Polysomnography

The EOG leads are placed 1 cm out and 1 cm up or down from the outer leads *The canthus is the junction of the upper and lower eyelids. The point at the outside of either eye in which the eyelids meet. * The electrode next to the left eye is E1 * The electrode next to the right eye is E2

*Recommended EEG montage for polysomnography. * Channels in a referential montage utilize the same reference or refeences for each channel.

*Alternative to a referntial montage . *Channels in a bipolar montage utilize two electrodes rather than an exploring and referece.

Shape of the waves help the reader determine the stage of sleep.

*A shift in EEG frequency lasting at least 3 seconds of sleep. *EEG's are also beneficial in displaying other events such as seizure activity and beta spindles

*Defined arrrangement of channels and signal derivations on a polysomnogram.

A distinct EEG waveform characterized by a sharp negative deflection followed by a slower postititive component. K- Complexes often occur immediately prior to sleep spindles, and are indicative of stage N2, although they can also occur in stage N3

Remains the same in the full EEG hoopup as it does for locating the 6 EEG electrode sites for performing a standard sleep study.

An additional mark is placed 20% of the down in the back from Cz. * This thee first mark for locating Pz

Remains the same. The marks placed 10% up form the pre-auricular points are the first marks for locating T 3 and T 4

Additional marks are placed at the 25% 20 % points, which will be almost directly over the pre-auricular points. These will intersect with the marks that are 10% up form teh pre- auricular points, giving the exact locations for T3 and T4.. Additional marks made in the back of the head are similar to the marks made for F7 and F8. In the back of the head, these are the locations for T5 and T6.

Additional mark is placed in the back of the head, 25% 20% of this measurement up form O1. This gives the first mark for P3. This is repeated on the right side for P4.

Measurement is made in the back of the head from T5 and T6, similar to the measurement made in the front of the head form F7 and F8. The 50% mark intersects with the mark placed 20% down in the back from Cz, and gives that exactg location for Pz. The 25% 20% marks inteersect with the first marks made for P3 and P4, and give the exact location for these two electrodes.

Fpz, Fp1, Fp2, Fz F3, F4, F7, F8, Cz, C3, C4, T3, T4, Pz, P3, P4, T5, T6, Oz, O1 and O2

1. Nasion 2. Inion 3. Left Pre-Auricular Point 4. Right Pre- Auricular Point