Konno S, Olmarker K, Byröd G, Rydevik B, Kikuchi S
Department of Orthopaedics, Sahlgren Hospital, University of Göteborg, Sweden.
Spine (Phila Pa 1976). 1995 Jun 1;20(11):1223-6. doi: 10.1097/00007632-199506000-00002.
Neurophysiologic reactions of cauda equina nerve roots to intermittently applied compression were assessed for two different modes of compression using a porcine model.
To assess the neurophysiologic reactions of cauda equina nerve roots to intermittently applied compression.
A number of experimental studies have been presented recently regarding the reaction pattern of spinal nerve roots to compression. These studies have used a continuous pressure level. For studies of pathophysiologic mechanisms behind neurogenic claudication, however, it would be more relevant to study the effects of intermittently applied compression.
The cauda equina was exposed and compression was applied by two inflatable balloons. Two different modes of compression were used. Either the two balloons were inflated and deflated simultaneously (intermittent compression), or just the caudal balloon was inflated and deflated while the cranial balloon was kept continuously inflated (continuous/intermittent compression). The experimental series were: intermittent compression at 10 mm Hg (n = 5) and 50 mm Hg (n = 5), and continuous/intermittent compression at 10 mm Hg (n = 5) and 50 mm Hg (n = 5). For both modes of compression the pressure in the balloons with intermittent inflation was maintained for 10 minutes and deflated for 5 minutes. This procedure was repeated in 8 cycles for 2 hours. Muscle action potentials were recorded in the tail muscles.
Compression at 10 mm Hg induced similar reductions of muscle action potentials for both compression modes. At 50 mm Hg, the effects were more pronounced at continuous/intermittent compression than at intermittent compression. The reduction of muscle action potentials was slightly more pronounced for 50 than for 10 mm Hg at intermittent compression. However, a statistically significant difference in the results was found only between 10 and 50 mm Hg at the continuous/intermittent compression mode.
The established model allows investigation of the effects of intermittent cauda equina compression, which might be clinically more relevant than continuous compression regarding the pathophysiologic mechanisms behind neurogenic claudication.
使用猪模型评估马尾神经根对间歇性施加压迫的神经生理反应，采用两种不同的压迫模式。
评估马尾神经根对间歇性施加压迫的神经生理反应。
最近有多项关于脊神经根对压迫反应模式的实验研究。这些研究采用的是持续压力水平。然而，对于神经源性间歇性跛行背后病理生理机制的研究，研究间歇性施加压迫的影响可能更具相关性。
暴露马尾，通过两个可充气气球施加压迫。采用两种不同的压迫模式。要么两个气球同时充气和放气（间歇性压迫），要么仅尾侧气球充气和放气，而头侧气球持续充气（持续/间歇性压迫）。实验分组为：10 mmHg间歇性压迫（n = 5）和50 mmHg间歇性压迫（n = 5），以及10 mmHg持续/间歇性压迫（n = 5）和50 mmHg持续/间歇性压迫（n = 5）。对于两种压迫模式，间歇性充气的气球中的压力维持10分钟，然后放气5分钟。此过程重复8个周期，共2小时。在尾部肌肉记录肌肉动作电位。
10 mmHg压迫时，两种压迫模式引起的肌肉动作电位降低相似。在50 mmHg时，持续/间歇性压迫的影响比间歇性压迫更明显。间歇性压迫时，50 mmHg比10 mmHg引起的肌肉动作电位降低略更明显。然而，仅在持续/间歇性压迫模式下，10 mmHg和50 mmHg之间的结果存在统计学显著差异。
所建立的模型能够研究间歇性马尾压迫的影响，就神经源性间歇性跛行背后的病理生理机制而言，这可能在临床上比持续压迫更具相关性。
