Department of Neurology, The Charles Shor Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, Ohio, U.S.A.
Pediatric Epilepsy and CHild Neurology (PEACH Neurology), Duluth, Georgia, U.S.A. ; and.
J Clin Neurophysiol. 2022 Nov 1;39(7):552-560. doi: 10.1097/WNP.0000000000000907. Epub 2022 Mar 24.
Electroclinical features in surgical candidates with epileptic spasms differ significantly from the other focal epilepsy phenotypes. EEG findings tend to be more diffuse and less localizing in children with epileptic spasms. These are illustrated with five case studies to highlight three different categories of findings on interictal and ictal EEG: lateralizing , nonlateralizing , and false lateralizing . Hemihypsarrhythmia on interictal EEG is the most striking lateralizing abnormality that occurs in a minority of surgical candidates. Persistent focal epileptiform discharges in one region or asymmetric physiologic rhythms decreased over the abnormal hemisphere may provide localization clues. Ictal EEG patterns are diffuse and nonlocalizing in over half of the patients. Ictal patterns are best expressed in the posterior head regions even in patients with epileptogenic zone in anterior regions. Semiologically, epileptic spasms tend to be symmetrical in majority of surgical candidates. Asymmetric spasms and coexisting focal seizures (concurrent or remote), when present, may provide localization findings. False lateralizing interictal or ictal EEG abnormalities, paradoxically higher over the healthier hemisphere, occur in the setting of large encephaloclastic/volume loss lesions. In these patients, the diffuse discharges are less expressed over the abnormal hemisphere with less cerebral tissue. Recognition of such false lateralizing findings is important to avoid excluding appropriate surgical candidates based on the EEG findings alone. Epileptogenic lesions are visible on brain MRI in majority of surgical candidates with epileptic spasms. Electroclinical findings are often concordant with the lesion, but discordant findings are not uncommon in children with epileptic spasms.
手术候选者的癫痫痉挛的电临床特征与其他局灶性癫痫表型有显著差异。癫痫痉挛患儿的脑电图发现往往更弥散，定位性更差。通过五个病例研究来说明三种不同类别的脑电图发作间期和发作期的发现：定位的、不定侧的和假性定位的。发作间期脑电图的半侧抽搐是一种最显著的定位异常，在少数手术候选者中出现。在异常半球持续出现的局部癫痫样放电或不对称的生理节律减少可能提供定位线索。超过一半的患者出现弥散且不定侧的发作期脑电图模式。即使在致痫区位于前区的患者中，发作期模式也最好在头部后区表达。从症状学上看，癫痫痉挛在大多数手术候选者中倾向于对称。当存在不对称性痉挛和共存的局灶性发作（同时或远程）时，可能提供定位发现。在大脑破坏性/容积性病变较大的情况下，会出现假性定位的发作间期或发作期脑电图异常，反常地在更健康的半球出现更高的异常。在这些患者中，弥散放电在异常半球上的表达较少，脑组织较少。认识到这种假性定位的发现很重要，以避免仅仅根据脑电图发现就排除合适的手术候选者。在大多数癫痫痉挛的手术候选者中，脑 MRI 上可以看到致痫性病变。电临床发现通常与病变一致，但在癫痫痉挛患儿中，不一致的发现并不少见。
