Epilepsy is a chronic recurrent transient brain dysfunction syndrome. It is characterized by abnormal neuronal discharges in the brain causing recurrent epileptic seizures. Epilepsy is one of the common neurological disorders and is second only to stroke in prevalence. The incidence of epilepsy is age-related. It is generally believed that the prevalence is highest within 1 year of age, followed by a gradual decrease after 1-10 years of age. There is no significant racial difference in prevalence.
The etiology of epilepsy is extremely complex and can be divided into three main categories, with a variety of factors affecting the onset of the disease.
1. Idiopathic epilepsy has a suspected genetic predisposition without other obvious causes, often starting at a particular age, with characteristic clinical and electroencephalographic manifestations and a clearer diagnosis.
2, symptomatic epilepsy central nervous system lesions affecting structure or function, etc., such as chromosomal abnormalities, focal or diffuse brain diseases, and certain systemic diseases caused by.
(1) Focal or diffuse brain disorders
(1) congenital anomalies embryonic development of various etiologies resulting in cerebral penetrance malformation, microcephaly, congenital hydrocephalus corpus callosum agenesis and cortical hypoplasia, perinatal fetal brain injury, etc.
②acquired brain injury such as traumatic brain injury, post-cranial surgery, post-stroke, post-cranial infection, acute alcohol intoxication.
(③ birth injury neonatal epilepsy incidence is about 1%, combined with birth injury during delivery mostly with cerebral hemorrhage or cerebral hypoxia damage, neonatal combined with congenital developmental malformation of the brain or birth injury, epilepsy incidence up to 25%.
④ inflammatory diseases including CNS bacterial, viral, fungal, parasitic, helminthic infections and neurological complications of AIDS
⑤ cerebrovascular diseases such as cerebral arteriovenous malformations, cerebral infarction and cerebral hemorrhage
(vi) Intracranial tumors primary tumors such as glioma, meningioma, etc.
(vii) genetic metabolic diseases such as tuberous sclerosis, cerebral-facial angiomatosis, phenylketonuria, etc.
(8) Neurodegenerative diseases such as Alzheimer’s disease, Pick’s disease, etc. About 1/3 of patients have combined seizures.
(2) Systemic diseases
(1) Hypoxic encephalopathy such as cardiac arrest, CO poisoning asphyxia, anesthesia accident and respiratory failure can cause myoclonic seizures or generalized grand mal seizures.
②Metabolic encephalopathies such as hypoglycemia, most often leading to seizures other metabolic and endocrine disorders such as hyperglycemia, hypocalcemia, hyponatremia, and uremia, hepatic encephalopathy and thyrotoxicosis can lead to seizures
(iii) Cardiovascular diseases such as cardiac arrest and hypertensive encephalopathy.
④ febrile convulsions febrile seizures leading to hippocampal sclerosis are an important cause of temporal lobe epilepsy secondary to generalized seizures and become refractory to epilepsy
(v) Eclampsia.
(6) Poisoning such as alcohol, isoniazid, carbazole and other drugs and heavy metal poisoning such as lead and thallium.
(3) Cryptogenic epilepsy is more common
Clinical manifestations suggest symptomatic epilepsy, but no definite cause has been found, and it may start at a specific age without specific clinical and EEG manifestations.
Clinical manifestations
1. Generalized tonic-clonic seizures (grand mal seizures) are seizures with generalized muscle twitching and loss of consciousness. They are more common with birth injury, traumatic brain injury, brain tumor, etc. Tonic-clonic seizures can occur at any age and are the most common type of seizure among all kinds of epilepsy. The typical seizures can be divided into four clinical phases: aura, tonic, clonic, and recovery. The EEG during the seizure is a typical explosive multi-spike and spike-slow wave synthesis, and each spike-slow wave synthesis may be accompanied by muscle jumping.
2. Simple partial seizures are symptoms caused by local cortical discharges in the brain corresponding to the function of that part of the brain, including motor, sensory, autonomic, and psychiatric symptoms and signs. They are divided into four groups.
(1) Those with motor symptoms.
(2) Those with somatosensory or specific sensory symptoms.
(3) Those with autonomic symptoms and signs.
(4) Those with psychiatric symptoms.
3. Complex partial seizures are also customarily called psychomotor seizures, accompanied by impaired consciousness. The aura mostly occurs before or when the loss of consciousness is imminent, so the patient can still recall after the seizure.
4.Absence seizures (petit mal seizures) are typically characterized by brief impairment of consciousness without aura or post-ictal symptoms.
5. Persistent status epilepticus refers to a single seizure lasting more than 30 minutes, or a seizure so frequent that the patient has not fully recovered from the previous seizure and has another seizure for a total time of more than 30 minutes. Persistent status epilepticus is an emergency requiring resuscitation.
Tests
1. Routine laboratory blood, urine and stool tests and determination of blood glucose and electrolytes (calcium and phosphorus).
2, cerebrospinal fluid examination such as viral encephalitis, increased white blood cell count, increased protein, bacterial infection, there is also a decrease in sugar and chloride. Brain parasitic disease may have eosinophilia; in the case of central nervous system syphilis, positive syphilis spirochete antibody test. Intracranial tumors can have increased intracranial pressure and increased protein.
3.Serum or cerebrospinal fluid amino acid analysis can detect possible amino acid metabolism abnormalities.
4.Neurophysiological examination is traditionally recorded by electroencephalogram. If subdural electrodes including wire electrodes and grid electrodes are placed in the brain in the area of possible epilepsy.
5, Neuroimaging CT and MRI have greatly improved the diagnosis of structural abnormalities in epileptic foci. PET can measure cerebral blood flow and neurotransmitter changes in the metabolism of glucose and oxygen in the brain; SPECT can also measure cerebral blood flow, metabolism, and neurotransmitter changes, but is not as accurate as PET in terms of quantification. MRS can measure changes in certain chemicals, such as acetylaspartate, choline-containing substances, creatine and lactate in the epileptic region.
6. Neurobiochemical examinations have been applied with ion-specific electrodes and microdialysis probes that can be placed in the epileptic region of the brain to measure certain biochemical changes between seizures, during and after seizures.
7. Neuropathological examination is a pathological examination of surgically removed epileptic lesions that can determine whether the cause of epilepsy is caused by brain tumor scarring, vascular malformation, sclerosing inflammation, developmental abnormalities, or other abnormalities.
8. Neuropsychological examination This examination can assess cognitive impairment and can determine on which side of the brain the epileptic lesion or region is located.4 Diagnosis Edit The diagnosis of epilepsy is mainly based on seizure history, a reliable and detailed description of the seizure process by witnesses, supplemented by evidence of epileptic discharges on EEG to confirm the diagnosis.
Differential diagnosis
1. Epileptic seizures need to be differentiated from various seizure disorders
(1) Hysteria.
(2) syncope.
(3) hyperventilation syndrome.
(4) migraine.
(5) transient ischemic attack.
(6) Seizure sleeping disorder.
In addition, epilepsy should be differentiated from seizure psychiatric symptoms and other visceral symptoms of seizures.
2. Identification of the etiology of symptomatic epilepsy and epilepsy syndrome
(1) Systemic diseases causing epilepsy
(1) Hypoglycemia.
(ii) Hypocalcemia.
(3) Amino aciduria, etc.
(2) Brain diseases causing epilepsy: history of birth injury, history of febrile convulsions, history of traumatic brain injury, history of stroke, etc. If localization signs and optic disc edema of intracranial tumor, head murmur of cerebral arteriovenous malformation, subcutaneous nodules of cerebral porcine cysticercosis (cysticercosis) are found during physical examination. Cerebral angiography, nuclear brain scan, CT, MRI and other examinations can help to differentiate.
Treatment
Treatment of epilepsy can be divided into five areas: seizure control, etiologic treatment, surgical treatment, general health and prevention. The most important of these is seizure control, which is currently based on drug therapy. Anti-epileptic drugs can be selected clinically according to the type of seizure, and once a drug and dose that can completely control seizures is found, it should be applied without interruption. Generally, after the seizures are completely controlled, if there are no adverse reactions, the medication should be continued for 3-5 years before considering discontinuation. Currently, it is recommended to use one drug and add a second drug only after confirming the failure of monotherapy. If the seizures are not controlled by a single drug, the combination of ethosuximide and sodium valproate, or one of them plus benzodiazepines, can be effective. In mixed epilepsy, the combination of drugs can be used according to the type of seizure, but no more than three drugs are appropriate. It is advisable to start with a small dose and then gradually increase the dose to the minimum effective dose that can control seizures without producing toxic reactions. The principle of adding new drugs and decreasing old ones is appropriate for changing medication. You can’t stop the medication suddenly. Some patients with organic encephalopathy may require lifelong medication; some advocate caution in discontinuing medication for those older than 30 years of age, as they have a higher recurrence rate after discontinuation and require long-term or lifelong medication. However, there are still 10-15% of patients who have difficulty controlling their seizures and can be treated surgically.
Prevention
To prevent the occurrence of epilepsy, a detailed family survey should be conducted to find out whether there are seizures and their characteristics among the patient’s siblings and close relatives. For some serious hereditary diseases that can cause mental retardation and epilepsy, prenatal diagnosis or neonatal screening should be performed to decide to terminate the pregnancy or to treat it early. To prevent birth accidents, neonatal birth injury is one of the important causes of epilepsy, and avoiding birth injury is important to prevent epilepsy.
The earlier the treatment, the smaller the brain damage, the less recurrence and the better the prognosis. Removal or alleviation of the primary cause of epilepsy such as intracranial occupational diseases, metabolic abnormalities, infections, etc., is also important for recurrent seizure cases.
The most important thing is that it is a chronic disease that can be prolonged for years or even decades, thus causing serious adverse effects on the patient’s physical, mental, marital and socio-economic status. The patient’s misfortune and frustration in family relations, schooling and employment, and restrictions on cultural and physical activities can not only cause stigma and pessimism, but also seriously affect the patient’s physical and mental development, which requires the community to give understanding and support to epilepsy patients.