Neuloh G, Schramm J
Universitätsklinikum Bonn, Klinik und Poliklinik für Neurochirurgie, Bonn, Germany.
Cent Eur Neurosurg. 2009 Nov;70(4):171-5. doi: 10.1055/s-0029-1225651. Epub 2009 Oct 22.
The present study explores the causes of occasional postoperative pareses despite unchanged or fully recovered intraoperative motor evoked potentials (MEPs) in supratentorial brain surgeries.
In a prospective, observational design, MEP monitoring results, motor outcome, and perioperative imaging were correlated in 200 procedures for brain tumours and cortical dysplasias critically related to motor areas and pathways.
Persisting pareses after unchanged or recovered MEPs occurred in four cases due to delayed ischemia, or venous congestive oedema. Transient new deficit in four cases after stable MEP monitoring occurred due to inadvertently strong stimulation bypassing the target lesion, due to marked postresectional oedema, and after cortical transsections for alleviation of epilepsy.
With technically adequate MEP monitoring, truly false-negative results missing manifest corticospinal impairment do not occur. However, sustained vascular dynamics (vasospasm, congestive oedema) may cause delayed pareses which are missed, or hardly reflected by intraoperative MEP changes. Even minor MEP changes must therefore be observed to prevent impending motor deficit.
本研究探讨幕上脑手术中尽管术中运动诱发电位（MEP）未变或已完全恢复，但仍偶尔出现术后轻瘫的原因。
采用前瞻性观察设计，对200例与运动区和运动通路密切相关的脑肿瘤和皮质发育异常手术的MEP监测结果、运动结局和围手术期影像学进行相关性分析。
MEP未变或恢复后仍持续出现轻瘫的有4例，原因是延迟性缺血或静脉充血性水肿。MEP监测稳定后出现短暂性新缺陷的有4例，原因是无意中强烈刺激绕过了目标病变、明显的切除后水肿以及为缓解癫痫进行皮质横断术后。
在技术上充分的MEP监测下，不会出现遗漏明显皮质脊髓损伤的真正假阴性结果。然而，持续的血管动力学变化（血管痉挛、充血性水肿）可能导致延迟性轻瘫，而术中MEP变化可能会遗漏或几乎无法反映这种情况。因此，即使是轻微的MEP变化也必须加以观察，以防止即将出现的运动功能障碍。
