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癫痫发作 I: 简介
对癫痫发作和癫痫的理解依赖于有助于识别、分类和管理这些疾病的关键定义。这些定义为识别、分类和管理发作性疾病提供了框架。
定义
癫痫发作是指大脑内突发的异常电活动放电，根据受累区域的不同，可导致意识状态、运动、感觉或行为发生改变。癫痫是一种慢性疾病，其特征是反复发生的非诱发性癫痫发作，反映出大脑由于遗…
癫痫发作是一过性脑内异常、过度的电活动所导致的、干扰正常神经功能的短暂发作性事件。癫痫是一种以反复发生、无诱因的癫痫发作为特征的慢性疾病。
一些癫痫发作会引起抽搐——即由于肌肉快速收缩导致的剧烈抖动。而另一些发作可能表现更为隐匿，不易识别。
局灶性发作起源于大脑的特定区域，可能伴有或不伴有意识障碍。当意识保持清醒时，临床上将感觉症状如刺痛感或异常气味称为先兆。
全面性发作同时影响大脑的两侧。患者可能会突然跌倒、身体僵硬，并出现节律性的抽搐。
前驱症状可能在数小时前出现，表现为非特异性的症状，如情绪变化或头痛。发作后状态是癫痫发作后的一段短暂时期，常表现为意识混乱或疲劳。
癫痫持续状态是一种危及生命的急症，定义为发作时间超过五分钟，或反复发作且在发作间期意识未恢复。
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Q1: What is the difference between a seizure and epilepsy?
A seizure is a transient episode of abnormal, excessive electrical activity in the brain that disrupts normal neurologic function. Epilepsy is a chronic disorder in which a person has a long-term tendency to have repeated, unprovoked seizures due to genetic, structural, or metabolic causes. Not everyone who experiences one seizure develops epilepsy.
Q2: What are the main types of seizures based on brain location?
Focal seizures begin in a specific brain region and may preserve awareness, causing sensory symptoms like tingling or unusual smells called an aura. Generalized seizures affect both brain hemispheres simultaneously and always impair consciousness, often causing a person to collapse, stiffen, and jerk rhythmically. These classifications help guide treatment and prognosis.
Q3: What is an aura and when does it occur?
An aura is a warning sensation or sensory symptom that may occur before some focal seizures when awareness is preserved. Common auras include tingling sensations, unusual smells, visual disturbances, or other perceptual changes. The aura provides patients with advance notice that a seizure may be beginning.
Q4: What happens during the postictal state after a seizure?
The postictal state is a temporary recovery period following a seizure, often marked by confusion, fatigue, or drowsiness. During this phase, the brain gradually returns to normal function. The duration and severity of postictal symptoms vary depending on seizure type and individual factors.
Q5: What is status epilepticus and why is it dangerous?
Status epilepticus is a life-threatening medical emergency defined as a seizure lasting more than five minutes or repeated seizures without regaining consciousness between episodes. This prolonged abnormal electrical activity can cause brain damage and requires immediate medical intervention. Increased intracranial pressure may develop during this critical state.
Q6: What is a convulsion and how does it differ from other seizures?
A convulsion is a seizure characterized by intense, involuntary muscle contractions causing violent shaking and rapid muscle movements. However, not all seizures are convulsive; some seizures, such as absence seizures, involve minimal movement or no visible muscle contractions despite abnormal brain electrical activity occurring.
Q7: What warning signs might appear before a seizure occurs?
A prodrome may appear hours before a seizure begins, presenting nonspecific symptoms like mood changes, headaches, or irritability. These early warning signs differ from an aura, which occurs immediately before focal seizures with preserved awareness. Recognizing prodromes can help patients prepare for potential seizures.