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O Spitzer

Publications and source records attributed to O Spitzer.

24 records · Page 2Linked to original sources

Vestibulo-ocular reflex as a parameter of seasickness susceptibility.

The vestibulo-ocular reflex (VOR) is known to be modulated in response to changing vestibular and optokinetic stimuli. The purpose of this study was to investigate possible relationships between VOR and future susceptibility and habituation to seasickness. Thirty candidates for future maritime service were exposed to a series of yaw axis smooth harmonic accelerations before and after 6 months of regular sailing, and their VOR gain and phase responses were recorded. Seasickness severity was estimated after 1 and 6 months of service by a questionnaire. We conclude that VOR gain at 0.01 Hz may serve as a physiologic correlate helping to predict seasickness susceptibility, and that the increase in phase lead at 0.02 Hz may mark the habituation process to sea conditions.

Acceleration↗

Three-years' experience of transdermal scopolamine: long-term effectiveness and side-effects.

A study was carried out in 68 otherwise healthy male naval crew members to assess the long-term effectiveness and side-effects of routine transdermal scopolamine administration for the prevention of seasickness. The transdermal patches were applied to the mastoid process before each sailing and the subjects generally used 2 patches a week. Check-ups were made every 3 months over a period of 3 years. The average reported seasickness severity (on a scale of 0 to 7) after 6 months at sea prior to the administration of transdermal scopolamine was 5.64 +/- 0.11 (mean +/- S.E.M.), in comparison with 3.14 +/- 0.23 post-administration (p less than 0.001). A significant improvement was found in the self-estimated performance at sea whilst receiving the drug: 65.7% +/- 3.38% (mean +/- S.E.M.), compared to 25% +/- 2.24% beforehand (p less than 0.001). Contact dermatitis precluded the use of transdermal scopolamine in 3 (4.4%) subjects. The only other significant side-effect was dryness of mucous membranes. In conclusion, transdermal scopolamine was found to be effective in the prevention of seasickness and improvement of performance at sea during 3 years of follow-up and routine administration of the drug was not complicated either by severe side-effects or by performance disturbances.

Administration, Cutaneous↗

The vestibulo-ocular reflex (VOR) under the influence of cinnarizine.

In a double-blind, placebo controlled, crossover study, we evaluated the effects of cinnarizine on the VOR of 55 healthy young subjects. VOR was evaluated by the Sinusoidal Harmonic Acceleration (SHA) test at frequencies of 0.01, 0.02, 0.04, 0.08 and 0.16 Hz. There was a reduction in VOR gain in 16 of the 20 SHA trials performed under the influence of cinnarizine alone (25 mg and 50 mg) and cinnarizine 25 mg in combination with 10 mg domperidone or 1 transdermal scopolamine patch. This decrease in VOR gain was significant in only a few SHA trials. Phase lead was not consistently affected by cinnarizine. No notable side effects were found for any of the drug groups. Our findings are in accord with the contention that increased resistance to seasickness produced either by drugs, or by the natural process of habituation to sea conditions, may be reflected by a decrease in VOR gain.

Adult↗

Clinical features of mal de debarquement: adaptation and habituation to sea conditions.

A survey conducted among 116 crew members of seagoing vessels confirmed that mal de debarquement (M-D) is a transient feeling of swinging, swaying, unsteadiness, and disequilibrium. None of the subjects requested medical attention, although there were isolated cases in which a strong sensation of swinging and unsteadiness caused transient postural instability and impaired the ability to drive. In most cases, the sensation of M-D appeared immediately on disembarking and generally lasted a few hours. In addition, subjects usually described bouts or attacks of M-D associated with changes in body posture, head position, or with closing of the eyes. M-D was reported by 72% of our subjects. Sixty-six percent of subjects reported a high incidence following their first voyages. A significant positive correlation was found between M-D and seasickness susceptibility. The nature of M-D may be explained within the framework of multisensorimotor adaptation and habituation to a new or abnormal motion environment. It is suggested that M-D represents a dynamic, multisensorimotor form of CNS adaptive plasticity.

Adaptation, Physiological↗

The vestibulo-ocular reflex and seasickness susceptibility.

VOR parameters were compared in subjects at the extremes of the seasickness susceptibility scale. Thirty-nine subjects highly susceptible to seasickness and 30 nonsusceptible subjects participated in the study. The VOR was evaluated by the Sinusoidal Harmonic Acceleration (SHA) test at frequencies of 0.01, 0.02, 0.04, 0.08, and 0.16 Hz. In subjects susceptible to seasickness, VOR gain was significantly higher at 0.02 and 0.04 Hz, and phase lead was significantly lower at 0.01, 0.02, 0.04, and 0.08 Hz, than in nonsusceptible subjects. Our findings are in agreement with the notion that the vestibular response will be more intense in subjects susceptible to motion sickness. The present results support the contention that a natural insusceptibility, or increased resistance to seasickness produced by adaptive responses to repeated sea exposures, may be reflected by lower VOR gain and higher phase lead.

Acceleration↗