VNS General Information Flashcards
What are high and low impedances on Demipulse generators?
Less than <= 5300
What is fibrosis? How does it relate to VNS?
Fibrosis equals scarring as it relates to body reacting to injury
This scarring can throw off impedances
Indications for VNS
Indicated for use as an adjunctive therapy and reducing the frequency of seizures in adults and adolescents over 12 years of age with partial onset seizures that are refractory to antiepileptic meds
If battery won’t interrogate what do you do?
Test Wand battery
Verify connections
Make sure programmer is plugged into wall
Verify Wand is over generator site
Rotate wand 45° with slight pressure and retest
Contraindications to VNS
Patient with a left vagotomy
Diathermy
What does magnet hope to achieve?
Shorten seizure
decrease intensity of seizure
shorten recovery period
stop seizure
How someone can benefit from VNS therapy
Fewer seizures
decreased intensity of seizures
quicker recovery time
long-lasting effectiveness that improves over time
What pathways does VNS work on?
Neurotransmitter expression – Norepinephrine increase – Gabba increase – Serotonin increase – Aspartate decrease
Cerebral blood flow
Changes in EE Desynchronization of EEG rhythms
Define duty cycle
The % of time the stimulator provides the therapy vs the time it is at rest
How is excessive stimulation defined?
Excessive is when on time is greater than off time
What are possible output current thresholds?
0.0 - 3.5 mA
What are possible signal frequency thresholds?
1-30 Hz
What are possible pulse width thresholds?
130 - 1000 micro seconds
What are possible on time thresholds?
7-60 seconds
What are possible off time thresholds?
0.2 - 180 minutes
