Validation of Posturographic Measurements in Adolescents

The impact of vestibular dysfunction on falls and postural instability in individuals with type 2 diabetes with and without diabetic polyneuropathy

Aim

This study aimed to determine the association between vestibular dysfunction, falls, and postural instability in individuals with type 2 diabetes (T2D) compared to healthy control individuals and to examine the impact of diabetic polyneuropathy (DPN).

Methods

This cross-sectional study included individuals with T2D with DPN (n = 43), without DPN (n = 32), and healthy controls (n = 32). Cervical and ocular vestibular evoked myogenic potentials (VEMP) were recorded, and latencies and amplitudes were determined. DPN was diagnosed based on nerve conduction studies and clinical scores. Postural instability was examined using a static posturographic balance system and calculated as an instability index (ST). Falls were recorded retrospectively during the past year. Group comparisons were conducted by using univariate and bivariate statistics.

Results

Individuals with T2D experienced more falls than healthy controls (T2D with DPN n = 12[38%], T2D without DPN n = 15[35%], controls n = 5[16%], p = 0.04). Individuals with T2D had decreased postural stability, T2D with DPN, ST (median of 52[iqi = 33; 77]), T2D without DPN, ST (median of 31[iqi = 24; 39]), controls ST (median of 26[iqi = 19; 33], p = 0.01), when comparing all three groups. Individuals with T2D had a greater number of no-responses in oVEMP compared to controls (T2D with DPN, n = 15[46.9%] T2D without DPN n = 25[58.1%], controls n = 9[28.1%], p = 0.04). No difference was found in cVEMP and oVEMP amplitudes in any of the groups. Irrespectively of DPN, fallers with T2D had decreased oVEMP and cVEMP latencies on the right ears, when comparing to non-fallers, respectively, n10 (fallers [median of 16, iqi=15;19 ms.] vs. non-fallers [median of 25 iqi=16;35 ms]); p13 (fallers [median of 16, iqi=15;17 ms.] vs. non-fallers [median of 15, iqi=8;16 ms.], p < 0.05).

Conclusion

Falls and postural instability were more frequent in individuals with T2D compared to healthy controls. Fallers with T2D had vestibular end-organ impairments based on the oVEMP and cVEMP latencies on the right but not the left ears, irrespective of DPN. Individuals with T2D had more frequent no-response of the oVEMP, indicating impaired vestibular nerve function.

Motion sickness and postural control among Danish adolescents

OBJECTIVE

Easily available clinical tests to evaluate postural control are needed. Furthermore, motion sickness (MS) and postural control are correlated. The aims of this study were to compare the internal validity of a set of clinical tests of postural control with the internal validity of static posturography and to evaluate possible associations between postural control and MS.

METHODS

We included healthy subjects from a primary school in Denmark who completed questionnaires about MS and underwent two rounds of clinical tests of postural control and static posturography using a Tetrax Interactive Balance System two weeks apart. For clinical tests of postural control, subjects were observed for up to 30 s standing on both legs, on one leg, on a pillow both with their eyes open and again with their eyes closed.

RESULTS

Twenty-one subjects were included: 71% males with an average age of 13.7 years. Agreement rates ranged from 62% to 95% between test and retest in clinical tests.; lowest for subjects standing on their non dominant leg with their eyes open and highest for subjects performing Romberg's test with their eyes closed along with subjects standing on a pillow with their eyes open. For several of these tests, almost all subjects were able to hold their balance for the full 30 s. Test-retesting using static posturography by Bland Altman plot showed datapoints scattered equally above and below the mean line indicating no systematic bias. Results of clinical tests and static posturography were not associated. MS was reported from 43% of subjects and a trend was observed with high sway scores from subjects suffering from MS. This was statistically insignificant.

CONCLUSIONS

Due to a ceiling effect, subjects achieved the same scores in both rounds of testing in several of the clinical tests, reducing the clinical importance of these tests. Compared to clinical tests, static posturography seemingly remains the superior method when it comes to evaluation of postural control, although not as easily applicable in a daily clinical setting. When comparing MS and postural control a trend was observed, indicating higher sway scores in subjects suffering from MS.

Effects of progressive resistance training in individuals with type 2 diabetic polyneuropathy: a randomised assessor-blinded controlled trial

AIMS/HYPOTHESIS

The aim of this study was to evaluate the effects of progressive resistance training (PRT) on muscle strength, intraepidermal nerve fibre density (IENFD) and motor function in individuals with type 2 diabetic polyneuropathy (DPN) and to compare potential adaptations to those of individuals with type 2 diabetes without DPN and healthy controls.

METHODS

This was an assessor-blinded trial conducted at the Neurology department, Aarhus University Hospital. Adults with type 2 diabetes, with and without DPN and healthy control participants were randomised to either supervised PRT or non-PRT for 12 weeks. Allocation was concealed by a central office unrelated to the study. The co-primary outcomes were muscle strength in terms of the peak torque of the knee and ankle extensors and flexors, and IENFD. Secondary outcome measures included the 6 min walk test (6MWT), five-time sit-to-stand test (FTSST) and postural stability index obtained by static posturography.

RESULTS

A total of 109 individuals were enrolled in three groups (type 2 diabetes with DPN [n = 42], type 2 diabetes without DPN [n = 32] and healthy control [n = 35]). PRT resulted in muscle strength gains of the knee extensors and flexors in all three groups using comparative analysis (DPN group, PRT 10.3 ± 9.6 Nm vs non-PRT -0.4 ± 8.2 Nm; non-DPN group, PRT 7.5 ± 5.8 Nm vs non-PRT 0.6 ± 8.8 Nm; healthy control group, PRT 6.3 ± 9.0 Nm vs non-PRT -0.4 ± 8.4 Nm; p<0.05, respectively). Following PRT the DPN group improved the 6MWT (PRT 34.6 ± 40.9 m vs non-PRT 2.7 ± 19.6 m; p=0.001) and the FTSST (PRT -1.5 ± 2.2 s vs non-PRT 1.5 ± 4.6 s; p=0.02). There was no change in IENFD following PRT in any of the groups.

CONCLUSIONS/INTERPRETATION

PRT improved muscle strength of the knee extensors and flexors and motor function in individuals with type 2 diabetic polyneuropathy at levels comparable with those seen in individuals with diabetes without DPN and healthy control individuals, while no effects were observed in IENFD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03252132 FUNDING: Research reported in this paper is part of the International Diabetic Neuropathy Consortium (IDNC) research programme, supported by a Novo Nordisk Foundation Challenge Program grant (grant no. NNF14OC0011633) and Aarhus University.

Static Body Balance in Children and Expert Adults Ballroom Dancers: Insights from Spectral Analysis of Shifts

OBJECTIVE

The purpose of this study was to assess the differences in maintaining body balance (influence of different sensorial sub-systems) in a representative sample of active Dance Sport competitors (children and adults).

METHODS

Overall, 13 children and 15 high-level adults sport dancers underwent a static equilibrium test on a force platform, in which 17 different parameters were examined, including a spectral analysis of shifts using an FFT algorithm that can assess the contribution of different somatic-sensory systems on maintaining body balance.

RESULTS

Younger subjects rely on their somatic-sensory reactions to maintain their balance, while adults rely more on the vestibular system, according to shifts' spectral analysis. No differences were noted between the male and female participants.

CONCLUSIONS

Children predominantly use the somatic-sensory system in body balance, while adults make more use of the vestibular system. According to these results and due to the trainability phases, exercises that challenge the somato-sensorial system are recommended to train balance in young dancers, while exercises that challenge the vestibular system are recommended in adult dancers which who have not developed exceptional somato-sensory balance abilities during their growth and training history.

Falls in individuals with type 2 diabetes; a cross-sectional study on the impact of motor dysfunction, postural instability and diabetic polyneuropathy

AIM

To estimate the incidence of falls in individuals with type 2 diabetes compared to healthy controls and to describe the characteristics of fallers with type 2 diabetes in relation to motor dysfunction, postural instability and diabetic polyneuropathy (DPN).

METHODS

This is a cross-sectional study of individuals with type 2 diabetes with DPN (n = 54), without DPN (n = 38) and healthy controls (n = 39). Falls were recorded within the preceding year. DPN was defined by clinical scores and nerve conduction studies. Motor function was assessed by a 6-min walk test (6 MWT), five-time sit-to-stand test (FTSST) and isokinetic dynamometry at the non-dominant ankle and knee. An instability index (ST) was measured using static posturography. Univariate and bivariate descriptive statistics were used for group comparisons.

RESULTS

Compared with healthy controls, individuals with diabetes had a higher incidence of falls 36%, (n = 33) versus 15%, (n = 6), p = 0.02. There were no differences in falls when comparing individuals with and without DPN. Fallers had an impaired 6 MWT versus non-fallers (450 ± 153 m vs. 523 ± 97 m respectively), a slower FTSST (11.9 ± 4.2 s vs. 10.3 ± 2.9 s respectively) and a higher ST (53 ± 29 vs. 41 ± 17 respectively), p < 0.02 for all.

CONCLUSION

Individuals with type 2 diabetes reported a higher number of falls within the preceding year compared to healthy controls, irrespective of the presence of DPN. The main factors associated with falls were increased postural instability, lower walking capacity and slower sit-to-stand movements. The 6 MWT, FTSST and posturography should be considered in future screening programs in identification of individuals at risk for falls.

Balance Ability in Low Back Pain Patients With Lumbosacral Radiculopathy Evaluated With Tetrax: A Matched Case-Control Study

Objective

To compare postural balance ability in patients with low back pain between groups with and without lumbosacral radiculopathy.

Methods

Patients who were referred for electromyography because of low back pain during the period from April 2017 through June 2018 were chosen as subjects. They were divided into groups with and without lumbosacral radiculopathy based on the results of electromyography. We used Tetrax (Sunlight Medical Ltd., Ramat Gan, Israel) to objectively evaluate postural balance ability, and to measure the fall risk, stability index, weight distribution index, and Fourier index.

Results

Patients in the lumbosacral radiculopathy group showed significantly higher fall risk (73.25 vs. 38.00; p<0.05), weight distribution index (8.57 vs. 5.00; p<0.05), and stability index (21.19 vs. 13.16; p<0.05) than those in the group without lumbosacral radiculopathy. The Fourier index at high-medium frequency was significantly increased in the lumbosacral radiculopathy group (8.27 vs. 5.56; p<0.05), whereas weight-bearing on the side of radiculopathy was significantly decreased.

Conclusion

Patients with lumbosacral radiculopathy have decreased postural balance compared with patients without this condition. Somatosensory disturbances in lumbosacral radiculopathy might cause postural balance impairment. Assessment and treatment plan not only for pain reduction but also for postural balance improvement should be considered in the management of patients with lumbosacral radiculopathy.

Age-related Assessment of Postural Control Development: A Cross-sectional Study in Children and Adolescents

The aim of this study was to outline an age-dependent range of posturography measures obtained from healthy children. One hundred and fifty healthy 4-18-year-old children underwent video Head Impulse Test and static posturography testing. Surface, length and power spectra values were compared between each group of pupils and 32 healthy adults. As well as a significant (p < 0.025) increase in surface and length, when compared to healthy adults, increased values within the low/middle frequency domain and within the high frequency domain were also observed in 4-13 and 4-7-year-old children, respectively. In conclusion, although the nature of postural control development remains largely undetermined, this study represents a first attempt to outline an age-dependent normal range of the relative contribution of inputs in typically developing children.