Epilepsy is a disease with a long course and characterized by recurrent clinical seizures, which seriously threatens the physical and mental health of patients. The diagnosis of epilepsy and the accurate determination of seizure types are prerequisites for proper treatment, rational use of medication and prognosis.
Common seizure types and diagnostic points
I. Generalized seizures
1. generalized tonic-clonic seizures (GTCS)
GTCS is the most obvious form of seizure, so it is also called grand mal in the past.
mal). Loss of consciousness, bilateral symmetrical tonicity followed by clonic movements and usually accompanied by vegetative nerve involvement are the main clinical features.
2.Absence seizures
(1) Typical aphasic seizures: sudden onset and stoppage of the seizure, manifested by sudden suspension or significant slowing of the movement, impaired consciousness, without or with mild motor symptoms (e.g., clonic/myoclonic/stonic/autonomic, etc.). Seizures usually last 5-20
seconds (<30 seconds). EEG during seizures
A bilaterally symmetrical, synchronized, 3-Hz (2.5 Hz-4 Hz) spike-and-slow integrated wave burst is observed. Hyperventilation can be triggered by hyperventilation in about 90% of patients with typical anhedonia. It is mainly seen in children and adolescents, such as childhood aphasic epilepsy and juvenile aphasic epilepsy, and rarely in adults.
(2) Atypical aphasia:
Seizures start and end more slowly than typical aphasia, with a lesser degree of impaired consciousness and more complex accompanying motor symptoms (e.g., automatism), often with reduced muscle tone, and seizures that may last more than 20 seconds. EEG during seizures
The EEG shows a slow (<2.5 Hz) spike-and-slow wave complex rhythm. It is mainly seen in patients with severe neuropsychiatric disorders, such as Lennox-Gastaut syndrome.
(3) Myoclonic akathisia: This is manifested by the presence of rhythmic 2.5-4.5 Hz clonic movements of the limbs with a tonic component along with the akathisia seizure. The EEG during the seizure is similar to that of a typical anhedonia.
(4) Aphasia with eyelid myoclonus: Aphasic seizures are accompanied by 5-6 Hz myoclonic movements in the eyelid and/or forehead muscles. The EEG during the seizure shows a comprehensive 3-6Hz
The EEG shows a comprehensive 3-6 Hz multi-spike slow wave synthesis.
3. Tonic seizures (tonic seizures).
The seizure is characterized by a continuous contraction of the muscles in the mid-axis of the trunk, proximal limbs bilaterally, or the whole body. It usually lasts 2-10 seconds, occasionally up to several minutes. The EEG at the onset
The EEG shows bilateral spike rhythms of increasing amplitude (20±5 Hz) or low amplitude rhythmic discharge activity of approximately 10 Hz. Tonic seizures are mainly seen in Lennox-Gastaut syndrome.
4. clonic seizures.
Clonic seizures are characterized by rhythmic (1-3Hz) bilateral limb twitches with or without impaired consciousness, lasting several minutes. The EEG during seizures is a comprehensive (multiple) spike or (multiple) spike-slow wave synthesis.
5, myoclonic seizures (myoclonic seizures).
The seizures are involuntary, rapid and brief, electric shock-like muscle twitches, each lasting 10-50 milliseconds, rarely exceeding 100
Each twitch lasts 10-50 ms and rarely exceeds 100 ms. It may involve the whole body or be limited to a localized muscle or muscle group. They may recur non-rhythmically. Typical EEG during seizures
The typical EEG during seizures is a full-blown multi-spike slow-wave syndrome that appears explosively. Myoclonic seizures are seen in patients with idiopathic epilepsy with a good prognosis (e.g., juvenile myoclonic epilepsy) as well as in epileptic encephalopathies with a poor prognosis and diffuse brain damage (e.g., Dravet
It is also seen in some epileptic encephalopathies with poor prognosis and diffuse brain damage (such as Dravet syndrome, Lennox-Gastaut syndrome).
6. atonic seizures.
It is manifested as a sudden loss or reduction of muscle tone in the head, trunk or limbs, with no obvious myoclonic or tonic component before the seizure. Seizures last about 1-2
seconds or longer. The clinical manifestation varies from mild to severe, with only nodding movements, to severe cases resulting in sudden falls while standing. EEG during seizure
The EEG during seizures may show a transient generalized 2-3 Hz (poly) spike-slow wave complex or sudden voltage depression. Atonic seizures are most often seen in epileptic encephalopathies (e.g., Lennox-Gastaut syndrome, Doose
syndrome).
Partial seizures
1.Simple partial seizures (SPS)
SPS: There is no impairment of consciousness during seizures. According to the origin of the discharge and the different parts involved, simple partial seizures can be expressed as motor, sensory, autonomic and psychotic seizures, the latter two rarely appear alone and often develop into complex partial seizures.
2. Complex partial seizures (CPS)
CPS): The seizures have varying degrees of impaired consciousness and may be accompanied by one or more simple partial seizure elements.
3.Secondarily generalised seizures
seizures): simple or complex partial seizures can be followed by generalized seizures, which can be followed by generalized tonic-clonic, tonic or clonic seizures. Essentially, they are still partial seizures.
III. Epileptic spasms
In the 2010 ILAE
In the 2010 ILAE classification report, epileptic spasms are explicitly included as a seizure type. Epileptic spasms can be of generalized origin, focal origin, or unknown origin. Epileptic spasms present as sudden, tonic contractions involving mainly the mid-trunk and proximal limb muscles bilaterally, lasting 0.2 to 2
The epileptic spasms are sudden, mainly involving the mid-trunk and proximal limbs, lasting 0.2-2 seconds. The former is more common and is characterized by episodic head nodding, often in a series of episodes after awakening. The EEG during the interictal period is highly arrhythmic or arrhythmia-like, and the seizure EEG
The EEG during seizures is diverse (voltage depression, high amplitude biphasic slow waves or spikes, etc.). Epileptic spasms are mostly seen in infants and young children, such as West syndrome, but can also be seen at other ages.
Reflex seizures
Reflex seizures are not a separate type of seizure. It can be either focal seizures or generalized seizures. The special feature is that the seizure has a special exogenous or endogenous precipitating factor, that is, each seizure is precipitated by a specific sensory stimulus, and there is a close lock time relationship between the seizure and the precipitating factor.
The triggers include non-pathological factors such as visualization, thinking, music, reading, eating, and manipulation. They can be simple sensory stimuli (e.g., flashing lights) or complex intellectual activities (e.g., reading, playing chess). Seizures induced by pathological situations such as fever, alcohol or drug withdrawal are not considered reflex seizures. Reflex seizures and spontaneous seizures can occur together in a single patient with epilepsy.