The evolutionary hypothesis of benign paroxysmal positional vertigo

Common Neurologic Diseases in Geriatric Dogs

The increase in the canine geriatric population means that veterinarians are more often confronted with diseases that are more prevalent in patients in this age group. As in other organ systems, degenerative, neoplastic, and vascular diseases are the most prevalent neurologic disorders in older dogs. A neurological disease in an older dog poses a challenge for the clinician due to the presence of concomitant diseases and age-related changes that make it difficult to interpret the neurological examination. In addition, given the age of the patients, some owners do not allow advanced imaging tests, and it is necessary to establish the most likely presumptive diagnosis to initiate treatment. Although many of these diseases can cause clinical signs that can be very upsetting, some of them can be managed with symptomatic therapy and have a good prognosis, such as idiopathic vestibular syndrome. Moreover, advances in and the greater availability of therapeutic options such as surgery and radiation therapy may increase survival and quality of life in diseases with a more serious prognosis, such as tumours. The aim of this review is to summarize the clinical presentation, diagnosis, and treatment of the more frequent diseases affecting the central nervous systems of geriatric dogs.

Current definition, diagnosis, and treatment of canine and feline idiopathic vestibular syndrome

Idiopathic vestibular syndrome (IVS) is one of the most common neurological disorders in veterinary medicine. However, its diagnosis and treatment varies between publications. The aim of the current study was to gather experts' opinion about IVS definition, diagnosis, and treatment. An online-survey was used to assess neurology specialists' opinion about the definition, diagnosis and treatment of IVS. The study demonstrated that the definition, diagnosis, and treatment of IVS are largely consistent worldwide, with the EU prioritising less frequently advanced imaging and more often otoscopy to rule out other diseases. IVS was defined by most specialists as an acute to peracute, improving, non-painful peripheral vestibular disorder that often affects cats of any age and geriatric dogs. Regarding diagnosis, a detailed neurological examination and comprehensive blood tests, including thyroid values, blood pressure, and otoscopic examination, was seen as crucial. A thorough workup may also involve MRI and CSF analysis to rule out other causes of vestibular dysfunction. Treatment of IVS typically involved intravenous fluid therapy and the use of an antiemetic, with maropitant once daily being the preferred choice among specialists. Antinausea treatment was considered, however, only by a handful specialists. This survey-based study provides valuable insights from neurology experts and highlights areas that require further research to bridge the gap between theory and practice.

Natural Mutations Affect Structure and Function of gC1q Domain of Otolin-1

Otolin-1 is a scaffold protein of otoliths and otoconia, calcium carbonate biominerals from the inner ear. It contains a gC1q domain responsible for trimerization and binding of Ca²⁺. Knowledge of a structure-function relationship of gC1q domain of otolin-1 is crucial for understanding the biology of balance sensing. Here, we show how natural variants alter the structure of gC1q otolin-1 and how Ca²⁺ are able to revert some effects of the mutations. We discovered that natural substitutions: R339S, R342W and R402P negatively affect the stability of apo-gC1q otolin-1, and that Q426R has a stabilizing effect. In the presence of Ca²⁺, R342W and Q426R were stabilized at higher Ca²⁺ concentrations than the wild-type form, and R402P was completely insensitive to Ca²⁺. The mutations affected the self-association of gC1q otolin-1 by inducing detrimental aggregation (R342W) or disabling the trimerization (R402P) of the protein. Our results indicate that the natural variants of gC1q otolin-1 may have a potential to cause pathological changes in otoconia and otoconial membrane, which could affect sensing of balance and increase the probability of occurrence of benign paroxysmal positional vertigo (BPPV).

[Study on the relationship between benign paroxysmal positional vertigo and sleep disturbance]

Objective:To explore the relationship between benign paroxysmal positional vertigo （BPPV） and sleep disorders through the analysis of subjective and objective sleep conditions. Methods:Forty-five patients with BPPV and fifty controls who met the inclusion and exclusion criteria were selected for Pittsburgh sleep quality index （PSQI） questionnaire survey and polysomnography （PSG） check, and SPSS 23.0 was used to compare and analyze the results. Results:Compared with the control group, patients with BPPV had changes in sleep structure, high apnea hypopnea index （AHI） and significantly decreased subjective sleep quality （P<0.05）, and there were significant differences in the PQSI scores of patients with BPPV before and after treatment （P<0.05）.Binary logistic regression analysis of BPPV and AHI showed that for every 1 increase in AHI index, the probability of BPPV increased by 1.8 times （OR=2.80, 95%CI=2.25-3.66）.After grouping AHI and performing regression analysis, it was found that the risk of BPPV in patients with AHI≥5 was 3.94 times that of patients with AHI <5（OR=3.94，95%CI=1.63-9.48）. Conclusion:Patients with BPPV have decreased sleep quality and altered sleep structure, and in this study, AHI is found to be a risk indicator for BPPV.

Risk Factors for the Recurrence of Benign Paroxysmal Positional Vertigo: A Systematic Review and Meta-Analysis

OBJECTIVE

Benign paroxysmal positional vertigo (BPPV) has a high recurrence rate, but the risk factor-associated recurrence are elusive.

METHODS

Searches were performed in PubMed, Embase, Cochrane library, Web of science, Chinese National Knowledge Infrastructure, and Sino Med up to November 3, 2019. The effect size was analyzed by odds ratio and 95% CI. Data from eligible studies were meta-analyzed using Stata version 15.0.

RESULTS

Our search resulted in a total of 4076 hits. Twenty-four outcomes of sixty articles were included in the meta-analysis. Risk factors for the recurrence of BPPV included female gender, age (≥65years), hyperlipidemia, diabetes, hypertension, migraine, cervical spondylosis, osteopenia/osteoporosis, head trauma, otitis media, abnormal vestibular evoked myogenic potential, and long use of computers. No significant differences were found in side, type of the involved semicircular canals, smoking, alcohol consumption, stroke, ear surgery, duration of vertigo before treatment, the times of repositioning, Meniere disease, sleep disorders, hypercholesterolemia, and 25-hydroxy vitamin D.

CONCLUSION

These findings strengthen clinical awareness of early warning to identify patients with potential relapse risk of BPPV and clinicians should counsel patients regarding the importance of follow-up after diagnosis of BPPV.