Unreliable association between self-reported sense of direction and peripheral vestibular function.

BACKGROUND: Uni- or bilateral peripheralvestibular impairment causes objective spatial orientation deficits, which can be measured using pen-and-paper-tests or sensorimotor tasks (navigation or pointing). For patients' subjective orientation abilities, questionnaires are commonly used (e.g., Santa Barbara sense of direction scale [SBSODS]). However, the relationship between subjective assessment of spatial skills and objective vestibular function has only been scarcely investigated. METHODS: A total of 177 patients (mean age 57.86 ± 17.53 years, 90 females) who presented in our tertiary Center for Vertigo and Balance Disorders underwent neuro-otological examinations, including bithermal water calorics, video head impulse test (vHIT), and testing of the subjective visual vertical (SVV), and filled out the SBSODS (German version). Correlation analyses and linear multiple regression model analyses were performed between vestibular test results and self-assessment scores. Additionally, groupwise vestibular function for patients with low, average, and high self-report scores was analyzed. RESULTS: Forty-two patients fulfilled the diagnostic criteria for bilateral vestibulopathy, 93 for chronic unilateral vestibulopathy (68 unilateral caloric hypofunction and 25 isolated horizontal vestibulo-ocular reflex deficits), and 42 patients had normal vestibular test results. SBSODS scores showed clear sex differences with higher subjective skill levels in males (mean score males: 4.94 ± 0.99, females 4.40 ± 0.94; Student's t-test: t-3.78, p < .001***). No stable correlation between objective vestibular function and subjective sense of spatial orientation was found. A multiple linear regression model could not reliably explain the self-reported variance. The three patient groups with low, average, and high self-assessment-scores showed no significant differences of vestibular function. CONCLUSION: Self-reported assessment of spatial orientation does not robustly correlate with objective peripheral vestibular function. Therefore, other methods of measuring spatial skills in real-world and virtual environments are required to disclose orientation deficits due to vestibular hypofunction.

Evaluation and diagnosis of pediatric patients with dizziness.

PURPOSE OF REVIEW: Children experiencing dizziness frequently go unevaluated or experience delays in correct diagnosis due to systemic and inherent barriers. While most causes of pediatric dizziness do not involve the peripheral vestibular system, otolaryngologists are frequently consulted for expert opinion. This study offers a broad overview of the leading causes of pediatric dizziness and imbalance to assist otolaryngologists with evaluating and managing this challenging population. RECENT FINDINGS: Evaluation of children with dizziness should exclude serious central nervous system conditions. Approximately 70% of nonhazardous cases of pediatric dizziness are caused by migraine-related conditions, concussion, or functional disorders. Etiologies for peripheral vestibular dysfunction include inner ear malformations and vestibular disorders more commonly seen in adults. Audiometric and vestibular testing can provide helpful information, although correct diagnosis depends on a detailed history. SUMMARY: Otolaryngologists should be familiar with the conditions that cause dizziness in children. While most underlying causes are outside their scope of practice, understanding possible etiologies can facilitate correct diagnosis and appropriate management.

Neuro-ophthalmic and Neuro-otologic Evaluation in Individuals with Motion Sickness Susceptibility.

Since the physiological background of motion sickness is not entirely clear, it was aimed to examine the physiological differences in groups consisting of individuals susceptible and non-susceptible to motion sickness. Sixty subjects [motion sickness (MS) group: 33 female, 3 male; 28.8 ± 8.1 years; control group: 19 female, 5 male; 24.5 ± 4.3 years] were included in the study. Near visual acuity test on the treadmill in the presence of visual stimulation, pattern visual-evoked potentials, oculomotor tests, and computerized dynamic posturography were applied. Receiver operating characteristic analysis was performed to determine the parameter that provides the excellent discrimination between the groups. The most effective parameter in differentiating the study groups was determined as dynamic visual acuity with 77.8% sensitivity and 95.8% specificity. Significant differences were found in the vestibular (mean ± standard deviation: 0.63 ± 0.17), visual (0.77 ± 0.18), and composite scores (73.11 ± 11.89) of the patients (P=.000) in posturographic evaluation. In the visual-evoked potential examination, a significant decrease was found in the amplitude values between the P100-N145 waves in the binocular (5.0 ± 2.8, P=.002), right eye (7.6 ± 3.2, P=.009) and left eye (7.9 ± 2.9, P=.016) in the symptomatic patients. In binocular oculomotor evaluation, directional asymmetric findings were obtained. It has been shown that the most effective test parameter that distinguishes the MS susceptible and non-susceptible individuals is the dynamic visual acuity value. Based on the results of neuro-physiological tests, it was suggested that a possible visual-vestibular integration disorder in individuals susceptible to motion sickness may affect visual and vestibular performance.

Differentiating Definite and Probable Ménière Disease: A Comprehensive Evaluation of Audio-Vestibular Function Testing Combined with Inner Ear MRI.

OBJECTIVES: To evaluate the differences between audio-vestibular function testing and inner ear gadolinium magnetic resonance imaging (MRI) in distinguishing definite Ménière disease (DMD) and probable Ménière disease (PMD), and to provide a reference for early clinical diagnosis and intervention. METHODS: A total of 116 patients diagnosed with DMD (n = 80) and PMD (n = 36) were enrolled. The differences in the results of pure tone audiometry, caloric test, and tympanic injection of gadolinium for contrast-enhanced MRI between the two groups were compared and analyzed. Parameters that could differentiate between the two conditions were identified, and the sensitivity and specificity and the area under the curve (AUC) of individual and combined indices in the differential diagnosis of DMD and PMD were evaluated. RESULTS: The hearing threshold and hearing asymmetry rate of the DMD group were significantly higher than those of the PMD group (p < 0.001), 98.8% and 30.6%, respectively. The abnormal rates of canal paresis (CP) and severity of endolymphatic hydrops in the DMD group were higher than those in the PMD group (p < 0.05). When combined with high-frequency hearing thresholds, hearing asymmetry, hearing curve type, endolymphatic hydrops, and abnormal CP, the diagnostic accuracy of DMD was improved compared to using high-frequency alone (p < 0.05). CONCLUSION: This study showed that PMD and DMD may represent two different stages in the development of MD disease. The comprehensive assessment of audio-vestibular function testing and inner ear MRI proves beneficial for early diagnosis, potentially contributing to the preservation of inner ear function.

Hyperventilation-Induced Nystagmus in Acute Unilateral Vestibulopathy: A Correlation with Vestibulo-ocular Reflex Gain and Clinical Implication.

Hyperventilation-induced nystagmus test (HINT) is capable of generating a response in 77.2% of cases of acute unilateral vestibulopathy (AUVP); both nystagmus toward the affected side (excitatory pattern) and toward the healthy side (inhibitory pattern) have been described. The aim of the study is to investigate the clinical and prognostic role of the test by evaluating its correlation with vestibulo-ocular reflex (VOR) gain. We evaluated 33 AUVP patients by performing the HINT and video head impulse test (V-HIT) during the acute phase and then at 15 and 90 days after the onset of the symptoms. The correlation between the VOR gain of the affected side and test responses was evaluated first, phase by phase, and then considering the pattern shown during the first assessments. Patients with a negative HINT had a higher mean VOR gain than patients with a positive test at both 15 and 90 days. Patients who showed an inhibitory pattern at the first assessment had a continuous improvement in V-HIT performance, while patients with an initial excitatory response had a transient decrease in gain at the subsequent evaluation (P=.001). No difference between these 2 groups emerged at 90 days (P=.09). The finding of a negative HINT during the follow-up correlates with good V-HIT performance and could be an indicator of good recovery. The inhibitory pattern is associated with a subsequent improvement; and it would be indicative of compensation. but, despite this, the prognostic value of the test is limited.

Normative values to Horus® computerized posturography in children. / Valores normativos para a posturografia computadorizada Horus® em crianças.

PURPOSE: Propose normalization values of the Horus® computerized posturography platform, in children aged 4 to 6 years, without auditory and/or vestibular complaints. METHODS: Cross-sectional study, 216 children aged 4 to 6 years participated. All the children underwent to visual screening, audiological evaluation and computerized posturography, which consists of research on stability limits and seven sensory conditions. The results were statistically analyzed using the tests non-parametric Kruskal-Walli, post hoc Dunn-Bonferroni for pairwise age comparisons and the Mann-Whitney U for sex analysis. Categorical data were presented in relative frequency and quantitative data in mean and standard deviation. RESULTS: Standardization values were described for the stability limit and for the seven sensory conditions. There was a difference for the stability limit between sex at 4 years old(p<0.007) and, in the comparison between ages 4 and 5 (p=0.005) and 4 and 6 years old(p<0.001). In the residual functional balance, comparison between ages, there was a difference between 4 and 5, 4 and 6, 5 and 6 years, however for different data. The presence of statistical difference for different evaluation data also occurred in the analysis by sex. In the sensory systems, the findings between ages showed differences for the vestibular system, right and left optokinetic visual dependence, tunnel visual dependence and for the composite balance index. CONCLUSION: It was possible to establish normative values for the Horus® posturography in healthy children aged 4 to 6 years.

OBJETIVO: Propor valores de normatização da plataforma de posturografia computadorizada Horus®, em crianças de 4 a 6 anos, sem queixas auditivas e/ou vestibulares. MÉTODO: Estudo transversal. Participaram 216 crianças na faixa etária de 4 a 6 anos. Todas realizaram triagem visual, avaliação auditiva e posturografia computadorizada composta por pesquisa do limite de estabilidade e sete condições sensoriais. Analisaram-se os resultados estatisticamente por testes não paramétrico Kruskal-Walli, post hoc Dunn-Bonferroni para comparações par-a-par nas idades e U de Mann-Whitney para análise entre sexo. Os dados categóricos foram apresentados em frequência relativa e os dados quantitativos pela média e desvio padrão. RESULTADOS: Foram descritos valores de normatização para o limite de estabilidade e para as sete condições sensoriais. Houve diferença para o limite de estabilidade entre sexos aos 4 anos (p<0,007) e, na comparação entre as idades 4 e 5 anos (p=0,005) e 4 e 6 anos (p<0,001). No equilíbrio funcional residual, comparação entre idades, houve diferença entre 4 e 5, 4 e 6 e, 5 e 6 anos, entretanto para diferentes dados. A presença de diferença estatística para diferentes dados da avaliação, ocorreu também na análise por sexo. Nos sistemas sensoriais os achados entre idades mostraram diferença para o sistema vestibular, dependência visual optocinética direita e esquerda, dependência visual túnel e para índice de equilíbrio composto. Sugere-se que para esta população, as respostas na posturografia sejam analisadas por faixa etária e sexo. CONCLUSÃO: Foi possível estabelecer valores normativos para a posturografia Horus® em crianças hígidas na faixa etária de 4 a 6 anos.

The First 100 Children Treated in a Newly Established Pediatric Vertigo Center.

BACKGROUND: Correctly diagnosing dizziness in children is essential for appropriate management; nevertheless, healthcare professionals face challenges due to children's limited ability to describe their symptoms and their cooperation during physical examination. The objective of this study is to describe the first 100 patients seen at a newly established pediatric vertigo center. METHODS: This is a retrospective review of a consecutive series of 100 patients seen at our pediatric vertigo clinic in a tertiary referral center from August 2019 until June 2022. Comprehensive clinical data were collected. The diagnoses were established by 2 pediatric otolaryngologists based on validated diagnostic criteria. Trends in diagnosis, investigation, and treatment of these patients were analyzed. RESULTS: A total of 100 children were included in the study. Vestibular migraine was the most common diagnosis (20%) followed by benign paroxysmal vertigo of childhood (14%). Eleven patients had combined pathologies. Fifteen out of 70 children (21%) had abnormal audiograms, 30 out of 48 children (62.5%) had abnormal vestibular testing, and 6 out of 31 (19%) patients had abnormal imaging. Fifty-one children received medical treatment, 23 received vestibular physiotherapy, and 9 patients had particle repositioning maneuvers; moreover, 17 of these patients received multimodal treatment. CONCLUSIONS: Our analysis suggests that imaging and audiology testing have relatively low yield in the assessment of pediatric vertigo. On the other hand, vestibular testing detected a high proportion of abnormalities, such as saccadic pursuit, vertical nystagmus, central positional nystagmus, and abnormal directional preponderance, particularly associated with vestibular migraine. Given the complexity of diagnosing vertigo in children, it is critical to establish multidisciplinary specialized centers capable of providing accurate diagnosis and treatment for these children.

[Test-retest reliability of subjective visual vertical from different head-tilt angles in young healthy adults].

Objective:To establish the normal values of subjective visual vertical （SVV） in different head deflection angles and analyze its test and retest reliability, in order to provide a reference for the clinical application of SVV in the evaluation of vestibular disorders. Methods:Thirty-one healthy young people were selected to wear VR glasses, and the SVV data were tested in five different head-tilt, namely, 0° in the upright head position, 45°in the left head position, 45° in the right head position, 90° in the left head position, and 90° in the right head position, and were re-tested 2 weeks later. Results:①The mean values of SVV at 5 different head-tilt angles of 0°, left 45°, right 45°, left 90°, and right 90° were -0.07±1.71, 4.30±5.39, -6.51±5.58, -3.76±7.42, and 0.40±8.02, respectively, The 95% confidence limits of SVV at 0°, left 45°, right 45°, left 90°, right 90°, and right 90° were （-3.42, 3.28）, （-6.26, 14.86）, （-17.45, 4.43）, （-18.30, 10.78）, and（-15.32, 16.12）, respectively; ②The absolute values of SVV at 4 different head-tilt angles of left 45°, right 45°, left 90°, and right 90° were 5.62±3.96, 6.90±5.07, 6.82±4.70 and 6.48±4.68, respectively. The 95% confidence limits of SVV at left 45°, right 45°, left 90°, right 90°, and right 90° were（0，12.11）,（0，15.21）,（0，14.53）and（0，14.16）, respectively. The asymmetry ratio is 10% for the absolute value of the 45 ° deviation and 3% for the absolute value of the 90° deviation; ③Intra-class correlation coefficients（ICC） for 0°, left 45°, right 45°, left 90°, right 90°were 0.757, 0.673, 0.674, 0.815, and 0.856, respectively. Conclusion:SVV has good retest reliability and high stability, and the SVV normal value data of different head deviation angles established in the present study can be used as a reference for the diagnosis and evaluation of vestibular disorders.

Cervical and Ocular Vestibular Evoked Myogenic Potentials in Fibromyalgia Syndrome Patients.

BACKGROUND:  Fibromyalgia syndrome (FMS) is a chronic pain condition that may be associated with dysfunction in the central nervous system. OBJECTIVE: The aim of this study was to assess the vestibulo-spinal reflex (VSR) and vestibulo-ocular reflex (VOR) in FMS using the cervical vestibular evoked myogenic potential (cVEMP) and ocular vestibular evoked myogenic potential (oVEMP) tests, respectively, and to evaluate their relation to disease severity. METHODS:  This study included 30 female FMS patients and 30 well-matched healthy controls. They underwent full history taking and assessment of the severity of dizziness/vertigo using the Dizziness Handicap Inventory; assessment of the severity of FMS symptoms using the Revised Fibromyalgia Impact Questionnaire; bedside examination of the dizzy patient; videonystagmography, cVEMP, and oVEMP tests; basic audiologic evaluation; and uncomfortable loudness level (UCL) testing. RESULTS:  Dizziness was reported in 46.6% and vertigo in 11.1% of patients. Abnormalities in cVEMP (50%) and oVEMP (63.3%) were mostly unilateral, irrespective of FMS severity. Disease duration affected only the oVEMP amplitude. Fibromyalgia syndrome patients had a statistically significant lower UCL and narrower dynamic range compared to controls. CONCLUSION:  The VSR and VOR are commonly affected in FMS patients, and findings suggest central sensitization involving the brain stem. We recommend routine cVEMP and oVEMP testing to assess brainstem function in FMS patients.

Clinical Assessment of the Nystagmus Fixation Suppression Test: An Experimental Study.

BACKGROUND:  Assessment of nystagmus fixation suppression can be used as an additional diagnostic tool for patients with an acute vestibular syndrome to distinguish between a central or peripheral cause. We investigated the ability of physicians to detect fixation suppression using a nystagmus simulation model. METHODS:  We used a nystagmus simulator to measure the accuracy of the nystagmus fixation suppression test. Fixation suppression was assessed randomly in 6170 trials by 20 otorhinolaryngologists and neurologists, segregated into 2 groups based on their neurootological experience, a beginner and an experienced group. The simulator presented random nystagmus slow velocity (SPV) reductions and presented 3 conditions with either changed nystagmus frequency, amplitude, or both. RESULTS:  The cutoff for the discernment of fixation suppression ranged from 1.2 to 14°/s nystagmus velocity difference. The more intense the baseline nystagmus was, the more difficult was the detection of fixation suppression. There was not significant difference (P >.05) in the cutoff values in the experts group compared to the novices for all 3 different conditions. Both, novices and experts, detected frequency changes easier than differences of the nystagmus amplitude. Test sensitivity was very low (19%-65%) for discernment of small nystagmus velocity differences of <2°/s by experts. CONCLUSION:  In our study, there was no difference between experts and novices in detection of nystagmus suppression by visual fixation. The examiners could only detect large suppression effects at low-intensity baseline nystagmus. Overall, the sensitivity and accuracy of a clinical fixation suppression test is low and the assistance with a video-oculography device is highly recommended.

Otology: Vertigo.

Vertigo, an unexpected feeling of self-motion, is no longer characterized simply by symptom quality but by using triggers and timing. Evaluating vertigo by triggers and timing not only distinguishes serious central causes from benign peripheral causes, but also narrows the differential diagnosis by further classifying vertigo as spontaneous episodic vestibular syndrome, triggered episodic vestibular syndrome, or acute vestibular syndrome. A targeted physical examination can then be used to further delineate the cause within each of these three vestibular categories. Neuroimaging and vestibular testing are not routinely recommended. In the management of vertigo, vestibular hypofunction can be treated with vestibular rehabilitation, which can be self-administered or directed by a physical therapist. Pharmacotherapy sometimes is indicated for vertigo based on triggers, timing, and the specific condition, but it is not always beneficial and is used more often for symptom reduction than as a cure. Transtympanic corticosteroid or gentamicin injections are recommended for patients who do not benefit from nonablative therapy. Surgical ablative therapy is reserved for patients who have not benefited from less definitive therapy and have nonusable hearing.

A Quantitative Study of the Head Pitching Test for Lateral Canal BPPV.

OBJECTIVES: Lateral semicircular canal BPPV (LSC-BPPV) is diagnosed with the Head Yaw Test (HYT) by observing nystagmus direction and comparing the nystagmus intensity on both sides according to Ewald's laws. Head Pitching Test (HPT) is a diagnostic maneuver performed in the upright position by bending the patient's head forward (bowing) and backward (leaning) and observing the evoked nystagmus. We aimed to assess the sensitivity of HPT in correctly diagnosing LSC-BPPV through the quantitative measurement of Bowing and Leaning nystagmus slow-phase velocity (SPV). METHODS: One hundred cases of LSC-BPPV were prospectively enrolled. HPT was performed, looking for pseudospontaneous, bowing, and leaning nystagmus. HYT was considered for the "final diagnosis." HPT was defined as "diagnostic" if the nystagmus was present in at least one position, "undiagnostic" if no nystagmus was detectable. The direction and the SPV of nystagmus in all positions were analyzed and compared to determine the degree of agreement between HPT and HYT. OUTCOMES: Sixty-four geotropic and 36 apogeotropic forms were diagnosed. HPT was diagnostic in 80 cases, with no difference between the two forms. According to Ewald's laws, the direction of stronger nystagmus evoked by HPT agreed with the HYT results in 39/52 (75%) cases in geotropic forms and 21/28 (75%) cases in apogeotropic forms. The agreement between HPT and HYT was "substantial" considering all the cases and "almost complete" considering only the patients with diagnostic HPT. CONCLUSION: Quantitative HPT is a valid test in diagnosing the affected side and form of LSC-BPPV, even if less reliable than HYT.

Positional End-Point Nystagmus in Patients with Diagnosis of Acute Unilateral Vestibulopathy.

INTRODUCTION: Recently, end-point nystagmus, traditionally observed in an upright position, has been identified in the Dix-Hallpike position among healthy subjects, suggesting a physiological origin.However, its characteristics in individuals with vestibular hypofunction remain unexplored. OBJECTIVE: To elucidate the impact of vestibular hypofunction on the characteristics of positional end-point nystagmus. METHODS: Thirty-one patients diagnosed with acute unilateral vestibulopathy according to Bárány Society criteria were selected. A video head impulse test was conducted in all participants, followed by McClure and Dix-Hallpike maneuvers with and without gaze fixation, and with the initial position of the eye in the straight-ahead position or in the horizontal end-point position. Nystagmus direction, sense, latency, slow-phase velocity, and duration were recorded. The relationship between these characteristics and video head impulse test values was analyzed. RESULTS: Positional end-point nystagmus was observed in 92.6% of subjects with vestibular hypofunction, significantly more than in healthy individuals. Nystagmus direction varied depending on the performed positional test and on the vestibulo-ocular reflex gains. Gaze occlusion and the initial horizontal end-point position increased its frequency. CONCLUSION: Vestibular hypofunction influences the manifestation of positional end-point nystagmus. Recognizing this nystagmus can aid in resolving diagnostic uncertainties and preventing the misdiagnosis of benign paroxysmal positional vertigo in subjects with acute unilateral vestibulopathy.

Vestibular Migraine and Recurrent Vertigo in Children: A Diagnostic Focus From a Tertiary Hospital Study.

BACKGROUND: To improve diagnostic precision in pediatric vertigo, particularly in Vestibular Migraine of Childhood (VMC), probable VMC (pVMC), Recurrent Vertigo of Childhood (RVC), and unspecified categories, by delineating clinical characteristics and prevalence to refine diagnostics and treatments. METHODS: Retrospective analysis of 102 pediatric patients (five to 18 years; 46 females, 56 males) at the Dizziness Center of the Otolaryngology Department in a tertiary-level hospital from January 2019 to December 2023. Patients were classified into VMC, pVMC, RVC, and indeterminate groups. Evaluations included audiometry and vestibular tests (video head impulse test [vHIT] or caloric testing), conducted in the audiology unit and vestibular testing laboratory. Data were analyzed using IBM SPSS 20.0. RESULTS: Diagnoses were 8.8% VMC, 31.4% pVMC, 51.0% RVC, and 8.8% indeterminate. Nausea and vomiting were common in VMC and pVMC; cochlear symptoms like tinnitus and hearing loss predominated in VMC. Although vestibular testing showed no significant group differences, VMC had more vHIT abnormalities and RVC had more caloric test anomalies. CONCLUSIONS: This study highlights the need for comprehensive diagnostics in pediatric vestibular disorders, revealing unique and overlapping traits across VMC, pVMC, and RVC. Insights call for further research to refine diagnostic criteria and improve treatment methods.

The Effect of Different Sensory Perturbations on Postural Control and Fall Risk in Benign Paroxysmal Positional Vertigo Patients.

BACKGROUND: Benign paroxysmal positional vertigo (BPPV) patients may experience balance problems in various environmental conditions other than positional dizziness. Therefore, there is a need to investigate the postural control abilities and the ability to use sensory inputs in BPPV patients in different conditions. OBJECTIVE: The aim of this study was to examine the postural control performance of middle-aged adult BPPV patients in easy and difficult balance tasks, the effect of vestibular stimulation on the maintenance of balance, and the risk of falling, by posturographic evaluation in various conditions. METHOD: A total of 26 patients diagnosed with posterior canal BPPV and 26 controls were included in the study. Sensory Organization Test (SOT), Vestibular Stimulation Test (VST), and fall risk assessment (FRA) were applied to the participants, respectively. RESULTS: Significant difference was observed in SOT medio-lateral (ML) plane in Conditions 2 and 5 (p < .05). A significant difference was observed in the vestibular score in the SOT ML plane. No significant difference was observed in VST test scores (p > .05). In the FRA test, a significant difference was observed in the energy and gain parameters in the anterio-posterior plane (p < .05). CONCLUSIONS: The current study examined postural control abilities of patients with BPPV in extensive external conditions and in both planes, using various sensory perturbations and stimulation. It was thought that while BPPV patients were in the active phase of the disease, their postural control skills in the ML plane decreased and they might be at risk of falling.

[Subacute ataxia associated with cerebellar ataxia, neuropathy and vestibular areflexia (CANVAS)]. / Ataxia subaguda asociada a ataxia cerebelosa, neuropatía y arreflexia vestibular (CANVAS).

Cerebellar ataxia, neuropathy, and vestibular areflexia syndrome (CANVAS) is a late onset neurodegenerative disorder. Its genetic basis has recently been identified in the gene encoding a subunit of the Replication Factor C (RFC1). We present the case of a 62-year-old woman who experienced a history of a biphasic presentation of imbalance and gait disorders, with rapid onset of symptoms followed by slow and progressive neurological deterioration. The diagnostic process was challenging, and numerous tests were conducted to rule out acquired and genetic causes of ataxia, leading to a diagnosis of late-onset idiopathic cerebellar ataxia. Subsequently, vestibular function tests identified severe bilateral vestibulopathy. This led to considering CANVAS among the diagnoses, which was ultimately confirmed through genetic testing (biallelic expansion of the pentanucleotide AAGGG in the RFC1 gene). This case highlights the importance of this new described genetic disease and its subacute presentation variant, emphasizing the relevance of objective vestibular function tests in idiopathic ataxias to achieve proper diagnosis and eventual genetic counseling for offspring.

El síndrome de ataxia cerebelosa, neuropatía y arreflexia vestibular (CANVAS) es un trastorno neurodegenerativo progresivo que se manifiesta en etapas tardías de la vida. Su base genética ha sido recientemente identificada en el gen que codifica la subunidad 1 del factor C de replicación (RFC1). Presentamos el caso de una mujer de 62 años con una historial de desequilibrio y deterioro de la marcha de presentación bifásica, con un inicio rápido de los síntomas seguido de un deterioro neurológico lento y progresivo. El proceso diagnóstico fue complejo y se realizaron numerosas pruebas para descartar causas adquiridas y genéticas de la ataxia, arribando al diagnóstico de ataxia cerebelosa de inicio tardío idiopática. Ulteriormente, las pruebas de función vestibular identificaron una grave vestibulopatía bilateral. Esto llevó a considerar el CANVAS entre los diagnósticos, que finalmente fue confirmado mediante pruebas genéticas (expansión bialélica del penta-nucleótido AAGGG en el gen RFC1). Este caso subraya la importancia de esta nueva enfermedad genética y su variante de presentación subaguda y enfatiza la relevancia de las pruebas objetivas de función vestibular en las ataxias consideradas idiopáticas para lograr un diagnóstico adecuado y un eventual asesoramiento genético a la descendencia.

Central Vestibular Dysfunction in Head Injury.

OBJECTIVES: This study aims to provide an overview of dizziness post head injury in those with prominent features for central vestibular dysfunction (CVD) in comparison to those with a post-traumatic peripheral vestibular etiology. STUDY DESIGN: Retrospective. SETTING: University Health Network (UHN) Workplace Safety and Insurance Board (WSIB) database from 1988 to 2018 were evaluated for post-traumatic dizziness. METHODS: The UHN WSIB neurotology database (n = 4291) between 1998 and 2018 was retrospectively studied for head-injured workers presenting with features for CVD associated with trauma. All patients had a detailed neurotological history and examination, audiovestibular testing that included video nystagmography (VNG) and cervical vestibular-evoked myogenic potentials (cVEMPs). Imaging studies including routine brain and high-resolution temporal bone computed tomography (CT) scans and/or intracranial magnetic resonance imaging (MRI) were available for the majority of injured workers. RESULTS: Among 4291 head-injured workers with dizziness, 23 were diagnosed with features/findings denoting CVD. Complaints of imbalance were significantly more common in those with CVD compared to vertigo and headache in those with peripheral vestibular dysfunction. Atypical positional nystagmus, oculomotor abnormalities and facial paralysis were more common in those with CVD. CONCLUSION: Symptomatic post-traumatic central vestibular injury is uncommon. It occurred primarily following high-impact trauma and was reflective for a more severe head injury where shearing effects on the brain often resulted in diffuse axonal injury. Complaints of persistent imbalance and ataxia were more common than complaints of vertigo. Eye movement abnormalities were highly indicative for central nervous system injury even in those with minimal change on CT/MRI.

Just Keep Spinning? The Impact of Auditory and Somatosensory Cues on Rotary Chair Testing.

PURPOSE: The purpose of this study was to determine whether providing realistic auditory or somatosensory cues to spatial location would affect measures of vestibulo-ocular reflex gain in a rotary chair testing (RCT) context. METHOD: This was a fully within-subject design. Thirty young adults age 18-30 years (16 men, 14 women by self-identification) completed sinusoidal harmonic acceleration testing in a rotary chair under five different conditions, each at three rotational frequencies (0.01, 0.08, and 0.32 Hz). We recorded gain as the ratio of the amplitude of eye movement to chair movement using standard clinical procedures. The five conditions consisted of two without spatial information (silence, tasking via headphones) and three with either auditory (refrigerator sound, tasking via speaker) or somatosensory (fan) information. Two of the conditions also included mental tasking (tasking via headphones, tasking via speaker) and differed only in terms of the spatial localizability of the verbal instructions. We used linear mixed-effects modeling to compare pairs of conditions, specifically examining the effects of the availability of spatial cues in the environment. This study was preregistered on Open Science Framework (https://osf.io/2gqcf/). RESULTS: Results showed significant effects of frequency in all conditions (p < .05), but the only pairs of conditions that were significantly different were those including tasking in one condition but not the other (e.g., tasking via headphones vs. silence). Post hoc equivalence testing showed that the lack of significance in the other comparisons could be confirmed as not meaningfully different. CONCLUSIONS: These findings suggest that the presence of externally localizable sensory information, whether auditory or somatosensory, does not affect measures of gain in RCT to any relevant degree. However, these findings also contribute to the increasing body of evidence suggesting that mental engagement ("tasking") does increase gain whether or not it is provided via localizable instructions.

Audiometric and Vestibular Function after Classic and Reverse Stapedotomy.

Background and Objectives: Besides classical stapedotomy, reverse stapedotomy has been used for many years in the management of otosclerosis. Our study aims to investigate whether reversing the surgical steps in stapedotomy impacts vestibular function and hearing improvement. Materials and Methods: A cohort of 123 patients underwent either classic or reverse stapedotomy procedures utilizing a fiber-optic argon laser. Audiological assessments, following the guidelines of the Committee on Hearing and Equilibrium, were conducted, including pure tone average, air-bone (AB) gap, overclosure, and AB gap closure. Vestibular evaluation involved pre- and postoperative comparison of rotatory test parameters, including frequency, amplitude, and slow phase velocity of nystagmus. Results: The study demonstrated an overall median overclosure of 3.3 (3.3, 5.0) dB and a mean AB gap closure of 20.3 ± 8.8 dB. Postoperative median AB gap was 7.5 (7.5, 11.3) dB in the reverse stapedotomy group and 10.0 (10.0, 12.5) dB in the classic stapedotomy group. While overclosure and AB gap closure were marginally superior in the reverse stapedotomy group, these differences did not reach statistical significance. No significant disparities were observed in the frequency, slow phase velocity, or amplitude of nystagmus in the rotational test. Conclusions: Although not always possible, reverse stapedotomy proved to be a safe surgical technique regarding postoperative outcomes. Its adoption may mitigate risks associated with floating footplate, sensorineural hearing loss, and incus luxation/subluxation, while facilitating the learning curve for less experienced ear surgeons.