[Influence of different head-trunk positions to the upbeat-nystagmus]

The neck torsion test (NTT) can be used to evaluate the cervico-ocular reflex (COR). We think there are two main reasons why NRT has failed to gain general acceptance in clinical practice: the test does not fully exploit the somatosensory examination potential, and electronystagmography has been most commonly used but is inferior to videonystagmography for a very low-amplitude nystagmus. These considerations have led us to develop a modified neck torsion test (mNTT) with three-dimensional video-oculographic (3D-VOG) recording. Sensors on the video glasses enable three-dimensional and continuous registration of the head position. Horizontal, vertical and rotatory eye movements are determined in six different head-body positions (right/left head tilt, ante/retroflexion of the head, and right/left body rotation). The basis for assessing the mNTT is described in detail. We used the mNTT to examine prospectively compensated, vestibularly deficient (n = 52), and cervically deficient (n = 93) patients with vertigo against a control group (n = 22). Our results show that upbeat-nystagmus (UBN) significantly differentiated the groups. This occurs most frequently in the tonic analysis phase of head inclination and reclination. UBN is differential-diagnostically discussed on the basis of these examination findings, and its cervical origin is elucidated with the aid of model conceptions. We conclude that our modified NRT is an improved instrument for COR determination. A suspected cervical somatosensory reduction warrants testing particularly for UBN.