Epilepsy is a brain disorder characterized by a persistent epileptogenic tendency. Epilepsy is not a single disease entity, but rather a chronic brain disease state with different etiologies and different clinical manifestations, but with recurrent seizures as a common feature. Traditionally, epilepsy is diagnosed when there are two clinical episodes (at least 24 hours apart) of unprovoked seizures. This is the commonly used, clinically operable diagnostic method.
The three elements of seizures.
1. Clinical manifestations: there can be a wide range of sensory, motor, vegetative, consciousness, emotional, memory, cognitive and behavioral disorders.
The seizures generally have the common features of sudden onset and termination, transient transient and self-limiting. The onset and termination of seizures can usually be determined by behavioral manifestations or EEG changes.
3. Abnormal hyper-synchronized brain discharges: This can only be confirmed by EEG examination. This is the most essential feature of seizures that distinguishes them from other seizure symptoms.
Common seizure types
1. Generalized tonic clonic seizure
It is a form of seizure with the most obvious manifestation, so it was also called grand mal seizure in the past. The main clinical features are consciousness, bilateral symmetric tonicity followed by clonic movements and usually accompanied by vegetative nerve involvement.
2.Absence seizures
(1) Typical aphasic seizure: The seizure is sudden and abrupt, manifested by abrupt suspension or significant slowing of movement, impaired consciousness, without or with mild motor symptoms (e.g., clonic/myoclonic/stonic/autonomic, etc.). Seizures usually last 5-20 seconds (<30 seconds). During the seizure, the EEG shows a bilaterally symmetrical and synchronized, 3-Hz (2.5 Hz-4 Hz) spike-and-slow integrated wave burst. 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 anhedonic epilepsy and juvenile anhedonic epilepsy, and rarely in adults.
(2) Atypical aphasia: Seizures start and end more slowly than typical aphasia, with a milder degree of impaired consciousness and more complex accompanying motor symptoms (e.g., automatism), usually with reduced muscle tone, and seizures that may last more than 20 seconds. The EEG shows a slow (<2.5 Hz) spike-and-slow wave complex rhythm during the seizure. It is mainly seen in patients with severe neuropsychiatric disorders, such as Lennox-Gastaut syndrome.
(3) Myoclonic akathisia: This is characterized by the presence of rhythmic 2.5-4.5 Hz clonic movements of the limbs with a tonic component in conjunction with the akathisia. The EEG during the seizure is similar to that of a typical anhedonia.
(4) Anhedonia with eyelid myoclonus: 5-6 Hz myoclonic movements in the eyelid and/or forehead muscles are seen in conjunction with anhedonia. The EEG shows a comprehensive 3-6Hz multi-spine slow wave synthesis during the seizure.
3. Tonic seizures
It is characterized by sustained contraction of the muscles in the mid-axis of the trunk, proximal limbs bilaterally, or the whole body, with muscle rigidity and no clonic component. It usually lasts 2-10 seconds, occasionally up to several minutes. The EEG during seizures 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 bilateral rhythmic (1-3Hz) jerking of the limbs with or without impairment of consciousness and last for several minutes. The EEG during the seizure is a comprehensive (multiple) spike wave or (multiple) spike-slow wave synthesis.
5. Myoclonic seizure
Myoclonic seizures are involuntary, rapid, brief, electric shock-like muscle twitches lasting 10-50 msec each, rarely exceeding 100 msec. It can involve the whole body or be limited to a local muscle or muscle group. They may recur non-rhythmically. The typical EEG during seizures is a full-blown multi-spike slow-wave syndrome that appears in bursts. Myoclonic seizures can be seen in patients with idiopathic epilepsy with a good prognosis (e.g., juvenile myoclonic epilepsy) or in epileptic encephalopathies with a poor prognosis and diffuse brain damage (e.g., Dravet syndrome, Lennox-Gastaut syndrome).
6. Atonic seizures
Sudden loss or reduction of muscle tone in the head, trunk, or extremities, with no apparent myoclonic or tonic component prior to the seizure. The seizure lasts about 1-2 seconds or longer. The clinical presentation varies from mild to severe, with only a nodding movement, to a sudden fall while standing in severe cases. The EEG during a seizure may show a brief 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).
How is the diagnosis of “epilepsy” confirmed?
If epilepsy is suspected. Patients can go to a regular epilepsy clinic for consultation and testing. An electroencephalogram is an essential test. In the past, the simple EEG (about 10 minutes, 8-lead EEG) was not able to diagnose the disease. Nowadays, long-range video EEG (V-EEG) is usually used internationally to replace it. It can not only continuously record the EEG activity of the patient in different states, but also record the somatic movements corresponding to the EEG activity, thus improving the diagnosis of epilepsy. When combined with evoked methods such as hyperventilation, flash stimulation, sleep deprivation, and special electrode monitoring, long-range video EEG can have a confirmatory diagnosis rate of epilepsy of more than 95%. Magnetic resonance imaging (MRI): Using modern high-field strength MRI imaging sequences, subtle lesions and abnormal sites of cortical structures in the brain can be detected. It can help clinicians determine the cause of epilepsy and thus guide them in targeted etiologic treatment.
Dangers of epilepsy
Epileptic death and traumatic brain injury. Due to the sudden and uncertain nature of seizures, the incidence of mortality and traumatic brain injury is significantly higher in patients with epilepsy than in normal subjects. The incidence of accidents is higher when the patient is in a high-risk environment, such as climbing heights, crossing roads, or by ponds. Epileptic mental disorders. Most patients with epilepsy have a mental mood disorder that manifests as anxiety, depression, mania, or aggressive behavior. This affects the patient’s employment, marriage, and family life to varying degrees. Some patients are sent to psychiatric hospitals and treated according to psychiatric disorders and get worse and worse.
Intellectual decline: The primary brain injury, combined with the effects of recurrent, long-term seizures on normal brain cells. If not treated in a timely manner, patients with epilepsy will experience varying degrees of intellectual, behavioral and cognitive dysfunction.
Side effects: Long-term drug use can lead to liver and kidney dysfunction, blood component abnormalities, bone marrow hematopoietic suppression, and facial deformation.
Can “epilepsy” be cured?
Although it is difficult to treat, epilepsy is not incurable. The majority of patients with epilepsy can be controlled to varying degrees as long as they undergo regular and systematic treatment as early as possible, so there is no need to be pessimistic and disappointed, but to actively and optimistically cooperate with doctors for early recovery.
The most important thing is to make sure that you have a good understanding of the situation.
People with “epilepsy” who are suitable for surgery
If there are tumors, parasites, brain abscesses and other lesions in the brain of epileptic patients; or if there is brain scar formation after previous brain injury or infection; or if there are vascular malformations or congenital developmental abnormalities in the brain, the surgery can receive better results.
a. Patients with intractable epilepsy whose long-term systemic treatment with antiepileptic drugs is not effective and even has a tendency to aggravate
b. Patients with frequent seizures that cause progressive decline in intelligence and other factors that affect normal life, work or study.
c. If neuroimaging examinations reveal a clear epileptogenic focus in the brain, surgery should be performed as early as possible.
d. If the epileptogenic foci are not in the important functional areas of the brain, the surgical results will be better and will not cause significant disability to the patient at the same time.