Progress in neuro-otology research in the last year

Herein, we summarize articles in the field of neuro-otology published in the Journal of Neurology over the last year. Topics included acute and chronic vertigo as well as auditory and ocular motor disorders. Characteristic lesion locations in Pusher syndrome are reported and the usefulness of bedside ocular motor tests in vertebrobasilar stroke is revisited. Probing the vestibular system and its value in predicting the outcome in vegetative state is discussed. Several articles address new diagnostic and therapeutic approaches in different disorders associated with chronic vestibular, auditory or gait deficits. In a series of case reports, we focus on different eye movement disorders in the vertical plane, which are often difficult to asses

Visually guided adjustments of body posture in the roll plane

Body position relative to gravity is continuously updated to prevent falls. Therefore, the brain integrates input from the otoliths, truncal graviceptors, proprioception and vision. Without visual cues estimated direction of gravity mainly depends on otolith input and becomes more variable with increasing roll-tilt. Contrary, the discrimination threshold for object orientation shows little modulation with varying roll orientation of the visual stimulus. Providing earth-stationary visual cues, this retinal input may be sufficient to perform self-adjustment tasks successfully, with resulting variability being independent of whole-body roll orientation. We compared conditions with informative (earth-fixed) and non-informative (body-fixed) visual cues. If the brain uses exclusively retinal input (if earth-stationary) to solve the task, trial-to-trial variability will be independent from the subject's roll orientation. Alternatively, central integration of both retinal (earth-fixed) and extra-retinal inputs will lead to increasing variability when roll-tilted. Subjects, seated on a motorized chair, were instructed to (1) align themselves parallel to an earth-fixed line oriented earth-vertical or roll-tilted 75° clockwise; (2) move a body-fixed line (aligned with the body-longitudinal axis or roll-tilted 75° counter-clockwise to it) by adjusting their body position until the line was perceived earth-vertical. At 75° right-ear-down position, variability increased significantly (p<0.05) compared to upright in both paradigms, suggesting that, despite the earth-stationary retinal cues, extra-retinal input is integrated. Self-adjustments in the roll-tilted position were significantly (p<0.01) more precise for earth-fixed cues than for body-fixed cues, underlining the importance of earth-stable visual cues when estimates of gravity become more variable with increasing whole-body rol

Head roll dependent variability of subjective visual vertical and ocular counterroll

We compared the variability of the subjective visual vertical (SVV) and static ocular counterroll (OCR), and hypothesized a correlation between the measurements because of their shared macular input. SVV and OCR were measured simultaneously in various whole-body roll positions [upright, 45° right-ear down (RED), and 75° RED] in six subjects. Gains of OCR were −0.18 (45° RED) and −0.12 (75° RED), whereas gains of compensation for body roll in the SVV task were −1.11 (45° RED) and −0.96 (75° RED). Normalized SVV and OCR variabilities were not significantly different (P>0.05), i.e., both increased with increasing roll. Moreover, a significant correlation (R 2=0.80, slope=0.29) between SVV and OCR variabilities was found. Whereas the gain of OCR is different from the gain of SVV, trial-to-trial variability of OCR follows the same roll-dependent modulation observed in SVV variability. We propose that the similarities in variability reflect a common otolith input, which, however, is subject to distinct central processing for determining the gain of SVV and OC

Baked bunnies, couple selfies, and video-call gardening: Visual communication in couple relationships during COVID-19

The emergence of the COVID-19 pandemic has had manifold societal implications. This paper reflects on the role of visual communication for maintaining relationship stability in couple relationships during the first wave of the pandemic, which we understand as a circumstantial turning point. The analysis is based on qualitative interviews with couples before, during, and after the first wave of COVID-19 in Switzerland, complemented by creative visual methods, follow-up surveys, and video calls. Our results show that visual practices are embedded in rather stable communication repertoires of couples during their relationship maintenance phase. Our study also points to the simultaneous use of a variety of visual practices, which led to a high “visual saturation”. These visual practices were found to contribute to relationship stability by reinforcing intimacy, a key factor in couple relationships, thereby shielding the relationships from circumstantial change

Obesity but not overweight is associated with increased mortality risk

The association between body mass index (BMI) and survival has been described in various populations. However, the results remain controversial and information from low-prevalence Western countries is sparse. Our aim was to examine this association and its public health impact in Switzerland, a country with internationally low mortality rate and obesity prevalence. We included 9,853 men and women aged 25-74years who participated in the Swiss MONICA (MONItoring of trends and determinants in CArdiovscular disease) study (1983-1992) and could be followed up for survival until 2008 by using anonymous record linkage. Cox regression models were used to calculate mortality hazard ratios (HRs) and to estimate excess deaths. Independent variables were age, sex, survey wave, diet, physical activity, smoking, educational class. After adjustment for age and sex the association between BMI and all-cause mortality was J shaped (non-smokers) or U shaped (smokers). Compared to BMI 18.5-24.9, among those with BMI≥30 (obesity) HR for all-cause mortality was 1.41 (95% confidence interval: 1.23-1.62), for cardiovascular disease (CVD) 2.05 (1.60-2.62), for cancer 1.29 (1.04-1.60). Further adjustment attenuated the obesity-mortality relationship but the associations remained statistically significant. No significant increase was found for overweight (BMI 25-29.9). Between 4 and 6.5% of all deaths, 8.8-13.7% of CVD deaths and 2.4-3.9% of cancer deaths could be attributed to obesity. Obesity, but not overweight was associated with excess mortality, mainly because of an increased risk of death from CVD and cancer. Public health interventions should focus on preventing normal- and overweight persons from becoming obes

Einfluss sozio-ökonomischer Faktoren auf die Verdichtungsstrategie von Gemeinden – Erkenntnisse aus dem Kanton Zürich

Planung und Koordination von Wachstumsprozessen in Städten und Gemeinden gewinnen in Zeiten stetig wachsender Bevölkerung zunehmend an Bedeutung. Insbesondere Siedlungsentwicklung nach innen, bei der durch Verdichtung mehr Menschen als bisher auf gleichem Raum leben und arbeiten, erfordert eine überlegte und nachhaltige Entwicklung der begrenzt zur Verfügung stehenden Flächen. Dazu werden Flächennutzungsvorschriften und Zonenpläne erstellt, die versuchen, die Siedlungsexpansion zu minimieren und stattdessen eine nachhaltige Verdichtung durch kompakte Siedlungsformen zu fördern. Dabei wird angenommen, dass sozio-ökonomische Faktoren wie (i) Pro-Kopf-Einkommen, (ii) Wohneigentumsquote, oder (iii) Raumnutzerdichte einen entscheidenden Einfluss auf die Wahl der Entwicklungsstrategie einer Gemeinde haben. Die vorliegende Masterarbeit befasst sich deshalb mit dem Einfluss sozio-ökonomischer Faktoren auf die Verdichtungsstrategie der Gemeinden im Kanton Zürich zwischen 1996 und 2019. Für die empirische Forschung wird ein Mixed-Methods Ansatz verwendet, der quantitative und qualitative Methoden kombiniert. In einem ersten Schritt wird dargestellt, wie sich Einzonungen (Siedlungsexpansion) und Aufzonungen (Verdichtung) in den Gemeinden des Kantons Zürich seit 1996 entwickelt haben. Im zweiten Schritt werden Fixed-Effects Regressionen durchgeführt, welche die Zusammenhänge der untersuchten sozio-ökonomischen Variablen prognostizieren. Der dritte Schritt besteht aus qualitativen Interviews mit Stadtplanerinnen von zwei Zürcher Gemeinden, in denen die wichtigen Faktoren für die Entstehung ihrer Entwicklungsstrategien beleuchtet werden. Die Ergebnisse der empirischen Forschung zeigen, dass sozio-ökonomische Faktoren in der Zürcher Raumplanung nur eine untergeordnete Rolle spielen. Die Entscheidung, warum Gemeinden eine bestimmte Zonierungsstrategie wählen, hängt in der Praxis nicht von sozio-ökonomischen Faktoren ab, sondern wird massgeblich von externen Faktoren, wie dem übergeordneten föderalistischen Planungs- und Gesetzesrahmen bestimmt. Diese Ergebnisse ermöglichen ein besseres Verständnis wichtiger Einflussfaktoren und damit fundiertere Entscheidungen in der Praxis. Die Arbeit zeigt auch, dass die Raumplanung im Kanton Zürich auf dem Weg zur gewünschten und notwendigen Plafonierung des Siedlungsflächenverbrauchs pro Person ist, da die Siedlungsexpansion in den letzten Jahren gebremst und die Verdichtung – wo sinnvoll – intensiviert werden konnte

Spatial orientation in patients with chronic unilateral vestibular hypofunction is ipsilesionally distorted

OBJECTIVE Acute unilateral peripheral-vestibular hypofunction (UVH) shifts the subjective visual vertical (SVV) ipsilesionally, triggering central compensation that usually eliminates shifts when upright. We hypothesized that compensation is worse when roll-tilted. METHODS We quantified SVV errors and variability in different roll-tilted positions (0°, ±45°, ±90°) in patients with chronic UVH affecting the superior branch (SVN; n=4) or the entire (CVN; n=9) vestibular nerve. RESULTS Errors in SVN and CVN were not different. When roll-tilted ipsilesionally 45° (9.6±5.4° vs. -0.2±6.4°, patients vs. controls, p<0.001) and 90° (23.5±5.7° vs. 16.8±8.8°, p=0.003), the patient's SVV was shifted significantly towards the lesioned ear. When upright, only a trend was noted (3.6±2.2° vs. 0.0±1.2°, p=0.099); for contralesional roll-tilts shifts were not different from controls. Variability was larger for CVN than SVN (p=0.046). With increasing disease-duration, adjustment errors decayed for ipsilesional roll-tilt and upright (p⩽0.025). CONCLUSIONS The reason verticality perception was distorted for ipsilesional roll-tilts, may be the insufficient integration of contralesional otolith-input. Similar errors in SVN and CVN suggest a dominant utricular role in verticality perception, albeit the sacculus may improve precision of SVV estimates. SIGNIFICANCE With deficiencies in central compensation being roll-angle dependent, extending SVV-testing to roll-tilted positions may improve identifying patients with chronic UVH

Pitfalls in the diagnostic evaluation of subacute combined degeneration

We report a case of a 43-year-old man presenting with a 2-week history of painless ascending sensory disturbances, suspected to be suffering from acute inflammatory polyneuropathy. On clinical examination, deep tendon reflexes were preserved and muscle strength was 5/5 everywhere. Gait was ataxic with positive Romberg test. Lumbar puncture was normal and electroneurography demonstrated demyelination. With spinal cord involvement centred on the posterior tracts on MRI, differential diagnosis focused on cobalamin deficiency. Initial laboratory work up showed nearly normal holotranscobalamin (43 pmol/L, normal>50) suggesting no vitamin B12 deficiency. Surprisingly, further testing including methylmalonic acid (3732 nmol/L, normal<271) and homocysteine (48.5 µmol/L, normal<10) showed an impairment of vitamin B12-dependent metabolism leading to the diagnosis of subacute combined degeneration. Only after repeated history taking did the patient remember having taken tablets containing cobalamin for 3 days before hospitalisation. In case of B12 deficiency, holotranscobalamin can rapidly normalise during supplementation, whereas methylmalonic acid and homocysteine might help to detect B12 deficiency in patients who recently started supplementation

Hypertrophy of the Inferior Olivary Nucleus Impacts Perception of Gravity

Interruption of the dentato-olivary projections, interconnecting the dentate nucleus (DN) and the contralateral inferior olivary nucleus (ION), is predicted to interfere with the DN’ role in estimating direction of gravity. In a patient with pendular nystagmus due to hypertrophy of the ION secondary to predominantly right-sided ponto-mesencephalic hemorrhage, perceived vertical shifted from clockwise to counter-clockwise deviations within 4 months. We hypothesize that synchronized oscillations of ION neurons induce a loss of inhibitory control, leading to hyperactivity of the contralateral DN and, as a result, to perceived vertical roll–tilt to the side of the over-active DN