Activation Procedures Flashcards
6 cards from real EEG practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Activation Procedures flashcards as text
What is the recommended distance between the photic stimulator and the patient's eyes during intermittent photic stimulation?
Answer: 30 cm
The standard distance for the photic stimulator is approximately 30 cm from the patient's closed eyes, providing adequate light intensity for activation while maintaining patient comfort and safety.
Which activation procedure is most effective for provoking absence seizures during a routine EEG?
Answer: Hyperventilation
Hyperventilation is the most effective provocative maneuver for absence seizures, eliciting 3 Hz spike-and-wave discharges in approximately 80-90% of patients with untreated typical absence epilepsy.
Eye closure sensitivity refers to which phenomenon during EEG recording?
Answer: Epileptiform discharges triggered specifically by the act of closing the eyes, distinct from normal alpha appearance
Eye closure sensitivity is a form of reflex epilepsy where epileptiform discharges are triggered by the act of closing the eyes, as opposed to the normal alpha rhythm that appears. It is distinct from fixation-off sensitivity.
What is the purpose of recording a period of wakefulness with eyes open and eyes closed before activation procedures?
Answer: To establish the baseline EEG background including posterior dominant rhythm frequency, reactivity, and symmetry
Baseline awake recording with eyes open and closed establishes the posterior dominant rhythm (frequency, amplitude, symmetry, reactivity), identifies any focal or generalized abnormalities, and provides comparison for interpreting changes during activation procedures.
Reflex epilepsy triggered by specific cognitive tasks (such as reading or calculating) is an example of:
Answer: Cognitive activation of seizures (thinking epilepsy or praxis-induced epilepsy)
Praxis-induced or cognitive-task-induced epilepsy is a form of reflex epilepsy where specific mental activities (reading, calculating, spatial tasks) trigger epileptiform discharges or seizures, most commonly in genetic generalized epilepsies.
During photic stimulation, the technologist notices the patient becoming agitated and the EEG shows generalized spike-and-wave activity outlasting the flash trains. The appropriate action is to:
Answer: Immediately stop photic stimulation and continue recording the after-discharge
A photoparoxysmal response that outlasts the stimulus (Type 4) is clinically significant and stimulation should be stopped immediately to prevent triggering a clinical seizure, while continuing to record the EEG.