Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Melbourne, Australia; Department of Paediatrics, School of Medicine, Chonnam National University, Gwangju, Korea.
Dev Med Child Neurol. 2014 Jan;56(1):85-90. doi: 10.1111/dmcn.12322. Epub 2013 Oct 25.
To show that atypical multifocal Dravet syndrome is a recognizable, electroclinical syndrome associated with sodium channel gene (SCN1A) mutations that readily escapes diagnosis owing to later cognitive decline and tonic seizures.
Eight patients underwent electroclinical characterization. SCN1A was sequenced and copy number variations sought by multiplex ligation-dependent probe amplification.
All patients were female (age range at assessment 5-26y) with median seizure onset at 6.5 months (range 4-19mo). The initial seizure was brief in seven and status epilepticus only occurred in one; three were febrile. Focal seizures occurred in four patients and bilateral convulsion in the other four. All patients developed multiple focal seizure types and bilateral convulsions, with seizure clusters in six. The most common focal seizure semiology (six out of eight) comprised unilateral clonic activity. Five also had focal or asymmetric tonic seizures. Rare or transient myoclonic seizures occurred in six individuals, often triggered by specific antiepileptic drugs. Developmental slowing occurred in all: six between 3 years and 8 years, and two around 1 year 6 months. Cognitive outcome varied from severe to mild intellectual disability. Multifocal epileptiform discharges were seen on electroencephalography. Seven out of eight patients had SCN1A mutations.
Atypical, multifocal Dravet syndrome with SCN1A mutations may not be recognized because of later cognitive decline and frequent tonic seizures.
表明非典型多灶性 Dravet 综合征是一种可识别的、与钠通道基因（SCN1A）突变相关的电临床综合征，由于认知能力下降和强直发作，很容易被漏诊。
8 名患者接受了电临床特征分析。通过多重连接依赖性探针扩增检测 SCN1A 基因的突变和拷贝数变化。
所有患者均为女性（评估时年龄 5-26 岁），中位发病年龄为 6.5 个月（范围 4-19 个月）。7 例患者的初始发作时间短暂，仅 1 例发生癫痫持续状态；3 例有热性惊厥。4 例患者出现局灶性发作，另 4 例出现双侧惊厥。所有患者均发展为多种局灶性发作类型和双侧惊厥，6 例出现发作群。最常见的局灶性发作表现（8 例中有 6 例）为单侧阵挛性活动。5 例患者还有局灶性或不对称性强直发作。6 例患者有罕见或短暂的肌阵挛发作，常由特定的抗癫痫药物触发。所有患者均出现发育迟缓：6 例在 3 岁至 8 岁之间，2 例在 1 岁 6 个月左右。认知结果从严重智力残疾到轻度智力残疾不等。脑电图可见多灶性癫痫样放电。8 例患者中有 7 例存在 SCN1A 突变。
伴有 SCN1A 突变的非典型多灶性 Dravet 综合征可能由于后期认知能力下降和频繁的强直发作而未被识别。
