Anastasopoulos D, Bhatia K, Bisdorff A, Bronstein A M, Gresty M A, Marsden C D
Department of Neurology, University of Ioannina Medical School, Greece.
Mov Disord. 1997 Jul;12(4):561-9. doi: 10.1002/mds.870120413.
Estimates of points of entering and exiting from upright posture were obtained from 25 seated, restrained patients with idiopathic spasmodic torticollis (ST) and matched normal subjects exposed to cycles of 1.5 degrees/s tilts in a flight simulator. Estimates were obtained for displacements in roll and pitch about upright and for yaw tilts about a rostrocaudal, "barbecue," axis with the subjects supinated. For both pitch and roll, normal subjects estimated entering upright when they were still approximately 1 degree from machine upright and perceived themselves to be upright through a mean arc of 6 degrees. In barbecue tilt, entering upright was estimated at 0.2 degree for an arc of 6 degrees. Patients estimated entering upright at 2.8 degrees in roll and 3 degrees in pitch but estimated exiting upright at the same tilt as normal subjects; that is, they were less specific in detecting verticality. Patients were normal in barbecue tilt. No relationship between tilt estimates and head deviation was found. There were no differences between normal subjects when tested with their head in normal posture and with an assumed tilt of 20 degrees. Normal subjects probably based their estimates on combined vestibular-somatosensory signals, whereas torticollis patients appeared to derive more from a vestibular signal. However, patients referred the vestibular signals to the trunk long axis when asked to indicate the whole-body vertical. The findings suggest disruption of the normal combined vestibuloproprioceptive mechanism for detecting body uprightness in ST.
在飞行模拟器中，对25名患有特发性痉挛性斜颈（ST）且坐在座椅上并系有安全带的患者以及匹配的正常受试者进行了1.5度/秒倾斜周期测试，以获取从直立姿势进入和退出的角度估计值。在受试者仰卧的情况下，获取了围绕直立状态的横滚和俯仰位移以及围绕前后“烧烤”轴的偏航倾斜的估计值。对于俯仰和横滚，正常受试者在距离机器直立状态仍约1度时估计进入直立状态，并在平均6度的弧度内感知自己处于直立状态。在“烧烤”倾斜中，对于6度的弧度，估计进入直立状态为0.2度。患者估计在横滚2.8度和俯仰3度时进入直立状态，但估计退出直立状态时与正常受试者的倾斜度相同；也就是说，他们在检测垂直度方面不够精确。患者在“烧烤”倾斜方面表现正常。未发现倾斜估计值与头部偏斜之间存在关联。正常受试者在头部处于正常姿势和假设倾斜20度时进行测试，结果无差异。正常受试者可能基于前庭 - 本体感觉信号的组合来进行估计，而斜颈患者似乎更多地依赖于前庭信号。然而，当被要求指出全身垂直方向时，患者将前庭信号参考到躯干长轴。研究结果表明，在特发性痉挛性斜颈中，检测身体直立状态的正常前庭 - 本体感受联合机制受到了破坏。
