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.
CONCLUSIONS: 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.

Sleep and circadian timing systems are constantly regulated by both photic and non-photic signals. Connections between the vestibular nuclei and the biological clock raise the question of the effect of peripheral vestibular loss on daily rhythms, such as the sleep-wake cycle and circadian rhythm. To answer this question, we compared the sleep and rest-activity rhythm parameters of 15 patients with bilateral vestibulopathy (BVP) to those of 15 healthy controls. Sleep and rest-activity cycle were recorded by a device coupling actimetry with the heart rate and actigraphy at home over 7 days. Subjective sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI). Sleep efficiency and subjective sleep quality were significantly reduced, and sleep fragmentation was increased in BVP patients compared to controls. BVP patients displayed a damped amplitude of the rest-activity rhythm and higher sleep fragmentation, reflected by a higher nocturnal activity compared to controls. These results suggest that both rest-activity and sleep cycles are impaired in BVP patients compared to healthy controls. BVP patients seem to have greater difficulty maintaining good sleep at night compared to controls. BVP pathology appears to affect the sleep-wake cycle and disturb the circadian rhythm synchronization. Nevertheless, these results need further investigation to be confirmed, particularly with larger sample sizes.

Cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS) is a recessively inherited neurodegenerative disorder caused by intronic biallelic, nonreference CCCTT/AAGGG repeat expansions within RFC1. To investigate how these repeats cause disease, we generated patient induced pluripotent stem cell-derived neurons (iNeurons). CCCTT/AAGGG repeat expansions do not alter neuronal RFC1 splicing, expression, or DNA repair pathway function. In reporter assays, AAGGG repeats are translated into pentapeptide repeat proteins. However, these proteins and repeat RNA foci were not detected in iNeurons, and overexpression of these repeats failed to induce neuronal toxicity. CANVAS iNeurons exhibit defects in neuronal development and diminished synaptic connectivity that is rescued by CRISPR deletion of a single expanded AAGGG allele. These deficits were neither replicated by RFC1 knockdown in control iNeurons nor rescued by RFC1 reprovision in CANVAS iNeurons. These findings support a repeat-dependent but RFC1 protein-independent cause of neuronal dysfunction in CANVAS, with implications for therapeutic development in this currently untreatable condition.

双侧前庭病（bilateral vestibulopathy，BVP）是指双侧前庭终器、神经或两者功能的严重降低或缺失的一种慢性前庭综合征，是一种基于前庭功能的诊断，而非疾病实体。其临床表现为不稳感，且有跌倒风险，极大降低了患者生活质量。BVP病因复杂、起病隐匿，易被漏诊或误诊。BVP的诊断需综合临床表现和多项前庭检查结果，然而Barany协会近年发布的共识仅能明确部分极重度患者的诊断。本文综述了BVP的临床新进展，包括症状、病因、分型、前庭功能检查和治疗策略等。.

OBJECTIVE: The vestibular system is closely connected to emotion-processing neuronal circuits. Patients with bilateral vestibulopathy (BVP), a chronic loss of vestibular function, show remarkably lower rates of psychiatric comorbidities and vertigo-related anxiety (VRA) than those with episodic vertigo/dizziness (v/d). This study aimed to evaluate whether patients with BVP differ from those with episodic v/d in terms of VRA, general anxiety, and cognitions about body and health.
METHODS: This cross-sectional study involved a subsample of 202 patients with episodic v/d (i.e., vestibular migraine, vestibular paroxysmia, or Menière\'s disease) and 43 patients with BVP. All patients underwent standardised neurological/neurotological examinations, structured clinical interviews (SCID-I), and self-report questionnaires, such as the Vertigo Handicap Questionnaire (VHQ), Beck Anxiety Inventory (BAI), Trait Anxiety from the State-Trait-Anxiety Inventory (STAI-T), and Cognitions About Body and Health questionnaire (CABAH). Non-parametric tests were used for analysis. Due to multiple testing, the significance level was set at p ≤ .008.
RESULTS: Patients with episodic v/d exhibited higher VRA levels than those with BVP. However, this difference was not statistically significant (p = .04; r = 0.15, small effect). Additionally, patients with BVP reported more catastrophizing cognitions (p < .001; r = 0.25, small effect) and bodily weakness (p = .003; r = 0.22, small effect) compared to those with episodic v/d. There were no differences in general anxiety levels (BAI and STAI-T) between patients with v/d and those with BVP.
CONCLUSIONS: Patients with episodic v/d and BVP differed in their appraisal (cognition). The difference in VRA (subjective feeling) was not statistically significant. These preliminary results are discussed using a component approach to emotions.

OBJECTIVE: Oscillopsia and unsteadiness are common and highly debilitating symptoms in individuals with bilateral vestibulopathy. A lack of adequate treatment options encouraged the investigation of vestibular implants, which aim to restore vestibular function with motion-modulated electrical stimulation. This review aims to outline the ocular and postural responses that can be evoked with electrical prosthetic stimulation of the semicircular canals and discuss potential approaches to further optimize evoked responses. Particular focus is given to the stimulation paradigm.
RESULTS: Feasibility studies in animals paved the way for vestibular implantation in human patients with bilateral vestibulopathy. Recent human trials demonstrated prosthetic electrical stimulation to partially restore vestibular reflexes, enhance dynamic visual acuity, and generate controlled postural responses. To further optimize prosthetic performance, studies predominantly targeted eye responses elicited by the vestibulo-ocular reflex, aiming to minimize misalignments and asymmetries while maximizing the response. Changes of stimulation parameters are shown to hold promise to increase prosthetic efficacy, together with surgical refinements and neuroplastic effects.
CONCLUSIONS: Optimization of the stimulation paradigm, in combination with a more precise electrode placement, holds great potential to enhance the clinical benefit of vestibular implants.

UNASSIGNED: The Bárány Society recently established diagnostic criteria for presbyvestibulopathy, an age-related bilateral vestibular impairments in older individuals. Drawing upon a cross-sectional database, this study delves into the demographic and clinical features of presbyvestibulopathy patients and investigates the implications of otolith dysfunction.
UNASSIGNED: The study retrospectively analyzed 1218 patients aged 60 years or older who visited the tertiary dizziness clinic in 2020, due to symptoms of dizziness or instability. By reviewing medical records, we gathered clinical information and laboratory vestibular test results, such as cervical and ocular vestibular evoked myogenic potentials, and subjective visual vertical.
UNASSIGNED: Out of 1218 patients aged 60 and above who reported dizziness or unsteadiness, 33 patients (2.7 %, with an average age of 74.2 ± 9.2 years) were diagnosed with presbyvestibulopathy. Deficiencies in horizontal angular vestibulo-ocular reflex were found in caloric tests (75 %), video head impulse tests (51.7 %), and rotatory chair tests (47.8 %), respectively. Otolith dysfunction was also observed, as shown by abnormal ocular and cervical vestibular evoked myogenic potentials in 62.96 % and 51.85 % of patients, and abnormal subjective visual vertical in 45.8 % of the cases.
UNASSIGNED: Among elderly patients experiencing consistent dizziness or instability, the incidence of presbyvestibulopathy was approximately 2.7 % over one year. Alongside the abnormalities detected in the horizontal angular vestibulo-ocular reflex, significant changes were also noted in the ocular and cervical vestibular evoked myogenic potentials, as well as in the subjective visual vertical tests. As a result, it\'s vital to underscore the significance of both otolithic function and vestibulo-ocular reflex in the fundamental mechanisms of presbyvestibulopathy.

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.

This article describes a rare case of necrotic xanthogranuloma in a 46-year-old patient who presented with the development of periorbital xanthelasms, progressive bilateral sensorineural hearing loss and bilateral vestibulopathy, followed by multiple myeloma and amyloidosis. For several years, the patient underwent standard rehabilitation for chronic sensorineural hearing loss and was fitted with a hearing aid. During hospitalisation for exacerbation of chronic bronchitis, monoclonal gammopathy was identified, and later, after careful examination and repeated biopsies, necrotic xanthogranuloma, multiple myeloma and AL-amyloidosis were confirmed. Targeted immunochemotherapy resulted in improvement of hearing and significant recovery of the vestibuloocular reflex bilaterally.
В статье представлен редкий случай некротической ксантогранулемы у пациента 46 лет, дебютировавшей с развития периорбитальных ксантелазм, прогрессирующей двусторонней сенсоневральной тугоухости и двусторонней вестибулопатии с последующим развитием множественной миеломы и амилоидоза. В течение нескольких лет пациент проходил стандартную реабилитацию по поводу хронической сенсоневральной тугоухости, слухопротезирован. Во время стационарного лечения по поводу обострения хронического бронхита выявлена моноклональная гаммапатия. В дальнейшем при тщательном обследовании и неоднократном взятии биопсийного материала верифицированы некротическая ксантогранулема, множественная миелома и AL-амилоидоз. В результате проведения таргетной иммунохимиотерапии удалось добиться улучшения слуховой функции и значительного восстановления вестибулоокулярного рефлекса с двух сторон.

A review of the literature on rehabilitation methods for bilateral vestibulopathy is presented using RSCI, Scopus and PubMed databases. The principles and effectiveness of physical vestibular rehabilitation, vestibular implants, galvanic vestibular stimulation, and biofeedback-based sensory substitution and augmentation systems are described. The advantages and disadvantages of each method and perspectives for their improvement are presented.
Представлен обзор литературы по базам РИНЦ, Scopus, PubMed, посвященной методам реабилитации пациентов с двусторонней вестибулопатией. Описаны принципы и эффективность физической вестибулярной реабилитации, вестибулярных имплантатов, подпороговой гальванической стимуляции, а также применение приборов сенсорного замещения или аугментации, направленных на стимуляцию биологической обратной связи. Показаны преимущества и недостатки каждого метода, перспективы их усовершенствования.