G is for generalized

1. G is for generalized • Activity that affects the brain as a whole, or is present in every channel of the EEG. • Also can use the word diffuse.

2. 7 y/o male being evaluated for episodes of starring off, occurring multiple times daily

3. H is for hyperventilation • Activation procedure consisting of deep regular breaths of about 18-24 bpm. This causes constriction of cerebral arteriolar system and hypoxia (low levels of oxygen in the blood). • Should be performed for 2-3 minutes • May cause normal high amplitude, generalized slowing pattern known as a “build-up response”. • Performed to illicit 3Hz generalized spike and wave discharges in patients with petit mal or absence seizures. • Contraindications include: cardiovascular problems, respiratory disorders, extreme hypertenison, subarachnoid hemorrhage, or recent stroke.

4. 6 y/o female being evaluated for behavioral problems…eeg to rule out seizures.Pt is currently on no medications

5. H is also for history • Document age, family history , pt symptoms, relevant medical history, behavior state of patient, last episode occurrence, medications, or auras. • Date and time of recording should also be annotated. As well as record ID.

6. I represents “Intermittent” • Term that means: happens sporadically. It is activity that may come and go.

7. K is for K-complex. • High amplitude delta wave activity that occur diffusely, but predominately over the vertex region. The slow, delta wave activity may be followed by a short period of 8-12 cps alpha-like activity. • Most prominate in stage II sleep. • Some sources say the are products of slight arousal. • Best seen in a transverse montage.

8. L is for localization • The act of isolating the origin of the abnormality. • In a referential montage, localize by highest amplitude. • In a bipolar montage, localize by phase reversal.

9. M is for montages.. • System of grouping electrode pairs in a specific order. • A referential montage consists of groupings of one active (scalp) electrode, and one inactive (non-cephalic) electrode. which exception of a Cz reference, where Cz is used as a reference site, but is technically active. A bipolar montage consists of electrode groupings which are both active (scalp) electrodes.

10. N is for notch, or 60hz filter! • An active setting used to filter out fast, 60cps artifact caused by electrical interference. • When notch filter is on, it can rid 60Hz artifact ( very fast, black “fuzzy” recording), but it can attenuate frequencies as low as 10Hz. • Source of artifact should be eliminated ( if possible) before the notch filter be used. • Caused by: recording in an electrically hostile environment, a bad ground electrode, a bad scalp or reference electrode, high impedances, bad jackbox.

11. O is for OIRDA • Occipital Intermittent rhythmic delta activity. • This abnormal slowing recorded from the posterior head regions. Usually after a stroke or trauma.

12. P is for parameters • The low filter will attenuate slower frequencies, but will not effect faster frequencies . The normal low filter setting is 1Hz. A higher LFF setting of 3Hz or 5Hz will attenuate greater amounts of slowing. • The high frequency filter will attenuate higher frequencies, but will not effect the slower ones. A normal HFF filter setting is 70Hz. A lesser HFF setting of 35Hz or 10Hz will attenuate a greater amount of faster activity.

13. Parameters continued……. • A normal paperspeed is 30mm/sec or 10sec/pg. • To enhance slowing, use a slower paperspeed of 15mm/sec or 20sec/pg. • In order to “spread out” faster frequencies to localize a abnormality, or to count out 60Hz contamination, increase the paperspeed to 60mm/sec, or 5sec/pg.

14. P also stands for polarity • If input 2 is more positive than input 1, pen deflection will go up. • If input 2 is more negative in relation to input 1, pen deflection will go down.

15. Pis also for Photic Stimulation • Activation procedure consisting of flashes of light focused on the pt’s facial region at selected frequencies. • May produce a driving response, which is a normal variant, identified as sinusoidal waveforms produced in the posterior head regions that are half, equal to, or double the rate of the photic speed. • May also produce abnormal responses: - Asymmetrical driving response ( driving response over only one side for posterior head region - Photo-Paroxysmal Response ( Generalized spike/wave discharges that often outlast the the photic stimulation. No clinical signs. - Photoconvulsive Response ( Pt sent into a T/C seizures that also outlast the photic stimulation.

16. Q is for Quiescence • Another term for inactivity or quietness. • Used to describe the EEG of a neonate born at or before 22 weeks conceptual age.

17. R is for RECORD • Record must have be acquired within 12 months of the exam. • Records must contain a minimum of 16 channels. • Records should not be indicative of: ECI, status epilepticus, surgical monitoring, ambulatory, long term epilepsy monitoring, neonatal recordings. • Record should contain at least one period of eye opening and closing.

18. Sis for Sleep • In a 1947 study of 500 cases of epilepsy, epileptic activity was more that twice as likely to occur during sleep. • This is especially true in cases of temporal lobe epilepsy. • Stage I characterized by attenuation of the background, slow rolling eye movements. • Stage II defined by sleep spindles • Stage III defined as 20-50% of the record

19. Trace Alternant

20. Tis for Time • Record should be a minimum of 20 minutes or 120 pages long no including calibration and bio-calibration

21. U is for Understand • BREECH rhythm is not an acceptable abnormality.

22. Vis for Vertex Sharp waves • Appear between 3-6 months of life. • Moderate to high amplitude, sharp and biphasic waves lasting 100-200msec in duration. • Usually a surface negative wave, followed by a positive component.