Fetter M, Dichgans J
Eberhard-Karls University, Department of Neurology, Tübingen, Federal Republic of Germany.
J Vestib Res. 1990;1(1):9-22.
To further elucidate possible central plastic adaptive processes during the recovery from a unilateral peripheral vestibular lesion, we investigated vestibular functions in humans over a period of 2 months after an acute unilateral labyrinthine lesion. A unilateral peripheral vestibular lesion creates both a tonic imbalance that causes spontaneous nystagmus and a decrease and directional asymmetry of dynamic vestibular responses. We establish that the tonic imbalance expressed by the spontaneous nystagmus rapidly decreased (similar to other species), whether the lesion remained complete or not. This rebalancing, in the case of complete lesions, is at least partly due to restoration of central vestibular tone on the lesioned side. This restoration of tone also explains, in the case of a complete lesion, the recovery of dynamic vestibular responses for high-velocity inhibitory stimulation of the remaining labyrinth. A clear recovery of the dynamic response for excitatory stimulation of the remaining labyrinth cannot be proven, as has been shown in monkeys during the first 4 days after a unilateral vestibular lesion. This is probably due to the fact that in our patients the first recording could not be performed before day 3 after the onset of symptoms. Therefore, any fast dynamic recovery may have been missed.
为了进一步阐明单侧外周前庭病变恢复过程中可能存在的中枢可塑性适应过程，我们对急性单侧迷路病变后的人类进行了为期2个月的前庭功能研究。单侧外周前庭病变会产生导致自发性眼球震颤的紧张性失衡，以及动态前庭反应的降低和方向不对称。我们发现，无论病变是否仍为完全性，由自发性眼球震颤所表现出的紧张性失衡都会迅速降低（与其他物种相似）。在完全性病变的情况下，这种重新平衡至少部分归因于病变侧中枢前庭张力的恢复。这种张力的恢复也解释了在完全性病变的情况下，对剩余迷路进行高速抑制性刺激时动态前庭反应的恢复。正如在猴子单侧前庭病变后的前4天所显示的那样，无法证实对剩余迷路进行兴奋性刺激时动态反应有明显恢复。这可能是因为在我们的患者中，症状出现后第3天才进行首次记录。因此，任何快速的动态恢复可能都被错过了。
