The influence of body position on Bielschowsky's test

Purpose: To investigate the veracity of Jampolsky's statement that Bielschowsky's head tilt test is inverted if performed with the patient in the upside-down position and to interpret its neuromuscular mechanism. Methods: We present a series of 10 patients selected from a referred sample who were diagnosed with superior oblique paresis. Hypertropia was measured in the primary position, with the head erect and tilted toward both shoulders with the patient in the erect, supine, and upside-down positions. The last position was achieved by hanging the patient upside-down. Results: As expected, our results showed the veracity of Jampolsky's statement. The forced head tilt difference was inverted or significantly decreased when the test was performed in the upside-down position. Moreover, in all patients, Bielschowsky's phenomenon was neutralized in the supine body position, in which hypertropia with the head erect tended to vanish. In 3 patients, it disappeared completely. Conclusions: This study showed that, in patients with superior oblique paresis, differences in the extent of hypertropia in Bielschowsky's test tended to vanish when the test was performed with the patient in the supine position and invert when it was performed with the patient in the upside-down position.

研究目的：验证Jampolsky提出的「当患者处于倒置体位时，贝尔肖斯基头倾斜试验（Bielschowsky's head tilt test）结果会反转」这一论断的正确性，并阐释其对应的神经肌肉机制。
研究方法：本研究纳入10例从转诊样本中筛选确诊为上斜肌麻痹（superior oblique paresis）的患者。分别测量患者在直立位、仰卧位和倒置体位下，处于眼原在位、头部直立及头部向双侧肩部倾斜状态时的上斜视（hypertropia）度数。倒置体位通过将患者头脚倒置实现。
研究结果：正如预期，本研究结果证实了Jampolsky论断的正确性。当试验在倒置体位下进行时，强迫头倾斜试验差值出现反转或显著降低。此外，所有患者在仰卧体位时，贝尔肖斯基现象均被抵消，此时头部直立状态下的上斜视症状趋于消失，其中3例患者症状完全消失。
研究结论：本研究表明，在上斜肌麻痹患者中，行贝尔肖斯基头倾斜试验时，若患者处于仰卧体位，试验中上斜视的差异程度会趋于消失；若患者处于倒置体位，则试验结果会出现反转。