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Competing Interests: The authors report no conflicts of interest.

Aims of the present article are: 1 ) assessing vestibular contribution to spatial navigation, 2 ) exploring how age, global positioning systems (GPS) use, and vestibular navigation contribute to subjective sense of direction (SOD), 3 ) evaluating vestibular navigation in patients with lesions of the vestibular-cerebellum (patients with downbeat nystagmus, DBN) that could inform on the signals carried by vestibulo-cerebellar-cortical pathways. We applied two navigation tasks on a rotating chair in the dark: return-to-start (RTS), where subjects drive the chair back to the origin after discrete angular displacement stimuli (path reversal), and complete-the-circle (CTC) where subjects drive the chair on, all the way round to origin (path completion). We examined 24 normal controls (20-83 yr), five patients with DBN (62-77 yr) and, as proof of principle, two patients with early dementia (84 and 76 yr). We found a relationship between SOD, assessed by Santa Barbara Sense of Direction Scale, and subject's age (positive), GPS use (negative), and CTC-vestibular-navigation-task (positive). Age-related decline in vestibular navigation was observed with the RTS task but not with the complex CTC task. Vestibular navigation was normal in patients with vestibulo-cerebellar dysfunction but abnormal, particularly CTC, in the demented patients. We conclude that vestibular navigation skills contribute to the build-up of our SOD. Unexpectedly, perceived SOD in the elderly is not inferior, possibly explained by increased GPS use by the young. Preserved vestibular navigation in cerebellar patients suggests that ascending vestibular-cerebellar projections carry velocity (not position) signals. The abnormalities in the cognitively impaired patients suggest that their vestibulo-spatial navigation is disrupted. NEW & NOTEWORTHY Our subjective sense-of-direction is influenced by how good we are at spatial navigation using vestibular cues. Global positioning systems (GPS) may inhibit sense of direction. Increased use of GPS by the young may explain why the elderly's sense of direction is not worse than the young's. Patients with vestibulo-cerebellar dysfunction (downbeat nystagmus syndrome) display normal vestibular navigation, suggesting that ascending vestibulo-cerebellar-cortical pathways carry velocity rather than position signals. Pilot data indicate that dementia disrupts vestibular navigation.

Objective: Horizontal semicircular canal site pathology of benign paroxysmal positional vertigo demonstrating three types of nystagmi on positional test were studied. We have attempted to design a protocol for its diagnosis and treatment., Methods: 320 patients of HSC-BPPV were subjected to two types of positional tests. Of these, patients with bilateral steady apogeotropic nysatgmus were treated with VAV modification of Semont's maneuver. Patients with unsteady or changing apo/geotropic signs were converted into steady geotropic ones by repetitive positional tests; followed by barbecue maneuver with forced prolong positioning., Results: Overall 88% of patients had a total recovery. 92% of patients with geotropic nystagmus showed no symptoms after second maneuveral sitting. 85% of patients with apogeotropic nystagmus recovered fully after third maneuveral sitting., Conclusions: Correct identification of subtypes of HSC-BPPV is based on provoked nystagmus by positional tests. After locating the site and side on the basis of nystagmic pattern, physician can apply the appropriate PRM., Level of Evidence: II a., (Copyright © 2022 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.)

Abstract: We report a case of pendular seesaw nystagmus caused by bitemporal hemianopia; the nystagmus disappeared while in darkness as previously described, but it also disappeared with monocular occlusion, which indicates the pivotal role of binocular vision in the pathogenesis., Competing Interests: The authors report no conflicts of interest., (Copyright © 2022 by North American Neuro-Ophthalmology Society.)

Objective: Cochleovestibulopathy is a distinguishable paraneoplastic phenotype. In this study, we evaluate clinical presentation, serological/cancer associations and outcomes of paraneoplastic cochleovestibulopathy., Methods: Retrospective chart review of patients with hearing impairment and/or vestibulopathy who underwent serological evaluations for paraneoplastic antibodies between January 2007 and February 2021 was performed., Results: Twenty-six patients were identified (men, n=23; median age, 45 years, range: 28-70). Biomarkers detected included: KLHL11-IgG‌ ‌(n=20,‌ ‌77% (coexisting LUZP4-IgG, n=8)),‌ ‌‌ANNA1-IgG‌ ‌ ‌(n=3,‌ ‌12%),‌ ‌amphiphysin-IgG‌‌ ‌(n=2,‌ ‌8%)‌ ‌and‌ ‌LUZP4-IgG‌‌ ‌(n=1,‌ ‌4%). Most common neoplastic association was ‌testicular‌/‌extra-testicular‌ ‌seminoma‌ ‌ (n=13,‌ ‌50%).‌‌ Hearing‌ impairment (bilateral, 62%) was ‌present‌ ‌in‌ ‌all‌ ‌patients.‌ ‌Fifteen patients (58%) had cochleovestibular dysfunction as their initial presentation before rhombencephalitis/encephalomyelitis manifestations (hearing loss, four; acute vertigo, eight; both, three). ‌Brain‌ ‌MRI‌ ‌demonstrated‌ ‌internal‌ ‌auditory‌ ‌canal‌ ‌enhancement‌ ‌in‌ ‌four ‌patients.‌ Audiometry commonly revealed severe-profound bilateral sensorineural hearing loss. Most patients ‌had‌ a refractory course ‌despite‌ ‌immunotherapy‌ ‌and/or‌ ‌cancer‌ ‌treatment‌., Conclusion: Cochleovestibulopathy commonly presents with rapidly progressive bilateral hearing loss and/or acute vertigo. However, in some patients, these symptoms present along with or following brainstem/cerebellar manifestations. KLHL11-IgG and seminoma are the most common serological and cancer associations, respectively. Recognition of this phenotype may aid in earlier diagnosis of paraneoplastic autoimmunity and associated cancer., Competing Interests: Competing interests: MBH, SDZE, AM and MJM have no competing interests to disclose. DD and SJP have a patent pending for leucine zipper 4 (LUZP4) and kelch-like protein 11 (KLHL11) as a marker for neurological autoimmunity and testicular germ cell tumours., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)