2.1 Neurophysiology Diagnostics Flashcards
Electrodes in EEG are connected from the head to the recording system, which are attached to the scalp according to a standardized system of electrode placement
Ten Twenty Placement
Where does the electrical signals come from?
Pyramidal cells of cerebral cortex
What type of EEG has standard 30 minute recording of awake and sleep EEG activity that can extend to 24 hrs recording video?
Surface/ scalp EEG
An EEG can determine changes in brain activity that may be useful in diagnosing brain disorders like:
Epilepsy or other seizure disorder Brain tumor Head injury Brain dysfunction Brain death in a persistent coma
Procedure: Pt will be ask not to sleep at night before the procedure or to stay up late or wake up early
Sleep deprivation test
Occurs often during sleep and are seizures originating in front of the brain that produces unusual symptoms that appear to be related to psychiatric problem or sleep disorder
Frontal lobe seizure
3Ps of frontal lobe seizure:
Pedaling motion
Pelvic thrusting
Profanity screams
How do you distinguished the left brain from right brain in an EEG?
RELO
Right side Even numbers
Left side Odd numbers
A test that detects electrical activity in the brain using small discs attached to the scalp.
Electroencephalography (EEG)
Different EEG activation procedures
S- leep deprivation H- yperventilation E- ye opening/ E-ye closure P- hotic stimulation S- ensory stimuli
Characteristics of normal sleep EEG
P- POST
S- Spindle
V- Vertex wave
Commonly seen on EEG and have been said to be more common during daytime naps than nocturnal sleep. Commonly seen in adolescents and middle aged adults
Positive Occipital Sharp Transient of Sleep
Powerful strobe of light is placed about 15 in from pt’s eyes and fleshed at frequencies of 1 to 20 per sec with the pt’s eyes open and close
Photic stimulation
Common procedure used in the EEG lab in children and adults using strobe of flashing lights at different frequencies to detect abnormal epileptogenic sensitivity to flickering light
Intermittent photic stimulation (IPS)
Patient is asked to breathe in and out deeply and rapidly 20x for 3 to 5 minutes
Hyperventilation
Considered most specific and sensitive test confirming a diagnosis of absence seizures
Generalized spike and wave pattern
Hyperventilation brings out seizures called
Staring spells or abscence
The pt is instructed to open and close his eyes. Then determine whether there are certain responses during closure or opening of the eye
Eye opening/ eye closure
Closing of the eyes indicate:
Opening of the eyes indicate:
Closed: negative wave deflection
Open: positive wave deflection
During EEG, the pt is instructed to raise his hands during the procedure or the pt is instructed to close and open his fists
Sensory stimuli
Abnormal EEG pattern seen in sensory stimuli
Spike and polyspike wave pattern or sharp transient of waves