Cognition in vestibular disorders: state of the field, challenges, and priorities for the future

Vestibular disorders are prevalent and debilitating conditions of the inner ear and brain which affect balance, coordination, and the integration of multisensory inputs. A growing body of research has linked vestibular disorders to cognitive problems, most notably attention, visuospatial perception, spatial memory, and executive function. However, the mechanistic bases of these cognitive sequelae remain poorly defined, and there is a gap between our theoretical understanding of vestibular cognitive dysfunction, and how best to identify and manage this within clinical practice. This article takes stock of these shortcomings and provides recommendations and priorities for healthcare professionals who assess and treat vestibular disorders, and for researchers developing cognitive models and rehabilitation interventions. We highlight the importance of multidisciplinary collaboration for developing and evaluating clinically relevant theoretical models of vestibular cognition, to advance research and treatment.

Vestibular, Central, and Non-Vestibular Etiologies of Vertigo and Disequilibrium: A Rural Hospital-Based Cross-Sectional Comparative Analysis

INTRODUCTION

Vertigo/dizziness is defined as disturbed postural awareness and could range from a feeling of sensation of spinning of self or surrounding. Dizziness or disturbed postural awareness is a common presentation in varying age groups. Vertigo has varied clinical presentations. Classically, there are four vertigo syndromes: vertigo, imbalance/disequilibrium, presyncope/lightheadedness, and psychogenic dizziness. The present study was conducted to examine the various etiologies involved in these syndromes and to help unmask the overlaps between them. This study also aimed to further classify the etiologies underlying these vertigo syndromes and overlaps into peripheral or vestibular, central, and non-vestibular. This would help develop a comprehensive management protocol for vertigo of any origin.

METHODS

A prospective observational cross-sectional study was undertaken in a rural hospital in Central India. We studied patients with giddiness and categorized them into vertigo syndromes according to the site of origin of vertigo. We also compared overlaps in the presentation of vertigo.

RESULTS

Out of the 80 patients that were studied, vertigo with disequilibrium was observed in 72.50% of the patients. Non-vestibular vertigo of cervicogenic origin was the common cause of vertigo seen in 36.25% of the patients occurring alone or in association with vestibular vertigo. Among patients with overlaps, vestibular vertigo with non-vestibular vertigo was the most common etiology observed in 89.65% of the patients with overlaps.

CONCLUSION

The syndrome of "vertigo with disequilibrium" was the commonest presentation in the patients studied, followed by "vertigo syndrome" as an isolated symptom, not associated with "disequilibrium." Ours is probably the first study to report this observation of overlaps of two syndromes, with diagnostic implications.

Post-traumatic peripheral vestibular disorders (excluding positional vertigo) in workers following head injury

Benign paroxysmal positional vertigo has typically been reported to be the most common cause of post-traumatic dizziness. There is however paucity in the literature about other peripheral vestibular disorders post-head injury. This article provides an overview of other causes of non-positional dizziness post-head trauma from our large institutional experience. The UHN WSIB Neurotology database (n = 4291) between 1998 and 2018 was retrospectively studied for those head-injured workers presenting with non-positional peripheral vestibular disorders. All subjects had a detailed neurotological history and examination and vestibular testing including video nystagmography, video head impulse testing (or a magnetic scleral search coil study), vestibular-evoked myogenic potentials, and audiometry. Imaging studies included routine brain and high-resolution temporal bone CT scans and/or brain MRI. Based on a database of 4291 head-injured workers with dizziness, 244 were diagnosed with non-positional peripheral vertigo. Recurrent vestibulopathy (RV) was the most common cause of non-positional post-traumatic vertigo. The incidence of Meniere's disease in the post-traumatic setting did not appear greater than found in the general population. The clinical spectrum pertaining to recurrent vestibulopathy, Meniere's disease, delayed endolymphatic hydrops, drop attacks, superior semicircular canal dehiscence syndrome, and uncompensated peripheral vestibular loss are discussed.