Activation procedure Flashcards
Hyperventilation (HV) – to induce changes in brain activity
particularly in detecting generalized epilepsy
Photic Stimulation (PS) – Flashing lights at various frequencies to assess photoparoxysmal responses
commonly used in patients with suspected photosensitive epilepsy.
What is the purpose of activation procedures in EEG?
To bring out abnormalities not seen in the baseline EEG and to enhance abnormalities already seen in the baseline EEG.
What is the effect of activation techniques on epileptiform activity?
They can amplify epileptiform activity, making abnormalities clearer.
Fill in the blank: Activation procedures in EEG can be used to _______ abnormalities already seen in the baseline EEG.
[enhance]
True or False: Activation procedures in EEG can only bring out new abnormalities.
False
What should be explained to the patient before starting the procedure?
The procedure itself to ensure cooperation
Clear communication enhances patient compliance and comfort.
What is the recommended breathing rate for the patient during the procedure?
18–24 deep breaths per minute (approximately 3–4 seconds per breath cycle)
This breathing rate helps optimize the effectiveness of the procedure.
What is the minimum duration for which HV should be performed?
3 minutes
Adequate duration is critical for capturing accurate results.
What should be minimized during the procedure to reduce artifact?
Movement of the head and body
Stillness is essential to ensure clean EEG recordings.
What is the role of the technologist during the procedure?
To pace the breathing rate and encourage the patient
Active engagement helps maintain the patient’s focus and adherence to the procedure.
What tool can be used to assist children in maintaining an effective HV rate?
A pinwheel
This playful tool can make the process more engaging for younger patients.
Why is timing important in the procedure?
It should be timed accurately
Proper timing ensures that the data collected is reliable and valid.
What should be noted regarding the patient during the procedure?
The patient’s effort level
Assessing effort helps evaluate the effectiveness of HV.
How long should EEG recording continue post-HV?
At least 1 minute
This allows for capturing any delayed responses that may occur after the procedure.
What happens to carbon dioxide levels due to increased breathing rate?
CO₂ is expelled faster than it is produced
This process leads to a reduction of carbon dioxide (PCO₂) levels.
What is hypocapnia?
Low CO₂ levels
Hypocapnia can lead to vasoconstriction.
What effect does hypocapnia have on cerebral blood vessels?
Causes narrowing of cerebral blood vessels
This narrowing reduces blood flow to the brain.
How does decreased cerebral blood flow affect the brain?
Can make the brain more excitable
This increased excitability can potentially trigger generalized 3 Hz spike-and-wave discharges in individuals with absence epilepsy.
Why is hyperventilation (HV) an important activation procedure in EEG?
It is important for evaluating absence seizures and other epilepsy types
The physiological effects of HV explain its significance in EEG testing.
What can recent intracranial hemorrhage cause in relation to cerebral blood flow?
HV can alter cerebral blood flow, increasing the risk of further bleeding.
HV refers to hyperventilation.
What effect can HV-induced vasoconstriction have after a recent TIA?
It may trigger another ischemic event.
TIA stands for Transient Ischemic Attack.
How can HV affect patients with a recent CVA?
Reduced cerebral blood flow from HV could worsen brain injury.
CVA stands for Cerebrovascular Accident or Stroke.
What is Moyamoya disease?
A condition causing abnormal blood vessel growth; HV can lead to dangerous ischemia.
