Table 2.
Studies addressing central neurological conditions (Sensorineural hearing loss and cochlear implant).
| References | Country | Study design | Participants | Age | Etiology and severity | Comorbidities | Vestibular assessment tools | Main results, outcomes and prevalence | NCO score |
|---|---|---|---|---|---|---|---|---|---|
| Sokolov et al. (40) | Canada | Cohort | 20 children with unilateral SNHL | Mean age: 8.8 y.o. | Unilateral SNHL; severe-profound SNHL (PTA = 96 dB), moderate-severe SNHL (PTA = 67 dB); mild-moderate SNHL | None specified | Caloric test vHIT cVEMP oVEMP |
Abnormal vestibular function found in 12/20 (60%) patients. Abnormal utricle response found in 4/12 (33%) of cases, through oVEMP testing. Abnormal saccular response absents in 3/18 (17%) of cases, through cVEMP testing. Overall otolothic dysfunction shown in 4/19 (21%) patients through either cVEMP and/or oVEMP testing. Abnormal horizontal canal function observed in 7/20 (35%) cases through vHIT testing and observed in 9/19 (48%) cases through calorictesting. |
5/9 |
| Raj and Gupta (21) | India | Cross sectional | 50 children with SNHL | Mean age: 5.48 y.o. Age range: 4–9y.o |
Congenital profound and severe SNHL |
None reported | Warm air caloric test | Abnormal vestibular function found in 9/48 (18.75%) cases through caloric testing | 7/10 |
| Thierry et al. (24) | France | Cohort, retrospective | 43 children with unilateral CI | Mean age: 2.9 y.o. Age range: 6–15.1y.o. |
Etiology of SNHL: genetic mutations, infections, Waardenburg syndrome, meningitis, Kallman syndrome, or idiopathic |
None specified | HIT Bithermal caloric test VEMP |
Decreased ipsilateral vestibular function post-CI observed in 8/43 (18.6%) children. Abnormal contralateral vestibular function found in 3/43 (7%) cases. Worsening of vestibular function post-CI experienced by 2/12 (16.7&) patients. Improvement of vestibular function found in 4/12 (4/12)cases. |
4/9 |
| Wolter et al. (43) | Canada | Cohort, retrospective | 187 Group 1: 22 children who experienced CI failure Group 2: 165 children who did not experience CIfailure |
Not specified | Etiology of SNHL: Meningitis, cochleovestibular anomaly, Usher syndrome, Connexin-26 mutation, Cytomegalovirus |
None specified | Bithermal caloric test Rotational head impulse test/vHIT VEMP |
Abnormal horizontal canal function found in 18/22 (81.8%) children with CI failure vs. 78/165 (47.3%) children without CI failure through bithermal caloric testing. Abnormal high frequency horizontal canal function found in 16/22 (72.2%) children with CI failure vs. 57/165 (34.5%) of children without CI failure through vHIT and/or high frequency rotational chair testing. Abnormal saccular function observed in 18/22 (81.8%) children with CI failure vs. 76/165 (46.1%) children without failure through VEMPtesting. |
6/9 |
| Devroede et al. (41) | Belgium | Cohort, Retrospective | 26 children with unilateral CI, before and after | Mean age: 6.75 y.o Age range: 1–13y.o |
SNHL as part of a clinical syndrome, genetic mutations, post meningitis, CMV infection, auditory neuropathy spectrum disorder, or idiopathic ± unilateral CI ± bilateral /contralateral CI |
None reported | Caloric test VEMP |
Pre-contralateral implantation, 2/26 (8%) showed bilateral areflexia, 16/26 (61%) showed hyporeflexia (i.e., 69% presented with hyporeflexia). Otholitic functioning was abnormal in 5/24 (21%) patients' pre-contralateral implantation, and in 9/24 (37%) post-contralateral implantation, as recorded through VEMP Horizontal canal function changed in 32% of the patients tested through caloric stimulation |
7/9 |
| Cushing et al. (46) | Canada | Cross sectional | Children Group 1: 119 children with unilateral CIs Group 2: 34 childrenpre-CI |
Mean age: 12.95 y.o Age range: 3.6–20y.o |
Profound SNHL with unilateral CI or before implantation procedure | None reported | Caloric test Rotatory chair test VEMP VOR |
Abnormal horizontal canal function found in: 69/139 (50%) through caloric testing, of which 18/69 (26%) reflect mild to moderate unilateral abnormalities, and 51/139 (37%) severe hypofunction or areflexia. Abnormal horizontal canal function found in: 64/139 (47%) through rotatory chair testing. Bilateral reduction in VOR seen in 29% (40/139) Absent saccular function bilaterally in 32/135 (21%) and unilaterally in 40/135 (30%) through VEMP. All children with meningitis (n = 11) and 46% with radiologic cochleovestibular anomalies (n = 31) had horizontal canal dysfunction, whereas 45 and 46%, respectively, displayed saccular dysfunction. |
10/10 |
| Schwab and Kontorinis (47) | Germany | Case control | Group 1: 40 children with SNHL Group 2l: 40 normal-hearingchildren |
Age range: 4–20 y.o, | Deaf of hearing -impaired children admitted for CI exam | None specified | Caloric test SOT, MCT,ADT |
Abnormal vestibular function found in 16/33 (40%) cases through caloric testing. Hypoexcitabililty of vestibular function found in 27/66 (41%) tested ears, whereas hyperexcitability found in 2/66 (3%) tested ears | 4/9 |
| Jafari and Asad Malayeri (48) | Iran | Case control | Group 1: 30 children with SNHL Group 2: 30 healthychildren |
Group 1: Mean age: 6.93 y.o Age range: 6–9 y.o Group 2: Mean age: 7.18 y.o Age range: 6–9y.o |
SNHL congenital or early acquired bilateral profound SNHL | None specified | VEMP, ABR, BOT-2, balance subtest | Abnormal vestibular function was found in 28/32 (87.5%) ears tested through VEMP. Asymmetrical vestibular response found in 4/30 (13.3%) cases through VEMP testing. No vestibular response found in 12/30 (40%) children through VEMPtesting. |
8/9 |
| Licameli et al. (13) | USA | Cohort | Group 1: 42 children with unilateral CI Group 2: 19 children pre andpost-CI |
Group 1: Mean age: 9 y.o Age range: 5–22 y.o Group 2: Mean age: 8 y.o Age range: 2–23y.o |
Patients in Group 1 being considered for a second CI on the contralateral side. | None reported | VOR Computerized dynamic posturography,VEMP |
60% of all patients had abnormal finding(s) in at least one laboratory test. Abnormal ipsilateral VOR response observed in 22/42 (52%) of Group 1. Abnormal findings on Computerized dynamic posturography testing found on 15/38 (39%) of Group 1, which indicate peripheral vestibular weakness and/or sensory organization deficit. Reduced or absent VEMP responses found on 12/15 (80%) of Group 1. Pre-CI, 2/19 (10%) of group 2 patients did not present any VEMP response. Post-CI, 16/19 (84%) of group 2 patients indicated disappearances or reduction of VEMP responses (elevation in VEMP thresholds and/or decrease in VEMPamplitudes). |
7/9 |
| Zhou et al. (19) | USA | Cohort, retrospective | Group 1: 23 children with bilateral SNHL Group 2: 12 healthy children |
Group 1: Age range: 2–16 y.o. Group 2: Age range: 4–18y.o |
SNHL: Moderate, severe, profound. SNHL etiology: bialletic GJB2 mutation, congenital cytomegalovirus infection, bacterial meningitis, cogan syndrome |
None specified | VEMP | Abnormal saccular function found in 21/23 (91.3%) through VEMP testing. | 3/9 |
| Jacot et al. (25) | France | Cohort, Prospective & retrospective | Children with SNHL, 89 of which participated after CI procedure | First examination: Mean age: 51 mon Age range: 7 mon−16.5 y.o Second examination: Mean age of 52.8 mon Age range: 7 mon−12y.o |
SNHL—to be implanted with CI Unilateral CI |
None reported | Bi-caloric test Earth vertical axis rotation Off vertical axis rotation VEMP |
Abnormal bilateral vestibular function found in 112/224 (50%), 45/224 (20%) showed complete areflexia, 50/224 (22.5%) showed partial asymmetrical hypo-excitability, and 17/224 (7.5%) showed partial symmetrical hypo-excitability. Changes of vestibular function post-CI found in 51/71 (71%), from which 7/70 (10%) acquired ipsilateral areflexia Long-term follow up reports partial recovery of vestibular responses is observed in 18.5% of the cases,post-CI |
7/9 |
| Cushing et al. (22) | Canada | Cross sectional | Children with unilateral CIs | Mean age: 3–19.3 y.o | Severe to profound SNHL with unilateral cochlear implants | None reported | Caloric test Rotatory chair test VEMP BOT-2 |
Abnormal horizontal canal function found in: 16/32 (50%) through caloric testing, and 14/37 (38%) through rotatory chair testing. Absent saccular function bilaterally in 5/26 (19%) and unilaterally in 5/26 (19%) through VEMP. Mean BOT-2 scores for children with SNHL and CI were significantly poorer than the norm. |
10/10 |
| Shinjo et al. (49) | Japan | Cross sectional | Children with SNHL | Mean age: 54.2 mon Age range: 31–97 mon (2.5–8y.o) |
Conditions included: Severe SNHL, fitted with hearing aids, congenital profound SNHL, progressive hearing impairment, LVA Etiology: infection, meningitis, congenital auditory nerve disease, common cavity malformation in the inner ear, cochlear nervemalformation |
None specified | Ice water caloric test Damped-rotational chair test VEMP |
Abnormal responses in at least 1 test found in 85% of children Asymmetrical canal responses found in 7/20 (35%) cases, hypo-reactions found in 2/20 (10%) cases, and absence of response observed in 8/20 (40%) cases, all through caloric testing. Decreased uni-directional canal response observed in 1/20 (5%) cases, decreased bidirectional response observed in 2/20 (10%) cases, and absence of response observed in 3/20 (15%) cases, all through rotational chair testing. Asymmetrical saccular response found in 6/20 (30%) cases, and absence of bilateral response found in 4/20 (20%) cases, all through VEMP testing. |
6/9 |
| Jin et al. (50) | Japan | Cross sectional | Group 1: 12 children who underwent CI surgery Group 2: 9 healthychildren |
Group 1: Mean age: 3.8y.o Age range: 2–7 y.o Group 2: Age range: 8 mon−10y.o |
Cochlear implantation (CI) | None | VEMP Calorictest |
Semicircular canal hypofunction found through ice water caloric testing in 6/10 (60%) of cases, and areflexia on 4/10 (40%), post implantation.Saccular function reduction observed in 7/12 (58.3%) of patients, through VEMP testing, post-implantation. | 9/10 |
| Bouccara et al. (51) | France | Cohort, Prospective | Children Group 1: 240 childrenpost-CI Group 2: 28 children assessedpre-CI | Mean age: 7.5 y.o Age range: 2–15y.o |
Idiopathic, genetic, or drug-related hearing loss | None reported | VNG | 9/268 children (3%) present with abnormalities as per the VNG assessment at some point after the implantation | 5/9 |
| Lisboa et al. (15) | Brazil | Cohort | Children with SNHL | Age range: 10–14 y.o | Severity of disease ranged from profound /severe bilateral to unilateral hearing loss | None reported | Ocular and labyrinthic tests Caloric Test RotatoryTest |
Alterations on caloric testing found in 25/26 (96.1%) patients, from which: Unilateral hyporreflexia was found in 4/26 (15.3%) patients Bilateral hyporreflexia was found in 20/26 (76.9%) patients Directional preference of asymmetrical nystagmus was found in 1/26 (3.8%)patients |
7/9 |
| Rine et al. (20) | USA | Cross sectional | Children with SNHL | Age range: 26–83 mon (2–6.9 y.o) | Profound bilateral hearing loss | Developmental delay | PDMS, SCPNT | Hypoactive vestibular function found in 20/39 (51.3%) cases through SCPNT. Hyperactive vestibular function found in 18/39 (46.2%) cases through SCPNT. Children with moderate to profound sensorineural hearing loss have a delay in gross motor development which is progressive and related to vestibular hypofunction. |
7/10 |
| Horak et al. (52) | USA | Case-control | Group 1: 54 normal developing children Group 2: 30 children with bilateral hearing impairment Group 3: 15 children with learning disabilities | Age range: 7–12 y.o. Mean age: 9.2y.o |
Bilateral hearing loss acquired within the first two years of life, congenital, post-meningitis, unknown etiology | None reported | Horizontal VOR Sensory organization for postural orientation test BOT for MotorProficiency |
Abnormal VOR observed in 20/30 (67%) patients. Hearing-impaired children with vestibular loss scored at the 29th percentile in motor proficiency because of a mean balance score only half thenormal. |
7/9 |
| Potter and Silverman (53) | USA | Case Control | Children with SNHL | Mean age: 6.1 y.o Age range: 5–8.11y.o. |
Hearing loss in the better ear ranged from 55 to 120 dB. Average hearing loss: 100.5dB. |
None reported | SCPNT Standing Balance subtests (eyes open and closed) of the Southern California Sensory Integrationtests |
Abnormal (hypoactive) vestibular response found in 20/34 (58.8%) of cases through rotatory test (scores compared to norms). 15/34 (44.1%) showed no response to vestibular stimulation. With eyes open, 44.1% of the deaf children had abnormal standing balance. With eyes closed, 35.3% had abnormalbalance. |
4/9 |
| Rosenblut et al. (54) | USA | Case Control |
Group 1: 107 children with SNHL Group 2: 57 aphasic children (not relevant) Group 3: 16 healthy children |
Age range: 3–13 y.o | SNHL resulting from: Meningitis family history, maternal rubella, complications during pregnancy, or congenital brain abnormality | Possible congenital brain abnormality | Nystagmus assessment through modification of the test originated by Fitzgerald and Hallpike | Depressed vestibular function found in 25/107 (23.4%) cases, and absent response reported in 27/107 (25.2%) according to nystagmus assessment. | 5/9 |
vHIT, video head impulse test; cVEMP, cervical vestibular evoked myogenic potential; oVEMP, ocular vestibular evoked myogenic potential; SOT, sensory organization test; MCT, motor control test; ADT, adaptation test; ABR, auditory brainstem response; BOT-2, Bruininks-oseretsky test (second edition); LVA, large vestibular aqueduct; VNG, Videonystagmography; PDMS, peabody developmental motor scale; SCPNT, Southern California post-rotatory nystagmus test; VOR, vestibulo-ocular reflex; y.o, years old; NOS score, Newcastle-OttawaScale.