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- Hafström, Anna
(författare)
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Perceived and functional balance control is negatively affected by diminished touch and vibration sensitivity in relatively healthy older adults and elderly
- 2018
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Ingår i: Gerontology and Geriatric Medicine. - : SAGE Publications. - 2333-7214. ; 4, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- Background: Severe diminished foot somatosensation, for example, caused by neuropathies and advanced aging, contributes to balance deficits and increased fall risk. However, little is known about somatosensory impairment and functional and subjective balance problems in relatively healthy elderly. Method: Vibration perception thresholds (VPTs) were assessed with a biothesiometer and tactile pressure sensation thresholds (TPSTs) with 20 monofilaments in 34 relatively healthy community-dwelling older adults (M = 69.4 years). Balance was evaluated with functional balance tests and questionnaires. A stepwise regression analysis was performed to determine the extent to which VPTs, TPSTs, and age could explain balance impairments. Results: High VPTs had negative effects on Berg Balance Scale and Dizziness Handicap Inventory scores (p ≤ .011), as did high TPSTs on walking speed and Figure-8 test (p ≤ .001). With visual information available, one-leg standing time (OLST) was significantly affected by ipsilateral VPTs on solid and TPSTs on compliant surface (p ≤ .002). Without visual information, age was the only factor with a main effect on OLST (p < .001). Age had no significant correlations with TPSTs or VPTs. Discussion: Somatosensation appears to be very important for perceived as well as functional balance control in older adults. Our findings have important clinical implications when assessing balance impairment and impending fall risk.
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- Malmström, Eva Maj, et al.
(författare)
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Co-morbidities to Vestibular Impairments—Some Concomitant Disorders in Young and Older Adults
- 2021
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Ingår i: Frontiers in Neurology. - : Frontiers Media SA. - 1664-2295. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Background: Dizziness and pain are common complaints that often appear concomitantly, with or without a causal relationship. However, these symptoms might maintain and exacerbate each other and other co-morbidities. Therefore, adequate rehabilitation may have to include an expanded focus on other deficits and preconditions, especially in older adults and in patients. Objective: To understand how frequently vestibular dysfunction coincided with medical conditions and aging, we studied two categories: Study 1: patients referred to a vestibular unit and Study 2: senior members in a fitness association. Method: Study 1: 49 patients [34 females/15 males; mean age 52 years (SEM 2.0)] seeking health care for balance disorders and vestibular deficits were asked in questionnaires about their perception of dizziness and pain, and emotional and functional strains. Study 2: 101 senior members in a fitness association [91 females/10 males; mean age 75 years (SEM 0.6)], were assessed for vestibular and balance deficits and for any co-morbidities. The participants were monitored for falls for 12 months after the initial assessments. Result: Study 1: Co-morbidity often existed between dizziness and pain (65%). The patients reported high emotional and functional strain related to their dizziness and pain. Patients older than 60 years reported longer durations of pain (p ≤ 0.028) but less emotional strain (p = 0.036), compared to younger patients. Study 2: 84% of the participants had a vestibular impairment, often without noticing any symptoms. Furthermore, 40% reported cardiovascular illnesses, 12% musculoskeletal disorders, and 63% reported other medical conditions. Forty-two percent experienced falls within 1 year after the initial assessments (thereof 42% in the group with vestibular deficits and 38% in the group without vestibular deficits). Conclusion: To enhance and preserve postural control, both in patients with vestibular deficits and in older adults, we suggest an expanded clinical perspective. Hence, we recommend detailed examinations of the vestibular system but simultaneously probing for possible co-morbidities. Since aging often entails deterioration of multimodal processes related to maintained mobility and postural stability, our results add focus on the importance of addressing balance disorders together with additional medical conditions.
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- Fransson, Per-Anders, et al.
(författare)
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Analysis of Postural Control Adaptation during Galvanic and Vibratory Stimulation
- 2001
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Ingår i: Proc. 23rd Annual EMBS International Conference (EMBC2001). ; , s. 1170-1173
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Konferensbidrag (refereegranskat)abstract
- The objective for this study was to investigate whether the postural control adaptation during galvanic stimulation of the vestibular nerve were similar to that found during vibration stimulation to the calf muscles. A method for adaptation analysis was used to analyze the evoked changes of posture, stimulus responses and the motion dynamics. The adaptive adjustments of postural control were similar during galvanic and vibratory stimulation, which suggests that the adaptation operate in the same way independent of the receptor systems affected by the disturbance. There was however a difference in the dynamic feedback properties of the measured responses.
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- Fransson, Per-Anders, et al.
(författare)
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Analysis of Short- and Long-Term Effects of Adaptation in Human Postural Control
- 2002
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Ingår i: Biological Cybernetics. - : Springer Science and Business Media LLC. - 1432-0770 .- 0340-1200. ; 86:5, s. 355-365
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Tidskriftsartikel (refereegranskat)abstract
- The short-term (i.e., days) and long-term (i.e., months) effects of adaptation to posturography examinations were investigated in 12 normal subjects who were repeatedly examined for five consecutive days and again after 90 days. The examinations were conducted both with eyes open and closed, and the perturbations were evoked by a pseudorandomly applied vibration stimulation to the calf muscles. The evoked anteroposterior responses were analyzed with a method considering adaptation in the slow changes in posture and in the stimulus-response relationship. Repetition of examinations on a daily basis revealed a gradual improvement of postural-control performance. The body sway induced by the stimulation was significantly reduced and the dynamical properties changed. Most of the improvements remained after 90 days, but some parameters such as the complexity of the control system used were increased to the initial level. The results confirm previous observations that postural control contains several partially independent adaptive processes, observed in terms of alteration of posture and as a progressive reduction of body sway induced by stimulation. The method used for the adaptation analysis in this study could be applied to analyze biological systems with multiple individual adaptive processes with different time courses or characteristics, or where the adaptation processes are related to multiple internal or external factors.
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| 6. |
- Hafström, Anna, et al.
(författare)
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Acute alcohol intoxication impairs segmental body alignment in upright standing.
- 2014
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Ingår i: Journal of Vestibular Research. - 1878-6464. ; 24:4, s. 297-304
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Tidskriftsartikel (refereegranskat)abstract
- Balance control when standing upright is a complex process requiring input from several partly independent mechanisms such as coordination, feedback and feedforward control, and adaptation. Acute alcohol intoxication from ethanol is recognized as a major contributor to accidental falls requiring medical care. This study aimed to investigate if intoxication at 0.06 and 0.10% blood alcohol concentration affected body alignment. Mean angular positions of the head, shoulder, hip, and knee were measured with 3D-motion analysis and compared with the ankle position in 25 healthy adults during standing with or without perturbations, and with eyes open or closed. Alcohol intoxication had significant effects on body alignment during perturbed and unperturbed stance, and on adaptation to perturbations. It induced a significantly more posterior alignment of the knees and shoulders, and a tendency for a more posterior and left deviated head alignment in perturbed stance than when sober. The impact of alcohol intoxication was most apparent on the knee alignment, where availability of visual information deteriorated the adaptation to perturbations. Thus, acute alcohol intoxication resulted in inadequate balance control strategies with increased postural rigidity and impaired adaptation to perturbations. These factors probably contribute to the increased risk of falling when intoxicated with alcohol.
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| 7. |
- Hafström, Anna, et al.
(författare)
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Effectuation of adaptive stability and postural alignment strategies are decreased by alcohol intoxication.
- 2014
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Ingår i: Human Movement Science. - : Elsevier BV. - 1872-7646 .- 0167-9457. ; 35:Apr 29, s. 30-49
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Tidskriftsartikel (refereegranskat)abstract
- Human stability control is a complex process comprising contributions from several partly independent mechanisms such as coordination, feedback and feed-forward control, and adaptation. Acute alcohol intoxication impairs these functions and is recognized as a major contributor to fall traumas. The study aimed to investigate how alcohol intoxication at .06% and .10% blood alcohol concentration (BAC) affected the movement spans and control of posture alignment. The angular positions of the head, shoulder, hip and knees relative to the ankles were measured with a 3D motion analysis system in 25 healthy adults during standing with eyes open or closed and with or without vibratory balance perturbations. Alcohol intoxication significantly increased the movement spans of the head, shoulders, hip and knees in anteroposterior and lateral directions during quiet stance (p⩽.047 and p⩽.003) and balance perturbations (p<.001, both directions). Alcohol intoxication also decreased the ability to reduce the movement spans through adaptation in both anteroposterior (p⩽.011) and lateral (p⩽.004) directions. When sober and submitted to balance perturbations, the subjects aligned the head, shoulders, hip and knees more forward relative to the ankle joint (p<.001), hence adopting a more resilient posture increasing the safety margin for backward falls. Alcohol intoxication significantly delayed this forward realignment (p⩽.022). Alcohol intoxication did not cause any significant posture realignment in the lateral direction. Thus, initiation of adaptive posture realignments to alcohol or other disruptions might be context dependent and associated with reaching a certain level of stability threats.
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| 9. |
- Hafström, Anna, et al.
(författare)
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Sentinel lymph node biopsy staging for cutaneous malignant melanoma of the head and neck.
- 2016
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Ingår i: Acta Oto-Laryngologica. - : Informa UK Limited. - 1651-2251 .- 0001-6489. ; 136:3
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Tidskriftsartikel (refereegranskat)abstract
- Conclusion Sentinel lymph node biopsies (SLNBs) can be performed safely and with reasonable accuracy in HNM patients. The outcome provides important prognostic information concerning DFS and further treatment. However, one must recognize that SLNB is a multidisciplinary procedure with a learning curve for all. Objectives To evaluate efficacy of performing SLNBs in a series of consecutive patients with cutaneous head and neck melanoma (HNM) ≥ T1b from introduction of the procedure and 10 years onward. Method End-points comprised of SLNB outcome, disease-free survival (DFS), and overall survival (OS). Results SNs were harvested in 128 of 160 patients (median Breslow = 2.0 mm, 29% ulcerated); success rate = 80.0%, or 92.1% if excluding patients where SLNBs were omitted due to non-localization on pre-operative imaging or because of SN-location in the parotid basin. Ten patients (7.8%) had positive SLNBs and were offered early completion neck dissections. Of the 146 patients available for follow-up (median = 27 months), 15.8% had recurrent disease. The risk of a regional nodal recurrence after a negative SLNB was 7.5%. SN-negative patients had improved DFS c.f. SN-positive patients (p < 0.001). A positive SLNB was the most important prognostic predictor of decreased DFS (hazard ratio = 5.70; p < 0.005), but had no significant impact on OS.
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