RESUMEN
This review describes symptoms of space motion sickness (SMS) observed in many cosmonauts during the first day in orbit. It also discusses similar symptoms detected in them upon return to the Earth which constitute the readaptation syndrome. The paper gives a detailed discussion of different theories that explain the etiology and pathogenesis of SMS and the post-flight readaptation syndrome, viz, sensory conflict or sensory mismatch, disorders in the labyrinthine paired function, and blood and cerebrospinal fluid (CSF) circulation. It is emphasized that none of the theories used separately can clarify all aspects of the origin and development of SMS. The authors main tain that the mechanisms underlying the above changes are not contradictory but rather interrelated and complementary. Each of them having a larger or smaller specific weight may be involved in the development of SMS. In some people marked vestibular asymmetry may become the leading factor, in others inadequate adaptive capabilities to fluid redistribution may result in blood and CSF disorders, and in still others sensory conflict may play the crucial role. A correlation between SMS and vestibular adaptation is discussed. Results of studying the vestibular function during and after real space flights are presented.
Asunto(s)
Medicina Aeroespacial , Mareo por Movimiento/etiología , Vuelo Espacial , Vestíbulo del Laberinto/fisiopatología , Ingravidez/efectos adversos , Adaptación Fisiológica , Circulación Cerebrovascular , Humanos , Presión Intracraneal , Mareo por Movimiento/prevención & control , PosturaRESUMEN
The system of medical selection of Soviet cosmonauts stemmed from that used in aviation medicine, particularly medical expertise of the flying personnel. Selection in the hospital included two-stage detailed clinical and physiological examinations using various provocative tests. The system of medical selection and clarification of medical requirements was improved and refined through regular observations over candidates and cosmonauts and careful analysis of their grounding due to medical problems. The American and Soviet systems of selection used at an early stage of space programs are compared and similarities and differences between them are indicated.
Asunto(s)
Administración de Personal/métodos , Selección de Personal/métodos , Vuelo Espacial , Estado de Salud , Humanos , Selección de Personal/normas , Aptitud Física , Psicofisiología , U.R.S.S. , Estados Unidos , Recursos HumanosRESUMEN
The data available suggest that a disorder in the labyrinthine paired function can be regarded as a factor responsible for the initiation and development of space motion sickness. This concept is based on the assumption that in the norm the vestibular function is to a certain extent asymmetric which is made for by a compensatory center in the central nervous system. Exposure to an unusual space environment leads to a disorder of this compensation and development of a "new" vestibular asymmetry. This exposure involves: elimination of the difference in the weight of otolith membranes, disorder of the canal-otolith interaction, asymmetric blood-CSF changes, distinct interhemispheric asymmetry, general stress. Vestibular asymmetry that develops in the weightless state may become sufficient for the generalization of afferent impulsation to normal stimuli and development of a strong reaction. Adaptation to weightlessness occurs due to rearrangements of the compensatory center which are responsible for lower vestibular asymmetry. The compensatory mechanisms that have evolved in weightlessness continue to function during a certain time interval after recovery. They facilitate a re-initiation of vestibular asymmetry and motion sickness that is mainly provoked by head movements, as in the weightless state.
Asunto(s)
Oído Interno/fisiopatología , Mareo por Movimiento/etiología , Enfermedades Profesionales/etiología , Vuelo Espacial , Humanos , Modelos Biológicos , Nistagmo Fisiológico , Postura , Sáculo y Utrículo/fisiopatología , Percepción Espacial/fisiología , Vestíbulo del Laberinto/fisiopatología , Ingravidez/efectos adversosAsunto(s)
Otolaringología , Vuelo Espacial , Animales , Fuerza Coriolis , Oído Interno/fisiología , Gravitación , Audición/fisiología , Humanos , Modelos Biológicos , Mareo por Movimiento/fisiopatología , Ruido/efectos adversos , Orientación/fisiología , Enfermedades Otorrinolaringológicas/fisiopatología , Postura , Factores de Tiempo , U.R.S.S. , Vestíbulo del Laberinto/fisiología , IngravidezRESUMEN
Some considerations on the mechanisms of vestibulo-vegetative disturbance in space flight are given on the basis of clinical observations, experience of otoneurological clinic, simulation experiments and examinations of cosmonauts. The starting point in these disturbances was a significant fact of blood redistribution in weightlessness and subsequent changes in hemodynamics, metabolism, etc. The body reactions to weightlessness seem to prepare pronounced vestibulo-vegetative reflexes to threshold and subthreshold vestibular stimuli induced by head and body movements in flight. Some aspects of the vestibular selection and training of cosmonauts are discussed from this point of view.
Asunto(s)
Sistema Nervioso Autónomo/fisiopatología , Enfermedades del Laberinto/etiología , Enfermedades del Sistema Nervioso/etiología , Vuelo Espacial , Vestíbulo del Laberinto/fisiopatología , Arteria Basilar , Circulación Cerebrovascular , Hemodinámica , Humanos , Inmovilización , Enfermedades del Laberinto/fisiopatología , Enfermedad de Meniere/etiología , Enfermedad de Meniere/fisiopatología , Microcirculación , Enfermedades del Sistema Nervioso/fisiopatología , Arteria Vertebral , Núcleos Vestibulares/fisiopatología , Equilibrio Hidroelectrolítico , IngravidezRESUMEN
Medical results obtained during missions of the Soyuz-12, Soyuz-13, Soyuz-14 spacecraft and the Salyut-3 orbital station are presented. The subjective feelings of the crewmembers (blood rush to the head, chest congestion, vegetative disturbances, etc), data of the inflight medical control and medical experiments as well as countermeasures used are described in detail. Results of postflight medical examinations at rest and using functional tests are also summarized. It is concluded that no abnormalities in the vital physiological functions of the crews developed inflight. The symptoms typical of the acute period of adaptation to weightlessness disappeared completely after the first flight days.