II-F. Activation techniques / contraindications

Question 1

A 7 year old female presents with spells of “spacing out” reported by teachers at her school. Of the following, which activation procedure is of most importance in assisting with diagnosis?
A) Sleep deprivation
B) Hyperventilation
C) Photic stimulation
D) Sleep

Answer 1

Hyperventilation

Question 2

Which of the following is most useful in the evaluation of temporal lobe seizures?
A) Awake EEG
B) Photic stimulation
C) Hyperventilation
D) Sleep EEG

Answer 2

Sleep EEG

Question 3

Photic light should be how far from a patient’s eyes?
A) 12 inches
B) 6 inches
C) 3 inches
D) 24 inches

Answer 3

12 inches

Question 4

What other EEG pattern would you expect to see in the patient with prominent photic driving response?
A) Lambda
B) Slowing in posterior region
C) Epileptiform discharges
D) OIRDA

Answer 4

Lambda

Question 5

HYPERVENTILATION
A) Hyperglycemia
B) Hypercapnia
C) Hypocapnia
D) Hypoatremia

Answer 5

Hypocapnia

Question 6

A subharmonic photic driving response is:
A) The exact frequency of the flash strobe
B) Twice the frequency of the flash strobe
C) Attenuation for duration of flash strobe
D) Half the frequency of the flash strobe

Answer 6

Half the frequency of the flash strobe

Question 7

When using the photic stimulator, the flash rate which would most commonly activate seizure activity would be
A) 4-7 flashes/second
B) 15-18 flashes/second
C) 1-3 flashes/second
D) 25-30 flashes/second

Answer 7

15-18 flashes/second.

Question 8

What is a sub harmonic response to photic stimulation?
A) Photic driving double the speed of the flash rate
B) An abnormal response to the photic stimulation
C) Photic driving at the exact frequency to the frequency rate
D) Photic driving at half the speed of the flash rate

Answer 8

Photic driving at half the speed of the flash rate

Question 9

Photoparoxysmal response:
A) EMG artifact time locked with flash frequency
B) Sub-harmonic pattern
C) Occipital pattern linked with flash rate
D) EEG response to light with spikes, spike-wave discharge and/or intermittent slow waves

Answer 9

EEG response to light with spikes, spike-wave discharge and/or intermittent slow waves.

Question 10

What type of response to photic stimulation is characterized by generalized spike-and-wave discharges continuing after the last flash?
A) Photic recruiting
B) Photoparoxysmal
C) Photomyogenic
D) Photoelectric

Answer 10

Photoparoxysmal

Question 11

Photic stimulation is most effective in evoking epileptiform abnormalities in patients with
A) a family history of seizures
B) focal occipital seizures
C) metabolic coma
D) syncope

Answer 11

a family history of seizures

Question 12

Which of the following would be considered an abnormal EEG presentation to photic stimulation?
A) Photomyogenic
B) Photoelectric
C) Photoparoxysmal
D) Photic driving

Answer 12

Photoparoxysmal

Question 13

Which of these is a contraindication for the activation procedure hyperventilation (HV)?
A) Photosensitivity
B) Sickle cell anemia or sickle cell trait
C) Tuberous sclerosis
D) Multiple sclerosis

Answer 13

Sickle cell anemia or sickle cell trait

Question 14

An asymmetric photic driving response right greater than left is:
A) A common finding
B) Indicative of severe cerebral dysfunction
C) Seen only in Absence seizures
D) Always abnormal

Answer 14

A common finding

Question 15

During hyperventilation, a 9 year-old patient develops generalized 100 - 300 microvolts slowing. If, within thirty seconds post hyperventilation, the record returns to its pre-hyperventiliation state, the reaction would be
A) suggestive of a tumor
B) compatible with a seizure disorder
C) suggestive of a metabolic disturbance
D) a normal response to hyperventilation

Answer 15

a normal response to hyperventilation.

Question 16

Photic Driving is most common at what frequencies?
A) 16-20 Hz
B) 25-30 Hz
C) 9-13 Hz
D) 1-4 Hz

Answer 16

9-13 Hz

Question 17

Photic induced epileptiform discharges are most likely associated with
A) meningitis
B) hepatic encephalopathy
C) barbiturate withdrawal
D) Down syndrome

Answer 17

barbiturate withdrawal.

Question 18

Which of the following procedures can be considered to be a “non-standard” activation:
A) Photic stimulation
B) Eyes open/closed
C) Listening to music
D) Sleep

Answer 18

Listening to music

Question 19

Which of the following activation procedures should be AVOIDED in a patient with a recent intracranial hemorrhage?
A) Photic stimulation
B) Hyperventilation
C) Sleep
D) Mental exertion

Answer 19

Hyperventilation

Question 20

Atypical Photic Response
A) Photic driving
B) Harmonic driving
C) Delta driving
D) Photomyogenic driving

Answer 20

Delta Driving

Question 21

Photic stimulation should be performed
A) With light 24” away from patient
B) While awake
C) During hyperventilation
D) During sleep

Answer 21

While awake

Question 22

What could be the cause for a build-up of slowing several minutes after the hyperventilation has been completed?
A) CVD
B) Moyamoya disease
C) Patient continues to hyperventilate
D) Focal lesion

Answer 22

Moyamoya disease

Question 23

An EEG obtained during sleep is of most value in which condition?
A) Vascular diseases
B) Space occupying lesions
C) Psychiatric disturbances
D) Complex partial seizures

Answer 23

Complex partial seizures

Question 24

Which activity does NOT typically cause an attenuation of the posterior dominant alpha rhythm in the normal adult?
A) Relaxed wakefulness with eyes closed
B) Having the patient solve a math problem with eyes closed
C) Light sleep
D) Having the patient open their eyes

Answer 24

Relaxed wakefulness with eyes closed