Guérit J M
Unité d'Explorations Electrophysiologiques du Système Nerveux, Cliniques Universitaires Saint-Luc, Brussels, Belgium.
Acta Neurol Belg. 1994;94(3):174-82.
The clinical usefulness of three-modality evoked potentials (TMEPs) has been widely demonstrated in acute coma, but is still a matter of debate in the persistent vegetative state. We observed that TMEPs in vegetative patients could be situated along a continuum, one extremity of which corresponds to absent cortical, but preserved brain-stem activities, and the other extremity to major abnormalities of somatosensory conductions at the midbrain level, but variable involvement of auditory pontine and visual cortical pathways. The former pattern is most often associated with ischemic-anoxic encephalopathy, while the latter is most often consecutive to head trauma. However, all intermediate states may be observed. TMEPs can usefully complement the clinical evaluation in answering two questions. The first one concerns the chances of subsequent improvement that are lower in the absence of quantitative TMEP evolution, but are likely to be higher in the presence of non-fixed mesencephalic dysfunction associated with a relative preservation of cortical function. The second question concerns the evaluation of remaining cognitive abilities that are more likely to be present if only mild abnormalities of cortical activities are found and if some cognitive EPs are still obtained.
三模态诱发电位（TMEPs）在急性昏迷中的临床实用性已得到广泛证实，但在持续性植物状态下仍存在争议。我们观察到，植物人患者的TMEPs可能处于一个连续体上，其一端对应皮质活动缺失但脑干活动保留，另一端对应中脑水平体感传导的主要异常，但听觉脑桥和视觉皮质通路的受累情况各不相同。前一种模式最常与缺血缺氧性脑病相关，而后一种模式最常继发于头部外伤。然而，所有中间状态都可能出现。TMEPs可以有效地补充临床评估，回答两个问题。第一个问题涉及后续改善的可能性，在没有定量TMEP演变的情况下可能性较低，但在存在与皮质功能相对保留相关的非固定性中脑功能障碍时可能较高。第二个问题涉及对剩余认知能力的评估，如果仅发现皮质活动轻度异常且仍能获得一些认知诱发电位，则更有可能存在剩余认知能力。
