Activations

Question 1

Describe photomyogenic response?

Answer 1

Brief, repetitive muscular spikes over the anterior regions of the head. The muscle potentials occur at the same rate as the photic and stop as soon as the photic is stopped

Question 2

What is the clinical affects of HV?

Answer 2

Respiratory alkalosis

tingling in hands, feet, mouth, dizziness, loss of consciousness

Question 3

Why is sleep deprivation considered an activation procedure?

Answer 3

24-36 hours of continuous waking time may stress a potentially epileptogenic brain so that abnormalities will appear in the waking EEG

Question 4

What is hyperventilation?

Answer 4

Deep/rapid breathing usually for a period of 3-5 min. Activates absence seizures

Question 5

Describe photic driving

Answer 5

A train of occipital waves driven by repetitive strobe flashes.
Measures the ability of the occipital lobe to follow strobe flashes at different frequencies with repetitive responses

Question 6

Contraindications for HV

Answer 6

1. Recent cardiac illness
2. Recent Stroke
3. Distressed breathing
4. Extreme Hypertension
5. SAH
6. Sickle Cell
7. Moya Moya

Question 7

What type of epilepsy is most likely to show abnormalities during sleep?

Answer 7

Complex partial seizure

Question 8

Describe a photoparoxysmal response (photoconvulsive)

Answer 8

An abnormal response to intermittent photic stim. Characterized by spike and wave and multiple spike and slow wave complexes. The response may or may not continue after photic is stopped.

Question 9

What electrographic changes are seen during HV?

Answer 9

Normal- bilaterally synchronous slow waves “build up”

Abnormal- Assymetric responses and epileptiform discharges

3 hz s/w often activated