Israel Medical Association Journal

Background: Seasickness is thought to result from conflicting inputs from the vestibular, visual and somatosensory systems. The otolithic organs, which are responsible for the sensation of linear acceleration and tilt, are important in the pathogenesis of seasickness. Vestibular evoked myogenic potentials test is an objective evaluation of saccular function.

Objective: To examine whether saccular function is related to the pathogenesis of seasickness.

Methods: VEMP1 was performed in 10 subjects susceptible to seasickness and in 14 non-susceptible subjects.

Results: Bilateral VEMP responses were obtained in 7 (50%) of the non-susceptible subjects and 1 (10%) of the susceptible subjects. No differences were found between the groups in P13 and N23 wave latencies, amplitudes, N13-P23 inter-peak latencies, and peak-to-peak asymmetry ratios. More subjects in the susceptible group had asymmetry ratios > 35%.   

Conclusions: The attenuated saccular response might be explained in the context of the neural-mismatch theory and/or the subjective vertical theory, as reflecting an adaptation effort to sea conditions. A larger study is necessary to determine whether a statistically significant difference in VEMP responses exists between seasickness-susceptible and non-susceptible subjects.
 

Background: An organ sharing system should achieve fairness and optimal graft longevity. Balancing between social and utilitarian considerations is a sensitive ethical, public and medical issue that requires a means to examine the consequences of any allocation policy or planned changes thereof.

Objective: To evaluate the performance and applicability of a computerized simulation model by examining the impact of two opposing organ allocation policies (social or utilitarian) on predicted organ distribution regarding age, waiting time, recipient sensitization measured by panel reactive antibody level and overall donor-recipient tissue matching (measured by the number of HLA antigen mismatches).

Methods: Using a computerized simulation model, virtual donors and recipients were emulated and organs were allocated according to either social algorithms or utilitarian policies. The resulting number of HLA mismatches, PRA[1], age, and waiting time distributions were compared between allocation strategies.

Results: Simulating allocation of 7,000 organs to 17,000 candidate recipients and implementing social policies yielded donor-recipient compatibility comparable to utilitarian policies (0–1 mm: 19.4% vs. 28%) while allocating 66.7% of organs to long waiters (>48 months).

Conclusion: This computerized simulation model is a valuable tool for decision-makers establishing or modifying organ allocation policies.