Update VertiGo – light affection of mobile VNG

Dizziness is one of the most frequent symptoms in outpatient practices. For the differentiation of peripheral or central pathogenesis of vertigo, history taking and clinical examination with the detection of nystagmus is elementary. The aim of this study was to investigate the effect of lighting for the detection of horizontal vestibular nystagmus while utilizing a conventional webcam. In the proof-of-concept study, caloric induced vestibular nystagmus was recorded with a conventional video-nystagmography and mobile webcam in addition to an external light source. The analysis of recorded data was performed with a self-developed software using computer vision techniques. The self-designed algorithm detected the existence of nystagmus and its direction in several cases. The experimental webcam-based vestibular nystagmography could be enhanced by improving lighting conditions. Currently, a clinical application for this technique is not approved. Further software improvements are necessary to increase its accuracy.

Nystagmus goggles: how to use them, what you find and what it means

A fundamental characteristic of peripheral vestibular nystagmus, in particular horizontal nystagmus, is that it is suppressed by visual fixation. This means that a patient with a vertigo attack of peripheral vestibular origin might have no obvious spontaneous nystagmus on clinical examination. Goggles that reduce or remove visual fixation allow the cliniican to observe nystagmus in this situation. Nystagmus goggles are essential for any clinician dealing with dizzy patients. Here, we discuss why this is so and how easy it is to acquire and use them.

VertiGo – a pilot project in nystagmus detection via webcam

Dizziness is one of the most common symptoms in medicine. For differentiation of peripheral or central origin of the vertigo, history and clinical examination with detection of a nystagmus is essential. The aim of this study was to detect horizontal vestibular nystagmus utilizing a webcam. In the feasibility study, caloric induced vestibular nystagmus was recorded with conventional video-nystagmography and webcam. Analysis of recorded data was performed with a developed software which used computer vision techniques. A designed algorithm detected nystagmus existence and their direction. The software was evaluated by an expert-rated video-nystagmography. Webcam-based vestibular nystagmus detection is possible. Currently, a clinical application is not approved. Further software improvements are necessary to increase its accuracy.

Suppressive control of optokinetic and vestibular nystagmus by the primate frontal eye field

In this study, electrical stimulation in the frontal eye field (FEF) suppressed the quick and slow phases of optokinetic and vestibular nystagmus at an intensity subthreshold for eliciting saccades. Furthermore, the activity of fixation neurons in the FEF was related to the suppression of optokinetic and vestibular nystagmus by visual fixation. This suggests that a common neuronal assembly in the FEF may contribute to the suppressive control of different functional classes of eye movements.

Upbeat Nystagmus

Upbeat nystagmus is a less common type of central vestibular nystagmus that is often transient. It is a vertical jerk-waveform nystagmus with downward slow phases and upward quick phases. In this chapter, we begin by reviewing the clinical features of upbeat nystagmus. Since it can be produced by lesions in a variety locations in the brainstem and cerebellum, we next describe the symptoms and signs that can help to localize the causative lesion. We list the causes of upbeat nystagmus. We then discuss the clinical and imaging findings in Wernicke encephalopathy, which is a common cause of upbeat nystagmus, and we review the management of Wernicke encephalopathy. Lastly, we briefly discuss the medical treatment options for persistent upbeat nystagmus.

Downbeat Nystagmus

Downbeat nystagmus is a common type of central vestibular nystagmus that often produces oscillopsia or blurred vision. It is a vertical jerk-waveform nystagmus with upward slow phases and downward quick phases. In this chapter, we begin by reviewing the clinical features of downbeat nystagmus. We next list the common causes for downbeat nystagmus, which include inherited cerebellar degenerations, acquired cerebellar degenerations, congenital hindbrain anomalies, stroke, tumors, and medications. We then discuss the workup and management of paraneoplastic cerebellar degeneration, which is most commonly associated with cancers of the lung, ovary, and breast. Lastly, we review medical treatment options for downbeat nystagmus.

Bárány’s Life in Uppsala and His Work with Lorente de Nó

Lorente de Nó came to Uppsala, Sweden, in 1924 to work with Robert Bárány, with the goal of studying the central nervous system pathways of the vestibular nystagmus response. Bárány’s 1907 book described a patient with a lesion involving the reticular formation of the pons close to the abducens nucleus who could generate only the slow phase of nystagmus. With stimulation, the patient’s eyes slowly deviated to one side and became pinned. The patient also had a loss of voluntary eye movements. Bárány concluded that there must be separate centers in the brainstem for the production of the slow and fast phases of nystagmus. He speculated that the center for generating fast phases was in the reticular substance next to the abducens nucleus and that this component was under the influence of cortical control. Nó would go on to perform studies of these central pathways for generating nystagmus in rabbit.