visual preferences, and UCI had only higher vestibular preferences than controls. Sensory preferences were not altered by rotating sound. Conclusions: The rotating sound destabilized BVP and BCI patients with binaural hearing while it stabilized UCI patients with monaural hearing and no sound rotation effect. This difference suggests that binaural auditory cues are exploited in BCI patients for their balance.

PMID: 30505289 [PubMed]

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via IFTTT

Spatial and temporal inhibition of FGFR2b ligands reveals continuous requirements and novel targets in mouse inner ear morphogenesis.

Related Articles

Spatial and temporal inhibition of FGFR2b ligands reveals continuous requirements and novel targets in mouse inner ear morphogenesis.

Development. 2018 Nov 30;:

Authors: Urness LD, Wang X, Doan H, Shumway N, Noyes CA, Gutierrez-Magana E, Lu R, Mansour SL

Abstract
Morphogenesis of the inner ear epithelium requires coordinated deployment of several signaling pathways, and disruptions cause abnormalities of hearing and/or balance. The FGFR2b ligands, FGF3 and FGF10, are expressed throughout otic development and are required individually for normal morphogenesis, but their prior and redundant roles in otic placode induction complicates investigation of subsequent combinatorial functions in morphogenesis. To interrogate these roles and identify new effectors of FGF3 and FGF10 signaling at the earliest stages of otic morphogenesis, we used conditional gene ablation after otic placode induction, and temporal inhibition of signaling with a secreted, dominant-negative FGFR2b ectodomain. We show that both ligands are required continuously after otocyst formation for maintenance of otic neuroblasts and for patterning and proliferation of the epithelium, leading to normal morphogenesis of both the cochlear and vestibular domains. Furthermore, the first genomewide identification of proximal targets of FGFR2b signaling in the early otocyst reveals novel candidate genes for inner ear development and function.

PMID: 30504125 [PubMed - as supplied by publisher]

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via IFTTT

Control Mechanisms of Static and Dynamic Balance in Adults With and Without Vestibular Dysfunction in Oculus Virtual Environments.

Related Articles

Control Mechanisms of Static and Dynamic Balance in Adults With and Without Vestibular Dysfunction in Oculus Virtual Environments.

PM R. 2018 Nov;10(11):1223-1236.e2

Authors: Lubetzky AV, Hujsak BD, Kelly JL, Fu G, Perlin K

Abstract
BACKGROUND: Deficits in sensory integration and fear of falling in complex environments contribute to decreased participation of adults with vestibular disorders. With recent advances in virtual reality technology, head-mounted displays are affordable and allow manipulation of the environment to test postural responses to visual changes.
OBJECTIVES: To develop an assessment of static and dynamic balance with the Oculus Rift and (1) to assess test-retest reliability of each scene in adults with and without vestibular hypofunction; (2) to describe changes in directional path and sample entropy in response to changes in visuals and surface and compare between groups; and (3) to evaluate the relation between balance performance and self-reported disability and balance confidence.
DESIGN: Test-retest, blocked-randomized experimental design.
SETTING: Research laboratory.
PARTICIPANTS: Twenty-five adults with vestibular hypofunction and 16 age- and sex-matched adults.
METHODS: Participants stood on the floor or stability trainers while wearing the Oculus Rift. For 3 moving "stars" scenes, they stood naturally. For a "park" scene, they were asked to avoid a virtual ball. The protocol was repeated 1-4 weeks later.
OUTCOME: Anteroposterior and mediolateral center-of-pressure directional path and sample entropy were derived from a force plate.
RESULTS: We observed good to excellent reliability in the 2 groups, with most intraclass correlations above 0.8 and only 2 at approximately 0.4. The vestibular group had higher directional path for the stars scenes and lower directional path for the park scene compared with controls, with large variability in the 2 groups. Sample entropy decreased with more challenging environments. In the vestibular group, less balance confidence strongly correlated with more sway for the stars scenes and less sway for the park scene.
CONCLUSION: Virtual reality paradigms can shed light on the control mechanism of static and dynamic postural control. Clinical utility and implementation of our portable Oculus Rift assessment should be further studied.
LEVEL OF EVIDENCE: II.

PMID: 30503230 [PubMed - in process]

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Electrophysiological and behavioral measures of some speech contrasts in varied attention and noise

Publication date: Available online 6 December 2018

Source: Hearing Research

Author(s): David Jackson Morris, John Tøndering, Magnus Lindgren

Abstract

This paper investigates the salience of speech contrasts in noise, in relation to how listening attention affects scalp-recorded cortical responses. The contrasts that were examined with consonant-vowel syllables, were place of articulation, vowel length and voice-onset time (VOT) and our analysis focuses on the correspondence between the effect of attention on the electrophysiology and the decrement in behavioral results when noise was added to the stimuli. Normal-hearing subjects (n=20) performed closed-set syllable identification in no noise, 0, 4 and 8 dB signal-noise ratio (SNR). Identification in noise decreased markedly for place of articulation, moderately for vowel length and marginally for VOT. The same syllables were used in two electrophysiology conditions, where subjects attended to the stimuli, and also while their attention was diverted to a visual discrimination task. Differences in global field power between the attention conditions from each contrast showed that that the effect of attention was negligible for place of articulation. They implied offset encoding of vowel length and were early (starting at 117 ms), and of high amplitude (>3 μV) for VOT. There were significant correlations between the difference in syllable identification in no noise and 0 dB SNR and the electrophysiology results between attention conditions for the VOT contrast. Comparison of the two attention conditions with microstate analysis showed a significant difference in the duration of microstate class D. These results show differential integration of attention and syllable processing according to speech contrast and they suggest that there is correspondence between the salience of a contrast in noise and the effect of attention on the evoked electrical response.

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p27Kip1 down-regulation as achieved by two clinically feasible means did not induce proliferation of supporting cells in the rat neonatal cochlea in vivo

Publication date: Available online 6 December 2018

Source: Hearing Research

Author(s): Sebastián A. Silva, Juan C. Maass

Abstract

In mammals, the cochlear sensory epithelium becomes quiescent early during development. After the first postnatal week, there is no cell replacement or proliferation, and severe damage leads to permanent deafness. Supporting cells’ trans-differentiation has been suggested as a way to regenerate cochlear hair cells after damage. However, they are also needed for proper functionality. Cdkn1b (p27^Kip1) participates in the cochlear terminal mitosis state achieved during development. Its expression is maintained in adult supporting cells and its postnatal deletion has induced cochlear proliferation in vitro and in vivo. Therefore, its manipulation has been proposed as a feasible way to induce proliferation of supporting cells after birth. Nevertheless, the literature is scarce regarding feasible methods to directly decrease p27^Kip1 in the clinical domain. The effects of p27^Kip1 knockdown using viral vectors are not completely elucidated and no pharmacological approaches to decrease p27^Kip1 in the cochlea have been tested in vivo before. This study explores the ability of p27^Kip1 messenger knockdown and pharmacological transcriptional inhibition to induce proliferation of supporting cells in the P0 neonatal rat cochlea in vivo. Respectively, lentiviral vectors transducing shRNA against p27^Kip1 were administered into the scala media or Alsterpaullone 2-Cyanoethyl into the round window niche. Cell markers and gene expression were assessed through immunostaining and qRT-PCR. Despite both methods significantly decreasing p27^Kip1 expression in vivo, signs of toxicity in the organ of Corti were not found; however, relevant proliferation was not found either. Finally, cochlear damage was added to increase the response in vitro, achieving only a mild to moderate proliferation induction. We conclude that our approaches were not able to stimulate the recall of supporting cell proliferation despite significantly decreased p27^Kip1 levels in vivo. Considering the evaluation of the cochlea at a very responsive stage, we propose that the level of isolated modification of p27^Kip1 expression in living mammals achievable through these approaches is insufficient to induce proliferation of supporting cells. Future proliferation induction experiments in the cochlea should study other methods and genes.

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Electrophysiological and behavioral measures of some speech contrasts in varied attention and noise

Publication date: Available online 6 December 2018

Source: Hearing Research

Author(s): David Jackson Morris, John Tøndering, Magnus Lindgren

Abstract

This paper investigates the salience of speech contrasts in noise, in relation to how listening attention affects scalp-recorded cortical responses. The contrasts that were examined with consonant-vowel syllables, were place of articulation, vowel length and voice-onset time (VOT) and our analysis focuses on the correspondence between the effect of attention on the electrophysiology and the decrement in behavioral results when noise was added to the stimuli. Normal-hearing subjects (n=20) performed closed-set syllable identification in no noise, 0, 4 and 8 dB signal-noise ratio (SNR). Identification in noise decreased markedly for place of articulation, moderately for vowel length and marginally for VOT. The same syllables were used in two electrophysiology conditions, where subjects attended to the stimuli, and also while their attention was diverted to a visual discrimination task. Differences in global field power between the attention conditions from each contrast showed that that the effect of attention was negligible for place of articulation. They implied offset encoding of vowel length and were early (starting at 117 ms), and of high amplitude (>3 μV) for VOT. There were significant correlations between the difference in syllable identification in no noise and 0 dB SNR and the electrophysiology results between attention conditions for the VOT contrast. Comparison of the two attention conditions with microstate analysis showed a significant difference in the duration of microstate class D. These results show differential integration of attention and syllable processing according to speech contrast and they suggest that there is correspondence between the salience of a contrast in noise and the effect of attention on the evoked electrical response.

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p27Kip1 down-regulation as achieved by two clinically feasible means did not induce proliferation of supporting cells in the rat neonatal cochlea in vivo

Publication date: Available online 6 December 2018

Source: Hearing Research

Author(s): Sebastián A. Silva, Juan C. Maass

Abstract

In mammals, the cochlear sensory epithelium becomes quiescent early during development. After the first postnatal week, there is no cell replacement or proliferation, and severe damage leads to permanent deafness. Supporting cells’ trans-differentiation has been suggested as a way to regenerate cochlear hair cells after damage. However, they are also needed for proper functionality. Cdkn1b (p27^Kip1) participates in the cochlear terminal mitosis state achieved during development. Its expression is maintained in adult supporting cells and its postnatal deletion has induced cochlear proliferation in vitro and in vivo. Therefore, its manipulation has been proposed as a feasible way to induce proliferation of supporting cells after birth. Nevertheless, the literature is scarce regarding feasible methods to directly decrease p27^Kip1 in the clinical domain. The effects of p27^Kip1 knockdown using viral vectors are not completely elucidated and no pharmacological approaches to decrease p27^Kip1 in the cochlea have been tested in vivo before. This study explores the ability of p27^Kip1 messenger knockdown and pharmacological transcriptional inhibition to induce proliferation of supporting cells in the P0 neonatal rat cochlea in vivo. Respectively, lentiviral vectors transducing shRNA against p27^Kip1 were administered into the scala media or Alsterpaullone 2-Cyanoethyl into the round window niche. Cell markers and gene expression were assessed through immunostaining and qRT-PCR. Despite both methods significantly decreasing p27^Kip1 expression in vivo, signs of toxicity in the organ of Corti were not found; however, relevant proliferation was not found either. Finally, cochlear damage was added to increase the response in vitro, achieving only a mild to moderate proliferation induction. We conclude that our approaches were not able to stimulate the recall of supporting cell proliferation despite significantly decreased p27^Kip1 levels in vivo. Considering the evaluation of the cochlea at a very responsive stage, we propose that the level of isolated modification of p27^Kip1 expression in living mammals achievable through these approaches is insufficient to induce proliferation of supporting cells. Future proliferation induction experiments in the cochlea should study other methods and genes.

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via IFTTT

Electrophysiological and behavioral measures of some speech contrasts in varied attention and noise

Publication date: Available online 6 December 2018

Source: Hearing Research

Author(s): David Jackson Morris, John Tøndering, Magnus Lindgren

Abstract

This paper investigates the salience of speech contrasts in noise, in relation to how listening attention affects scalp-recorded cortical responses. The contrasts that were examined with consonant-vowel syllables, were place of articulation, vowel length and voice-onset time (VOT) and our analysis focuses on the correspondence between the effect of attention on the electrophysiology and the decrement in behavioral results when noise was added to the stimuli. Normal-hearing subjects (n=20) performed closed-set syllable identification in no noise, 0, 4 and 8 dB signal-noise ratio (SNR). Identification in noise decreased markedly for place of articulation, moderately for vowel length and marginally for VOT. The same syllables were used in two electrophysiology conditions, where subjects attended to the stimuli, and also while their attention was diverted to a visual discrimination task. Differences in global field power between the attention conditions from each contrast showed that that the effect of attention was negligible for place of articulation. They implied offset encoding of vowel length and were early (starting at 117 ms), and of high amplitude (>3 μV) for VOT. There were significant correlations between the difference in syllable identification in no noise and 0 dB SNR and the electrophysiology results between attention conditions for the VOT contrast. Comparison of the two attention conditions with microstate analysis showed a significant difference in the duration of microstate class D. These results show differential integration of attention and syllable processing according to speech contrast and they suggest that there is correspondence between the salience of a contrast in noise and the effect of attention on the evoked electrical response.

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via IFTTT

p27Kip1 down-regulation as achieved by two clinically feasible means did not induce proliferation of supporting cells in the rat neonatal cochlea in vivo

Publication date: Available online 6 December 2018

Source: Hearing Research

Author(s): Sebastián A. Silva, Juan C. Maass

Abstract

In mammals, the cochlear sensory epithelium becomes quiescent early during development. After the first postnatal week, there is no cell replacement or proliferation, and severe damage leads to permanent deafness. Supporting cells’ trans-differentiation has been suggested as a way to regenerate cochlear hair cells after damage. However, they are also needed for proper functionality. Cdkn1b (p27^Kip1) participates in the cochlear terminal mitosis state achieved during development. Its expression is maintained in adult supporting cells and its postnatal deletion has induced cochlear proliferation in vitro and in vivo. Therefore, its manipulation has been proposed as a feasible way to induce proliferation of supporting cells after birth. Nevertheless, the literature is scarce regarding feasible methods to directly decrease p27^Kip1 in the clinical domain. The effects of p27^Kip1 knockdown using viral vectors are not completely elucidated and no pharmacological approaches to decrease p27^Kip1 in the cochlea have been tested in vivo before. This study explores the ability of p27^Kip1 messenger knockdown and pharmacological transcriptional inhibition to induce proliferation of supporting cells in the P0 neonatal rat cochlea in vivo. Respectively, lentiviral vectors transducing shRNA against p27^Kip1 were administered into the scala media or Alsterpaullone 2-Cyanoethyl into the round window niche. Cell markers and gene expression were assessed through immunostaining and qRT-PCR. Despite both methods significantly decreasing p27^Kip1 expression in vivo, signs of toxicity in the organ of Corti were not found; however, relevant proliferation was not found either. Finally, cochlear damage was added to increase the response in vitro, achieving only a mild to moderate proliferation induction. We conclude that our approaches were not able to stimulate the recall of supporting cell proliferation despite significantly decreased p27^Kip1 levels in vivo. Considering the evaluation of the cochlea at a very responsive stage, we propose that the level of isolated modification of p27^Kip1 expression in living mammals achievable through these approaches is insufficient to induce proliferation of supporting cells. Future proliferation induction experiments in the cochlea should study other methods and genes.

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Electrophysiological and behavioral measures of some speech contrasts in varied attention and noise

Publication date: Available online 6 December 2018

Source: Hearing Research

Author(s): David Jackson Morris, John Tøndering, Magnus Lindgren

Abstract

This paper investigates the salience of speech contrasts in noise, in relation to how listening attention affects scalp-recorded cortical responses. The contrasts that were examined with consonant-vowel syllables, were place of articulation, vowel length and voice-onset time (VOT) and our analysis focuses on the correspondence between the effect of attention on the electrophysiology and the decrement in behavioral results when noise was added to the stimuli. Normal-hearing subjects (n=20) performed closed-set syllable identification in no noise, 0, 4 and 8 dB signal-noise ratio (SNR). Identification in noise decreased markedly for place of articulation, moderately for vowel length and marginally for VOT. The same syllables were used in two electrophysiology conditions, where subjects attended to the stimuli, and also while their attention was diverted to a visual discrimination task. Differences in global field power between the attention conditions from each contrast showed that that the effect of attention was negligible for place of articulation. They implied offset encoding of vowel length and were early (starting at 117 ms), and of high amplitude (>3 μV) for VOT. There were significant correlations between the difference in syllable identification in no noise and 0 dB SNR and the electrophysiology results between attention conditions for the VOT contrast. Comparison of the two attention conditions with microstate analysis showed a significant difference in the duration of microstate class D. These results show differential integration of attention and syllable processing according to speech contrast and they suggest that there is correspondence between the salience of a contrast in noise and the effect of attention on the evoked electrical response.

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p27Kip1 down-regulation as achieved by two clinically feasible means did not induce proliferation of supporting cells in the rat neonatal cochlea in vivo

Publication date: Available online 6 December 2018

Source: Hearing Research

Author(s): Sebastián A. Silva, Juan C. Maass

Abstract

In mammals, the cochlear sensory epithelium becomes quiescent early during development. After the first postnatal week, there is no cell replacement or proliferation, and severe damage leads to permanent deafness. Supporting cells’ trans-differentiation has been suggested as a way to regenerate cochlear hair cells after damage. However, they are also needed for proper functionality. Cdkn1b (p27^Kip1) participates in the cochlear terminal mitosis state achieved during development. Its expression is maintained in adult supporting cells and its postnatal deletion has induced cochlear proliferation in vitro and in vivo. Therefore, its manipulation has been proposed as a feasible way to induce proliferation of supporting cells after birth. Nevertheless, the literature is scarce regarding feasible methods to directly decrease p27^Kip1 in the clinical domain. The effects of p27^Kip1 knockdown using viral vectors are not completely elucidated and no pharmacological approaches to decrease p27^Kip1 in the cochlea have been tested in vivo before. This study explores the ability of p27^Kip1 messenger knockdown and pharmacological transcriptional inhibition to induce proliferation of supporting cells in the P0 neonatal rat cochlea in vivo. Respectively, lentiviral vectors transducing shRNA against p27^Kip1 were administered into the scala media or Alsterpaullone 2-Cyanoethyl into the round window niche. Cell markers and gene expression were assessed through immunostaining and qRT-PCR. Despite both methods significantly decreasing p27^Kip1 expression in vivo, signs of toxicity in the organ of Corti were not found; however, relevant proliferation was not found either. Finally, cochlear damage was added to increase the response in vitro, achieving only a mild to moderate proliferation induction. We conclude that our approaches were not able to stimulate the recall of supporting cell proliferation despite significantly decreased p27^Kip1 levels in vivo. Considering the evaluation of the cochlea at a very responsive stage, we propose that the level of isolated modification of p27^Kip1 expression in living mammals achievable through these approaches is insufficient to induce proliferation of supporting cells. Future proliferation induction experiments in the cochlea should study other methods and genes.

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Gait initiation and partial body weight unloading for functional improvement in post-stroke individuals

Publication date: Available online 6 December 2018

Source: Gait & Posture

Author(s): Gabriela L. Gama, Melissa L. Celestino, José A. Barela, Ana M.F. Barela

Abstract

Background

To better understand gait initiation in individuals with stroke and suggest possible training strategies, we compared the gait initiation of individuals with stroke and age-matched controls, and we examined the influence of different amounts of body weight support (BWS) during the execution of gait initiation in individuals with stroke.

Materials and Methods

Twelve individuals with stroke and 12 age-matched controls initiated gait after a verbal command at a self-selected and comfortable speed, and individuals with stroke also initiated gait wearing a harness with 0%, 15%, and 30% of BWS. Length and velocity of the first step, distance between heels, and weight bearing in both lower limbs in the initial position were calculated. We also assessed the displacement and average velocity of the center of pressure (CoP) in the medial-lateral (ML) and anterior-posterior (AP) directions in 3 distinct sections during gait initiation, which correspond to the CoP position toward the swing limb, stance limb and progression line, respectively.

Results

Individuals with stroke presented shorter and slower step, shorter and slower CoP-ML and CoP-AP toward swing limb and Cop-ML towards stance limb, and longer and faster CoP-AP toward stance limb compared to their peers. The BWS lead individuals with stroke to decrease step length and to increase CoP-ML displacement and average velocity toward stance limb.

Conclusion

Individuals with stroke present impairments in executing gait initiation mainly during the preparation period and the employment of an overground BWS system promotes a better performance. These results suggest that BWS is a functional strategy that enables individuals with stroke to modulate gait initiation and it could be adopted for gait intervention.

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Kinematics reduction applied to the comparison of highly-pronated, normal and highly-supinated feet during walking

Publication date: Available online 6 December 2018

Source: Gait & Posture

Author(s): E. Sanchis-Sales, P.J. Rodríguez-Cervantes, J.L. Sancho-Bru

Abstract

Background

Kinematic analysis could help to study how variations in the static foot posture affect lower limb biomechanical function. The analysis of foot kinematics is complex because it involves managing the time-dependent joint angles in different joints and in all three planes of motion. But it could be simplified if joint angles are coordinated.

Methods

The kinematics of the ankle, midtarsal and metatarsophalangeal joints were registered in 20 highly-pronated, 30 normal and 20 highly-supinated subjects (assessed by the Foot Posture Index – FPI) as they walked barefoot. Coordination for each sample was analysed through principal component analysis applied to the dorsiflexion, abduction and inversion angles measured. Finally, a systematic comparison among the samples was performed through a set of ANOVAs applied to the reduced variables corresponding to the factors found.

Results

Three principal components (coordination patterns) accounted for about 70% of the variance of the joint angles, and were affected by the FPI. The main coordination in normal feet was the supination movement, while in highly-supinated and highly-pronated feet it was the flexion coordination of all foot joints, which could work against adaptation in cases of varying terrain. The original joint angles were reduced to three factors, and the ANOVAs applied to them showed that highly-pronated feet presented a delayed propulsion peak and smaller ranges of motion during propulsion regarding all factors, and that highly-supinated feet require more pronation time to fully support the foot during walking.

Significance

The coordination patterns of normal feet might be considered the normal patterns used for an efficient gait, and may help in planning surgical procedures and designing foot prostheses or orthotics. Dimensional reduction makes it possible to perform more systematic kinematic analyses, which have revealed that highly-pronated feet are in poorer propulsive condition, and this in turn may make them more prone to injury.

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Intrinsic foot muscle size can be measured reliably in weight bearing using ultrasound imaging

Publication date: Available online 6 December 2018

Source: Gait & Posture

Author(s): Melinda M. Franettovich Smith, Julie A. Hides, Paul W. Hodges, Natalie J. Collins

Abstract

Background

The intrinsic foot muscles (IFMs) are important contributors to optimal foot function. While assessment of IFM morphology using ultrasound imaging in non-weight bearing has been established, this does not evaluate the foot in its primary functional position of weight bearing.

Research question

Is ultrasound imaging a reliable and clinically feasible method of measuring IFM morphology in weight bearing, do these measures differ to those from non-weight bearing and are they associated with participant characteristics?

Methods

Ultrasound images were obtained by a single rater from twenty-four healthy participants on two occasions, one week apart. Images were taken in weight bearing (bilateral stance) and non-weight bearing (seated). Cross-sectional area and dorsoplantar thickness of the abductor hallucis muscle, and dorsoplantar thickness of the muscles of the first interstitium were measured from acquired images. A second rater also acquired images at the first session. Participant characteristics included age, height, weight, sex, foot posture and foot mobility.

Results

Measurements of IFM morphology demonstrated high reliability within and between test sessions, as well as between raters (ICCs > 0.8). Our findings suggest that changes of 10-18% could be considered to exceed measurement error. Larger IFM size was related to larger body size (taller, heavier), foot posture (longer foot, higher arch, wider midfoot) and male sex.

Significance

This study is the first to describe a reliable and clinically feasible method of measuring IFM morphology in weight bearing. These measurements could be used in future studies to assess IFM morphology in patient populations and to evaluate the effect of intervention. Body size and foot posture explained between 20 and 41% of the variance in measurements and should be considered when comparing IFM morphology between individuals. The establishment of reliable measurements in weight bearing provides a crucial step towards the future evaluation of IFM function using ultrasound imaging.

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Non-motor predictors of freezing of gait in Parkinson’s disease

Publication date: Available online 6 December 2018

Source: Gait & Posture

Author(s): Sarah J. Banks, Ece Bayram, Guogen Shan, Denise R. LaBelle, Brent Bluett

Abstract

Background

The etiology of freezing of gait in Parkinson’s disease (PD) is yet to be clarified. Non-motor risk factors including cognitive impairment, sleep disturbance and mood disorders have been shown in freezing of gait.

Research question: We aimed to determine the predictive value of non-motor features in freezing of gait development.

Methods

Data were obtained from the Parkinson’s Progression Markers Initiative. Fifty PD patients with self-reported freezing of gait, and 50 PD patients without freezing of gait at the fourth year visit were included. Groups were matched for Movement Disorders Society-Unified Parkinson’s Disease Rating Scale Part III scores. Several cognitive and non-cognitive tests were used for non-motor features at baseline and over time. Executive function, visuospatial function, processing speed, learning and memory tests were used for cognition. Non-cognitive tests included sleepiness, REM sleep behavior disorder, depression and anxiety scales.

Results

Patients with freezing of gait had higher scores on sleepiness, REM sleep behavior disorder, depression and anxiety scales. However, predictor model analysis revealed that baseline processing speed, learning and sleepiness scores were predictive of self-reported freezing of gait development over time.

Significance

Our findings suggest that specific cognitive deficits and sleep disorders are predictive of future freezing of gait. These features may be helpful in identifying underlying networks in freezing of gait and should be further investigated with neuroimaging studies.

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The relationship between trunk position sense and postural control in ataxic individuals

Publication date: Available online 6 December 2018

Source: Gait & Posture

Author(s): Özge Onursal Kılınç, Ender Ayvat, Fatma Ayvat, Gülşah Sütçü, Muhammed Kılınç, Songül Aksoy, Sibel Aksu Yıldırım

ABSTRACT

Background

The proprioceptive system plays a role in the maintenance of postural control more than the visual and vestibular systems in ataxic patients with postural control disorders, but the relationship between trunk proprioception and postural control has not been sufficiently investigated yet. This relationship can provide a different perspective to the ataxia rehabilitation.

Research Question: This study aimed to examine the relationship between trunk position sense and postural control in ataxic individuals by comparing them to healthy individuals.

Methods

Twenty ataxic and 20 healthy individuals were included. The Sensory Organization Test, Limits of Stability Test, and Unilateral Stance Test in the Computerized Dynamic Posturography and Berg Balance Scale were used to evaluate postural control. The Baseline Digital Inclinometer (Norwalk, CA, USA) measured trunk position sense.

Results

It was found that repositioning error degree of the trunk position sense was higher in ataxic individuals than in healthy individuals, including scores of clinical and objective tests in postural control evaluation: they were lower in ataxic individuals (p < 0.05). As a result, trunk position sense was associated with almost all evaluated parameters, including sensory integration, postural sway, limits of stability, and functional balance (p < 0.05).

Significance

The impairment of postural control, which is the most important cause of activity and participation limitations in ataxic patients, is not only affected by motor disorders, but by sensory disturbances. Our study demonstrated that impairment of the trunk position sense in ataxic individuals was higher than that of healthy individuals, and affected the different components of postural control.

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Gait initiation and partial body weight unloading for functional improvement in post-stroke individuals

Publication date: Available online 6 December 2018

Source: Gait & Posture

Author(s): Gabriela L. Gama, Melissa L. Celestino, José A. Barela, Ana M.F. Barela

Abstract

Background

To better understand gait initiation in individuals with stroke and suggest possible training strategies, we compared the gait initiation of individuals with stroke and age-matched controls, and we examined the influence of different amounts of body weight support (BWS) during the execution of gait initiation in individuals with stroke.

Materials and Methods

Twelve individuals with stroke and 12 age-matched controls initiated gait after a verbal command at a self-selected and comfortable speed, and individuals with stroke also initiated gait wearing a harness with 0%, 15%, and 30% of BWS. Length and velocity of the first step, distance between heels, and weight bearing in both lower limbs in the initial position were calculated. We also assessed the displacement and average velocity of the center of pressure (CoP) in the medial-lateral (ML) and anterior-posterior (AP) directions in 3 distinct sections during gait initiation, which correspond to the CoP position toward the swing limb, stance limb and progression line, respectively.

Results

Individuals with stroke presented shorter and slower step, shorter and slower CoP-ML and CoP-AP toward swing limb and Cop-ML towards stance limb, and longer and faster CoP-AP toward stance limb compared to their peers. The BWS lead individuals with stroke to decrease step length and to increase CoP-ML displacement and average velocity toward stance limb.

Conclusion

Individuals with stroke present impairments in executing gait initiation mainly during the preparation period and the employment of an overground BWS system promotes a better performance. These results suggest that BWS is a functional strategy that enables individuals with stroke to modulate gait initiation and it could be adopted for gait intervention.

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Kinematics reduction applied to the comparison of highly-pronated, normal and highly-supinated feet during walking

Publication date: Available online 6 December 2018

Source: Gait & Posture

Author(s): E. Sanchis-Sales, P.J. Rodríguez-Cervantes, J.L. Sancho-Bru

Abstract

Background

Kinematic analysis could help to study how variations in the static foot posture affect lower limb biomechanical function. The analysis of foot kinematics is complex because it involves managing the time-dependent joint angles in different joints and in all three planes of motion. But it could be simplified if joint angles are coordinated.

Methods

The kinematics of the ankle, midtarsal and metatarsophalangeal joints were registered in 20 highly-pronated, 30 normal and 20 highly-supinated subjects (assessed by the Foot Posture Index – FPI) as they walked barefoot. Coordination for each sample was analysed through principal component analysis applied to the dorsiflexion, abduction and inversion angles measured. Finally, a systematic comparison among the samples was performed through a set of ANOVAs applied to the reduced variables corresponding to the factors found.

Results

Three principal components (coordination patterns) accounted for about 70% of the variance of the joint angles, and were affected by the FPI. The main coordination in normal feet was the supination movement, while in highly-supinated and highly-pronated feet it was the flexion coordination of all foot joints, which could work against adaptation in cases of varying terrain. The original joint angles were reduced to three factors, and the ANOVAs applied to them showed that highly-pronated feet presented a delayed propulsion peak and smaller ranges of motion during propulsion regarding all factors, and that highly-supinated feet require more pronation time to fully support the foot during walking.

Significance

The coordination patterns of normal feet might be considered the normal patterns used for an efficient gait, and may help in planning surgical procedures and designing foot prostheses or orthotics. Dimensional reduction makes it possible to perform more systematic kinematic analyses, which have revealed that highly-pronated feet are in poorer propulsive condition, and this in turn may make them more prone to injury.

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Intrinsic foot muscle size can be measured reliably in weight bearing using ultrasound imaging

Publication date: Available online 6 December 2018

Source: Gait & Posture

Author(s): Melinda M. Franettovich Smith, Julie A. Hides, Paul W. Hodges, Natalie J. Collins

Abstract

Background

The intrinsic foot muscles (IFMs) are important contributors to optimal foot function. While assessment of IFM morphology using ultrasound imaging in non-weight bearing has been established, this does not evaluate the foot in its primary functional position of weight bearing.

Research question

Is ultrasound imaging a reliable and clinically feasible method of measuring IFM morphology in weight bearing, do these measures differ to those from non-weight bearing and are they associated with participant characteristics?

Methods

Ultrasound images were obtained by a single rater from twenty-four healthy participants on two occasions, one week apart. Images were taken in weight bearing (bilateral stance) and non-weight bearing (seated). Cross-sectional area and dorsoplantar thickness of the abductor hallucis muscle, and dorsoplantar thickness of the muscles of the first interstitium were measured from acquired images. A second rater also acquired images at the first session. Participant characteristics included age, height, weight, sex, foot posture and foot mobility.

Results

Measurements of IFM morphology demonstrated high reliability within and between test sessions, as well as between raters (ICCs > 0.8). Our findings suggest that changes of 10-18% could be considered to exceed measurement error. Larger IFM size was related to larger body size (taller, heavier), foot posture (longer foot, higher arch, wider midfoot) and male sex.

Significance

This study is the first to describe a reliable and clinically feasible method of measuring IFM morphology in weight bearing. These measurements could be used in future studies to assess IFM morphology in patient populations and to evaluate the effect of intervention. Body size and foot posture explained between 20 and 41% of the variance in measurements and should be considered when comparing IFM morphology between individuals. The establishment of reliable measurements in weight bearing provides a crucial step towards the future evaluation of IFM function using ultrasound imaging.

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Non-motor predictors of freezing of gait in Parkinson’s disease

Publication date: Available online 6 December 2018

Source: Gait & Posture

Author(s): Sarah J. Banks, Ece Bayram, Guogen Shan, Denise R. LaBelle, Brent Bluett

Abstract

Background

The etiology of freezing of gait in Parkinson’s disease (PD) is yet to be clarified. Non-motor risk factors including cognitive impairment, sleep disturbance and mood disorders have been shown in freezing of gait.

Research question: We aimed to determine the predictive value of non-motor features in freezing of gait development.

Methods

Data were obtained from the Parkinson’s Progression Markers Initiative. Fifty PD patients with self-reported freezing of gait, and 50 PD patients without freezing of gait at the fourth year visit were included. Groups were matched for Movement Disorders Society-Unified Parkinson’s Disease Rating Scale Part III scores. Several cognitive and non-cognitive tests were used for non-motor features at baseline and over time. Executive function, visuospatial function, processing speed, learning and memory tests were used for cognition. Non-cognitive tests included sleepiness, REM sleep behavior disorder, depression and anxiety scales.

Results

Patients with freezing of gait had higher scores on sleepiness, REM sleep behavior disorder, depression and anxiety scales. However, predictor model analysis revealed that baseline processing speed, learning and sleepiness scores were predictive of self-reported freezing of gait development over time.

Significance

Our findings suggest that specific cognitive deficits and sleep disorders are predictive of future freezing of gait. These features may be helpful in identifying underlying networks in freezing of gait and should be further investigated with neuroimaging studies.

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The relationship between trunk position sense and postural control in ataxic individuals

Publication date: Available online 6 December 2018

Source: Gait & Posture

Author(s): Özge Onursal Kılınç, Ender Ayvat, Fatma Ayvat, Gülşah Sütçü, Muhammed Kılınç, Songül Aksoy, Sibel Aksu Yıldırım

ABSTRACT

Background

The proprioceptive system plays a role in the maintenance of postural control more than the visual and vestibular systems in ataxic patients with postural control disorders, but the relationship between trunk proprioception and postural control has not been sufficiently investigated yet. This relationship can provide a different perspective to the ataxia rehabilitation.

Research Question: This study aimed to examine the relationship between trunk position sense and postural control in ataxic individuals by comparing them to healthy individuals.

Methods

Twenty ataxic and 20 healthy individuals were included. The Sensory Organization Test, Limits of Stability Test, and Unilateral Stance Test in the Computerized Dynamic Posturography and Berg Balance Scale were used to evaluate postural control. The Baseline Digital Inclinometer (Norwalk, CA, USA) measured trunk position sense.

Results

It was found that repositioning error degree of the trunk position sense was higher in ataxic individuals than in healthy individuals, including scores of clinical and objective tests in postural control evaluation: they were lower in ataxic individuals (p < 0.05). As a result, trunk position sense was associated with almost all evaluated parameters, including sensory integration, postural sway, limits of stability, and functional balance (p < 0.05).

Significance

The impairment of postural control, which is the most important cause of activity and participation limitations in ataxic patients, is not only affected by motor disorders, but by sensory disturbances. Our study demonstrated that impairment of the trunk position sense in ataxic individuals was higher than that of healthy individuals, and affected the different components of postural control.

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