Playing the Background
Refers to the waveforms being uninterrupted by periods of flat or very attenuated activity.
Continuity
In drowsiness you can also see ____, in which high amplitude, synchronized slow waves arise in the transitions from waking to sleep and sleep to waking, respectively. (5-11yrs)
Hypnagogic or Hypnapompic Hypersynchrony
POSTS is the acronym for what?
Positive Occipital Sharp Transients of Sleep
This stage is marked by a diffuse attenuation of amplitudes, with a range of frequencies amongst the background that can look similar to an awake state. It most noted for the rapid eye movements that arise.
STAGE IV: RAPID EYE MOVEMENT SLEEP
The PDR should be symmetric in both frequency and amplitude; if there is a more than ___% difference in amplitude or a more than 1 Hz difference in frequency between sides, this is abnormal
more than 50% difference
Component of organization, in which both the left and right sides appear, largely, the same in terms of both amplitude and frequency?
Symmetry
Stage ____ sleep is characterized by the arrival of sleep spindles and K complexes, although both vertex waves and POSTS persist into stage
Stage II
Found in stage I sleep, bilateral phase reversing discharges over the central regions. They can come alone or in runs, but even when they appear very sharp or high amplitude they are not epileptiform
Vertex Waves
The cornea is positively charged, so when a patient looks to their right, the right eye cornea moves closer to the F8 electrode, leading to a _____ charge/deflection seen at F8
Positive
_____ describes how many waves there are per second,and is measured in hertz (Hz). The main four in increasing order: delta, theta, alpha and beta
Frequency
________is the resting frequency of the occipital region when eyes are closed and the patient is resting quietly. It is a vital part of a normal EEG and among the first things you should look for?
Posterior Dominant Rhythm (PDR)
Symmetric bursts of 12-14 Hz activity arising from the reticular nucleus of the thalamus; they are so named because they can look like thread, is called what?
Sleep spindles
Very high amplitude, symmetric waveforms with initial negative followed by a slow positive phase, often - but not always followed by a sleep spindle
K Complexes
The ______ of an EEG tracing refers, broadly, to how the waveforms appear across the entirety of the page, and includes continuity, symmetry, and the anterior posterior gradient.
Organization
What EEG pattern is affected by Eye Opening and Eye Closing?
Posterior Dominate Rhythm (PDR)
In photic stimulation, a light is flashed in trains of increasing frequencies to look for ______, in which the background rhythm becomes time locked and in sync with each light flash.
Photic Driving
What phenomena marks the alternative name of STAGE IV sleep
RAPID EYE MOVEMENT
What stage of sleep has all of the architecture from earlier sleep phases (vertex waves, POSTS, spindles and K complexes), but usually become somewhat less organized, and often disappear altogether?
STAGE III: SLOW WAVE SLEEP
_____ can arise from structural entities such as tumors or bleeds. Changes can be subtle. Ex: the left hemisphere has higher amplitude, slower delta activity compared to the right side.
Asymmetries
Many medications, particularly those with sedative, anesthetic, or anticonvulsant properties, can cause ____________ on the EEG. This is often seen with benzodiazepines, barbiturates, and propofol.
Increased Beta Activity
The other major type of provocation is ______, which should not be done in patients with chronic respiratory issues, or those with a recent stroke or myocardial infarction.
Hyperventilation
BELL’S PHENOMENON gives positive and negative deflections based on the movement of what?
EYES
Classically, they have a "sail-like" appearance, and can come in singles or runs. They arise in stage I sleep but can persist throughout the later stages of sleep
POSTS
___, is noted by faster, lower amplitude frequencies present towards the front of the brain while slower, higher amplitude frequencies are found in the back of the brain
Anterior Posterior (AP) Gradient
In severe overdose cases, some medications can lead to a __________ pattern on the EEG, where periods of high-amplitude activity alternate with periods of great attenuation.
Burst Suppression