Abstract
Prolonged bed rest often induces disturbed balance. However, there are few reports on this pathophysiological condition. Schellong's test, otolithic functional test and spontaneous, gaze, and positional nystagmus tests were performed to evaluate the influence of prolonged bed rest on the vestibular system and the autonomic nervous system in orthopedic patients without direct injury to the vestibular system.
Systolic and diastolic blood pressure and heart rate were serially measured every 2 minutes in the supine position for 10 minutes and in the standing position for 10 minutes. We used a tilt chair apparatus which was electrically driven as far as 30 degrees at a speed of 1 degree per second. Eye movement was observed using a nystagmograph and recorded by a CCD-camera in front of the eyes. Spontaneous, gaze, and positional nystagmus were tested using the nystagmograph.
Schellong's test was positive in 75% of the patients. Prolonged bed rest evoked abnormal findings on the otolithic functional test and nystagmus tests.
It was suggested that prolonged bed rest induced autonomic nervous dysfunction and vestibular dysfunction.
