The neurons in the cerebral cortex have the activity of the biological activity, which is a constant rhythm potential changes in the cerebral cortex. In the clinical work, the brain cortex nerve cell group was observed by bipolar or unipolar recording method, which recorded the potential difference between two points on the scalp, or the potential difference between the scalp and the electrode or the special electrode. Brain waves are formed by the cell bodies and dendrites. However, the potential of a single neuron is not sufficient to change the surface of the cortex. Only a large number of neurons can change the surface of the cortex.
The EEG of normal people and some patients with intracranial lesions and some systemic diseases is different, so it can be used as an auxiliary diagnosis method for a disease. Brain waves are mainly used for epilepsy, intracranial lesions, brain injury, cerebral vascular disease examination.
1, EEG
Be seized desirable from a sitting or lying position, with collodion or rubber strips (or elastic band) electrode cap made of the electrode fixed in certain regions of the scalp, with a wire and EEG recorder connected and tracings of 8, 12, 16, 20 or 32 graph.
2, normal EEG (adult)
(1) a wave rhythm of 8 ~ 13 times per second, the amplitude of the `1100uV in the following, in the occipital region appear most.
(2) the amplitude of the beta wave is not more than 50 V.
(3) theta distribution in the frontal and temporal lobe, 40 V only accounted for 25%.
(4) delta wave in the frontal, 20 V less than 10%. The EEG changes in sleep, but it has a certain regularity. Children and old people with large EEG variation.
3, pathological EEG
In the onset of epilepsy, the EEG can have a sudden occurrence of high - wave amplitude discharge, known as the seizure of epilepsy or epileptic discharge, common waveform is not spike wave and sharp wave. Intracranial lesions may have focal EEG slow wave (theta and Bo). Diffuse or focal changes in the EEG of cerebral vascular disease. EEG of internal diseases, such as hepatic coma, serious heart and lung diseases associated with cerebral hypoxia and nephropathy with azotemia can diffuse theta delta waves and wave EEG changes.