Finsterer Josef
Krankenanstalt Rudolfstiftung, Messerli Institute, Vienna, 1180, Austria.
Wellcome Open Res. 2020 Jun 24;5:51. doi: 10.12688/wellcomeopenres.15758.2. eCollection 2020.
Stroke-like episodes (SLEs) are a hallmark of mitochondrial encephalopathy, lactic acidosis, and stroke-like episode (MELAS) syndrome but occur in other mitochondrial disorders (MIDs) as well. The morphological equivalent of the SLE is the stroke-like lesion (SLL) on magnetic resonance imaging (MRI). The pathophysiology of SLLs is under debate, but several hypotheses have been raised to explain the phenomenon. Of these, the metabolic, epileptogenic, and vascular hypotheses are the most frequently discussed. There are several arguments for and against these hypotheses, but a consensus has not been reached which of them provides the correct explanation. A recent consensus statement generated by a panel of experts applying the Delphi method, favoured the epileptogenic hypothesis and recommended treatment of SLEs with antiepileptic drugs, irrespective if the patient presented with a seizure or epileptiform discharges on electroencephalography (EEG) or not. We disagree with this general procedure and provide the following arguments against the epileptogenic hypothesis: 1. not each SLE is associated with seizures. 2. epileptiform discharges may be absent on EEG during a SLE. 3. SLLs are not restricted to the cortex. 4. antiseizure-drugs (ASDs) may not prevent the progression or recurrence of a SLL. 5. ASDs may terminate seizures but no other phenotypic feature of a SLE. 6. patients already under ASDs are not immune from developing a SLL. 7. SLLs usually last longer than seizures. 8. no animal model supports the epileptogenic hypothesis. The strongest arguments for the metabolic hypothesis are that SLLs are not confined to a vascular territory, that the oxygen-extraction fraction within a SLL is reduced, and that there is hypometabolism within a SLL on FDG-PET. SLLs may respond to antioxidants, NO-precursors, steroids, or the ketogenic diet. ASDs should be applied only if there is clinical or electrophysiological evidence of seizure-activity.
类卒中发作（SLEs）是线粒体脑肌病伴乳酸血症和类卒中发作（MELAS）综合征的一个标志，但也见于其他线粒体疾病（MIDs）。SLE在形态学上的对应表现是磁共振成像（MRI）上的类卒中病灶（SLL）。SLL的病理生理学存在争议，但已提出多种假说来解释这一现象。其中，代谢、致痫和血管假说讨论最为频繁。支持和反对这些假说的观点都有，但尚未就哪种假说能提供正确解释达成共识。最近一个专家小组采用德尔菲法得出的共识声明支持致痫假说，并建议使用抗癫痫药物治疗SLEs，无论患者脑电图（EEG）上是否出现癫痫发作或癫痫样放电。我们不同意这种一般做法，并提出以下反对致痫假说的理由：1.并非每个SLE都与癫痫发作相关。2.SLE发作期间EEG上可能没有癫痫样放电。3.SLL并不局限于皮质。4.抗癫痫药物（ASDs）可能无法预防SLL的进展或复发。5.ASDs可能终止癫痫发作，但不能消除SLE的其他表型特征。6.已经服用ASDs的患者仍可能发生SLL。7.SLL通常比癫痫发作持续时间更长。8.没有动物模型支持致痫假说。支持代谢假说的最有力论据是，SLL并不局限于血管分布区域，SLL内的氧摄取分数降低，以及氟代脱氧葡萄糖正电子发射断层扫描（FDG-PET）显示SLL内存在代谢减退。SLL可能对抗氧化剂、一氧化氮前体、类固醇或生酮饮食有反应。只有在有临床或电生理证据表明存在癫痫活动时才应使用ASDs。
