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BACKGROUND: Both the dynamic visual acuity (DVA) test and the video head-impulse test (vHIT) are fast and simpleways to assess peripheral vestibulopathy. After losing peripheral vestibular function, some patients show better DVA performance than others, suggesting good compensatory mechanisms. It seems possible that compensatory covert saccades could be responsible for improved DVA. OBJECTIVE: To investigate VOR gain and compensatory saccades with vHIT and compare them to the DVA of patients with unilateral peripheral vestibulopathy. METHODS: VOR gain deficit and compensatory saccades were measured with vHIT. VOR gain was calculated for each trial as mean eye velocity divided by mean head velocity during 4 samples between 24 ms - 40ms after peak head acceleration. DVA was then assessed. VHIT was analyzed for percentage of covert saccades and for cumulative overt saccade amplitude. Twenty-four patients with unilateral vestibular deficit were included.Acontrol group of 113 healthy subjects provided normal data. RESULTS: On the affected side, pathologic values for DVA (mean 0.83 logMAR±0.25 SD) and VOR gain (mean 0.16±0.13) were obtained, whereas the healthy side showed normal values (0.53 logMAR±0.15 for DVA and 0.89±0.18 for VOR gain). Yet, DVA performance on the affected side was significantly better in patients with higher covert saccade percentage (p = 0.012) and lower cumulative overt saccade amplitude (p < 0.001). CONCLUSION: Compensatory covert saccades seen in vHIT correlate with improved performance of DVA-testing in patients with unilateral peripheral vestibular loss. Hence, in addition to testing peripheral vestibulopathy, our results indicate a way for assessing rehabilitatory compensation in such patients by DVA in addition to vHIT. [ABSTRACT FROM AUTHOR]

Downbeat nystagmus (DBN) observed in head-hanging positions, may be of central or peripheral origin. Central DBN in head-hanging positions is mostly due to a disorder of the vestibulo-cerebellum, whereas peripheral DBN is usually attributed to canalolithiasis of an anterior semicircular canal. Here, we describe an atypical case of a patient who, after head trauma, experienced severe and stereotypic vertigo attacks after being placed in various head-hanging positions. Vertigo lasted 10-15 s and was always associated with a robust DBN. The provocation of transient vertigo and DBN, which both showed no decrease upon repetition of maneuvers, depended on the yaw orientation relative to the trunk and the angle of backward pitch. On a motorized, multi-axis turntable, we identified the two-dimensional Helmholtz coordinates of head positions at which vertigo and DBN occurred ( y -axis: horizontal, space-fixed; z -axis: vertical, and head-fixed; x -axis: torsional, head-fixed, and unchanged). This two-dimensional area of DBN-associated head positions did not change when whole-body rotations took different paths (e.g., by forwarding pitch) or were executed with different velocities. Moreover, the intensity of DBN was also independent of whole-body rotation paths and velocities. So far, therapeutic approaches with repeated liberation maneuvers and cranial vibrations were not successful. We speculate that vertigo and DBN in this patient are due to macular damage, possibly an unstable otolithic membrane that, in specific orientations relative to gravity, slips into a position causing paroxysmal stimulation or inhibition of macular hair cells., Competing Interests: The authors have no conflicts of interest to declare., (Copyright © 2021 by S. Karger AG, Basel.)

Objectives: The aim of the present study was to investigate current treatment practices and self-reported effectiveness in Ménière's disease., Materials and Methods: Members of two Italian Ménière's disease support (n=170) with ≥6-month history of Ménière's disease were administered an online survey about recent treatments. Vertigo episode count, work absenteeism, and limitations in family life, social life, work, or travel as included in the Social Life and Work Impact of Dizziness Questionnaire before and after recent treatments were queried., Results: Twenty-four different treatments were reported for Ménière's disease, with dietary modifications (55%), diuretics (47%), and betahistine (41%) being the most common. The majority (71%) received multiple simultaneous treatments. Prior to the most recent treatments, 78%-89% of respondents indicated limitations in family or social life, work, or traveling. After their most recent treatment, respondents reported improvements in mean vertigo episode counts (5.7±7.6 vs. 2.6±4.6, p<0.001), days off work per month (10.1±9.2 vs. 4.2±6.7, p<0.001), and proportions indicating limitations in any functional measure assessed (p<0.05). These findings were consistent regardless of treatment approach (p<0.05 for all). Intratympanic gentamicin provided the greatest reductions in vertigo count, functional limitations, and work absenteeism (p<0.01 for all), as well as the fewest respondents reporting post-treatment functional limitations (16%-37%)., Conclusion: Despite many treatment approaches targeting different proposed pathophysiology for Ménière's disease in this cross-sectional survey, all treatments are reported as effective by patients. These findings support a prominent placebo effect in Ménière's disease and highlight challenges in studying treatment outcomes; there is a critical need to better understand Ménière's disease.

Carbamoylphosphate synthetase 1 (CPS1) is the first enzyme of the urea cycle. CPS1 deficiency is a rare autosomal-recessively inherited disorder that can lead to life-threatening hyperammonemia. Since there is no reliable biochemical marker for this disease, diagnosis relies on molecular means which is often done by RNA-based mutation analysis. Skin fibroblasts have been frequently used as a source of RNA while peripheral blood cells do not yield sufficient amounts of specific RNA. To avoid the costly and laborious use of cultured fibroblasts, we tried to use stimulated lymphocytes as an alternative. This was effectively achieved by short-term culture of full heparin blood in the presence of phytohemagglutinin. Hereby, subsequent reverse transcriptase-PCR of the CPS1 transcript became feasible and allowed to detect 16 different mutations (10 missense, 3 deletions, 2 nonsense, 1 duplication; 7 novel mutations) in 14 consecutive patients with CPS1 deficiency. When compared to retrospective data on cultured fibroblasts, the adapted method allowed substantial shortening of the median time to diagnosis (24 days versus 122 days, respectively). Besides disease causing mutations, we detected CPS1 transcript variants including one cryptic exon in RNA from lymphocytes with higher frequency than in RNA from fibroblasts. This underlines that all mutations found in RNA need to be confirmed by DNA sequencing. In conclusion, the presented approach improves the diagnostics of CPS1 deficiency. Besides the shortened time to diagnosis, the method is of particular importance for confirmation of findings of next generation sequencing and gene chips., (Copyright © 2012 Elsevier Inc. All rights reserved.)