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Tu S, Li T, Carroll AS, Mahoney CJ, Huynh W, Park SB, Henderson R, Vucic S, Kiernan MC, Lin CSY. Central neurodegeneration in Kennedy's disease accompanies peripheral motor dysfunction. Sci Rep 2024; 14:18331. [PMID: 39112530 PMCID: PMC11306389 DOI: 10.1038/s41598-024-69393-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 08/05/2024] [Indexed: 08/10/2024] Open
Abstract
Spinal and bulbar muscular atrophy (SBMA), or Kennedy's disease (KD), is a rare hereditary neuromuscular disorder demonstrating commonalities with amyotrophic lateral sclerosis (ALS). The current study aimed to define functional and central nervous system abnormalities associated with SBMA pathology, their interaction, and to identify novel clinical markers for quantifying disease activity. 27 study participants (12 SBMA; 8 ALS; 7 Control) were recruited. SBMA patients underwent comprehensive motor and sensory functional assessments, and neurophysiological testing. All participants underwent whole-brain structural and diffusion MRI. SBMA patients demonstrated marked peripheral motor and sensory abnormalities across clinical assessments. Increased abnormalities on neurological examination were significantly associated with increased disease duration in SBMA patients (R2 = 0.85, p < 0.01). Widespread juxtacortical axonal degeneration of corticospinal white matter tracts were detected in SBMA patients (premotor; motor; somatosensory; p < 0.05), relative to controls. Increased axial diffusivity was significantly correlated with total neuropathy score in SBMA patients across left premotor (R2 = 0.59, p < 0.01), motor (R2 = 0.63, p < 0.01), and somatosensory (R2 = 0.61, p < 0.01) tracts. The present series has identified involvement of motor and sensory brain regions in SBMA, associated with disease duration and increasing severity of peripheral neuropathy. Quantification of annualized brain MRI together with Total Neuropathy Score may represent a novel approach for clinical monitoring.
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Affiliation(s)
- Sicong Tu
- Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Sydney, 2050, Australia.
- School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, 2050, Australia.
| | - Tiffany Li
- Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Sydney, 2050, Australia
- School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, 2050, Australia
| | - Antonia S Carroll
- Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Sydney, 2050, Australia
- Department of Neurology and Neurophysiology, St Vincent's Hospital, Sydney, 2010, Australia
| | - Colin J Mahoney
- Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Sydney, 2050, Australia
| | - William Huynh
- Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Sydney, 2050, Australia
- Prince of Wales Clinical School, The University of New South Wales, Sydney, 2052, Australia
| | - Susanna B Park
- Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Sydney, 2050, Australia
- School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, 2050, Australia
| | - Robert Henderson
- Royal Brisbane and Women's Hospital, University of Queensland, Brisbane, 4029, Australia
| | - Steve Vucic
- Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Sydney, 2050, Australia
- Brain and Nerve Research Centre, Concord Clinical School, The University of Sydney, Sydney, 2137, Australia
| | - Matthew C Kiernan
- Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Sydney, 2050, Australia
- Department of Neurology, Royal Prince Alfred Hospital, Sydney, 2050, Australia
| | - Cindy S-Y Lin
- Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Sydney, 2050, Australia.
- School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, 2050, Australia.
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Wang Y, Sung C, Huang J, Pei Y, Chang B. A protocol for tactile function assessment using JVP domes: Feasibility study and preliminary results. Brain Behav 2023; 13:e3123. [PMID: 37334446 PMCID: PMC10454274 DOI: 10.1002/brb3.3123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 05/30/2023] [Accepted: 06/01/2023] [Indexed: 06/20/2023] Open
Abstract
BACKGROUND Touch is a crucial sense for perceiving the spatial characteristics of objects. The JVP dome was developed to evaluate tactile spatial acuity using a grating orientation task. There were few studies depicting sequences and details for the entire task, including practice, training, and testing sessions. Therefore, we proposed and elaborated a protocol for the grating orientation task using the staircase method, which required fewer testing trials compared with the method of constant stimuli. METHODS Twenty-three healthy participants were enrolled in this experiment. The JVP domes with 11 different groove widths were used. Tactile discrimination thresholds were estimated using a two-down-one-up staircase method. The experiment comprised practice, training, and testing sessions, conducted by trained examiners who performed grating stimulation on participants' index fingerpads. RESULTS All participants passed the required accuracy in the practice and training sessions. Eight transition points were obtained in the testing session for each participant. The tactile discrimination thresholds were determined from the last six transition points. We obtained the mean tactile discrimination threshold as 1.8 ± 0.75 mm (n = 23). The results demonstrated that the proposed protocol was successfully applied to assess tactile discrimination thresholds. CONCLUSIONS The present study investigated the protocol of grating orientation tasks requiring a small number of testing trials with the assurance of the task quality. The feasibility study and preliminary results indicated the potentiality of this protocol for future clinical application.
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Affiliation(s)
- Yung‐Jung Wang
- School of Medicine, College of MedicineChang Gung UniversityTaoyuanTaiwan
- Department of Medical EducationChang Gung Memorial Hospital at Linkou Medical CenterTaoyuanTaiwan
| | - Chung‐Tung Sung
- School of Medicine, College of MedicineChang Gung UniversityTaoyuanTaiwan
- Department of Medical EducationChang Gung Memorial Hospital at Linkou Medical CenterTaoyuanTaiwan
| | - Jian‐Jia Huang
- Department of Physical Medicine and RehabilitationChang Gung Memorial Hospital at Linkou Medical CenterTaoyuanTaiwan
- Center of Vascularized Tissue AllograftChang Gung Memorial Hospital at Linkou Medical CenterTaoyuanTaiwan
- Master of Science Degree Program in Innovation for Smart MedicineChang Gung UniversityTaoyuanTaiwan
| | - Yu‐Cheng Pei
- School of Medicine, College of MedicineChang Gung UniversityTaoyuanTaiwan
- Department of Physical Medicine and RehabilitationChang Gung Memorial Hospital at Linkou Medical CenterTaoyuanTaiwan
- Center of Vascularized Tissue AllograftChang Gung Memorial Hospital at Linkou Medical CenterTaoyuanTaiwan
- Master of Science Degree Program in Innovation for Smart MedicineChang Gung UniversityTaoyuanTaiwan
| | - Bao‐Luen Chang
- School of Medicine, College of MedicineChang Gung UniversityTaoyuanTaiwan
- Department of NeurologyChang Gung Memorial Hospital at Linkou Medical CenterTaoyuanTaiwan
- Neuroscience Research CenterChang Gung Memorial Hospital at Linkou Medical CenterTaoyuanTaiwan
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Sung CT, Wang YJ, Huang JJ, Pei YC, Lin LC, Mai WH, Chang BL. A Novel Tactile Function Assessment Using a Miniature Tactile Stimulator. SENSORS (BASEL, SWITZERLAND) 2023; 23:1844. [PMID: 36850441 PMCID: PMC9966508 DOI: 10.3390/s23041844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Revised: 01/29/2023] [Accepted: 02/03/2023] [Indexed: 06/18/2023]
Abstract
Several methods for the measurement of tactile acuity have been devised previously, but unexpected nonspatial cues and intensive manual skill requirements compromise measurement accuracy. Therefore, we must urgently develop an automated, accurate, and noninvasive method for assessing tactile acuity. The present study develops a novel method applying a robotic tactile stimulator to automatically measure tactile acuity that comprises eye-opened, eye-closed training, and testing sessions. Healthy participants judge the orientation of a rotating grating ball presented on their index fingerpads in a two-alternative forced-choice task. A variable rotation speed of 5, 10, 40, or 160 mm/s was used for the tactile measurement at a variety of difficulties. All participants met the passing criteria for the training experiment. Performance in orientation identification, quantified by the proportion of trials with correct answers, differed across scanning directions, with the highest rotation speed (160 mm/s) having the worst performance. Accuracy did not differ between vertical and horizontal orientations. Our results demonstrated the utility of the pre-test training protocol and the functionality of the developed procedure for tactile acuity assessment. The novel protocol performed well when applied to the participants. Future studies will be conducted to apply this method to patients with impairment of light touch.
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Affiliation(s)
- Chung-Tung Sung
- Department of Medical Education, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan 33305, Taiwan
- School of Medicine, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Yung-Jung Wang
- Department of Medical Education, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan 33305, Taiwan
- School of Medicine, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Jian-Jia Huang
- Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan 33305, Taiwan
- Center of Vascularized Tissue Allograft, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan 33305, Taiwan
- Master of Science Degree Program in Innovation for Smart Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Yu-Cheng Pei
- School of Medicine, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
- Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan 33305, Taiwan
- Center of Vascularized Tissue Allograft, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan 33305, Taiwan
- Master of Science Degree Program in Innovation for Smart Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Lei-Chi Lin
- School of Medicine, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Wen-Hsin Mai
- School of Chinese Medicine, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Bao-Luen Chang
- School of Medicine, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
- Department of Neurology, Chang Gung Memorial Hospital at Linkou Medical Center, Taoyuan 33305, Taiwan
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Smith SG, Yokich MK, Beaudette SM, Brown SHM, Bent LR. Cutaneous Sensitivity Across Regions of the Foot Sole and Dorsum are Influenced by Foot Posture. Front Bioeng Biotechnol 2022; 9:744307. [PMID: 35096786 PMCID: PMC8792506 DOI: 10.3389/fbioe.2021.744307] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 11/04/2021] [Indexed: 01/13/2023] Open
Abstract
Understanding the processing of tactile information is crucial for the development of biofeedback interventions that target cutaneous mechanoreceptors. Mechanics of the skin have been shown to influence cutaneous tactile sensitivity. It has been established that foot skin mechanics are altered due to foot posture, but whether these changes affect cutaneous sensitivity are unknown. The purpose of this study was to investigate the potential effect of posture-mediated skin deformation about the ankle joint on perceptual measures of foot skin sensitivity. Participants (N = 20) underwent perceptual skin sensitivity testing on either the foot sole (N = 10) or dorsum (N = 10) with the foot positioned in maximal dorsiflexion/toe extension, maximal plantarflexion/toe flexion, and a neutral foot posture. Perceptual tests included touch sensitivity, stretch sensitivity, and spatial acuity. Regional differences in touch sensitivity were found across the foot sole (p < 0.001) and dorsum (p < 0.001). Touch sensitivity also significantly increased in postures where the skin was compressed (p = 0.001). Regional differences in spatial acuity were found on the foot sole (p = 0.002) but not dorsum (p = 0.666). Spatial acuity was not significantly altered by posture across the foot sole and dorsum, other than an increase in sensitivity at the medial arch in the dorsiflexion posture (p = 0.006). Posture*site interactions were found for stretch sensitivity on the foot sole and dorsum in both the transverse and longitudinal directions (p < 0.005). Stretch sensitivity increased in postures where the skin was pre-stretched on both the foot sole and dorsum. Changes in sensitivity across locations and postures were believed to occur due to concurrent changes in skin mechanics, such as skin hardness and thickness, which follows our previous findings. Future cutaneous biofeedback interventions should be applied with an awareness of these changes in skin sensitivity, to maximize their effectiveness for foot sole and dorsum input.
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Affiliation(s)
- Simone G.V.S. Smith
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, ON, Canada
| | - Maiya K. Yokich
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, ON, Canada
| | - Shawn M. Beaudette
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, ON, Canada
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada
| | - Stephen H. M. Brown
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, ON, Canada
| | - Leah R. Bent
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, ON, Canada
- *Correspondence: Leah R. Bent,
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Murata J, Murata S, Kodama T, Nakano H, Soma M, Nakae H, Satoh Y, Kogo H, Umeki N. Age-Related Changes in the Response of Finger Skin Blood Flow during a Braille Character Discrimination Task. Healthcare (Basel) 2021; 9:healthcare9020143. [PMID: 33535715 PMCID: PMC7912848 DOI: 10.3390/healthcare9020143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/25/2021] [Accepted: 01/27/2021] [Indexed: 11/16/2022] Open
Abstract
We hypothesized that age-related changes in sensory function might be reflected by a modulation of the blood flow response associated with tactile sensation. The aim of the present study was to clarify how the blood flow response of the fingers during concentrated finger perception is affected by aging. We measured the tactile-pressure threshold of the distal palmar pad of the index finger and skin blood flow in the finger (SBF) during Braille reading performed under blind conditions in young (n = 27) and older (n = 37) subjects. As a result, the tactile-pressure threshold was higher in older subjects (2.99 ± 0.37 log10 0.1 mg) than in young subjects (2.76 ± 0.24 log10 0.1 mg) (p < 0.01). On the other hand, the SBF response was markedly smaller in older subjects (−4.9 ± 7.0%) than in young subjects (−25.8 ± 15.4%) (p < 0.01). Moreover, the peak response arrival times to Braille reading in older and young subjects were 12.5 ± 3.1 s and 8.8 ± 3.6 s, respectively (p < 0.01). A decline in tactile sensitivity occurs with aging. Blood flow responses associated with tactile sensation are also affected by aging, as represented by a decrease in blood flow and a delay in the reaction time.
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Affiliation(s)
- Jun Murata
- Department of Physical and Occupational Therapy, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8520, Japan; (H.K.); (N.U.)
- Correspondence: ; Tel.: +81-95-819-7923
| | - Shin Murata
- Department of Physical Therapy, Faculty of Health Sciences, Kyoto Tachibana University, Kyoto 607-8175, Japan; (S.M.); (T.K.); (H.N.)
| | - Takayuki Kodama
- Department of Physical Therapy, Faculty of Health Sciences, Kyoto Tachibana University, Kyoto 607-8175, Japan; (S.M.); (T.K.); (H.N.)
| | - Hideki Nakano
- Department of Physical Therapy, Faculty of Health Sciences, Kyoto Tachibana University, Kyoto 607-8175, Japan; (S.M.); (T.K.); (H.N.)
| | - Masayuki Soma
- Course of Rehabilitation, Department of Health Sciences, Tohoku Fukushi University, Miyagi 981-8522, Japan; (M.S.); (H.N.); (Y.S.)
| | - Hideyuki Nakae
- Course of Rehabilitation, Department of Health Sciences, Tohoku Fukushi University, Miyagi 981-8522, Japan; (M.S.); (H.N.); (Y.S.)
| | - Yousuke Satoh
- Course of Rehabilitation, Department of Health Sciences, Tohoku Fukushi University, Miyagi 981-8522, Japan; (M.S.); (H.N.); (Y.S.)
| | - Haruki Kogo
- Department of Physical and Occupational Therapy, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8520, Japan; (H.K.); (N.U.)
| | - Naho Umeki
- Department of Physical and Occupational Therapy, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8520, Japan; (H.K.); (N.U.)
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Kuehn E, Perez-Lopez MB, Diersch N, Döhler J, Wolbers T, Riemer M. Embodiment in the aging mind. Neurosci Biobehav Rev 2018; 86:207-225. [DOI: 10.1016/j.neubiorev.2017.11.016] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 11/10/2017] [Accepted: 11/21/2017] [Indexed: 12/24/2022]
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Jerosch-Herold C. Assessment of Sensibility after Nerve Injury and Repair: A Systematic Review of Evidence for Validity, Reliability and Responsiveness of Tests. ACTA ACUST UNITED AC 2016; 30:252-64. [PMID: 15862365 DOI: 10.1016/j.jhsb.2004.12.006] [Citation(s) in RCA: 149] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2004] [Accepted: 12/06/2004] [Indexed: 11/15/2022]
Abstract
Recovery of sensibility after peripheral nerve injury and repair needs to be assessed using psychometrically robust measures. In this study the literature was reviewed to identify what tests are available to quantify sensibility and to assess their validity, reliability and responsiveness. The databases Medline, CINAHL, Embase and AMED were searched for studies reporting the psychometric properties of sensibility tests. While there is a plethora of tests and studies reporting the outcomes after peripheral nerve suture only a few of the tests have evidence of validity, reliability and responsiveness. Currently the touch threshold test using monofilaments such as the Weinstein Enhanced Sensory Test (WEST) or Semmes–Weinstein Monofilament Test (SWMT) and the shape–texture identification (STI™) test for tactile gnosis are the only tests which meet criteria for a standardized test and have had their psychometric properties evaluated and quantified.
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Affiliation(s)
- C Jerosch-Herold
- School of Allied Health Professions, University of East Anglia, Norwich NR4 7TJ, UK.
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Evaluation of Cutaneous Spatial Resolution and Pressure Threshold Secondary to Digital Nerve Repair. Plast Reconstr Surg 2016; 137:1203-1212. [DOI: 10.1097/prs.0000000000002023] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Master S, Tremblay F. Task-related enhancement in corticomotor excitability during haptic sensing with the contra- or ipsilateral hand in young and senior adults. BMC Neurosci 2012; 13:27. [PMID: 22416786 PMCID: PMC3325869 DOI: 10.1186/1471-2202-13-27] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Accepted: 03/14/2012] [Indexed: 11/16/2022] Open
Abstract
Background Haptic sensing with the fingers represents a unique class of manipulative actions, engaging motor, somatosensory and associative areas of the cortex while requiring only minimal forces and relatively simple movement patterns. Using transcranial magnetic stimulation (TMS), we investigated task-related changes in motor evoked potential (MEP) amplitude associated with unimanual haptic sensing in two related experiments. In Experiment I, we contrasted changes in the excitability of the hemisphere controlling the task hand in young and old adults under two trial conditions, i.e. when participants either touched a fine grating (smooth trials) or touched a coarse grating to detect its groove orientation (grating trials). In Experiment II, the same contrast between tasks was performed but with TMS applied over the hemisphere controlling the resting hand, while also addressing hemispheric (right vs. left) and age differences. Results In Experiment I, a main effect of trial type on MEP amplitude was detected (p = 0.001), MEPs in the task hand being ~50% larger during grating than smooth trials. No interaction with age was detected. Similar results were found for Experiment II, trial type having a large effect on MEP amplitude in the resting hand (p < 0.001) owing to selective increase in MEP size (~2.6 times greater) for grating trials. No interactions with age or side (right vs. left) were detected. Conclusions Collectively, these results indicate that adding a haptic component to a simple unilateral finger action can elicit robust corticomotor facilitation not only in the working hemisphere but also in the opposite hemisphere. The fact that this facilitation seems well preserved with age, when task difficulty is adjusted, has some potential clinical implications.
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Affiliation(s)
- Sabah Master
- School of Psychology, University of Ottawa, Ottawa, Ontario, Canada
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Master S, Larue M, Tremblay F. Characterization of human tactile pattern recognition performance at different ages. Somatosens Mot Res 2011; 27:60-7. [PMID: 20528583 DOI: 10.3109/08990220.2010.485959] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
This study examined tactile pattern recognition performance in human observers (N = 44) in the context of a letter recognition task at the fingertip. Participants were recruited from three different age groups (youth, n = 17; young adults, n = 14; seniors, n = 13) to examine age-related differences in performance. The influence of gender (males vs females) and hand (right vs left) was also examined. Performance was characterized in terms of both response accuracy and associated response times (RTs). Patterns of confusion between letters were also examined. Results showed that age was the most important factor in determining the capacity of our participants to perform fast and accurate pattern recognition. In this respect, younger participants (i.e., youth and young adults) clearly outperformed seniors by showing not only better accuracy and less confusion but also 2-3 times faster RT. By comparison, the combined influence of "hand" and "gender" on recognition performance was only marginal. These results indicate that the ability to perform complex tactile pattern recognition is already well established in youth 10-14 years of age with only minor refinements occurring later in early adulthood. With advancing age, such ability becomes far less efficient, as judged by the drastic increase in RT observed in seniors, in spite of a relatively good accuracy. This suggests that alterations not only at the peripheral receptor level but also at the central processing level might play an important role in limiting the ability of seniors to perform fast and efficient pattern recognition at the fingertip.
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Affiliation(s)
- Sabah Master
- School of Psychology, Faculty of Social Sciences, University of Ottawa, Ottawa, ON, Canada
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Master S, Tremblay F. Tactile-dependant corticomotor facilitation is influenced by discrimination performance in seniors. Behav Brain Funct 2010; 6:16. [PMID: 20205734 PMCID: PMC2841084 DOI: 10.1186/1744-9081-6-16] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Accepted: 03/05/2010] [Indexed: 11/18/2022] Open
Abstract
Background Active contraction leads to facilitation of motor responses evoked by transcranial magnetic stimulation (TMS). In small hand muscles, motor facilitation is known to be also influenced by the nature of the task. Recently, we showed that corticomotor facilitation was selectively enhanced when young participants actively discriminated tactile symbols with the tip of their index or little finger. This tactile-dependant motor facilitation reflected, for the large part, attentional influences associated with performing tactile discrimination, since execution of a concomitant distraction task abolished facilitation. In the present report, we extend these observations to examine the influence of age on the ability to produce extra motor facilitation when the hand is used for sensory exploration. Methods Corticomotor excitability was tested in 16 healthy seniors (58-83 years) while they actively moved their right index finger over a surface under two task conditions. In the tactile discrimination (TD) condition, participants attended to the spatial location of two tactile symbols on the explored surface, while in the non discrimination (ND) condition, participants simply moved their finger over a blank surface. Changes in amplitude, in latency and in the silent period (SP) duration were measured from recordings of motor evoked potentials (MEP) in the right first dorsal interosseous muscle in response to TMS of the left motor cortex. Results Healthy seniors exhibited widely varying levels of performance with the TD task, older age being associated with lower accuracy and vice-versa. Large inter-individual variations were also observed in terms of tactile-specific corticomotor facilitation. Regrouping seniors into higher (n = 6) and lower performance groups (n = 10) revealed a significant task by performance interaction. This latter interaction reflected differences between higher and lower performance groups; tactile-related facilitation being observed mainly in the former group. Latency measurements and SP durations were not affected by task conditions. Conclusions The present findings provide further insights into the factors influencing task-dependant changes in corticomotor excitability in the context of aging. Our results, in particular, highlight the importance of adjusting task demands and controlling for attention when attempting to elicit task-specific motor facilitation in older persons engaged in fine manual actions. Such information could be critical in the future for planning interventions to re-educate or maintain hand function in the presence of neurological impairments.
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Affiliation(s)
- Sabah Master
- School of Rehabilitation Sciences, University of Ottawa, Ottawa, Ontario K1H8M5, Canada
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Cattaneo Z, Bhatt E, Merabet LB, Pece A, Vecchi T. The influence of reduced visual acuity on age-related decline in spatial working memory: an investigation. AGING NEUROPSYCHOLOGY AND COGNITION 2008; 15:687-702. [PMID: 18608051 DOI: 10.1080/13825580802036951] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
To investigate the relationship between visual acuity and cognitive function with aging, we compared low-vision and normally-sighted young and elderly individuals on a spatial working memory (WM) task. The task required subjects to memorise target locations on different matrices after perceiving them visually or haptically. The haptic modality was included as a control to look at the effect of aging on memory without the confounding effect of visual deficit. Overall, age and visual status did not interact to affect WM accuracy, suggesting that age does not exaggerate the effects of visual deprivation. Young participants performed better than the elderly only when the task required more operational processes (i.e., integration of information). Sighted participants outperformed the visually impaired regardless of testing modality suggesting that the effect of the visual deficit is not confined to only the most peripheral levels of information processing. These findings suggest that vision, being the primary sensory modality, tends to shape the general supramodal mechanisms of memory.
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Affiliation(s)
- Zaira Cattaneo
- Department of Psychology, University of Pavia, Pavia, Italy.
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Grant AC, Fernandez R, Shilian P, Yanni E, Hill MA. Tactile spatial acuity differs between fingers: a study comparing two testing paradigms. ACTA ACUST UNITED AC 2007; 68:1359-62. [PMID: 17378421 DOI: 10.3758/bf03193734] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Tactile spatial acuity (TSA) is a reliable and reproducible measure of somatosensory system function that has been used to study abroad range of subject populations. Although TSA is most often assessed at the fingertip, published studies employing identical stimuli disagree on whether TSA differs between the fingers of neurologically normal subjects. Using a validated grating orientation discrimination task, we determined TSA bilaterally at the index and ring fingers of 16 healthy young adults. Motivated by earlier work, we utilized two stimulus presentation paradigms, the method of constant stimuli (MCS) and a staircase (SC) method. We found that TSA was significantly higher (the discrimination threshold was lower) at the index than at the ring finger, which was consistent with a prior study. Although mean thresholds at both fingers were higher when measured with the SC than with the MCS paradigm, this difference did not reach statistical significance (p = .14). These findings should facilitate both design and interpretation of future studies investigating TSA.
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Abstract
Young (21-26 years, n=20) and old (55-86 years, n=25) participants were tested for their ability to recognize raised letters (6-mm high, 1-mm relief) by touch. Spatial resolution thresholds were also measured with grating domes to derive an index of the degree of afferent innervation at the fingertip. Letter recognition in the young group was very consistent and highly accurate (mean, 86% correct), contrasting with the performance of the old group, which was more variable and comparatively low in accuracy (mean, 53% correct). In both groups, spatial resolution thresholds accounted for a substantial portion of the variance in the performance, suggesting a strong link between age-dependent variations in tactile innervation and recognition accuracy. The patterns of errors in the old group showed that an inability to encode internal elements specific to certain letters was at the source of most confusion among letters. Whether this inability reflected only deficient peripheral encoding mechanisms or some other alterations at the central level is discussed.
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Affiliation(s)
- Hélène Manning
- Faculty of Health Sciences, School of Rehabilitation Sciences, University of Ottawa, Ontario, Canada
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15
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Sanger TD, Kukke SN. Abnormalities of tactile sensory function in children with dystonic and diplegic cerebral palsy. J Child Neurol 2007; 22:289-93. [PMID: 17621498 DOI: 10.1177/0883073807300530] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Recent studies have shown the presence of sensory dysfunction in adults with focal dystonias. The authors hypothesize that children with secondary dystonia due to cerebral palsy may share a similar sensory dysfunction. To test this hypothesis, they evaluated tactile spatial discrimination threshold using Johnson, Van Boven, Phillips domes in 10 children with cerebral palsy and upper extremity dystonia, 8 children with diplegic cerebral palsy without involvement of the arms, and 21 unaffected children. Both patient groups had poor tactile discrimination compared with controls. The authors therefore conclude that children with secondary dystonia and diplegia due to cerebral palsy have deficits of tactile sensation that are similar to deficits seen in adults with focal dystonia. These results are the first to test the spatial discrimination threshold using Johnson, Van Boven, Phillips domes in children with cerebral palsy.
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Affiliation(s)
- Terence D Sanger
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305-5235, USA.
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16
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Tremblay F, Mireault AC, Dessureault L, Manning H, Sveistrup H. Postural stabilization from fingertip contact II. Relationships between age, tactile sensibility and magnitude of contact forces. Exp Brain Res 2005; 164:155-64. [PMID: 15754171 DOI: 10.1007/s00221-005-2238-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2004] [Accepted: 11/11/2004] [Indexed: 11/26/2022]
Abstract
In the present report, we extend our previous observations on the effect of age on postural stabilization from fingertip contact (Exp Brain Res 157 (2004) 275) to examine the possible influence of sensory thresholds measured at the fingertip on the magnitude of contact forces. Participants (young, n=25, 19-32 years; old, n=35, 60-86 years) underwent psychophysical testing of the right index finger to determine thresholds for spatial acuity, pressure sensitivity and kinesthetic acuity. Spatial acuity was determined from the ability to detect gaps of different widths, while Semmes-Weinstein monofilaments were used for pressure sensitivity. Kinesthetic acuity was determined by asking participants to discriminate plates of different thicknesses using a thumb-index precision grip. These tests were selected on the basis that each reflected different sensory coding mechanisms (resolution of spatial stimuli, detection of mechanical forces and integration of multi-sensory inputs for hand conformation) and thus provided specific information about the integrity and function of mechanoreceptive afferents innervating the hand. After log transformation, thresholds were first examined to determine the influence of age (young and old) and gender (male, female) on tactile acuity. Sensory thresholds were then entered into multiple linear regression models to examine their ability to predict fingertip contact forces (normal and tangential) applied to a smooth surface when subjects stood with eyes closed on either a firm or a compliant support surface. As expected, age exerted a significant effect (p<0.01) on all three thresholds, but its impact was greater on spatial acuity than on pressure sensitivity or kinesthetic acuity. Gender had a marginal impact on pressure sensitivity thresholds only. The regression analyses revealed that tactile thresholds determined at the index fingertip accounted for a substantial proportion of the variance (up to 30%) seen in the contact forces deployed on the touch-plate, especially those exerted in the normal direction. The same analyses further revealed that much of the variance explained by the models arose from inter-individual differences in tactile spatial acuity and not from differences in pressure sensitivity or in kinesthetic acuity. Thus, of all three tests, the spatial acuity task was the most sensitive at detecting differences in hand sensibility both within and between age groups and, accordingly, was also better at predicting the magnitude of fingertip forces deployed for postural stabilization. Since spatial acuity is critically dependent upon innervation density, we conclude that the degree of functional innervation at the fingertip was likely an important factor in determining the capacity of older participants to use contact cues for stability purposes, forcing the most affected individuals to exert unusually high pressures in order to achieve stabilization in the presence of reduced tactile inputs arising from contact with the touched surface.
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Affiliation(s)
- François Tremblay
- School of Rehabilitation Sciences, Faculty of Health Sciences, University of Ottawa, 451 Smyth, Ottawa, Ontario, Canada.
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17
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Tremblay F, Mireault AC, Dessureault L, Manning H, Sveistrup H. Postural stabilization from fingertip contact: I. Variations in sway attenuation, perceived stability and contact forces with aging. Exp Brain Res 2004; 157:275-85. [PMID: 15205866 DOI: 10.1007/s00221-004-1830-4] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2003] [Accepted: 12/22/2003] [Indexed: 10/26/2022]
Abstract
In this study, we compared the ability of young (n=10, 19-32 years) and older subjects (n=35, 60-86 years) to use fingertip contact as a balance aid during quiet stance under various conditions to determine whether aging would influence contact strategies. Experimental trials (duration, 60 s) included two visual conditions (vision; no vision), three fingertip contact conditions (no touch; smooth touch; rough touch) and two support surface conditions (firm; foam). In trials with contact, participants were required to maintain a light contact with their right index fingertip on an instrumented touch-plate. Subjects were not constrained to exert minimal contact force, although they were aware that the touch-plate was not designed for physical support. From displacements of the centre of foot pressure (COP), mean sway amplitude (MSA) was computed in the anterior-posterior (COP(AP)) and medio-lateral (COP(ML)) directions. Subjective estimates of stability were also obtained by asking participants to rate perceived stability on a visual analog scale in each condition. Mean normal force (FN) and mean resultant tangential force (F(TAN)) were computed from contact force data applied on the touch plate. In both age groups, touch conditions had a substantial effect on MSA in the AP direction under both support surface conditions, with reductions averaging between 40-55% when touch was allowed. Reductions in the ML direction, though less important (8-12% on average), were nevertheless highly significant, especially in the older subjects when standing on the foam. In the two groups, vision and texture had only marginal impact on MSA computed on both support surfaces. Contrasting with sway measurements, stability ratings were highly influenced by visual conditions in both age groups. Only in conditions of deficient support (foam surface) and absent vision did the perceived effect of touch exceed that of vision. Age had a major impact, however, on contact forces deployed during trials with touch. While individuals in the young group typically produced forces of <1 N (mean FN, 0.32+/-0.15 N) to achieve postural stabilization, older subjects tended to use higher, though not too excessive, contact forces (mean FN, 1.21+/-0.75 N) under the same conditions. From these findings, we conclude that the ability to use contact cues from the fingertip as a source of sensory information to improve postural stability is largely preserved in healthy older adults. The increase in contact force deployed by older individuals to achieve postural stabilization is interpreted as a compensatory strategy to help overcome age-related loss in tactile sensation, an issue that will be further addressed in a companion paper.
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Affiliation(s)
- François Tremblay
- School of Rehabilitation Sciences, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, Canada.
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18
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Vega-Bermudez F, Johnson KO. Fingertip skin conformance accounts, in part, for differences in tactile spatial acuity in young subjects, but not for the decline in spatial acuity with aging. ACTA ACUST UNITED AC 2004; 66:60-7. [PMID: 15095940 DOI: 10.3758/bf03194861] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The ability of the skin to conform to the spatial details of a surface or an object is an essential part of our ability to discriminate fine spatial features haptically. In this study, we examined the extent to which differences in tactual acuity between subjects of the same age and between younger and older subjects can be accounted for by differences in the properties of the skin. We did so by measuring skin conformance and tactile spatial acuity in the glabrous skin at the fingertip in 18 younger (19-36 years old) and 9 older (61-69 years old) subjects. Skin conformance was measured as the degree to which the skin invaded the spaces in the psychophysical stimuli. There were several findings. First, skin conformance accounted for 50% of the variance in our measure of tactile spatial acuity (the threshold for grating orientation discrimination) between the younger subjects. The subjects with more compliant skin had substantially lower thresholds than did the subjects with stiffer skin. Second, the skin of the younger subjects was more compliant across than along the skin ridges, and this translated into significantly greater performance when the gratings were oriented along than when oriented across the skin. Third, skin conformance was virtually identical in the younger and the older subjects. Consequently, skin conformance cannot account for the loss of spatial acuity reported in earlier studies and confirmed in this study. We infer that the loss must be neural in origin.
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Affiliation(s)
- Francisco Vega-Bermudez
- Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, Maryland 21218, USA.
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Tremblay F, Wong K, Sanderson R, Coté L. Tactile spatial acuity in elderly persons: assessment with grating domes and relationship with manual dexterity. Somatosens Mot Res 2003; 20:127-32. [PMID: 12850821 DOI: 10.1080/0899022031000105154] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
In this study, we sought to better define the limit of spatial resolution at the fingertips of elderly participants (n = 30, age 60-95 years) using an extended set of JVP grating domes, incorporating four new grating dimensions (2.5-, 3.5-, 4.0- and 4.5-mm width). A secondary aim was to examine whether deficits in tactile acuity could be related to hand dysfunction in older adults. Spatial resolution thresholds were determined by the finest grating whose orientation (dominant index finger) could be reported reliably. Manual dexterity was assessed with the Grooved Pegboard Test (GPT). The extended set of domes improved threshold measurements in a majority of participants (21/30). Still, accurate threshold estimates could not be obtained in one third of the participants, mostly in the older age group (8/9, 74-95 years). Grating resolution thresholds at the index finger were strongly correlated (r = 0.66, p<0.01) with dexterity scores derived from the GPT. From these results, we conclude that the 2.5- and 3.5-mm grating domes are suitable additions when assessing spatial acuity at the fingertips of older subjects between 60 and 70 years of age (mean threshold, 2.7+/-0.6 mm). For the older ones, the 4.0- and 4.5-mm domes can improve threshold measurements but interpretation of values can be complicated by the presence of undiagnosed pathologies (e.g., diffuse polyneuropathy) as people advance in age. The strong relationship between grating resolution thresholds and dexterity scores indicates that an impaired spatial acuity at the fingertips may translate into great difficulties in tasks requiring fine manipulations. These findings have important implications for the assessment of hand function in older adults.
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Affiliation(s)
- François Tremblay
- Physiotherapy Program, School of Rehabilitation Sciences, Faculty of Health Sciences, University of Ottawa, Ontario, Canada K1H 8M5.
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