Genton Pierre, Bureau Michelle
Centre Saint-Paul, Hôpital Henri Gastaut, Marseille, France.
CNS Drugs. 2006;20(11):911-6. doi: 10.2165/00023210-200620110-00004.
Among the epileptic syndromes that are defined mainly on the basis of a characteristic seizure type, epilepsy with myoclonic absences (EMA) stands out as a somewhat controversial entity. This is because the sound and evident clinical characteristics on which it was identified some 30 years ago have evolved, mostly as a consequence of changes in the practical management of epilepsies and to the description of myoclonic components in a variety of other generalised epilepsies with absences. Myoclonic absences (MA) are described as typical absences with sudden onset and offset that are associated with generalised spike and wave (SW) discharges on the ECG, with distinctive traits. Clinically, absences are associated with axial hypertonia (the subject usually bends forward and slightly raises their shoulders and arms), and jerks synchronous with the SW discharges. Neurophysiologically, axial hypertonia and rhythmic jerks may be recorded on polygraphic surface electromyogram leads in association with the typical SW discharges; as such, despite an ECG, the diagnosis may be missed in the absence of video documentation of the seizure and/or adequate polygraphy. MA need to be distinguished from absences with other types of prominent myoclonic accompaniment (perioral, eyelid, limbs).The prognosis of EMA remains variable. Modern therapeutic combinations, such as valproic acid and ethosuximide, or valproic acid and lamotrigine, are usually effective; however, in a proportion of patients, seizures are resistant to drug treatment. These patients may experience cognitive deterioration and, in some cases, evolution towards a more severe form of epilepsy, including the Lennox-Gastaut syndrome. The more benign cases usually present with MA as the only seizure type, while patients who experience other seizures, especially generalised tonic-clonic seizures, in association with MA may have a less favourable outcome.
在主要基于特征性发作类型定义的癫痫综合征中，肌阵挛失神癫痫（EMA）是一个颇具争议的实体。这是因为大约30年前确定该综合征时所依据的明确且明显的临床特征已经发生了演变，这主要是由于癫痫实际管理方式的变化以及在各种其他伴有失神的全身性癫痫中对肌阵挛成分的描述所致。肌阵挛失神（MA）被描述为典型的失神发作，起病和终止突然，心电图上伴有全身性棘慢波（SW）放电，具有独特特征。临床上，失神发作伴有轴性肌张力增高（患者通常向前弯腰并轻微抬起肩膀和手臂），以及与SW放电同步的抽搐。神经生理学上，在多导睡眠图表面肌电图导联上可记录到轴性肌张力增高和节律性抽搐，与典型的SW放电相关；因此，尽管有心电图，但如果没有发作的视频记录和/或充分的多导睡眠图检查，可能会漏诊。MA需要与伴有其他类型明显肌阵挛伴随症状（口周、眼睑、肢体）的失神发作相鉴别。EMA的预后仍然存在差异。现代治疗组合，如丙戊酸和乙琥胺，或丙戊酸和拉莫三嗪，通常有效；然而，一部分患者的发作对药物治疗耐药。这些患者可能会出现认知功能恶化，在某些情况下，会演变为更严重的癫痫形式，包括 Lennox-Gastaut 综合征。病情较良性的病例通常仅以MA作为唯一的发作类型，而伴有MA同时还经历其他发作，尤其是全身性强直阵挛发作的患者，预后可能较差。
