Fee James W, Miller Freeman
Research Department, Alfred I duPont Hospital for Children, Wilmington, DE 19899, USA.
Dev Med Child Neurol. 2004 Apr;46(4):273-81. doi: 10.1111/j.1469-8749.2004.tb00482.x.
The general aim of this study was to examine the stiffness and damping characteristics (rate at which oscillations diminish) of limbs of a small population of patients with spastic cerebral palsy (CP) during the Leg Drop Pendulum Test while under general anesthesia and to compare them with patients without CP, both awake and under similar anesthetized conditions. To facilitate a quantitative comparison the authors defined a set of parameters that reflect the stiffness and damping of limbs with spasticity under general anesthesia. To give these parameters more meaning a similar set was constructed for children without disabilities under conditions of normal wakefulness and under anesthesia. The test population of 10 patients with spasticity ranged in age from 4 to 19 years and had a mean age of 10 years 9 months (SD 5 years 10 months); there were four females and six males. The control population consisted of eight patients without disabilities who ranged in age from 7 to 19 years with mean age of 13 years 9 months (SD 3 years 3 months); there were six females and two males. To even out the populations, two limbs from the non-affected sides of two patients with hemiplegic spasticity (both female) were used in the control group. The Leg Drop Pendulum Test was administered to 10 limbs with spastic CP and 10 control limbs under general anesthesia. The two test populations were chosen from patients who were previously scheduled to undergo surgery. Two measures compared limbs of those under anesthetic with those under alert conditions: the damped natural frequency and the damping ratio. The natural frequency is the frequency at which a pendulum oscillates as it comes to rest; the damping ratio is a measure of how quickly the oscillations diminish. In spasticity, active muscle tone disappeared under anesthesia. In both groups the underlying biomechanics of the limb varied considerably. In controls the variation seemed to be growth related.
本研究的总体目标是，在全身麻醉状态下，通过腿部下落摆锤试验，检测一小群痉挛性脑瘫（CP）患者肢体的刚度和阻尼特性（振荡衰减速率），并将其与非CP患者在清醒和类似麻醉状态下的情况进行比较。为便于进行定量比较，作者定义了一组参数，以反映全身麻醉下痉挛性肢体的刚度和阻尼。为使这些参数更具意义，还针对无障碍儿童在正常清醒状态和麻醉状态下构建了一组类似参数。10名痉挛患者的测试人群年龄在4至19岁之间，平均年龄为10岁9个月（标准差5岁10个月）；其中有4名女性和6名男性。对照组由8名无障碍患者组成，年龄在7至19岁之间，平均年龄为13岁9个月（标准差3岁3个月）；其中有6名女性和2名男性。为使两组人群均衡，对照组使用了两名偏瘫性痉挛患者（均为女性）非患侧的两条肢体。在全身麻醉下，对10条痉挛性CP肢体和10条对照肢体进行了腿部下落摆锤试验。这两个测试人群均选自先前计划接受手术的患者。两种测量方法比较了麻醉状态下和清醒状态下人群的肢体情况：阻尼固有频率和阻尼比。固有频率是摆锤静止时振荡的频率；阻尼比是衡量振荡衰减速度的指标。在痉挛状态下，麻醉时主动肌张力消失。两组中肢体的潜在生物力学均有很大差异。在对照组中，这种差异似乎与生长有关。
