Epilepsy is a sudden, recurrent and transient central nervous system dysfunction caused by abnormal hyper-synchronous discharge of brain neurons, manifested as consciousness, motor, sensory, mental or autonomic dysfunction. The prevalence of epilepsy is about 3.5‰ to 4.8‰. In recent years, most children with epilepsy have received regular treatment, and about 80% of them can obtain complete control, and most of them can learn and live normally.
I. Diagnosis
(A) Medical history
The International League Against Epilepsy states that two or more similar unprovoked seizures are usually required to consider the diagnosis of epilepsy. A detailed history taking and a thorough physical examination should be performed. Multiple seizure forms may be present simultaneously in the same patient.
(ii) Clinical manifestations
1. Clinical manifestations of seizures
Focal seizures.
Also known as partial seizures. The excessive neuronal discharge starts in one part of the brain and the clinical manifestations are limited to one side of the body.
(1) Simple focal seizures.
(1) Motor seizures.
It is the most common type of simple focal seizures. They mostly manifest as convulsions on one side of a part of the body, such as limbs, hands, feet, fingers, toes, corners of the mouth, eyelids and so on. It can also manifest as rotational seizures, postural seizures, or Jacksonian seizures. Jacksonian seizures refer to the expansion of abnormal discharges along the motor areas of the cerebral cortex. The way and order of muscle twitch expansion is related to the areas innervated by the motor cortex, such as the seizure starts from the corner of the mouth on one side first, and then spreads to the hands, arms, shoulders, trunk, lower limbs, etc. After partial seizures, temporary paralysis can occur at the site of the twitch, called Todd’s palsy.
②Sensory seizures.
It is manifested as episodic somatic sensory abnormalities or specific sensory abnormalities.
③Autonomic symptoms seizures.
Apnea, change in respiratory rhythm, cyanosis, pallor, flushing, salivation, vomiting. Autonomic symptoms are more frequent in infants than in older children, but older children rarely have seizures with autonomic symptoms as the main component, and autonomic seizures alone are rare.
④ Psychotic seizures.
They can be manifested as hallucinations, delusions, memory impairment, cognitive impairment, emotional impairment or language impairment, etc. However, psychotic symptomatic seizures alone are rare and are mostly seen in the course of complex focal seizures.
(2) Complex focal seizures.
They are seen in temporal lobe epilepsy and partial frontal lobe epilepsy. All seizures in this category have varying degrees of impaired consciousness, often with psychiatric symptoms, and are often accompanied by repeated stereotyped automatism, such as swallowing, chewing, lip licking, hand clapping, groping, and self-talk. This type of seizure can be preceded by focal seizure symptoms and followed by impaired consciousness, or the seizure can begin with impaired consciousness, abnormal mental behavior or automaticity.
(3) Focal seizures evolve into full-blown seizures.
Generalization from simple focal or complex focal seizures to generalized seizures, or may develop from simple focal seizures to complex focal seizures followed by generalized seizures.
Generalized seizures.
It refers to the simultaneous discharge of both hemispheres at the beginning of the seizure, and the seizure is often accompanied by impaired consciousness.
(1) Disorientation seizure.
The main symptom is impaired consciousness.
The typical anhedonic seizure starts suddenly, without aura, and is characterized by the cessation of ongoing activities, double gaze, which lasts for a few seconds to recover, usually no more than 30 seconds, and can often continue the original activity after the seizure, and cannot recall the seizure. The EEG shows symmetrical, synchronous, diffuse 3-Hz spike-slow complex waves on both sides, and hyperventilation can easily induce a typical aphasic attack.
Atypical aphasic seizures are slow in onset and cessation, with more pronounced changes in muscle tone than typical aphasia; the EEG shows slow spikes of 1.5 to 2.5 Hz with abnormal background activity. Most often seen in children with extensive brain damage.
(2) Tonic-clonic seizures.
Also known as grand mal seizures, mainly manifesting as impaired consciousness and generalized convulsions, typically in three phases, i.e. tonic, clonic and late convulsive phases, but pediatric seizures are often atypical. During the seizure, there is a sudden loss of consciousness and tonic contraction of the whole body muscles; the child may fall down suddenly with a scream, pause in breathing, cyanosis, eyes rolled up, pupils dilated, tonicity of the limbs and trunk, sometimes in the state of corkscrew; the seizure lasts for several seconds to tens of seconds and enters the clonic phase, with rhythmic convulsions of the whole body, which lasts for 30 seconds or longer and gradually stops. The child may have urinary incontinence after the cessation of the clonic phase. After the seizure, the child often shows headache, drowsiness and weakness, and may even develop autonomic symptoms before fully awake, which is called postictal state. In the tonic phase, the EEG shows fast activity of 10 or more times per second, with slowing frequency and high amplitude; in the clonic phase, in addition to high amplitude spikes, slow waves appear intermittently. In the interictal phase, there may be spike waves, multi-spike waves or sharp waves.
(3) Tonic seizures.
It is manifested by long duration (>3 seconds or longer) and intense muscle contraction, which fixes the body in a particular position. The EEG during seizure is fast activity or fast rhythmic multi-spike waves of low amplitude 9-10Hz or more.
(4) Clonic seizures.
The limbs, trunk or face show rhythmic jerking. Sometimes it can be continuous. The EEG during seizure is 10 Hz or more of fast activity and slow waves, sometimes spike-like waves.
(5) Myoclonic seizure.
It is characterized by a sudden, rapid and powerful electroshock-like contraction (<0.4 sec) of a muscle or muscle group in a certain area, or even the whole body, causing sudden and rapid jerking of the limbs, head and neck, trunk or whole body. It can occur singly or as a continuous seizure. The EEG during the seizure is multi-spike slow wave or spike slow and sharp slow integrated wave.
(6) Dystonic seizure.
The seizure is caused by sudden loss of muscle tone and postural change, which is manifested as head droop, shoulder droop, hip flexion and knee flexion or fall. The EEG is multi-spine slow wave or spike slow wave during the seizure.
(7) Spastic seizures.
Most commonly seen in infantile spasms, the seizure is manifested by head nodding, arm extension, bending, kicking or overextension-like movements. Its muscle contraction duration (0.2 to 4 seconds) is longer than myoclonus but shorter than tonic seizures.
2.Persistent status epilepticus
Traditionally, status epilepticus refers to “a seizure lasting more than 30 minutes; or repeated seizures lasting more than 30 minutes, during which consciousness cannot be restored.” In 2001, the International League Against Epilepsy (ILAE) proposed a new definition: “clinical signs of seizures that do not stop after a seizure duration that exceeds that of most patients with this seizure type, or recurrent seizures in which the function of the central nervous system does not return to normal baseline during the interictal period”. Almost all types of seizures can be of a persistent nature, but convulsive epilepsy is the most common, accounting for more than 75% of all pediatric persistent seizures and mainly manifesting as persistent clonus. Non-convulsive status epilepticus is most often seen in Lennox-Gastaut syndrome, which is characterized by atypical aphasic seizures with prolonged confusion and may be accompanied by myoclonic or atonic seizures. Causes of persistent status epilepticus can often be found in children with epilepsy, such as sudden withdrawal of medication, improper medication changes, infections, and hyperthermia. In non-epileptic children, persistent status epilepticus is mostly associated with acute brain injury, and febrile convulsions can also occur.
(iii) Auxiliary tests
1.Electroencephalogram.
EEG is one of the objective indicators to diagnose epilepsy and determine the type of seizure, such as the presence of spike wave, spike wave, spike slow or spike slow complex wave, high amplitude paroxysmal slow wave and other epileptic waveforms, which is beneficial to the diagnosis of epilepsy. However, nearly 40% of conventional EEGs are normal during the interictal period in children with epilepsy; therefore, 1 normal EEG cannot exclude epilepsy, and dynamic EEG or video EEG can be done if necessary.
2. Imaging examinations (cranial CT, MRI).
Abnormalities in brain structures, such as intracranial calcifications, occupancies, malformations, parasites and neuronal migration disorders leading to epilepsy can be detected. Negative imaging examinations do not exclude the diagnosis of epilepsy.
3. Single photon emission tomography (SPECT).
It can detect cerebral blood flow and metabolic rate, and identify the area of epileptic origin.
(iv) Classification
In 1981, the International League Against Epilepsy (ILAE) developed a classification scheme for seizures based on the type of clinical seizures and EEG changes.
In 1985, ILAE classified epilepsy and epilepsy syndromes based on clinical seizure classification, combined with etiology, age of onset, and regression, and then revised in 1989. a new classification scheme was proposed in May 2001, and many new epilepsy syndromes were introduced.
Pediatric seizures are classified as.
1. Focal seizures
(1) Simple focal seizures.
(1) Motor seizures
(2) Sensory seizures
(3) Autonomic seizures
④Psychotic seizures
(2) Complex focal seizures
(3)Focal seizures transformed into generalized seizures
2. Generalized seizures
(1)Tonic-clonic seizures
(2)Tonic seizure
(3)Clonic seizure
(4)Anhedonic seizures
(1)Typical aphasic seizure
(2) Atypical aphasic seizure
(5)Myoclonic seizures
(6)Atonic seizures
(7)Infantile spasms
3. Other seizures of unknown classification
Differential diagnosis
The disease should be distinguished from breath-holding seizures, syncope, hysterical convulsions, and hypoglycemic seizures.