Chapter 34 Electroencephalogram (EEg Wakefulness and sleep
Chapter 34 Electroencephalogram (EEG), Wakefulness and Sleep
I. Electroencephalogram (EEG)
I. Electroencephalogram (EEG)
Brain Waves and EEG o normal brain function involves continuous electrical activity ● Brain wave The undulations in the recorded electrical potentials Change with age, sensory stimuli, brain disease, and the psychoses o An electroencephalogram (EEG The entire record of the brain wave be used to diagnose and localize brain lesions, tumors infarcts infections. abscesses. and epileptic lesions A flat EEG (no electrical activity) is clinical evidence of death
I. Brain Waves and EEG ⚫ Normal brain function involves continuous electrical activity ⚫ Brain Wave – The undulations in the recorded electrical potentials – Change with age, sensory stimuli, brain disease, and the psychoses ⚫ An electroencephalogram (EEG) – The entire record of the brain wave – be used to diagnose and localize brain lesions, tumors, infarcts, infections, abscesses, and epileptic lesions – A flat EEG (no electrical activity) is clinical evidence of death
The eEG be recorded with Scalp electrodes through the unopened skull or with electrodes on or in the brain Time(sec) Blink artifacts 3 6 8 9 → WAw/vww一 AwwA A-50 Electrode Alpha rhythms Beta rhythms positions A normalEEg
The EEG be recorded with Scalp electrodes through the unopened skull or with electrodes on or in the brain. A normal EEG
EEG Patterns o Alpha: low-amplitude, Slow. synchronous Alpha WrwhwMlMinua waves indicating an idling”br rain Beta Recorded from occipital, parietal and frontal regions Theta mn/ruM ● Person is awake, relaxed, with eyes close d ∧、w 50 uV Delta 8-13Hz sec 20~100uV
EEG Patterns ⚫ Alpha: low-amplitude, slow, synchronous waves indicating an “idling” brain – Recorded from occipital, parietal and frontal regions. ⚫ Person is awake, relaxed, with eyes closed. – 8-13 Hz – 20 ~100 V