Blanks J P, McPherson D, Foltz E L
Neurosurgery. 1985 Dec;17(6):877-82. doi: 10.1227/00006123-198512000-00001.
Recent clinical experience has shown that significant neurological symptoms and deficits occur in patients who have been shunted for hydrocephalus when "overshunting" produces unusual negative intracranial pressure (ICP). Therefore, the effect of acute negative ICP .on the early auditory evoked response (AER) was studied in the normal New Zealand rabbit. ICP was reduced to -50, -100, and -150 mm H2O below base line pressure. The AER after rarefaction auditory stimulation was obtained from ongoing electroencephalographic activity at the base line ICP and at each of the three negative ICP levels. Off-line statistical evaluation of the AER showed minimal changes in the absolute and interpeak latencies of N-0 to P-5 at some negative pressures. However, no statistically significant changes were observed for any of the measures for grouped data. At the negative ICP levels studied, the cerebrospinal fluid (CSF) pulse pressure was considerably augmented over base line measures. Such augmentation of the CSF pulse pressure may be the cause of the minimal effects observed on the AER, which may be due to a neuropraxic effect rather than ischemia from cerebral perfusion pressure changes.
近期临床经验表明，因“过度分流”导致颅内压异常降低时，接受脑积水分流术的患者会出现明显的神经症状和功能缺损。因此，研究了急性颅内压降低对正常新西兰兔早期听觉诱发电位（AER）的影响。将颅内压降至低于基线压力50、100和150毫米水柱。在基线颅内压以及三个颅内压降低水平下，通过持续的脑电图活动获取稀疏听觉刺激后的听觉诱发电位。对听觉诱发电位的离线统计评估显示，在某些负压下，N-0至P-5的绝对潜伏期和峰间潜伏期变化极小。然而，对于分组数据的任何测量指标，均未观察到统计学上的显著变化。在所研究的颅内压降低水平下，脑脊液（CSF）脉压较基线测量值显著增大。脑脊液脉压的这种增大可能是导致听觉诱发电位观察到极小影响的原因，这可能是由于神经失用效应而非脑灌注压变化导致的缺血。
