Brief introduction of electroencephalogram

Electroencephalograph (EEG) is a method of checking brain function by amplifying or displaying the brain's spontaneous bioelectricity through an electroencephalograph. It is safe, noninvasive and easy to perform. It can not only understand the physiological functions of the brain, but also reflect the pathological changes of the brain.

[indications]

1. identify brain organic diseases and functional diseases: seizures, mental disorders, deafness, blindness and other organic or functional diseases.

2. the auxiliary diagnosis, differential diagnosis and location of various brain diseases are commonly used in epilepsy, encephalitis, brain abscess, intracranial hematoma, brain tumor, brain parasitic disease, cerebrovascular disease and other kinds of encephalopathy and coma patients.

3. to understand whether the brain is involved in patients with systemic diseases, such as whether there is intracranial metastases, infection, poisoning, liver or renal diseases, or not, whether or not it causes brain damage.

4. follow up to understand the changes of brain diseases, curative effect and brain development, and help understand brain aging and brain death Meilun.

[contraindication]

1. severe scalp trauma, extensive or open craniocerebral trauma, unable to place electrodes or cause infection due to examination.

2. critically ill patients should not be moved, and EEG is not portable and can not be moved to bedside examiners.

3. extremely agitated, unable to calm him down with the examiners.

[preparatory work]

1. make an appointment in advance, wash your hair with soap and water the day before, and keep your scalp clean.

2. before the examination, sedatives, hypnotics and antiepileptic drugs should be suspended for 1 to 3 days.

3. before eating, it should not be fasting. If you can not eat or vomit, you should give glucose intravenously.

4. if there is an increase in intracranial pressure and need help, the dehydrant should be depressurized for 1 hours before the examination, such as intravenous drip or injection of mannitol.

5. before the examination should be explained to the patient, do not wear nylon clothing, avoid tension, blink, bite, swallow or other activities; sweat should be wiped out to avoid the effect of the impact of false difference. Patients should also be told to close their eyes, open their eyes or take deep breaths.

6. sleep maps for children who are unable to cooperate with children who are unable to cope with mental disorders or those who are prone to epilepsy during sleep should be given sedatives and hypnotics when necessary.

[clinical application]

1. to assist in the diagnosis and differential diagnosis of brain diseases.

(1) to assist in the diagnosis of epilepsy, to distinguish epilepsy from hysteria or mental illness. Epileptic discharge is often seen in epileptic EEG. It can also help type epileptic type [all types of epilepsy have specific EEG changes, such as general clonic tonic seizures often spinous waves, often 3Hz spinous wave synthesis, baby spasm often high amplitude loss of law, complex partial (psychomotor) episodes often seen in the temporal lobe paroxysmal high wave slow wave or spinous wave, myoclonus often Multi spinous slow wave... It can also help distinguish epilepsy from primary or secondary (the former is symmetrical and synchronous, the latter is usually localized, dissymmetrical and asynchronous).

(2) to help identify whether coma is caused by sleeping pills poisoning, hypnotic poisoning is usually characterized by high amplitude and rapid activity.

(3) to help identify the early diagnosis of encephalitis, and some encephalitis (such as herpes simplex encephalitis, subacute sclerosing encephalitis, cavernous encephalopathy) have special periodic waves, so EEG is helpful for diagnosis.

(4) help distinguish between dementia and pseudodementia. EEG is often abnormal, slow waves increase, and false ones are normal.

(5) help to judge the intracranial metastasis of cancer. Intracranial metastases are often seen as localized or diffuse slow waves or multifocal.

(6) to help early diagnosis of hepatic encephalopathy, three phase waves appear in EEG of liver disease, suggesting hepatic encephalopathy. Other metabolic encephalopathy can also be seen in three phases, and should be confirmed by medical history and other examinations.

(7) repeated examination can help to distinguish cerebrovascular diseases or brain tumors. Cerebrovascular disease usually improves after several weeks, and brain tumors continue to deteriorate.
2. help locate localization of brain lesions: EEG helps differentiate lesions from diffuse, localized or multifocal lesions. When the clinical location is not obvious, EEG is often used as a screening tool for the diagnosis of intracranial lesions, so it is often used for locating intracranial lesions. EEG can also be used to locate brain damage.

3. help to understand the evolution of brain disease and the state of brain function: repeated examination helps to understand the improvement, deterioration, or recurrence of the disease, such as the improvement of EEG after the brain tumor operation, and the recurrence in the follow-up of the follow-up.

4. help judge the curative effect of the disease, estimate the prognosis and guide the medication: as the norm of EEG as the norm to judge the curative effect of epilepsy, whether the treatment should continue or can be gradually reduced or stopped. The curative effect of various brain diseases before and after treatment or EEG before and after operation can be understood. Patients with encephalopathy or encephalitis are chronically unconscious. Their low EEG indicates poor prognosis.

5. to help judge brain aging or developmental disorders and brain death: premature senility is not consistent with age rhythm slowing down, rapid wave increases. Slow wave frequencies of developmental disorders are often lower than their actual age. Clinical manifestations of coma, brainwave flat without wave, such as excluding machine failure, in addition to low temperature, anesthetic drugs can not recover in 24 hours, we should consider brain death.

6. other: can help determine the depth of anesthesia, so as to avoid the inhibition of over depth and irreversible; can understand the changes in brain function in other diseases, such as spontaneous hypoglycemia, EEG slow wave and / or epileptic discharge; hyperthyroidism basic rhythm increase; Pediatrics commonly used in brain injury, brain hypoxia and brain development disorders; gynecology can be used in eclampsia prison. Sometimes, it can be used for judging deafness and false blindness.