tk;1Passive head-up tilt and exercise result in specific changes in the spectral characteristics of heart rate (HR) variability as a result of reduced vagal and enhanced sympathetic outflow. Recently analytic methods based on nonlinear system theory have been developed to characterize the nonlinear features in HR dynamics. This study was designed to assess the changes in the fractal and complex...

AIM To evaluate the possible relation between adenosine sensitive syncope and tilt induced vasovagal syncope. METHODS An ATP test and a head up tilt test were performed in 175 consecutive patients with syncope of uncertain origin. The ATP test consisted of the rapid intravenous injection of 20 mg of ATP; a positive response was defined as the induction of a ventricular pause (maximum RR inter...

The functional status of the velocity storage mechanism was studied in patients at long-term follow-up (2 to 4 years) after unilateral vestibular neurectomy. The time constant of the vestibulo-ocular reflex (VORtc), the effect of head tilt on postrotatory nystagmus, optokinetic after-nystagmus (OKAN), and nystagmus after rapid head shaking were studied in 10 patients. In agreement with previous...

BACKGROUND Several inferior oblique (IO) weakening methods exist for correction of superior oblique palsy (SOP). A previously reported method involved recession and anteriorization according to IO overaction (IOOA) grade, which might be subjective and cause upgaze limitation and opposite vertical strabismus. Therefore, this study attempted to examine the efficacy of modified graded recession an...

PURPOSE Residual head tilt has been reported in patients with superior oblique muscle palsy (SOP) after surgery to weaken the inferior oblique (IO) muscle. The treatments for these patients have not received appropriate attention. In this study, we evaluated the superior rectus (SR) muscle recession as a surgical treatment. METHODS The medical records of 12 patients with SOP were retrospectiv...

1. Plasma catecholamines, plasma renin activity, plasma aldosterone and haematocrit were measured in four subjects with physiologically complete cervical spinal cord transections, before, during and after head-up tilt to 45 degrees for 30 min. Plasma catecholamines were measured in five normal male volunteers in the supine position and after head-up tilt to 45 degrees for 10 min. 2. After 10 mi...

A fundamental challenge for maintaining spatial orientation and interacting with the world is knowledge of our orientation relative to gravity, i.e., head tilt. Sensing gravity is complicated because of Einstein's equivalence principle, in which gravitational and translational accelerations are physically indistinguishable. Theory has proposed that this ambiguity is solved by tracking head tilt...

TO THE EDITOR: We read the article by Wang and Lewis (2016) with a great interest. In this study, using the axis shift and dumping index, they found that the “residual sensory conflict” correlates with motion sickness susceptibility in patients with vestibular migraine. This could explain the motion intolerance and episodic vertigo that characterize vestibular migraine based on dysfunction of t...

IN 1895 Leonard Hill' concluded from his experimental work on the blood pressure and heart rate of animals that the effect of changing the position afforded a most delicate test of the vasomotor mechanism. The development of accurate methods of continuous recording made it possible to confirm these conclusions in man. Previous studies2 3 of normal subjects established a definite pattern of bloo...