Disclosures. Vestibular Loss in the Pediatric Population: Does vestibular loss. affect more than balance? Learner Objective. Outline 12/15/2015

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1 Vestibular Loss in the Pediatric Population: Does vestibular loss affect more than Kristen Janky, Ph.D. Disclosures Employed by Boys Town National Research Hospital Consulting for Otometrics Received Speaker Honorarium Work discussed has been funded by: 1) Centers of Biomedical Research Excellence (CoBRE) Grant No.: 1P20GM Grant Title: Center for Perception and Comm in Children Project 5: Gaze Stability in Children with Hearing and VL 2) Grant No.: 5P30DC Grant Title: Core Center for Communication Disorders Core C: Human Research Subjects Learner Objective Learners will be able to describe the consequences of vestibular loss in the pediatric population. If a child is diagnosed with hearing loss, are there indications the child may also have vestibular loss? Are there specific consequences of vestibular loss that warrant attention? Photo from: 6raQxc/s1600/Cute baby girl child picture.jpg Outline 1. What is the vestibular system? 2. Do all children with hearing loss have vestibular loss? Does vestibular loss in children affect more than What is the vestibular system? Superior Utricle Posterior Horizontal Saccule Altered from: The.Brain.in.Space page 75 ear vestibular system.png 1

2 What is the vestibular system? What is the vestibular system? Semicircular Canals: ANGULAR ACCELERATION Otolith Organs: LINEAR ACCELERATION Rotary Chair Video Head Impulse Test ng%20head.jpg#turning%20head Copy%20of%20Copy%20of%20Trail%20Run.JPG What is the vestibular system? What is the vestibular system? Ocular VEMP Cervical VEMP Superior Canal vhit Utricle ovemp Posterior Canal vhit Horizontal Canal vhit, Rotary Chair, caloric Saccule cvemp Altered from: The.Brain.in.Space page 75 ear vestibular system.png Prevalence of Vestibular Loss Hearing loss occurs in 1 6 of 1000 newborns ASHA The incidence of vestibular dysfunction estimated between 30 91% (Shinjo et al, 2007; Tribukait et al., 2004; Zhou et al., 2009) Incidence higher (Angeli et al. 2003) As severity of hearing loss increases Post natally acquired cases (meningitis, CMV, ototoxicity) Some syndromic deafness (Usher, Waardenburg, Pendred) Labyrinthine dysplasia Prevalence of Vestibular Loss in Children with Cochlear Implants 2 Categories 1. Prevalence of vestibular loss related to the etiology and severity of the hearing loss 2. The additional risk of vestibular loss associated with the process of cochlear implantation. 2

3 Prevalence of Vestibular Loss in Children with Cochlear Implants 1. Prevalence of vestibular loss related to the etiology and severity of the hearing loss 50% have some degree of vestibular loss 20 30% have bilateral loss Jacot et al. (2009), Jin et al. (2006), Cushing et al (2013), Janky et al. (2015) Vestibular Loss Normal Vestibular Vestibular Loss Bilateral Vestibular Loss Normal Vestibular Prevalence of Vestibular Loss 2. The additional risk of vestibular loss associated with the process of cochlear implantation % some change to vestibular function (Jacot et al, 2009, Jin et al, 2006) 10% complete loss of function in implanted ear (Jacot et al., 2009) Vestibulo ocular Maintain steady vision during head movements Vestibulospinal Maintain posture Vestibulocolic Righting reflex; stabilizes head From Halmagyi & Curthoys, In Herdman Jacobson & Shepard, 2008 Children with significant vestibular loss: Are delayed in gaining head control (Inoue 2013) and in sitting, standing, and walking. Typically developing children sit, stand, and walk at 6 8 m, m, and m, respectively Children with vestibular loss sit, stand and walk at 8 18 m, 9 20 m and m, respectively (Kaga1999) Selectivity of vestibular loss: Infants with absent otolith function (absent VEMP) have been reported to walk later than those with normal otolith function (present VEMP) (Inoue 2013). Older children with residual otolith function (present cvemp) are reported to have better static balance than children without otolith function (absent cvemp) (De Kegel 2012, Jafari 2011, Shall2009) 3

4 Patients with CI failure had significantly higher rate of vestibular loss Bilateral horizontal canal loss increased the odds of CI failure by 7.6 Even though children with vestibular loss may be late to sit, stand, walk, and crawl, are there long lasting effects of vestibular loss in children? When looked at over time, this delay was found to be progressive (Rine et al., 2000) In older children with CI, significant deficits on standardized tests of motor function have been documented Are there are other implications to having vestibular loss? Children with bilateral vestibular loss were more likely to have gross motor delay compared to children with normal vestibular function. Janky et al., Unpublished data The Developmental Profile 3 (DP 3), a standardized screening tool for developmental delays Children with gross motor delay had: Significantly lower standard scores (SS) on the physical subscale [F (1,17) = 9.413, p = 0.007] significantly lower SS on the adaptive behavior subscale [F (1,17) = 8.297, p = 0.01] and the social emotional subscale [F (1,16) = 4.777, p = 0.044], suggesting that the impact of vestibular loss extends beyond gross motor function. Janky et al., Unpublished data Consequences of Vestibular Loss In Adults: Reduced dynamic visual acuity Difficulty reading Decreased quality of life Increased risk of falling Cognitive dysfunction (Herdman 1998a, Guinand 2012, Hall 2004, Whitney 2009). It seems only reasonable to hypothesize that children with vestibular loss might have similar difficulties to adults Decreased Quality of Life Adults with bilateral vestibular loss have reduced : Scores on the Short Form Health Survey, Dizziness Handicap Inventory (DHI) and an increased fear of falling (Guinand et al., 2012) Scores on the DHI and Health Utility Index Mark 3 (HUI3) (Sun et al., 2014) Adaptation to vestibular could be related to personal attitude (Grunfeld et al., 2000) Quality of life and postural control improves with vestibular rehab in both adults and children (Tsukamoto et al., 2015; Rajendran et al., 2013) 4

5 Vestibular Loss and Cognition In animal studies: Spatial memory deficits, which deteriorated in those with bilateral loss and improved in those with unilateral loss. (Zheng et al.) In adults with vestibular loss: Hippocampal atrophy (Brandt et al., 2005) Hippocampus: consolidates info from short to long term memory and spatial navigation. Deficits in short term and working memory (Hanes et al., 2006) PET imaging showed decreased bi lateral activation in the parietoinsular vestibular cortex (PIVC) during caloric stimulation in adults with bilateral vestibular loss compared to healthy controls (Bense et al, 2004) In children with vestibular loss: Some speculate a critical window for certain facets of cognitive function development Reduced Children with sensorineural hearing loss and bilateral vestibular loss found to have significantly worse dynamic visual acuity (DVA) during head movement (Braswell 2006a, Martin 2012, Rine 2003, Rine 2013) Janky & Givens, 2015 LogMAR LogMAR 1. Reading acuity* scores were significantly worse in children with vestibular loss 2. Reading acuity scores correlated with dynamic visual acuity. Children with Cochlear Implants and Vestibular Loss have significantly reduced dynamic visual acuity (DVA), when completed passively (pdva) and actively (adva) * Reading acuity = smallest print size that can be read Adults with bilateral vestibular loss performed significantly worse at visual acuity while standing and walking. No deficit in static visual acuity; however, out of 16 subjects with vestibular loss, n = 3 had BVL 5

6 Why would vestibular loss cause breakdowns in static acuity? Is static visual acuity affected in children with vestibular loss? Braswell & Rine (2004) used reading words Influenced by linguistic skills? Hillman et al (2000) used 5 letter targets Influenced by working memory? Therefore, we hypothesize that if static visual acuity is truly affected by vestibular loss, reductions in visual acuity should be present in response to single letter targets, which are less likely influenced by linguistic, attention, or working memory factors Why would vestibular loss cause breakdowns in static acuity? Neither Hillman et al (1999) nor Braswell and Rine (2004) provide a rationale for why static visual acuity may be affected in adults and children with vestibular loss. One possibility could be the allocation of attentional resources. An individual has a set amount of attention and cognitive resources available to allocate to mental tasks Kahneman s Capacity Model of Attention Or some other factors, such as cognition? Or a combination? Preliminary Unpublished Data Much of the data reported is unpublished and therefore has not undergone peer review. THE EFFECTS OF VESTIBULAR LOSS ON STATIC AND DYNAMIC VISUAL ACUITY Hypotheses: Children with Vestibular Loss will have significantly worse dynamic visual acuity. If static visual acuity is affected by vestibular loss, deficits should occur in response to single letter targets, which are less likely influenced by linguistic, attention, or working memory factors If outcomes are dependent on resource allocation, performance should be degraded as postural challenge at the base of support increases Methods Subjects Age Cochlear Implant Category NO YES TOTAL

7 Methods Vestibular Testing Visual Acuity Testing Subjects positioned at 12.5 ft Combination of 10 Letters: C, D, H, K, O, N, S, R, V, A and Z (NIH Toolbox) 4 postural conditions sitting, standing, standing on foam, and tandem stance Visual Acuity Testing 1 Letter Presentation 5 Letter Presentation Sitting Standing Standing on Foam Tandem Stance Sitting Standing Standing on Foam Tandem Stance Sitting Active Passively Visual Acuity Testing RESULTS 1 Letter Presentation 5 Letter Presentation Percent of children with normal responses In random order At random LOGMAR 0.3, 0, 0.3, 0.7, 1.0, corresponding to Snellen visual acuity of 20/10, 20/20, 20/40, 20/100, 20/200 Subjects wore a head mounted rate sensor positioned in the plane of the horizontal canal (O Navi, Vista, CA, USA) Software was modified from the NIH Toolbox DVA test. Visual targets were presented when head velocities were d/s. vhit HC + vhit PC + vhit AC + cvemp + ovemp + CNH* 100% 100% 97% 99% 79% CCI** 68% 66% 71% 53% 34% *4 CNH did not complete vertical vhit **1 CCI could not complete VEMP due to bilateral atresia + Chi square analysis demonstrated that CCI had a significantly higher rate of vestibular loss (p < 0.001) compared to CNH for all tests of vestibular function. 7

8 Grouping Subjects 1 CNH = 34 CCI NV = 10 CCI VL = 7 6 ACTIVE PASSIVE * * CCI with scores of < 5 = CCI with vestibular loss (CCI VL) group CCI with scores >5 = CCI with normal vestibular group (CCI NV) For adva, there were no significant mean differences between groups (F(2,45) = 2.851, p = 0.068) For pdva, significant mean differences were noted (F(2,44) = 4.45, p = 0.017), CCI VL performed more poorly than CNH and CCI NV Similar adva between groups was an unexpected finding. Schubert et al (2008) demonstrated that DVA can improve with the use of gaze stability exercises due to an increase in avor and an increase in the number of compensatory saccades. Therefore, to investigate this relationship, VOR gain and saccade latency were compared to a and pdva. Gain = eye velocity head velocity There was a significant mean difference in vhit gain between groups (F (2, 47) = 50.02, p < 0.001). vhit gain was significantly correlated with pdva (r = 0.395, p = 0.006); however, not with adva (r = 0.214, p = 0.148). VOR saccade latency were compared to a and pdva. 8

9 Single Letter Static Acuity Five Letter Static Acuity Static Visual Acuity Single and Five Letter Visual Acuity Resource allocation, or the interaction of balance, does not significantly affect static visual acuity. Is visual acuity significantly affected in CCI with or without vestibular loss? Single Letter Visual Acuity SIT Five Letter Visual Acuity SIT 9

10 Static Visual Acuity Contrary to our hypothesis, (preliminarily) it does not appear that static visual acuity is significantly affected in children with vestibular loss Discussion Our findings demonstrate that: CCI with vestibular loss have poorer passive dynamic visual acuity compared to CNH and CCI with normal vestibular function Static visual acuity is not significantly affected in CCI with vestibular loss Increased postural challenge at the base of support does not differentially affect visual acuity in CCI with vestibular loss. Discussion Strike out? If CCI VL have difficulties with reading, it s important to differentiate whether this is an acuity issue or something more complex, but our findings suggest its NOT an acuity issue. CCI are a heterogeneous group and many factors can be affecting performance: Speech, language, access to sound (age of implantation, preimplant hearing status) and other co morbidities. Therefore, future directions are to investigate the influence of other factors, such as speech, language, cognition, etc Discussion One area of concern was our inability to detect a significant difference between groups on active DVA. This could be because: 1. CCI with vestibular loss in this study were well compensated. Schubert et al (2008) demonstrated that DVA can improve with the use of gaze stability exercises due to an increase in avor and an increase in the number of compensatory saccades. 2. Methodology flaw Duration of optotype (85 ms) Algorithm Future Directions Does vestibular loss in children with cochlear implants affect more than We don t feel the full impact of vestibular loss is currently known in children. Future work is needed to investigate the effects of vestibular loss on visual acuity, cognition, quality of life, and social interactions in children. What do we do with this information? The full impact of vestibular loss in children is not currently known; however, research todate demonstrates that the presence of vestibular loss may account for some of the variability in children with hearing loss s success. 10

11 What do we do with this information? 1) You can do your own screening for vestibular loss. Seconds What do we do with this information? 2) Refer for vestibular testing WHO? 1) Children with hearing loss whose etiology (or severity) is associated with vestibular loss; Usher, meningitis, otoxicity, aud neuropathy, malformations, profound HL, Waardenburg s, rubella, CMV, anoxia 2) Children with gross motor developmental delay (particularly with hearing loss); and 3) Children who receive a cochlear implant Dizziness or regression of gross motor function following CI What do we do with this information? 3) Enroll kids in Vestibular Rehabilitation While there are not a lot of studies quantifying the benefit of PT, limited studies suggest: Improved balance Improved QOL Improved visual acuity Improved reading acuity Reduce CI Failure by decreasing falls DON T: Assume children with vestibular loss will catch up to their peers without some help. Learner Objective Revisited Learners will be able to describe the consequences of vestibular loss in the pediatric population. Delayed gross motor function, which can be progressive over time Reduced dynamic visual acuity (Braswell 2006a, Martin 2012, Rine 2003, Rine 2013, Janky et al., 2015) Relationship between DVA and reading acuity children need larger print size for comfortable reading Decreased Quality of Life which can be improved with the use of VBRT Limited suggestions for cognitive difficulties Questions? Thank You Diane Givens, MS, PT, NCS Megan Thomas, AuD Meggie Dallapiazza, AuD Student UW Research study supported by: 1) Centers of Biomedical Research Excellence (CoBRE) Grant No.: 1P20GM Grant Title: Center for Perception and Communication in Children Project 5: Gaze Stability in Children with Hearing and Vestibular Loss Denis Fitzpatrick, PhD 2) Grant No.: 5P30DC Grant Title: Core Center for Communication Disorders Core C: Human Research Subjects 11