Influence of a vestibular dysfunction on the motor development of hearing impaired children

Hearing impaired children have a higher risk for motor deficits and more specifically balance deficits. Since balance control requires integration of visual, somatosensory, and vestibular information by the central nervous system to generate motor responses that keep the body in balance, the balance problems of hearing impaired children might not be surprising. The vestibule and the cochlea are closely related both anatomically and developmentally. Consequently, it is reasonable to presume that many hearing impaired children have concomitant vestibular loss. However, all mechanisms causing poor balance are not yet investigated systematically in auditory impaired children. The main objective of this thesis was to identify the predictive ability of vestibular function test results as well as other factors like the degree of the hearing loss, the etiology of the hearing loss, a cochlear implantation, and additional disabilities on the motor performance in hearing impaired children. Beforehand, the usefulness of different assessment tools to evaluate postural stability in children needed to be investigated. This aim was achieved through different studies: reliability and validity of posturography and clinical balance tests in children between 6 and 12 years, usefulness of the norm reference values of the Alberta Infant Motor Scales (AIMS) in Flemish infants between 0 and 18 months, and reliability and validity of the Ghent Developmental Balance Test (GDBT) in children between 18 months and 5 years. Reliable information regarding postural stability of typically developing children and hearing impaired children between 6 and 12 years may be obtained utilizing posturography and clinical balance tests. From different COP (Center of Pressure) stability parameters, sway velocity is the most reliable parameter. The standard deviation (SD) of sway velocity, sway area, SD of anterior–posterior and SD of medio-lateral COP data showed moderate to excellent reliability but some caution must be taken into account in some conditions, like in bipedal standing with eyes open. Clinical balance tests have proven to be as reliable as the sway velocity of posturography. Correlations among the different balance assessment tools were low, confirming that posturography and clinical balance tests are two different constructs in the assessment of balance control. They provide different but complementary information. Therefore, an assessment protocol for balance consisting posturography as well as clinical balance tasks is proposed. Balance cannot be evaluated by a single test and it can only be interpreted in relation to different tests used in an assessment. New reference values are needed for the AIMS, an assessment tool to examine the gross motor movement repertoire in infancy, for accurate identification of infants at risk for motor developmental delay. The lower motor scores seen in Flemish infants seems to be related to the sleep position, the amount of play time in prone, in supine, and in a sitting device. Tummy time in a supervised environment and variation in play positioning must be advocated to optimize early motor milestone acquisition. The GDBT is a new assessment tool for the evaluation of balance in toddlers and preschool children. The GDBT appears to be a promising outcome measurement tool to screen for balance difficulties and to plan intervention programs aimed at improving balance. Test-retest and inter-rater reliability of the GDBT is excellent. Correlations between the GDBT and balance subscales of other motor assessment tools are moderate to high while correlations with subscales measuring constructs other than balance are low, confirming the construct validity of the GDBT. Hearing impaired children are at risk for balance deficits. The balance deficits can be predicted by vestibular function test results, rotatory chair and Vestibular Evoked Myogenic Potential (VEMP) testing, as well as by the etiology of the hearing impairment. Presence of a VEMP response is an important clinical parameter because comparison of motor performance among hearing impaired children between those with present and absent VEMPs showed significant differences in balance performance. The three most important predictor variables on motor performance by bivariate regression analyses are the vestibular–ocular reflex (VOR) gain value of the rotatory chair test at 0.01 and 0.05 Hz frequency, as well as the VEMP asymmetry ratio. Multivariate regression analyses suggest that the VOR asymmetry value of the rotatory chair test at 0.05 Hz and the etiology of the hearing loss seem to have additional predictive value. It can be concluded that balance deficits in hearing impaired children are strongly associated with the function of the vestibular apparatus and that reliable and valid test protocols are available to evaluate the balance performance in children. Those test protocols are important for future research about the influence of a cochlear implantation on the motor performance of hearing impaired children

Ghent developmental balance test, manual

Balance is a fundamental component of movement, involving the ability to recover from instability and to avoid instability, to anticipate balance disturbances. Various developmental motor disorders cause poor balance, resulting in difficulties with postural control and disturbing the development of numerous activities of daily living. To plan interventions for these young children with motor disabilities, a specific measure to evaluate balance is an essential part of the assessment. Most of the standardized developmental motor tests encompass balance tasks. However the isolated balance items can not be interpreted. Therefore, we aim to develop a new assessment tool to evaluate balance from independent walking to 6 years of age. The Ghent Developmental Balance Test aims at offering a complete developmental series of tasks, reflecting specifically the development of the child’s balance abilities. This test is fit for typically developing children between 18 months and six years zero months or for children with a similar level of balance control

Gentse evenwichtstest: handleiding

Evenwicht is een fundamentele voorwaarde tot bewegen. Het is de mogelijkheid om een toestand van instabiliteit te herstellen en/of een toestand van instabiliteit te vermijden door te anticiperen op evenwichtsverstoringen. Verschillende ontwikkelingsstoornissen kunnen leiden tot een verstoring van de motorische ontwikkeling, vaak is dit gekoppeld aan een verstoorde ontwikkeling van het evenwicht. Verstoorde evenwichtsreacties leiden tot moeilijkheden met posturale controle en beïnvloeden de ontwikkeling van verschillende activiteiten van het dagelijkse leven. Om de behandeling van jonge kinderen met motorische stoornissen te plannen en te evalueren, is een specifiek meetinstrument om evenwicht te evalueren essentieel. Er zijn een aantal gestandaardiseerde testen beschikbaar om de motorische vaardigheden van kinderen te evalueren. De meeste gestandaardiseerde motorische testen bevatten een aantal evenwichtstaken. Sommige testen bieden zelfs een specifieke subscore voor evenwicht aan. Desondanks stellen we vast dat op basis van een grondige screening van de testen er een nood is aan een testbatterij om specifiek het evenwicht van peuters en kleuters te evalueren. De Gentse evenwichtstest werd ontwikkeld om het evenwicht te evalueren van kinderen vanaf het moment van zelfstandig stappen tot en met de leeftijd van 5 jaar. De test biedt een complete reeks van evenwichtstaken aan in een ontwikkelingsvolgorde welke de specifieke ontwikkeling van het evenwicht weerspiegelt. De test kan worden toegepast voor typisch ontwikkelende kinderen van 18 maanden tot en met 5 jaar of voor kinderen met een gelijkaardig niveau van evenwichtscontrole

Examining the impact of cochlear implantation on the early gross motor development of children with a hearing loss

Objective: As deaf children are now implanted at a very early age, the influence of a cochlear implant (CI) on the early motor development of children with a hearing loss becomes relevant. Design: Forty-eight children with a hearing loss were included in this controlled prospective follow-up study and were subdivided into a CI group (n = 23) receiving a CI during the follow-up period and a control group (n = 25) receiving no CI during the follow-up period. All children were assessed around the ages of 6 (T1), 12 (T2), 18 (T3), and 24 (T4) months with a motor test battery consisting of the Peabody Developmental Motor Scales-2 (PDMS-2), Alberta Infant Motor Scales (AIMS) (only at T1 and T2), and Ghent Developmental Balance Test (GDBT) (only at T3 and T4). In addition, collic vestibular-evoked myogenic potential testing was performed in all children. Group differences in PDMS-2 Gross Motor Quotient (GMQ), Fine Motor Quotient, AIMS z score, and GDBT z score were analyzed using Linear Mixed Model (LMM) analysis for repeated measures. Results: For PDMS-2 GMQ, the LMM revealed significant effects for group (p = 0.04), test moment (p < 0.001), and for the interaction between these two factors (p = 0.035). Contrasts indicated that the CI group showed a greater deterioration in PDMS-2 GMQ between T2 and T3 compared with that showed by the control group (p = 0.002). The LMM for PDMS-2 Fine Motor Quotient and AIMS z score showed no significant effects. For GDBT z score, the LMM pointed out significant effects for group (p = 0.013) and test moment (p < 0.001), but no significant interaction between these two factors. Contrasts indicated that the CI group performed significantly weaker than the control group at both test moments (T3 and T4; all p < 0.012) and that both groups showed a significant recovery in GDBTz scores between T3 and T4 (all p < 0.012). Conclusions: This study shows that the trajectory of gross motor development can be changed in children with a hearing loss after a cochlear implantation. Implanted children show a drop in their gross motor performance within the age range of 6 to 18 months, at which period the majority of the implantations took place, with a tendency of recovery toward the age of 2 years. However, longer follow-up will be necessary to trace whether the implanted children catch up their motor delay in comparison with nonimplanted children with a hearing loss at later age

Impact of a cochlear implantation on vestibular and balance functioning

Objective: Because the influence of Cochlear Implants (CI) on vestibular and balance functioning is still unclear, 2 controlled prospective follow-up studies were done. Methods: This first study was a follow-up study of deaf infants that received CI during their first years of life. CI group and control group were assessed around the ages of 6, 12, 18 and 24 months with a motor test battery and collic Vestibular Evoked Myogenic Potential (cVEMP). The second study was a follow-up study of older children that received CI within 4 to 12 years. The Ci group was evaluated by a motor test battery, cVEMP and rotationary chair testing before and after the implantation. The matched control group was tested twice with the same duration between the 2 test moments as for the CI group. Results and conclusions: Both studies showed that a CI has a negative impact on the gross motor development. The implanted children of the first study showed a drop in their gross motor performance within the age range of 6 to 18 months, at which period the majority of the implantations took place. The second study showed a deterioration in the balance performance after the implantation. The impact of CI on vestibular tests, showed no remarkable significant findings but showed clear trends of lower rotatory gain values and lower cVEMP amplitude values after the implantation. longer follow-up will be necessary to trace if the implanted children catch up their motor delay in comparison to non-implanted hearing impaired children