Treatment of Gravitational Pulling Sensation in Patients With Mal de Debarquement Syndrome (MdDS): A Model-Based Approach

Perception of the spatial vertical is important for maintaining and stabilizing vertical posture during body motion. The velocity storage pathway of vestibulo-ocular reflex (VOR), which integrates vestibular, optokinetic, and proprioception in the vestibular nuclei vestibular-only (VO) neurons, has spatio-temporal properties that are defined by eigenvalues and eigenvectors of its system matrix. The yaw, pitch and roll eigenvectors are normally aligned with the spatial vertical and corresponding head axes. Misalignment of the roll eigenvector with the head axes was hypothesized to be an important contributor to the oscillating vertigo during MdDS. Based on this, a treatment protocol was developed using simultaneous horizontal opto-kinetic stimulation and head roll (OKS-VOR). This protocol was not effective in alleviating the MdDS pulling sensations. A model was developed, which shows how maladaptation of the yaw eigenvector relative to the head yaw, either forward, back, or side down, could be responsible for the pulling sensation that subjects experience. The model predicted the sometimes counter-intuitive OKS directions that would be most effective in re-adapting the yaw eigenvector to alleviate the pulling sensation in MdDS. Model predictions were consistent with the treatment of 50 patients with a gravitational pulling sensation as the dominant feature. Overall, pulling symptoms in 72% of patients were immediately alleviated after the treatment and lasted for 3 years after the treatment in 58% of patients. The treatment also alleviated the pulling sensation in patients where pulling was not the dominant feature. Thus, the OKS method has a long-lasting effect comparable to that of OKS-VOR re-adaptation. The study elucidates how the spatio-temporal organization of velocity storage stabilizes upright posture and how maladaptation of the yaw eigenvector generates MdDS pulling sensations. Thus, this study introduces a new way to treat gravitational pull which could be used alone or in combination with previously proposed VOR re-adaptation techniques

Postural and cognitive precursors of post-bout motion sickness and concussion-related symptoms in boxers

University of Minnesota Ph.D. August 2014. Major: Kinesiology. Advisor: Thomas A. Stoffregen. 1 computer file (PDF); vii, 106 pages, appendix A.Background: Motion sickness is characterized by subjective symptoms that include dizziness and nausea. Studies have shown that subjective symptoms of motion sickness are preceded by differences in standing body sway between those who experience the symptoms and those who are not. Boxers often report dizziness and nausea immediately after bouts. We predicted that pre-bout standing body sway would differ between boxers who experienced post-bout motion sickness and those who did not. Methodology/Principal Findings: We collected data on standing body sway before bouts. During measurement of body sway participants performed two visual tasks. In addition, we varied stance width (the distance between the heels). Postural testing was conducted separately before and after participants' regular warm-up routines. After bouts, we collected self-reports of motion sickness incidence and symptoms. Results revealed that standing body sway was greater after warm-up than before warm-up, and that wider stance width was associated with reduced sway. Eight of 15 amateur boxers reported motion sickness after a bout. Two statistically significant interactions revealed that standing body sway before bouts differed between participants who reported post-bout motion sickness and those who did not. Conclusions/Significance: The results suggest that susceptibility to motion sickness in boxers may be manifested in characteristic patterns of body sway. It may be possible to use pre-bout data on postural sway to predict susceptibility to post-bout motion sickness

The role of non-invasive camera technology for gait analysis in patients with vestibular disorders

Purpose of the study Current balance assessments performed in clinical settings do not provide objective measurements of gait. Further, objective gait analysis typically requires expensive, large and dedicated laboratory facilities. The aim of this pilot study was to develop and assess a low-cost, non-invasive camera technology for gait analysis, to assist the clinical assessment of patients with vestibular disorders. Materials and methods used This is a prospective, case-controlled study that was developed jointly by the local Neurotology Department and the Centre for Sports Engineering Research. Eligible participants were approached and recruited at the local Neurotology Clinic. The gait assessment included two repetitions of a straight 7-metre walk. The gait analysis system, comprised of a camera (P3215-V, Axis Communications, Sweden) and analysis software was installed in an appropriately sized clinic room. Parameters extruded were walking velocity, step velocity, step length, cadence and step count per meter. The effect sizes (ESB) were calculated using the MatLab and were considered large, medium or small if >0.8, 0.5 and 0.2 respectively. This study was granted ethical approval by the Coventry and Warwickshire Research Ethics Committee (15/WM/0448). Results Six patients with vestibular dysfunction (P group) and six age-matched healthy volunteers (V group) were recruited in this study. The average velocity of gait for P group was 1189.1 ± 69.0 mm·s-1 whereas for V group it was 1351.4 ± 179.2 mm·s-1, (ESB: -0.91). The mean step velocities were 1353.1 ± 591.8 mm·s-1 and 1434.0 ± 396.5 mm·s-1 for P and V groups respectively (ESB: -0.20). The average cadence was 2.3 ± 0.9 Hz and 2.0 ± 0.5 Hz for P and V groups respectively (ESB: 0.60). The mean step length was 620.5 ± 150.7 mm for the P group and 728.5 ± 86.0 mm for the V group (ESB = -1.26). The average step count per meter was 1.7 ± 0.3 and 1.4 ± 0.1 for P and V groups respectively (ESB = 3.38). Conclusion This pilot study used a low-cost, non-invasive camera technology to identify changes in gait characteristics. Further, gait measurements were obtained without the application of markers or sensors to patients (i.e. non-invasive), thus allowing current, clinical practice to be supplemented by objective measurement, with minimal procedural impact. Further work needs to be undertaken to refine the device and produce normative data. In the future, similar technologies could be used in the community setting, providing an excellent diagnostic and monitoring tool for balance patients

International Air Carrier\u27s Liability to Passengers Under the Warsaw Convention 1929 and the Montreal Convention 1999

The Warsaw Convention 1929, officially referred to as the Convention for the Unification of Certain Rules Relating to International Transportation by Air, established and elaborated, as one of its major tenets, the principle of the air carrier\u27s liability for damage caused to passengers, baggage and goods, and also for damage caused by delay. The rules of the Warsaw Convention are being applied all over the world and have demonstrated their reliability and usefulness. The passenger knows that, wherever and whenever he flies, there is a certain degree of uniformity in the rules governing the carrier\u27s liability, while the carrier, being aware of the extent of his liability, can make arrangements to insure himself against possible losses. It is therefore appropriate to examine the nature and the development of the legal grounds on which the air carrier\u27s liability rests, and their impact on everyday practice. Chinese aviation law regulations need to be modernized to correspond with global developments in the industry. As a first target, the low limitation of air damage recovery needs change, and more detailed implementing regulations are needed to determine the extent and quantum of damages caused by air accident. China needs to unify limits on liability regarding international carriage with those existing in other countries. This will certainly benefit both the aviation and insurance industries. Apart from the problem of low limitation, another important task is to clarify the interpretation of Article 17 of the Warsaw Convention 1929 and the Montreal Convention 1999, which is crucial to international air carrier\u27s liability to passengers. This is the main purpose of the present dissertation. By suggesting that (1) China should interpret accident broadly to provide more, but reasonable protections to passengers; (2) China should adopt tripartite approach to interpret from embarking to disembarking to catch up with modem changes of civil aviation, and (3) China should not allow recovery for pure mental injuries but only to allow recovery of mental distress which flowing from a bodily injury to best serve the purpose of the Conventions. The author wishes to clarify some uncertainties of legal practice in the area of international air carrier\u27s liability to passengers in China

Human reproduction in space. Late results

Objectius de Desenvolupament Sostenible::3 - Salut i BenestarPostprint (published version

International Air Carrier\u27s Liability to Passengers Under the Warsaw Convention 1929 and the Montreal Convention 1999

The Warsaw Convention 1929, officially referred to as the Convention for the Unification of Certain Rules Relating to International Transportation by Air, established and elaborated, as one of its major tenets, the principle of the air carrier\u27s liability for damage caused to passengers, baggage and goods, and also for damage caused by delay. The rules of the Warsaw Convention are being applied all over the world and have demonstrated their reliability and usefulness. The passenger knows that, wherever and whenever he flies, there is a certain degree of uniformity in the rules governing the carrier\u27s liability, while the carrier, being aware of the extent of his liability, can make arrangements to insure himself against possible losses. It is therefore appropriate to examine the nature and the development of the legal grounds on which the air carrier\u27s liability rests, and their impact on everyday practice. Chinese aviation law regulations need to be modernized to correspond with global developments in the industry. As a first target, the low limitation of air damage recovery needs change, and more detailed implementing regulations are needed to determine the extent and quantum of damages caused by air accident. China needs to unify limits on liability regarding international carriage with those existing in other countries. This will certainly benefit both the aviation and insurance industries. Apart from the problem of low limitation, another important task is to clarify the interpretation of Article 17 of the Warsaw Convention 1929 and the Montreal Convention 1999, which is crucial to international air carrier\u27s liability to passengers. This is the main purpose of the present dissertation. By suggesting that (1) China should interpret accident broadly to provide more, but reasonable protections to passengers; (2) China should adopt tripartite approach to interpret from embarking to disembarking to catch up with modem changes of civil aviation, and (3) China should not allow recovery for pure mental injuries but only to allow recovery of mental distress which flowing from a bodily injury to best serve the purpose of the Conventions. The author wishes to clarify some uncertainties of legal practice in the area of international air carrier\u27s liability to passengers in China